(OBQ04.118) What muscles are responsible for the most common deformity after antegrade intramedullary nailing for a subtrochanteric femur fracture?

1. Hip abductors and iliopsoas muscle

    

    

    

2. Hip internal rotators and iliopsoas muscle

    

    

    

3. Quadriceps and iliopsoas muscle

    

    

    

4. Hamstring and iliopsoas muscle

    

5. Quadriceps and hip adductors

PREFERRED RESPONSE ▼ 1 CORRECT

DISCUSSION: The most common deformity after antegrade nailing of a subtrochanteric femur fracture is varus and procurvatum (or flexion). This is caused by the hip abductors and iliopsoas pulling the proximal fragment into abduction and flexion, while the distal fragment is pulled into adduction from the adductors.

The reference by French et al is a review on 45 patients with subtrochanteric fractures treated with cephalomedullary interlocked nailing. Based on femoral neck-shaft angle, 61% of the fractures were reduced in at least 5º varus. The authors attributed this malalignment to failure to counteract muscle forces acting on the proximal fragment, combined with the adducted position of the distal femur during portal creation.

The reference by Ricci et al is a report of 403 femoral shaft fractures treated with intramedullary nailing. Patients with proximal femoral shaft fractures were found to have the highest incidence of malalignment. The most common deformity in this group was varus, followed by procurvatum (or flexion).

(OBQ09.222) A patient with an intertrochanteric hip fracture undergoes reduction and dynamic hip screw application. The post-operative radiographs demonstrate that the lag screw is superior in the femoral head with a tip-apex distance of 40 millimeters. This patient is at increased risk of what complication?

1. lag screw cutout

    

    

    

2. osteonecrosis

    

    

    

3. osteoarthritis

    

    

    

4. peri-prosthetic fracture

    

5. lag screw breakage

PREFERRED RESPONSE ▼ 1 CORRECT

DISCUSSION: Baumgaertner et al in their classic study in 1995 determined that the position of the lag screw in the femoral head influenced the risk of cutout of a dynamic hip screw construct in treatment of intratrochanteric fractures. They had no cutouts if the tip-apex distance on the combined AP and lateral radiographs was less than 25 millimeters. Subsequent studies demonstrated a decreased cutout rate once people were aware of the tip-apex distance importance.

(SBQ07.16) The anterolateral branch of the anterior circumflex artery supplies blood to what aspect of the proximal humerus?

1. Anterior portion of humeral head

    

    

    

2. Lesser tuberosity

    

    

    

3. Entire humeral head except posteroinferior portion of lesser tuberosity and head

    

4. Entire humeral head except posteroinferior portion of greater tuberosity and head

    

    

5. Entire humeral head except entire greater tuberosity

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: The anterolateral branch of the anterior circumflex artery, called the arcuate artery terminally, provides blood supply to the entire humeral head, lesser tuberosity and greater tuberosity except for a small posterior area. The posterior portion of the greater tuberosity and a small posteroinferior portion of the humeral head are supplied by the posterior circumflex artery. This was supported by a cadaveric study by Gerber et al who performed an anatomical study of the arteries of the humeral head to determine their intraosseous distributions. They injected a radiopaque suspension into the anterior circumflex, posterior circumflex, suprascapular, thoracoacromial, or subscapular artery and then analyzed the specimens macroscopically and radiographically. The humeral head was shown to have been perfused by the anterolateral ascending branch of the anterior circumflex artery in all specimens. The posterior circumflex artery vascularized only the posterior portion of the greater tuberosity and a small posteroinferior part of the head. Illustration A depicts the humeral head vascular supply with #2 being the posterior circumflex, #3 being the anterior circumflex arteries, and #4 being the anterolateral humeral circumflex artery.

(OBQ05.25) A 70-year-old woman with known osteoporosis sustains a distal radius fracture of her dominant arm with some metaphyseal comminution. Adequate maintenance of reduction by non-operative treatment is unsuccesful. Which plating option provides the most appropriate treatment of this fracture?

1. semitubular

    

    

    

2. dynamic compression

    

    

    

3. limited-contact dynamic compression

    

    

    

4. peri-articular locked

    

5. pelvic reconstruction

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: Egol et. al. studied locked and conventional plates. They concluded that locked plates may be increasingly indicated for indirect fracture reduction, diaphyseal/metaphyseal fractures in osteoporotic bone, bridging severely comminuted fractures, and the plating of fractures where anatomical constraints prevent plating on the tension side of the bone. Conventional plates remain the fixation method of choice for periarticular fractures that demand perfect anatomical reduction, and certain types of non-unions that require increased stability for union.

(OBQ07.62) If a percutaneous iliosacral screw is placed too anteriorly, and the screw exits anterior to the sacral ala before re-entering the sacral body, what will be the most likely finding postoperatively?

1. Lack of ankle dorsiflexion

    

    

    

2. Lack of ankle plantarflexion

    

    

    

3. Lack of knee extension

    

    

    

4. Loss of bowel and/or bladder control

    

5. Lack of great toe extension

PREFERRED RESPONSE ▼ 5 CORRECT

DISCUSSION: This question is a simple review of anatomy and nerve innervation. The L5 root is at risk with an "in-out-in" screw, as described in the question, as the nerve root is just anterior to the sacral ala as it enters the true pelvis. L5 is primarily evaluated by extensor hallucis longus function. L4 is tested with tibialis anterior function and S1 by gastroc-soleus function (ankle plantarflexion).

(OBQ07.39) The Cotton test evaluates which of the following structures?

1. Calcaneofibular ligament

    

    

    

2. Lateral ulnar collateral ligament of the elbow

    

    

    

3. Ligamentum flavum

    

    

    

4. Deep deltoid ligament

    

5. Ankle syndesmosis

PREFERRED RESPONSE ▼ 5 CORRECT

DISCUSSION: The inferior tibiofibular syndesmosis is a fibrous articulation consisting of four ligaments; the elasticity of these ligaments permits axial, vertical, anterior, posterior, and mediolateral motion at the ankle syndesmosis during weight bearing. Nielson et al reported that the level of the fibular fracture does not correlate reliably with the integrity or extent of the interosseous membrane (IOM) tears identified on MRI in operative ankle fractures. Therefore, one cannot consistently estimate the integrity of the IOM and subsequent need for transsyndesmotic fixation based solely on the level of the fibular fracture. This supports the need for intraoperative stress testing (ie, external rotation stress or Cotton test) of the ankle syndesmosis in all operative ankle fractures. The study by Leeds et al noted a correlation between syndesmosis reduction (initial and final) and outcomes (radiographic and clinical). Of note, the Cotton test was originally described around 1910 by Frederic J. Cotton as the "talar glide test" evaluating the medial/lateral translation of the talus in the mortise. A positive result, indicating disruption of the deltoid ligament or ankle syndesmosis, was defined as translation of greater than 1mm.

(OBQ10.72) All of the following indicators of resuscitation may be within normal limits for a trauma patient that is in "compensated" shock EXCEPT:

1. Systolic blood pressure

    

    

    

2. Urine output

    

    

    

3. Heart rate

    

    

    

4. Serum lactate

    

5. Mean arterial pressure

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: Historically, normal blood pressure, heart rate, and urine output have been endpoints to signal complete resuscitation in the polytrauma patient. The review article by Porter et al states that there is a high incidence of patients (as much as 85%) in "compensated" shock despite normal vital signs and urine output parameters. Compensated shock is secondary to a maldistribution of blood flow and tissue oxygenation as splanchnic organs have less distribution of the cardiac output compared to the heart and the brain. The article by Elliott is also a review, and it states that serum lactate is the best indicator of peripheral organ perfusion and tissue oxygenation. It also states that base deficit and gastric mucosal pH are appropriate end points to determine the complete resuscitation of trauma patients.

(OBQ05.38) A 30-year-old man sustains a head injury as well as a femur and pelvis fractures as the result of a rollover motor vehicle accident. He is initially comatosed, but recovers cognitive function after 10 days in the hospital. Soon after awakening he complains of wrist pain and an x-ray demonstrates a distal radius fracture. What is the most likely explanation for this delayed diagnosis?

1. wrist x-ray not initially obtained

    

    

    

2. x-ray obtained, but MRI necessary for diagnosis not obtained

    

    

    

3. forearm x-ray initially obtained did not show fracture

    

    

    

4. CT initially performed, but no 3-D images reconstructed

    

5. wrist x-ray initially obtained did not show fracture

PREFERRED RESPONSE ▼ 1 CORRECT

DISCUSSION: According to the cited article by Born et al, who prospectively studied the incidence of delayed recognition of skeletal injury at a Level I trauma center over an 18-month period, the majority of missed skeletal injuries result from failure to image the affected extremity. These authors identified 39 fractures in 26 of 1,006 consecutive blunt trauma patients that were not diagnosed in a timely fashion (delays ranging from 1-91 days). Although other factors contributed to the diagnostic failure (23% were visible on admission films and not recognized; 10% were not visible due to inadequate x-rays of appropriate limb; 13% had adequate x-rays but diagnosis could not be made from initial studies), 55% of the fractures that were delayed in diagnosis resulted from failure to image the affected extremity. They went on to conclude that, “although the delay of fracture identification was not felt to contribute to additional long-term cosmetic, functional, or neurologic problems,” continued radiographic surveillance is necessary to prevent diagnostic failure.

(OBQ07.176) The flexor hallucis longus tendon is at greatest risk of injury with a lateral-to-medial drill or screw during fixation of what structure?

1. Lisfranc fracture-dislocation

    

    

    

2. Navicular body fracture

    

    

    

3. Intra-articular calcaneus fracture

    

    

    

4. Nutcracker cuboid fracture

    

5. Talar neck fracture

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: A drill bit or screw that penetrates the subchondral area of the posterior facet of the calcaneus can lead to direct injury of the flexor hallucis longus as it runs just inferior to the sustentaculum tali on its way to its insertion on the first phalanx of the great toe. A medial calcaneal groove is seen where this structure runs from superior to inferior. Injury to the flexor hallucis longus tendon can be acute or attritional. Bajammal et al investigated intra-articular calcaneus fractures and reported that patients who were NOT receiving Workers' Compensation, were younger (less than twenty-nine years old), had a moderately lower Böhler angle (0 degrees to 14 degrees ), a comminuted fracture, a light workload, or an anatomic reduction or a step-off of < or =2 mm after surgical reduction (p = 0.04) scored significantly higher on the scoring scales after surgery compared with those who were treated nonoperatively.

(OBQ09.233) Which of the following statements is true regarding treatment of intertrochanteric hip fractures with an intramedullary nail versus a sliding hip screw?

1. The use of intramedullary nail has increased in the last ten years

    

    

    

2. The use of sliding hip screws has increased in the last ten years

    

    

    

3. Medicare reimbursement is more for a sliding hip screw

    

4. Intramedullary nails have demonstrated superior outcomes in randomized-controlled studies

    

    

5. Sliding hip screw is superior for treatment of reverse obliquity intertrochanteric fractures PREFERRED RESPONSE ▼ 1

CORRECT

DISCUSSION: Anglen et al reviewed the database of orthopaedic surgeons taking Step II of the boards and found that the use of intramedullary nails for intertrochanteric hip fractures dramatically increased from 3% in 1999 to 67% in 2006. The authors call attention to the fact that Medicare reimbursement was higher until 2010 for intramedullary nails despite a lack of definitive evidence demonstrating that they are the superior treatment. Furthermore, they noted that patients managed with intramedullary nailing had more procedure-related complications compared to plate fixatoin. Forte et al found geographic differences in the use of intramedullary nails not explained by patient-related factors. Barton et al conducted a randomized controlled trial and found no difference in outcomes between the gamma nail and sliding hip screw for standard obliquity intertrochanteric hip fractures.

(OBQ07.198) Residual end-organ hypoperfusion in a polytraumatized patient is shown by which of the following?

1. Urine output of 0.8 mL/kg/hr

    

    

    

2. SpO2 < 90%

    

    

    

3. Platelet count < 80

    

    

    

4. Base excess of +3.0 mEq/L

    

5. Serum lactate of 4.5 mmol/L

PREFERRED RESPONSE ▼ 5 CORRECT

DISCUSSION: Traditional endpoints for shock, including BP, HR, and urine output are good endpoints for uncompensated shock, but most trauma patients are in a state of compensated shock, where these endpoints have normalized. There is evidence that continued inadequate tissue perfusion exists in these patients, causing anaerobic metabolism, development of tissue acidosis and oxygen debt. New endpoints for adequate resuscitation include serum lactate (normal < 2 mmol/L), base deficit (normal -2 to +2, anything less than -2 indicates hypoperfusion), and gastric mucosal pH (normal is 7.30 - 7.35). Lactate is produced by breakdown of pyruvate by cells in the absence of O2. Normalization of lactate within 24 hours has been shown to be a good prognostic indicator in the trauma patient. Base deficit is a global marker of tissue hypoperfusion. The referenced article by Roberts et al is an excellent review of damage control orthopedics and the basic science behind this concept. The referenced article by Porter et al is a review of the available measurable end points in looking for appropriate resuscitation.

(OBQ11.172) Which of the following methods accurately describes the measurement of tip-apex-distance as it relates to placement of a lag screw in the femoral head?

1. Summation of the distance between the end of the screw and the apex of the femoral head on AP and lateral radiographs

    

    

    

2. Distance from the acetabular teardrop to the tip of the screw on an AP radiograph of the hip

    

    

    

3. Multiplication of the distance between the end of the screw and the apex of the femoral head on AP and lateral radiographs

    

    

    

4. Distance from the center of the lesser trochanter to the tip of the screw on an AP hip radiograph

    

5. Summation of the distance between the tip of the greater trochanter and end of the screw on AP and lateral hip radiographs

PREFERRED RESPONSE ▼ 1 CORRECT

DISCUSSION: TIp-apex distance (TAD) as it relates to a lag screw in the femoral head is the summation of the distance between the end of the screw and the apex of the femoral head on AP and lateral radiographs. This is shown in Illustration A.

TAD is a useful intraoperative indicator of deep and central placement of the lag screw in the femoral head, regardless of whether a nail or a plate is chosen to fix a fracture. A TAD of <25mm has been shown to minimize the risk of fixation cut-out in stable and unstable intertrochanteric hip fractures.

Baumgaertner et al examined factors leading to the failure of sliding hip screws (SHS) in the treatment of 198 intertrochanteric fractures. They determined that the tip-apex distance (TAD) is a reproducible, standard measurement to predict SHS failure. The average TAD for successful fractures was 24mm while the average TAD for failures was 38mm. No screw with a TAD <25mm failed. Calculation of the TAD is shown in Illustration B.

Kyle et al reviewed 622 intertrochanteric fractures. For unstable patterns, a SHS was superior to a fixed angle nail. Early ambulation and weight bearing contributed to improved results

(OBQ06.133) A 72-year-old female presents to your office with a 24-month old painful nonunion of a 3-part fracture of the proximal humerus. She has been treated conservatively with range of motion exercises but continues to complain of debilitating pain and dysfunction. Operative management should include:

1. Closed reduction and percutaneous pinning

    

    

    

2. Open reduction and internal fixation

    

    

    

3. Rotator cuff repair with possible latissimus dorsi tendon transfer

    

    

    

4. Shoulder arthroplasty

    

5. Open bone grafting

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: Treatment of a chronic nonunion of the proximal humerus in the elderly should be treated with arthroplasty when possible. Critical attention should be paid to correct all deformities: tuberosity positioning, articular surface realignment, soft tissue balancing, rotator cuff repair (when needed), and treatment of soft tissue contractures. Attempts at internal fixation should be performed with caution in this patient population, due to general osteopenia and significant rates of loss of fracture reduction.

The referenced article by Cheung et al reviews treatment options for proximal humeral nonunions and reports successful use of arthroplasty in treating elderly osteoporotic proximal humeral nonunions as a pain relieving procedure.

Dines reported a case series of 20 chronic post-traumatic proximal humerus fractures including nonunions that were treated with shoulder arthroplasty achieving fair to excellent results in 90% at mid-term follow-up

(OBQ08.246) In addition to lengthening the achilles, transfer of which tendon is important for functional ambulation after performing a Chopart amputation of the foot?

1. peroneus brevis

    

    

    

2. peroneus longus

    

    

    

3. tibialis anterior

    

    

    

4. tibialis posterior

    

5. flexor hallucis longus

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: The partial foot amputation through the talonavicular and calcaneocuboid joints is also known as the Chopart amputation. The Chopart amputation may result in significant equinovarus deformity with anterior weight bearing through the scar line, predisposing to skin breakdown over time. Therefore, lengthening of the Achilles tendon and transfer of the tibialis anterior to the talar neck should also be performed in conjunction with this disarticulation. The tib ant transfer results in dorsiflexion and distributes the weight-bearing portion more centrally and the lengthening of the Achilles tendon is necessary to accommodate this posteriorly. Transfer of the tibialis anterior or posterior tibialis to the calcaneous would exacerbate the equinovarus deformity. Shortening of the Achilles tendon would also exacerbate the anterior loading of the scar.

(OBQ07.194) Postoperative varus alignment of an unstable subtrochanteric femur fracture treated with an intramedullary nail has been shown to be related to which of the following factors?

1. Use of a piriformis entry nail through a greater trochanteric entry portal

    

    

    

2. Use of a greater trochanteric entry nail through a piriformis entry portal

    

3. Use of a lateral entry nail through a piriformis entry portal

    

    

4. Use of a femoral distractor device to obtain reduction

    

    

5. Use of a fracture table to obtain reduction PREFERRED RESPONSE ▼ 1

CORRECT

DISCUSSION: Usage of a piriformis (straight) nail through a greater trochanteric entry portal will bring the fracture into varus, as the greater trochanteric entry site's axis is lateral to the femoral shaft, and advancement of the nail causes the two axes to become colinear, leading to varus. The referenced study by Ostrum notes that usage of a greater trochanteric starting point is safe in obese patients; he recommends usage of a larger incision and maximum leg adduction. The referenced study by Winquist et al is a classic review of femoral nailing, and emphasizes the importance of starting point selection and fracture reduction to maximize clinical outcomes (99.1% union rate in their series of 520 patients).

(OBQ10.52) A patient presenting with scapulothoracic dissocation and ipsilateral extremity neurologic injury is most likely to have which of the following outcomes?

1. Glenohumeral arthritis

    

    

    

2. Return of 3/5 motor strength in distal extremity

    

    

    

3. Full return of extremity sensory function only

    

    

    

4. Flail extremity

    

5. Death

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: Scapulothoracic dissociation is a high-energy injury resulting from massive traction injury to the shoulder girdle with disruption of the scapulothoracic articulation. The most common long term result from this injury is complete loss of motor and sensory function of the extremity (flail limb), with death in the acute or semi-acute period also common.

The referenced study by Althausen et al found that outcomes from this injury were: a flail extremity in 52%, early amputation in 21%, and death in 10%.

The other referenced study by Ebraheim et al found that 12/15 patients had a complete brachial plexus injury and that none recovered any function (the other 3 patients died in the acute period).

(OBQ08.196) Which of the following treatments of an oligotrophic supracondylar femoral nonunion has been shown to have the best outcome?

1. Retrograde femoral nailing

    

    

    

2. Hybrid external fixation

    

    

    

3. Usage of a percutaneous locking plate

    

4. Open reduction and plating with autograft

    

    

5. Open reduction and plating with adjunct calcium phosphate PREFERRED RESPONSE ▼ 4

CORRECT

DISCUSSION: Oligotrophic femoral supracondylar nonunions have been shown to be best treated with open reduction and plating (revision if previous surgery) and usage of autologous bone grafting.

The first study by Bellabarba et al is a case series of 100% union rate (n=19) of supracondylar femoral nonunions treated with revision ORIF and autografting. The second study by Chapman et al is a case series of 100% union rate (n=18) of supracondylar nonunions treated with single or double plating and autograft. The referenced study by Rodriguez et al is an excellent review of the general principles and concepts of nonunions and their treatment.

(OBQ07.19) Your 25-year-old patient complains of anterior knee pain after retrograde femoral nailing for a diaphyseal fracture and asks you why you didn’t perform antegrade nailing as he has seen on the internet. You tell him that retrograde nailing is your preferred technique over antergrade nailing for diaphyseal femoral fractures because it has been shown to have?

1. Increased rate of union

    

    

    

2. Decreased rate of infection

    

    

    

3. Shorter operative time

    

    

    

4. Lower rates of hip pain

    

5. Lower rates of knee pain

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: Patients with retrograde femoral nails commonly have knee pain, while antegrade nails commonly have hip pain, abductor weakness and heterotopic ossification of the abductors. Ostrum’s randomized prospective study of 100 patients with reamed femoral nails found 22% of antegrade nail patients had proximal hip pain, weak hip abductors or trendelenburg gait. No significant difference was found in set-up time, operative time, knee motion or pain, or infection rates. Ricci performed a retrospective study of 293 fractures and found that the antegrade femoral nail group had more hip pain (10% vs 4%) and the retrograde nail group had more knee pain (36% vs 9%). There was no difference in healing, malunion, non-union or other complications. Tornetta performed a randomized controlled comparison of 69 femur fractures and found more problems of length and rotation using a retrograde nailing. There was no difference in time to union, operating time, blood loss, complications, size of nail or reamer, or transfusion requirements

(OBQ06.269) All of the following techniques can help to prevent apex-anterior angulation during intramedullary nailing of proximal one-third tibia fractures EXCEPT:

1. posterior blocking screw

    

    

    

2. posterior starting hole

    

    

    

3. interlocking the nail in a semi-extended knee position

    

    

    

4. anteriorly directing the nail

    

5. anterior blocking screw

PREFERRED RESPONSE ▼ 5 CORRECT

DISCUSSION: Sagittal malalignment is commonly seen after nailing proximal tibia fractures. The start point as well as the direction of the nail can lead to sagittal deformity. Freedman found in nailing tibia fractures that malalignment was seen in 58% of proximal third fractures, 7% of middle third fractures, and 8% of distal third fractures. Of the malaligned fractures, 83% were either segmental or comminuted. Lang found that a medialized nail entry point and a posteriorly and laterally directed nail insertion angle contributed to malalignment. It is logical that a fracture that is reamed and then nailed in the posterior direction will lead to a gap anteriorly, and that posterior comminution will lead to anterior angulation as the fracture hinges on the intact cortex anteriorly. An anterior starting hole will tend to lead to more of a posterior nail direction. Tornetta found that using only 15 degrees knee flexion (semi extended) eliminated the extension force of the quadriceps on the proximal fragment, which otherwise would have tended to cause anterior angulation at the fracture site; therefore interlocking in flexion leads to anterior angulation. Krettek found that a posteriorly placed blocking screw is meant to prevent posterior placement of the nail and therefore encourages decreased anterior angulation of the fracture. Henley found that if the fracture is high and the nail bend is within the distal fracture fragment, as the nail is inserted, the nail will drive the distal fragment posteriorly.

(OBQ04.27) Intramedullary nailing of proximal tibial shaft fractures are technically demanding, and use of an extended medial parapatellar incision with a semiextended technique can prevent what common deformity at the fracture site?

1. Valgus

    

    

    

2. Varus

    

    

    

3. Recurvatum

    

    

    

4. Procurvatum

    

5. Rotational deformity

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: Valgus and flexion is the most common deformity seen after intramedullary nailing of proximal tibia fractures. The semi-extended nailing position helps overcome the procurvatum or flexion deformity of the fracture.

Lang et al. reported in their study of 32 proximal third tibia fractures that 56% of the fractures had 5 degrees or more valgus angulation and 28% had 10 degrees or more valgus angulation. Angulation in the AP plane ranged from 0 degrees to 20 degrees, all of which was apex anterior. Nineteen (59%) fractures demonstrated 5 degrees or more angulation, and 7 (22%) fractures demonstrated 10 degrees of more angulation.

Tornetta advocates use of extended medial parapatellar incision with the leg in a semiextended position to allow for a more proximal and lateral starting point. This modified starting point forces the nail to overcome the tendency of the fracture to flex (apex anterior) and go into valgus.

(OBQ09.40) What risk factor leads to the highest rate of postoperative loss of reduction in unstable posterior pelvic ring injuries?

1. Type of anterior fixation

    

    

    

2. Male sex

    

    

    

3. Usage of a transiliac bar

    

4. Vertical sacral fracture

    

    

5. Sacroiliac joint fracture-dislocation PREFERRED RESPONSE ▼ 4

CORRECT

DISCUSSION: According to the referenced article by Griffin et al, the risk of postoperative loss of reduction is greatest with a vertical sacral fracture pattern (13%, all within 3 weeks). There was no significant association between failure and anterior fixation method, iliosacral screw arrangement or length, or any demographic or injury variable.

Their conclusion: "Percutaneous iliosacral screw fixation is a useful technique in the management of vertically unstable pelvic fractures, but a vertical sacral fracture should make the surgeon more wary of fixation failure and loss of reduction."

(OBQ04.188) Placing the starting point for an antegrade femoral nail too anterior to the axis of the medullary canal can lead to what intraoperative complication?

1. Nail incarceration

    

    

    

2. Loss of locking screw trajectory into the lesser trochanter

    

    

    

3. Creation of a procurvatum deformity

    

    

    

4. Iatrogenic fracture of the proximal fragment

    

5. Decrease in hoop stresses

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: Usage of an anterior starting point that is too anterior leads to creation of significant hoop stresses in the proximal segment, potentially leading to iatrogenic fracture of the proximal segment. The referenced study by Johnson et al reviews the topic of femoral bursting and he notes that even shifting 6mm too far anteriorly can lead to proximal femoral fracture creation. He also reported that overreaming the canal by at least 0.5mm diameter is necessary to decrease hoop stresses throughout the femur, likely due to a mismatch in the radius of curvature of the femur and intramedullary nail.

(OBQ07.106) A child in a MVA has a Glasgow Coma Scale score of 14. His injuries have been graded as severe but not life-threatening injury to the chest (3 points), moderate injury to the abdomen (2 points), and severe injuries but with probable survival injury to the the face or neck (4 points) using the criteria for the Modified Injury Severity Score (MISS). There are no injuries to extremities/pelvis . Based on this information, what is the child’s total MISS score?

1. 7

2. 9

3. 25

4. 29

5. 30

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: The MISS for children categorizes injuries into five body areas: 1) neurologic, 2) face & neck, 3) chest, 4) abdomen & pelvic contents, 5) extremities & pelvic girdle. Each of these are scored 1-5 with 1 being minor, 2 moderate, 3 severe but not life threatening, 4 severe with probable survival, and 5 critical with uncertain survival. The total score for the MISS, like the Injury Severity Score (ISS), is the sum of the squares for the highest injury score grades in the three most severely injured body regions. Therefore, in this case: chest (3x3) + abdomen (2x2) + face/neck (4x4) = 9+4+16 = 29. The Glasgow coma scale would be 1, which is less than the scores of 3 of the other areas so it is excluded. Loder in 1987 showed that in 78 polytrauma pediatric patients, no deaths were seen when the MISS is <40. Mortality was 50% for scores >40 and 75% for scores >50. The Mayer article is a good overview of the MISS.

(OBQ05.272) An anterior approach to the sacroiliac joint is indicated with which of the following concomitant injuries?

1. Ipsilateral symphysis dislocation

    

    

    

2. Ipsilateral posterior wall acetabular fracture

    

    

    

3. Contralateral sacral ala fracture

    

    

    

4. Contralateral sacroiliac dislocation

    

5. L5-S1 retrolisthesis

PREFERRED RESPONSE ▼ 1 CORRECT

DISCUSSION: An anterior approach to the sacroiliac joint is indicated with the presence of a symphysis dislocation, which can be reduced through the same approach. The other choices are all relative contraindications to this approach. A sacroiliac dislocation or malalignment can lead to gait abnormalities, pelvic obliquity, back or buttock pain, as well as neurological changes. The first referenced article by Simpson et al noted that an anterior approach was safe and that excellent results correlated significantly with anatomic reductions of the SI joint. The second reference discusses pelvic ring injuries in depth and covers typical treatment protocols.

(OBQ08.272) A patient sustains a transection of the posterior cord of the brachial plexus from a knife injury. This injury would affect all of the following muscles EXCEPT?

1. Subscapularis

    

    

    

2. Latissimus dorsi

    

    

    

3. Supraspinatus

    

    

    

4. Teres minor

    

5. Brachioradialis

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: The posterior cord of the brachial plexus gives rise to the 1) upper subscapular nerve 2) lower subscapular nerve 3) thoracodorsal nerve 4) axillary nerves 5) radial nerve. The upper subscapular nerve innervates the subscapularis. The lower subscapular nerve innervates teres major and also subscapularis. The thoracodorsal nerve innervates latissimus dorsi. The axillary nerves innervates deltoid and teres minor. The radial nerve innervates the triceps, brachioradialis, wrist extensors, and finger extensors. The supraspinatus is innervated by the suprascapular nerve off the upper trunk and therefore would not be affected by an injury to the posterior cord. The anatomy of the brachial plexus is shown in Illustration A.

(OBQ05.195) A 58-year-old man underwent distal radius ORIF with a volar locking plate yesterday. Preoperatively, he reported some mild sensory disturbances in the volar thumb and index finger, but had 2-point discrimination of 6mm in each finger. Now, he complains of worsening hand pain and sensory disturbances in his volar thumb and index finger. Two-point discrimination is now >10mm in these fingers. Radiographs show a well-fixed fracture in good alignment. What is the most appropriate treatment at this time?

1. Strict elevation

    

    

    

2. Removal of hardware

    

    

    

3. Immediate carpal tunnel release

    

    

    

4. Carpal tunnel release if no resolution at 6-12 weeks

    

5. Trial of night splinting

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: This patient had mild median parasthesias preoperatively that have significantly worsened postoperatively. Immediate carpal tunnel release is the most appropriate next step in treatment.

Mack et al reported on ten cases of acute carpal tunnel syndrome (ACTS) and six cases of nerve contusion in patients with acute median neuropathy associated with blunt wrist trauma. The patients with ACTS initially had normal sensation and subsequently developed objective sensory loss (2-point discrimination greater than 15 mm) in the median nerve distribution associated with severe wrist pain. In contrast, patients with nerve contusion injuries had immediate sensory loss and symptoms were nonprogressive. Four of five patients with ACTS who underwent carpal tunnel release within 40 hours of the onset of numbness had normal 2-point discrimination within 96 hours. Neuropathy, secondary to nerve contusion without coexisting ACTS, may be treated initially by observation.

Ford et al reported of five cases of ACTS. Four with delayed treatment had poor outcomes while the one patient with early CTR had full recovery. All patients with ACTS had increasing and severe pain in the wrist with parasthesia and impaired sensation in the median distribuation. These symptoms initially weren’t present after wrist trauma, but developed rapidly in the next few hours.

(OBQ10.199) Excision of heterotopic bone about the forearm or elbow can be done with limited recurrence rates as early as which of the following after initial injury?

1. Once ankylosis of the forearm or elbow occurs

    

    

2. 6 weeks

    

    

    

3. 6 months

    

    

    

4. 12 months

    

    

    

5. 18 months

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: Excision of heterotopic bone about the elbow and forearm was classically treated once the bone was mature and no further bone development was occuring (bone scan became negative). However, several studies have shown that earlier removal before this point in time is safe, when done in conjunction with radiation therapy (XRT).

The referenced study by McAuliffe et al is a retrospective review of heterotopic ossification (HO) about the elbow followed by 100 cGY (5 fractions over 1 week) of XRT as early as 3 months post-injury. They were able to achieve an average arc of motion > 100 degrees.

The other referenced study by Beingessner et al is a review of HO excision of the forearm. They found that excision and XRT, followed by 6 weeks of indomethacin, led to an increase of forearm motion from an average of 17 degrees to 136 degrees when the excision was done at 4 months post-injury.

(OBQ05.187) When viewing pelvic injury radiographs, which of the following describes the findings diagnostic of an isolated transverse acetabular fracture?

1. Fracture line crossing the acetabulum with disruption of the iliopectineal and ilioischial lines

    

    

    

2. Disruption of the iliopectineal and ilioischial lines, with extension into the iliac wing and obturator ring

    

    

    

3. Disruption of the iliopectineal and ilioischial lines, with extension into the obturator ring

    

4. Isolated disruption of the iliopectineal line, with an intact ilioischial ine

    

    

5. Isolated disruption of the ilioischial line, with an intact iliopectineal ine PREFERRED RESPONSE ▼ 1

CORRECT

DISCUSSION: Transverse acetabular fractures separate the innominate bone into two fragments, the superior iliac and the inferior ischiopubic, by a single fracture line that crosses the acetabulum horizontally. The iliopectineal and ilioischial lines are disrupted on the AP pelvis radiograph. Axial CT scan of this fracture pattern at the level of the dome will show a vertical anterior to posterior fracture line. Illustrations A-C show AP and Judet pelvic radiographs of a transverse fracture. Illustration D demonstrates the axial CT appearance of this fracture type. Answer choice 2 is describing a both column injury, and answer choice 3 describes a T-type fracture pattern. Answer choices 4 and 5 describe an anterior column and posterior column injury respectively. Judet et al provide one of the first comprehensive reviews on acetabular surgical approaches, fracture types, and radiographic anatomy. Illustration E demonstrates the acetabular classification scheme developed by Judet.

(OBQ05.132) Which of the following has been shown to have similar biochemical and clinical characteristics as iliac crest autograft?

1. BMP-2

    

    

    

2. BMP-7 with collagen matrix carrier

    

    

    

3. Hydroxyapatite cement

    

4. Platelet rich plasma with allograft cancellous bone carrier

    

    

5. Femoral intramedullary reaming contents

PREFERRED RESPONSE ▼ 5 CORRECT

DISCUSSION: In multiple studies, femoral intramedullary reaming debris has been shown to have similar biochemical characteristics as iliac crest autograft. Intramedullary reaming products have osteogenic potential with viable cells while BMP's are osteoinductive cytokines.

Hoegel et al found that the reamings had alkaline phospatase activity, indicating living osteoblasts. The amount of activity was independent of the reamer sizes and reamer design.

Frolke et al concluded that reaming debris supports callus building (healing) as much as conventional iliac crest bone grafting in an animal fracture gap model.

(OBQ04.204) Patients who sustain bilateral femoral shaft fractures when compared to unilateral femur fractures have higher rates of the following EXCEPT:

1. closed head injury

    

    

    

2. mortality

    

    

    

3. thoracic injury

    

    

    

4. open skull fractures

    

5. pelvic fractures

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: Copeland et al performed a retrospective analysis using their trauma registry data on consecutive blunt trauma patients with unilateral (800 patients) or bilateral (85 patients) femoral shaft fractures. Patients with bilateral femoral fractures had a significantly higher Injury Severity Score (30.2 versus 24.5, p < 0.05) and higher mortality rate (25.9 vs 11.7%, p < 0.014) than patients with unilateral femoral fractures. Bilateral fracture patients also had significantly more closed head injuries,open skull fractures, intraabdominal injuries requiring surgical intervention, and pelvic fractures. The rates of thoracic injury were similar (answer 3). Regression analysis of variables evident on admission revealed a significant correlation between bilateral femoral fractures and death; however, other factors (shock, closed head injury, and thoracic injury) had much stronger correlations with mortality

(OBQ05.157) In a pilon fracture, the Chaput fragment typically maintains soft tissue attachment via which of the following structures?

1. Interosseous ligament

    

    

    

2. Anterior inferior tibiofibular ligament

    

    

    

3. Posterior inferior tibiofibular ligament

    

    

    

4. Deltoid ligament

    

5. Tibiotalar ligament

PREFERRED RESPONSE ▼ 2 CORRECT

DISCUSSION: The Chaput fragment, highlighted by the arrow in Illustration A, is the anterolateral fragment of the distal tibia. This section of bone attaches to the anterior inferior tibiofibular ligament and is often hinged off this structure due to the fracture. A pilon fracture is often split into three main fragments at the joint level (Illustration B): Chaput fragment (anterolateral), Volkmann fragment (posterolateral), and a medial fragment. The Volkmann fragment is the attachment site of the posterior inferior tibiofibular ligament. The Wagstaff fragment is the fibular corollary to the Chaput fragment, and serves as the other attachment of the anterior inferior tibiofibular ligament

(OBQ05.152) During open reduction and internal fixation of a both bone forearm fracture, restoration of the radial bow has been associated with which of the following?

1. Wrist extension strength

    

    

    

2. Wrist flexion strength

    

    

    

3. Forearm rotation

    

4. Elbow range of motion

    

    

5. Decreased incidence of synostosis PREFERRED RESPONSE ▼ 3

CORRECT

DISCUSSION: Restoration of the anatomy of the radial bow directly correlates with the range of motion postoperatively (pronation-supination). The referenced study by Schemitsch et al found that restoration of the normal radial bow was related to the functional outcome. A good functional result (more than 80 percent of normal rotation of the forearm) was associated with restoration of the normal amount and location of the radial bow. Similarly, the recovery of grip strength was associated with restoration of the location of the radial bow toward normal.

(OBQ07.98) Which of the following associated type acetabular fracture patterns is defined based on the fact that all articular segments are detached from the intact portion of the ilium, which remains attached to the sacrum through the sacroiliac joint?

1. Posterior wall/ posterior column

    

    

    

2. Transverse

    

    

    

3. T-Type

    

    

    

4. Anterior column/ posterior hemitransverse

    

5. Both columns

PREFERRED RESPONSE ▼ 5 CORRECT

DISCUSSION: There are 5 simple and 5 associated fracture types according to the classification system created by Judet and Letournel. The key feature which distinguishes both column fractures from other associated types is that all articular segments are detached from the intact portion of the ilium, which remains attached to the sacrum through the SI joint. Although the transverse plus posterior wall, T-shaped, and anterior plus posterior hemi-transverse fractures all show involvement of the anterior and posterior columns, they are not “both columns” because a portion of the articular surface remains in its normal position, attached to intact ilium. The intact ilium is responsible for the "spur sign" noted most prominently on the obturator oblique radiograph.

(OBQ10.115) Regarding the role of the orthopaedic surgeon in addressing domestic and family violence, all of the following statements are true EXCEPT:

1. Report all cases of child abuse, as this is required by all states

    

    

    

2. Report all cases of adult spousal or intimate partner abuse, as this is required by all states

    

    

    

3. Hospitalize elderly victims who are in immediate danger and help develop a plan to ensure their safety

    

    

    

4. Advocate for appropriate legislation and public policy on violence and abuse related to health care

    

5. Orthopedic surgeons are responsible for knowing the reporting laws and procedures for suspected abuse

PREFERRED RESPONSE ▼ 2 CORRECT

DISCUSSION: Reporting requirements for adult spousal or intimate partner abuse is not standardized among states and it is the responsibility of the orthopaedic surgeon to understand the laws of his or her

state. The AAOS Advisory statement gives information to assist in meeting the ethical and legal obligations on Domestic and Family Violence and Abuse.

Domestic and family violence affects over 10% of the US population (approximately 32 million Americans). Child abuse and neglect contributed to 1,400 fatalities in 2002 and there was 565,747 reports of suspected elder abuse.

Reporting of suspected child abuse is required in all states. The orthopaedic surgeon should hospitalize elderly victims who are in immediate danger and help develop a plan to insure their safety.

(OBQ06.218) Which of the following amputations will lead to the greatest oxygen requirement per meter walked following prosthesis fitting?

1. Above-knee-amputation (transfemoral)

    

    

    

2. Below-knee-amputation (transtibial)

    

    

    

3. Through Knee

    

    

    

4. Syme

    

5. Midfoot

PREFERRED RESPONSE ▼ 1 CORRECT

DISCUSSION: The general trend is increasing energy requirement for more proximal amputations. Amputation should be performed at the lowest possible level in order to preserve the most function. Pinzur compared 5 patients with amputations at midfoot, Syme’s, BKA, through knee, and AKA with five controls. Walking speed and cadence decreased while oxygen consumption per meter walked increased with each more proximal amputation. The only exception is the Syme which was the most energy efficient even though it is more proximal to the midfoot amputation.

(OBQ09.137) The pelvic spur sign on plain radiography is pathognomonic for which of the following injuries?

1. Transtectal transverse acetabular fracture

    

    

    

2. Vertical shear pelvic ring injury

    

    

    

3. Displaced H-type sacral fracture

    

4. Both column acetabular fracture

    

    

5. Anterior-posterior type III pelvic ring injury PREFERRED RESPONSE ▼ 4

CORRECT

DISCUSSION: The pelvic spur sign is pathognomonic for a both column acetabular fracture. It is best seen on an AP or obturator oblique x-ray. The spur is the intact portion of the ilium, still attached to the axial skeleton and seen posterosuperior to the displaced acetabulum (typically medially displaced).

Illustration A shows the spur sign (arrows) on a CT image, while illustration B shows an obturator oblique of the pelvis and the spur sign is shown with the long tailed arrow (on the left of the image).

(OBQ11.193) A 45-year-old male sustains a proximal third tibia fracture as an isolated injury and elects to undergo operative treatment with intramedullary nailing. Postoperative radiographs show excessive procurvatum deformity. Which of the following operative techniques would have helped to best avoid the procurvatum deformity?

1. Tibial nailing with increased knee flexion

    

    

    

2. Lateral blocking screw in the proximal fragment

    

3. Medial blocking screw in the proximal fragment

    

    

4. Anterior blocking screw in the proximal fragment

    

    

5. Posterior blocking screw in the proximal fragment PREFERRED RESPONSE ▼ 5

CORRECT

DISCUSSION: Posterior blocking screws in the proximal tibial segement help to avoid tibial procurvatum deformity and malunion. Proximal third tibia fractures are often times difficult to reduce anatomically due to the tendency for both valgus and flexion deformity at the fracture site. The posterior blocking screw helps to eliminate the tendency for the nail to be too posterior and cause the fracture to flex. Blocking screws should be placed on the concavity of the deformity to minimize the procurvatum and valgus deformities of this fracture pattern.

Krettek et al looked at the importance of using blocking screws during intramedullary nailing of metaphyseal fractures using small diameter nails. They found less procurvatum deformity and malunions associated with using of blocking screws and found no complication with their utilization.

Ricci et al reviewed fractures of the proximal third of the tibial shaft treated with intramedullary nails and blocking screws. Their results supported that blocking screws were effective in maintaining alignment of fractures of the proximal third of the tibial shaft treated by intramedullary nailing.

Hiesterman et al review different reduction techniques to avoid malalignment, including the use of a proper starting point and insertion angle, blocking screws, unicortical plates, and a universal distractor.

Illustration A shows a radiograph utilizing posterior proximal and distal blocking screws to prevent procurvatum deformity.

(OBQ07.269) Which of the following patients who sustained a calcaneal fracture will most likely undergo an eventual subtalar fusion?

1. Male worker's compensation patient who participates in heavy labor work with an inital Böhler angle less than 0 degrees

    

    

    

2. Female worker's compensation patient who participates in heavy labor work with an inital Böhler angle >15 degrees

    

    

    

3. Male non-worker's compensation patient who participates in heavy labor work with an inital Böhler angle less than 0 degrees

    

    

    

4. Male worker's compensation patient who participates in heavy labor work with an inital Böhler angle >15 degrees

    

5. Female non-worker's compensation patient who participates in heavy labor work with an inital Böhler less than 0 degrees

PREFERRED RESPONSE ▼ 1 CORRECT

DISCUSSION: The Level 2 study by Czisy et al is a review of a randomized trial database that analyzed the prospective clinical outcome of 45 patients who failed closed or open treatment of a displaced intraarticular calcaneal fractures. The cohort underwent a subtalar fusion by distraction bone-block arthrodesis for subtalar arthritis. They found that male worker's compensation patients who participate in heavy labor work with a fracture pattern with Böhler angle less than 0 degrees were the most likely to undergo a subtalar fusion.

The meta-analysis by Randle et al reviewed 6 clinical studies comparing the results of operative vs. conservative management of calcaneal fracture studies. They found a trend for nonoperatively treated patients to have a higher risk of experiencing severe foot pain than did operatively treated patients, however they could not draw any definitive conclusions guiding treatment

(OBQ09.246) Percutaneous placement of a lateral proximal tibial locking plate that extends down to the distal third of the leg is associated with postoperative decreased sensation of which of the following distributions?

1. Medial hindfoot

    

    

    

2. Lateral hindfoot

    

    

    

3. First dorsal webspace

    

    

    

4. Dorsal midfoot

    

5. Plantar foot

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: Placement of long lateral tibial plates have been shown to have a risk of iatrogenic injury to the superficial peroneal nerve, which has a sensory distribution to the dorsal foot. This risk is seen especially with percutaneous approaches, such as those used with the LISS plate. The first reference by Deangelis et al found a risk of superficial peroneal injury with percutaneous screw placement of holes 11-13 in the LISS plate. The second referenced article by Roberts et al noted a slightly increased distance to the neurovascular bundle when interlocking tibial nails in a lateral to medial direction (compared to medial to lateral locking) and slightly increased biomechanical strength when locking in a medial to lateral direction. The third referenced article by Wolinsky et al notes a risk of iatrogenic injury to the deep peroneal nerve and anterior tibial artery with an anterolateral approach to the distal tibia, but notes the superficial peroneal nerve is safe with an appropriate exposure.

(OBQ11.264) A 34-year-old female sustains a proximal third tibia fracture as an isolated injury and elects to undergo operative treatment with intramedullary nailing. Which of the following operative techniques would help to best avoid a procurvatum deformity of the tibia?

1. Semiextended position during nailing

    

    

    

2. Lateral blocking screws in proximal tibia fragment

    

    

    

3. Use of a radiolucent triangle to flex the knee

    

4. Anterior blocking screw in the proximal tibia fragment

    

    

5. Medial parapatellar arthrotomy avoiding the patellar tendon PREFERRED RESPONSE ▼ 1

CORRECT

DISCUSSION: The semiextended position for intramedullay nailing of proximal tibia shaft fractures has shown to cause less complications of flexion deformity and malunion. Proximal third tibia fractures are often times difficult to reduce anatomically due to the tendency for both valgus and flexion deformity at the fracture site. The semiextended position helps to eliminate the tendency for the fracture to flex, due to the avoidance of excessive knee flexion during the reduction. Illustration A is an example of semiextended positioning for tibial nailing. Illustration B shows radiograph utilizing posterior blocking screws to prevent procurvatum deformity.

Tornetta et al looked at the semiextended intramedullary nailing of proximal tibia fractures. Of the 24 patients nailed using this technique, 19 had no anterior angulation, while only 5 had less than 5 degrees of flexion deformity.

In their study, Kubiak et al also advocate the semiextended position for tibial nailing. They note better control of fracture alignment and stabilization especially in the sagittal plane, and better ability to obtain imaging and maintenance of reduction during nail insertion and locking.

(OBQ06.33) The greatest amount of iatrogenic injury to the piriformis tendon is associated with which of the following?

1. Antegrade piriformis entry femoral nailing

    

    

    

2. Antegrade greater trochanteric entry femoral nailing

    

3. Retrograde femoral nailing

    

    

4. External fixation of a femoral shaft fracture

    

    

5. Open reduction and internal fixation of an intertrochanteric fracture PREFERRED RESPONSE ▼ 1

CORRECT

DISCUSSION: The greatest amount of injury to hip abductor musculature is seen with piriformis starting points as compared to the other options listed above. Increased rate of injury to the piriformis tendon, medial femoral circumflex artery branches, gluteus minimus, and superior gluteal nerve branches are noted with the piriformis starting site. Increased injury to the gluteus medius is seen with a greater trochanteric starting point. The referenced study by Dora et al noted increased injury to the piriformis tendon with a piriformis starting point (as compared to a more lateral insertion site). The classic referenced article by Johnson et al notes that anterior placement of the starting point >6mm over the recommended start leads to increased hoop stresses and possible burst-type fractures. The classic referenced study by Winquist et al reviewed their series of 520 femur fractures treated by antegrade nailing; they report a 99.1% union rate.

(OBQ07.147) All of the following have been shown to increase the risk of refracture following removal of forearm plates used for internal fixation EXCEPT:

1. initial fracture comminution

    

    

    

2. initial fracture displacement

    

    

    

3. use of 3.5 mm dynamic compression plate

    

4. plate removal before 12 months

    

    

5. immediate weight bearing as tolerated following removal PREFERRED RESPONSE ▼ 3

CORRECT

DISCUSSION: The Rumball et al article reviewed factors which influenced refracture after removal of the forearm plates. The factors that appeared to influence the refracture rate were degree of initial displacement and comminution, physical characteristics of the plate, early removal and lack of postremoval protection. Plates removed under 15 months showed an increased risk of refracture. There were no fractures in this series using the 3.5 DCP plate. Deluca et al concluded that, in retrospect, radiolucency at the site of the original fracture was seen in most patients (with refracture) when the plate was removed. Chapman et al found that all the refractures in their group had been intially treated with a

4.5 DCP plate, and that none of the patients with a 3.5 DCP had a refracture.

(OBQ09.223) A patient wakes up with a foot drop following open reduction internal fixation of a posterior wall/posterior column acetabular fracture. What position of the leg causes the highest intraneural pressure in the sciatic nerve?

1. hip and knee extension

    

    

    

2. hip flexion to 90, knee extension

    

    

    

3. hip internal rotation, knee flexion to 90

    

    

    

4. hip and knee flexion to 90

    

5. hip extension, knee flexion to 90

PREFERRED RESPONSE ▼ 2 CORRECT

DISCUSSION: Borrelli et al examined the intraneural pressure of the sciatic nerve with the hip and knee in various different positions. They found that the "sciatic nerve appeared to exceed published critical thresholds for alterations of blood flow and neural function only when the hip was flexed to 90 degrees and the knee was fully extended." As a result, the leg is typically position with the hip in extension (or minimal flexion) and the knee in about 90 degrees of flexion when performing acetabular surgery via a posterior approach.

(OBQ09.210) A 32-year-old man presents to the emergency department with a humeral shaft fracture. He has wrist drop as well as impaired finger and thumb extension. Which motor function would be expected to recover last?

1. Elbow extension

    

    

    

2. Forearm supination

    

    

    

3. Wrist extension in radial deviation

    

    

    

4. Middle finger MCP extension

    

5. Index finger MCP hyperextension

PREFERRED RESPONSE ▼ 5 CORRECT

DISCUSSION: The patient is presenting with radial nerve palsy secondary to his humerus fracture. Motor recovery proceeds in a proximal to distal direction.

Abrams et al detailed the order of innervation of the radial nerve and found the following order (proximal to distal): brachioradialis, extensor carpi radialis longus, supinator, extensor carpi radialis brevis, extensor digitorum communis, extensor carpi ulnaris, extensor digiti quinti, abductor policis longus, extensor policis longus, extensor policis brevis, and extensor indicis proprius.

Branovacki et al found a slightly different pattern: brachioradialis, extensor carpi radialis longus, superficial sensory, extensor carpi radialis brevis, supinator, extensor digitorum/extensor carpi ulnaris, extensor digiti minimi, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus and extensor indicis proprius.

While both extensor digitorum and extensor indicis proprius extend the index finger MCP joint, only extensor indicis proprius hyperextends the index finger past neutral

(OBQ04.123) A 34-year-old male has persistent anterolateral ankle pain after a snowboarding injury 1 week ago and is unable to bear weight. Radiographs taken in the emergency room were negative. What is the next step in management?

1. MRI

    

    

    

2. Bone Scan

    

    

    

3. CT scan

    

    

    

4. Diagnostic injection

    

5. Repeat radiographs

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: Fractures of the lateral process of the talus are frequently overlooked and should always be considered in the differential diagnosis of ankle pain in snowboarders. The common mechanism for fracture is dorsiflexion of the ankle and inversion of the hindfoot.

The reference by Vlahovich et al is a case report of a talus fracture in a snowboarder and argues the importance of CT scans in evaluating these injuries as radiographs may fail to show the injury and amount of displacement and comminution of the fracture.

The reference by Tucker et al is a review of the literature which emphasized the importance of early diagnosis to avoid long term complications. They recommend short leg casting for nondisplaced fractures and surgery for displaced or comminuted fractures.

(OBQ04.163) Non-operative treatment of displaced intra-articular calcaneal fractures require late subtalar fusion for post-traumatic arthritis in what percentage of patients?

1. 16%

2. 4%

3. 1%

4. 52%

5. 87%

PREFERRED RESPONSE ▼ 1 CORRECT

DISCUSSION: Howard et al reported on complications following management of displaced intra-articular calcaneal fractures. 469 patients were randomized into ORIF and non-operative groups. ORIF patients were more likely to develop complications (overall 25% vs 18% of non-op) with fractures of increasing severity (Sanders IV) developing more complications regardless of management strategy. The most common complication in the non-operative group was secondary late arthrodesis for posttraumatic arthritis which occured 16% (37 of 233 patients). In the ORIF group 16% of patients mostly developed superficial wound infections (10 of those 36 developed deep infection as well) followed by hardware malposition (5.8%) as the two most common complications.

(OBQ09.168) At the elbow, the anterior bundle of the medial collateral ligament inserts at which site?

1. Radial tuberosity

    

    

    

2. 3mm distal to the tip of the coronoid

    

    

    

3. Anteromedial process of the coronoid

    

4. Medial border of the olecranon fossa

    

    

5. Radial side of ulna at origin of annular ligament PREFERRED RESPONSE ▼ 3

CORRECT

DISCUSSION: The anterior bundle of the medial collateral ligament of the elbow inserts at the anteromedial process of the coronoid, also known as the sublime tubercle. Fractures at this site have been shown to have worse results with nonoperative treatment, due to increased rates of instability and post-traumatic arthrosis.

The referenced articles by Ring and Steinmann are great reviews of the topic of coronoid fractures. They review the diagnosis, treatment options, rehabilitation, and outcomes of these injuries. They focus on the importance of the coronoid in elbow stability, especially with base fractures, or ones that involve the sublime tubercle.

Illustration A depicts the anterior bundle of the MCL insertiing at the sublime tubercle.

(OBQ07.207) Partial patellectomy is the recommended treatment for which of the following injuries?

1. Vertical patella fractures

    

    

    

2. Patellar tendon rupture

    

    

    

3. Comminuted inferior pole fracture

    

4. Stellate patella fracture

    

    

5. Chronic quadriceps tendon rupture PREFERRED RESPONSE ▼ 3

CORRECT

DISCUSSION: Partial patellectomy is a recommended treatment for a comminuted superior or inferior pole fracture measuring <50% of the patella's height. The area can be excised and a technique of quadriceps tendon (superior pole) or patellar tendon (inferior pole) repair can then be undertaken.

The referenced study by Saltzman et al reported maintenance of range of motion and strength (85% of

the contralateral) with partial patellectomy at an average of 8.4 years follow up.

Furthermore, Marder et al showed that change in patellofemoral forces is minimized by attaching the patellar tendon/quad tendon anteriorly on the remaining patella. Their study also showed that by resecting more of the inferior pole that contact stress increased as the size of the discarded portion of the patella increased.

(OBQ04.11) A 40-year-old male who sustained an open pilon fracture 2 weeks ago is scheduled for a below-the-knee amputation (BKA). What laboratory value is the best predictor for wound healing?

1. serum albumin level

    

    

    

2. total protein level

    

    

    

3. calcium levels

    

    

    

4. C-reactive protein

    

5. ESR

PREFERRED RESPONSE ▼ 1 CORRECT

DISCUSSION: Albumin is the best measure of nutrition that is vital for wound healing. Total protein is a valuable measure as well, however it is not as sensitive as albumin levels. Calcium levels and ESR/C-reactive protein levels play no role.

(OBQ12.18) A 36-year-old man sustains blunt chest trauma, an open right femur fracture, and a closed left tibia fracture following a high-speed MVC. Upon presentation to the emergency room, blood pressure is 80/40, HR 135, and urine output is .4 cc/kg/hr. Fluids and blood products are administered, and the patient is transferred to the ICU for further care. Which of the following indicates adequate resuscitation has been achieved?

1. Systolic blood pressure > 120

    

    

    

2. Heart rate between 60-100

    

    

    

3. Urine output equals 0.4 cc/kg/hr

    

    

    

4. Gastric intramucosal pH of 7.4

    

5. Normal mentation

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: Of the following variables, only a normal gastric mucosal pH (>7.3) is associated with restoration of tissue oxygenation.

Shock is an abnormality of the circulatory system that results in inadequate organ perfusion and tissue oxygenation. This leads to anaerobic metabolism with the development of lactic acidosis and oxygen debt. Shock is either classified as compensated or uncompensated. Compensated shock exists when there is evidence of ongoing inadequate tissue perfusion despite the normalization of blood pressure, heart rate, and urine output. Uncompensated shock occurs when there is inadequate tissue perfusion and abnormal blood pressure, heart rate, and urine output. Thus, a patient may have normal vital signs but still be in a state of compensated shock that requires additional resuscitation.

Porter et al. review the optimal end points of resuscitation in trauma patients. They conclude that using traditional end points such as blood pressure, urine output and heart rate, may leave up to 85% of patients in "compensated" shock. They urge the use of lactate, base deficit, and gastric intramucosal pH as appropriate end points of resuscitation.

Roberts et al. discuss various aspects of damage control orthopaedics in the multiply injured trauma patient. Although they do not discuss the end points for resuscitation, they note that they presence of shock is a clinical parameter associated with adverse outcomes in the trauma patient.

Incorrect answers:

Answers 1-3: A patient may have normalized blood pressure, heart rate, and urine output but may still be in a state of compensated shock requiring further resuscitation. Answer 5: Mental status is not used to determine adequacy of resuscitation following a polytrauma.

(OBQ07.6) A 7-year-old male is struck by a motor vehicle while crossing the street and suffers an open tibia fracture with a crush injury of the ipsilateral foot. After multiple attempts at limb salvage, the family and treating surgeon elect to proceed with a knee disarticulation. What complication of pediatric amputations is avoided with a knee disarticulation as opposed to a transtibial amputation?

1. Neurogenic pain

    

    

    

2. Bone overgrowth

    

    

    

3. Hip flexion contracture

    

    

    

4. Hip adduction contracture

    

5. Leg length inequality

PREFERRED RESPONSE ▼ 2 CORRECT

DISCUSSION: Bone overgrowth is a poorly understood phenomenon in which the bone end undergoes disorganized appositional growth following amputation in a skeletally immature patient. Overgrowth is the most common complication following transosseous amputation in pediatric patients.

Krajbich reviews the management of pediatric patients with lower-limb deficiences and amputations. He advocates disarticulation as opposed to transosseous amputation when possible as bone overgrowth has not been observed in bone ends covered by articular cartilage.

O'neal et al retrospectively reviewed their rates of surgical revision for bone overgrowth in pediatric and adolescent amputees. The highest rates of revision were seen with metaphyseal-level amputations (50%) and with traumatic amputations (43%).

Benevenia et al reviewed their rates of overgrowth in skeletally immature transosseous amputees using an autogenous epiphyseal transplant from the amputated limb to cap the medullary canal. They found that only 1 of 10 patients undergoing amputation with this technique had complications due to bone overgrowth, compared with 6 of 7 patients undergoing traditional transosseous amputation.

Illustration A is a clinical photo of bone overgrowth eroding through the soft tissue in a transhumeral amputee. Illustration B demonstrates the radiographic appearance of bone overgrowth in a transtibial amputation.

Incorrect Answers:

Answer 1. Neurogenic pain is a concern for adults, but rarely occurs in children. Answer 3. Flexion contracture is not a common complication following amputation in pediatric patients. Answer 4. Adduction contracture is not a common complication following amputation in this patient population.

Answer 5. The proximal tibial physis, important for longitudinal growth of the limb, would be sacrificed with a knee disarticulation, meaning the residual limb will be shorter than if the patient had a transtibial amputation.

(OBQ06.60) A 46-year-old woman sustains an extra-articular fracture of the distal radius and undergoes open reduction and internal fixation with a volar plate and screw construct. During postoperative recovery from this injury, what benefit does formal physical therapy have as compared to a patient-guided home exercise program?

1. Greater grip strength at 6 months

    

    

    

2. Less wrist pain at 1 year

    

3. Better hand dexterity at 1 year

    

    

    

    

4. No difference in functional outcomes

    

5. Quicker return to work

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: There are no significant benefits demonstrated with formal physical therapy following distal radius fracture ORIF compared to a patient-guided home exercise program.

The reference by Wakefield and McQueen is a randomized controlled trial of 96 patients, comparing formal hand physiotherapy to a home exercise regimen. There was no difference in grip strength, pronation/supination, radial/ulnar deviation, or hand function. The authors concluded that there were no significant benefits to formal physiotherapy.

The study by Souer et al is a level I study evaluating formal therapy and patient-guided exercise program for patients who underwent ORIF of a distal radius fracture with a volar plate and screw construct. This study showed a significant decrease in wrist ROM and grip strength with formal therapy. There were no differences in arm-specific disability (DASH score) at any time point.

(OBQ09.205) A patient sustains a severe lower extremity injury. What can be said about his outcome at 2 years if he chooses reconstruction over amputation?

1. He has a higher risk of rehospitalization

    

    

    

2. He has a higher chance of returning to work

    

    

    

3. He will have a higher overall SIP (Sickness Impact Profile) score

    

    

    

4. His psychosocial SIP score will improve with time

    

5. He will have a better SIP score if he did not complete high school

PREFERRED RESPONSE ▼ 1 CORRECT

DISCUSSION: Severe lower extremity injury patients undergoing reconstruction have a higher rate of rehospitalization at 2 years. This question is based on data published by the LEAP study group, a multi-centered study of severe extremity injuries treated with either amputation or reconstruction.

Bosse et al found that at 2 years the SIP score and return to work were not statistically signficantly different between amputation and reconstruction groups. Reconstruction patients had a higher risk of rehospitalization. The psychosocial subscale of SIP did not improve with time. Risk factors for poorer SIP score were: rehospitalization for a major complication, a low educational level, nonwhite race, poverty, lack of private health insurance, poor social-support network, low self-efficacy (the patient's confidence in being able to resume life activities), smoking, and involvement in disability-compensation litigation.

MacKenize et al evaluated factors influential in returning to work (RTW) after severe lower extremity injury. Characteristics that correlated with higher rates of RTW included younger age, higher education, higher income, the presence of strong social support, and employment in a white-collar job that was not physically demanding. Receipt of disability compensation had a strong negative effect on RTW.

(OBQ09.201) A 33-year-old man requires a transfemoral amputation because of a mangling injury to his leg. Six months after the amputation he has persistent difficulty with ambulation because his femur bone moves into a subcutaneous position in his lateral thigh. It persists despite a well-fitted prosthesis. What technical error is the most likely cause of his disfunction?

1. inadequate posterior skin flap

    

    

    

2. inadequate anterior skin flap

    

3. failure to bevel the distal femur

    

    

4. lack of abductor myodesis to femur

    

    

5. lack of adductor myodesis to femur PREFERRED RESPONSE ▼ 5

CORRECT

DISCUSSION: Pinzur et al highlight the fact that amputations are reconstructive procedures and should leave the patient with a functional residual limb. Adductor myodesis is a critical part of a transfemoral amputation. If it is not performed, then the abductors and hip flexors can cause the femur to abduct, leading to severe problems with gait. The gait disturbance persists despite proper prosthetic fitting. A transfemoral amputation is usually performed with equal anterior and posterior flaps.

(OBQ09.243) A 79-year-old woman with osteoporosis presents with a displaced, severely comminuted olecranon fracture involving the proximal 40%. Which of the following represents the most appropriate treatment?

1. Intramedullary screw

    

    

    

2. Kirschner wire tension band

    

    

    

3. Total elbow arthroplasty

    

4. Fragment excision and triceps advancement

    

    

5. Hinged elbow brace with early active range-of-motion PREFERRED RESPONSE ▼ 4

CORRECT

DISCUSSION: Multiple treatments exist for olecranon fractures. Tension band construct (Illustration A) and intramedullary screw or k-wire placement are typically reserved for non-comminuted olecranon fractures, whereas plate and screw fixation (Illustration B) is used for comminuted fractures. Hak et al review olecranon fracture treatment and state that fragment excision and triceps advancement is most appropriate in elderly, osteoporotic patients with severely comminuted fractures involving the proximal 30-40% of the olecranon. Veillette et al state that when performing a triceps advancement for treatment of an olecranon fracture, between 50% and 70% of the olecranon articular surface can be excised without compromising elbow stability provided the coronoid and distal trochlea are preserved.

When excision and triceps advancement is performed, the triceps should be attached adjacent to the articular surface.

(OBQ07.174) A 70-year-old woman trips on the grass while playing golf and sustains a displaced comminuted femoral neck fracture. What is the optimal treatment for this patient?

1. Open reduction internal fixation

    

    

    

2. Bipolar hemiarthroplasty

    

    

    

3. Total hip arthroplasty

    

4. Unipolar hemiarthroplasty

    

    

5. Traction and non operative treatment PREFERRED RESPONSE ▼ 3

CORRECT

DISCUSSION: The answer is total hip arthroplasty (#3).Both references suggest that elderly active individuals should be treated with a primary total hip after displaced femoral neck fractures.

Keating et al randomized 207 patients to be either treated with ORIF, bipolar hemiarthroplasty, or total hip arthroplasty. There was no mortality difference among the three groups, however the rate of secondary surgery was highest in the ORIF group (39% compared with 5% in the group treated with bipolar hemiarthroplasty and 9% in the group treated with total hip replacement). Furthermore, the fixation group had the worst hip-rating-questionnaire and EuroQol scores at four and twelve months.

Tidermark et al in a randomized controlled trial, studied the difference between ORIF and total hip replacement in 102 patients. The total hip replacement group showed a lower overall complication rate (36% versus 4%) and higher hip function scores in regard to pain, movement and walking.

Illustration A shows the division of proximal femur fractures according to location.

(OBQ06.266) In trauma patients with multiple injuries, patients with scapula fractures have been shown to have an association with which of the following, as compared to patients without scapula fractures?

1. Increased length of hospital stay

    

    

    

2. Increased mortality rate

    

    

    

3. Increased rate of extremity fracture(s)

    

4. Increased Injury Severity Scores

    

    

5. Increased length of intensive care unit stay PREFERRED RESPONSE ▼ 4

CORRECT

DISCUSSION: According to the reference by Veysi et al, patients presenting to a trauma center with scapula fractures have an increased rate of pulmonary complications and increased Injury Severity Scores (ISS), but have no difference in mortality, length of ICU stay, or overall hospital stay. No differences were seen in abdominal or head injury rates either. A lower rate of extremity fractures was seen as compared to non-scapular fracture patients in their series.

According to the referenced study by Brown et al, rib fx (44%) are the most common associated injury with scapula fractures.

(OBQ05.178) A 42-year-old male sustains a closed, isolated ulna shaft fracture with 2mm displacement and 3 degrees valgus angulation. He is treated conservatively with early range of motion but presents at one year with a painful atrophic nonunion. What treatment is indicated at this time?

1. Dynamic splinting

    

    

    

2. Open autogenous cancellous bone grafting

    

    

    

3. Open reduction internal fixation with autogenous bone grafting

    

4. Closed reduction and percutaneous pinning

    

    

5. Use of an implantable ultrasound device PREFERRED RESPONSE ▼ 3

CORRECT

DISCUSSION: Appropriate treatment of an atrophic nonunion of the ulna includes open reduction and internal fixation with autogenous bone grafting. The atrophic nature of the nonunion reveals that biology, and not necessarily stability, is the major issue of the nonunion. The referenced article by Ring et al reviews a case series of these patients and found that even in the face of significant preoperative bone resorption, good clinical outcomes and union rate is possible with open plating and grafting. The article by Street reviews intramedullary nailing/pinning of the forearm, and found a 7% nonunion rate with this technique.

(OBQ05.271) A through-knee disarticulation has been shown to have what advantage over a traditional above-knee (transfemoral) amputation?

1. Decreased rate of prosthesis adjustment

    

    

    

2. Less postoperative time to final prosthesis fitting

    

3. Decreased neuroma formation

    

    

4. Decreased rate of revision

    

    

5. Less energy expenditure with ambulation PREFERRED RESPONSE ▼ 5

CORRECT

DISCUSSION: A through-knee disarticulation has been shown to have decreased energy expenditure with ambulation, improved limb proprioception, improved sitting capabilities, decreased hip joint flexion contracture incidence, and improved lever arm for mobilization. Knee disarticulation is also recommended in children to prevent overgrowth of the distal femur which may be seen in transfemoral amputations (if the physis remains open). No difference in prosthesis fitting has been shown between transfemoral amputation and through-knee disarticulation. The referenced paper by Pinzur et al is a excellent review of knee disarticulation, from technique to outcomes.

(OBQ06.115) Lateral malleolus fractures can be treated with a variety of techniques, including posterior antiglide plating or lateral neutralization plating. What is an advantage of using lateral neutralization plating instead of posterior antiglide plating?

1. Decreased joint penetration of distal screws

    

    

    

2. Increased rigidity

    

    

    

3. Decreased need for delayed hardware removal

    

    

    

4. Decreased peroneal irritation

    

5. Improved distal fixation

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: Posterior antiglide plating is a technique that involves placement of a plate on the posterior aspect of the distal fibula, using the plate as a reduction tool and direct buttress against distal fracture fragment displacement.

Schaffer et al showed from a biomechanical standpoint that posterior antiglide plating was superior to lateral neutralization plating for distal fibula fracture fixation.

Weber et al reported a (30/70) 43% rate of plate removal secondary to peroneal discomfort. In addition, peroneal tendon lesions were found in 9 of the 30 patients.

(OBQ06.129) Increasing the oxygen gradient for diffusion is the mechanism of action for what method of treatment for compartment syndrome?

1. Open fasciotomy

    

    

    

2. Percutaneous fasciotomy

    

    

    

3. High-dose anti-inflammatories

    

4. Hyperbaric oxygen therapy

    

    

5. Negative pressure wound therapy PREFERRED RESPONSE ▼ 4

CORRECT

DISCUSSION: Hyperbaric oxygen therapy (HBO) allows patients to breathe 100% oxygen in a chamber under conditions of increased barometric pressure. This tremendous partial pressure of oxygen supports gas diffusion for a much greater distance than under normal conditions, thus delivering oxygen to relatively ischemic and hypoxic tissues. Trauma-related indications for HBO therapy include carbon monoxide intoxication, gas gangrene, crush injury, compartment syndrome, necrotizing fasciitis, treatment of chronic osteomyelitis, support of grafts and flaps, and burns. Contraindications relate to issues of gas exchange, oxygen sensitivity, and technical safety. The cited reference is a useful review article of hyperbaric oxygen therapy in extremity trauma.

(OBQ05.175) What is the Injury Severity Score (ISS) for a patient with an open chest wound (Abbreviated Injury Scale, AIS=4), colon transection (AIS=4), femoral fracture (AIS=3), shoulder dislocation (AIS=2), and a thyroid gland contusion (AIS=1)

1. 11

2. 13

3. 41

4. 45

5. 46

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: Injury Severity Score (ISS) scores are used to define injury severity for research purposes. The score is based on anatomic and severity indicies. Injury severity is based upon the AIS (abbreviated injury scale). AIS scores range from 1-6 where 1 is a minor laceration or contusion and 6 is a unsurvivable severe injury. An example of a 6 is a crushed head or brain whereas a 5 is a crushed larynx. Open pelvic fracture and femoral shaft fracture come in at 3 and large joint dislocations are a level 2 injury. ISS is the sum of the squares for the highest AIS grades in the three most severely injured ISS body regions. An ISS greater than 18 reflects multiply injured patients and that a transfer to a trauma center is indicated. So in this case, it would be (4x4)+(4x4)+(3x3)= 16+16+9=41. The AIS table can be found in Miller 5th ed p571. Recently, the New Injury Severity Score (NISS) has been developed and found by some authors (Lavoie et al & Balogh et al) to be more reliable indicator of length of stay and ICU stay. The NISS differs from the ISS in that the NISS sums the squares of the 3 most significant injuries (even if they occur in the same anatomic area). The ISS sums the 3 most significant injuries in 3 separate anatomic areas.

(OBQ08.149) What is the most common mode of failure of the lateral ulnar collateral ligament associated with an elbow dislocation?

1. ligament avulsion off the humeral origin

    

    

    

2. ligament avulsion off the ulnar insertion

    

    

    

3. midsubstance rupture

    

4. bony avulsion of the humeral origin

    

    

5. combined proximal and distal ligament avulsions PREFERRED RESPONSE ▼ 1

CORRECT

DISCUSSION: The lateral ulnar collateral ligament (LUCL) is often injured with elbow dislocations, and is most commonly injured at the proximal origin. McKee noted that in 62 consecutive operative elbow dislocations and fracture/dislocations, the LUCL was ruptured in all of the patients, proximally in 32, bony avulsion proximally in 5, midsubstance rupture in 18, ulnar detachment in 3, ulnar bony avulsion in only 1, and combined patterns in 3. Pugh et al established a standard protocol to treat elbow fracture dislocations (terrible triad) which includes coronoid repair, radial head repair/replacement, LUCL repair, and MCL and/or external fixation as needed.

(OBQ10.155) Isolated exchange reamed interlocking nailing is most likely indicated as the next step in treatment for which of the following clinical scenarios:

1. Tibial shaft nonunion with a 4cm bone defect

    

    

    

2. Infected tibial shaft nonunion

    

    

    

3. Hypertrophic tibial shaft nonunion with an oblique fracture pattern

    

4. Atrophic tibial shaft nonunion

    

    

5. Delayed union of a transverse tibial shaft fracture 3 months post-op

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: If a hypertrophic nonunion is present, it is most likley a mechanical issue. Hypertrophic nonunion (Illustration A) has approximately an 85-90% incidence of union with exchange reamed nailing. A nonunion that has bone loss or appears atrophic (Illustration B) will usually require improved mechanical stability as well as biological stimulation in the form of either autograft or an osteoinductive substance like BMP. A bone defect of up to 5-6cm in length can usually acheive union with bone grafting. In the presence of an infected nonunion, the infectious process needs to be addressed prior to the introduction of any revision hardware. If a patient does not show radiographic signs of tibial fracture union for 9 months and does not have progression toward healing for 3 consecutive months, then revision surgery would be indicated.

Tempelman et al looked at 71 tibial shaft fractures treated with nonlocked or dynamically locked IM nails and found a loss of alignment in 11% of the fractures that were not transverse in nature. They concluded that these nailing techniques should not be used in the treatment of spiral or oblique tibial shaft fractures.

(OBQ10.180) A 35-year-old male sustains a posterior column/posterior wall acetabular fracture. Which of the following is the preferred approach for open treatment of this injury?

1. Modified Stoppa approach

    

    

    

2. Extended iliofemoral approach

    

    

    

3. Kocher-Langenbach approach

    

    

    

4. Ilioinguinal approach

    

5. Combined

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: Operative treatment is indicated for most displaced acetabular fractures to allow early ambulatory function and to decrease the chance of post-traumatic arthritis. Among the various surgical approaches, the Kocher-Langenbach allows direct exposure of both the posterior column and posterior wall. Indications for using this exposure include posterior wall fractures, posterior column fractures, combined posterior wall/posterior column fractures, and simple transverse fractures.

(OBQ11.230) What structure is 7cm from the acromion and at greatest risk of injury during a deltoid splitting approach for a proximal humerus fracture?

1. Radial nerve

    

    

    

2. Suprascapular nerve

    

    

    

3. Axillary nerve

    

    

    

4. Axillary artery

    

5. Axillary vein

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: The axillary nerve is located approximately 7cm from the tip of the acromion. The axillary nerve comes off the of the brachial plexus (middle trunk, posterior division, posterior cord) carrying fibers from C5 and C6. The axillary nerve travels through the quadrangular space with the posterior circumflex humeral artery and vein to innervate the teres minor and deltoid muscles and supply sensation over the lateral shoulder.

Based on the knowledge of the course of the axillary nerve, and potential complications regarding the

vascular supply to the humeral head with the delto-pectoral approach, some authors are suggesting deltoid-splitting approach to the proximal humerus for reduction and fixation of proximal humeral fractures.

Cetik et al evaluated 24 cadaver shoulders to better identify the course of the axillary nerve and identify the "safe zones" for deltoid-splitting incisions. They found the distance from the tip of the acromion to the axillary nerve varied depending on patient specific factors like arm length and they identified a "safe area" where dissection was free of injury to the axillary nerve (Illustrations A and B).

(OBQ04.227) A 45-year-old diabetic woman with a gangrenous foot undegoes a Chopart amputation without tendon transfer or lengthening. Which type of deformity is the most likely complication of this procedure?

1. Valgus deformity

    

    

    

2. Varus deformity

    

    

    

3. Equinus deformity

    

    

    

4. Cavus deformity

    

5. Planus deformity

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: The Chopart amputation is an amputation of the foot at the level of the calcaneocuboid and talonavicular level. Historically, its use has been criticized because an amputation at this level results in a muscular imbalance with flexor predominance and equinus deformity that eventually leads to stump breakdown. To prevent this complication it should be coupled with Achilles tenotomy (vs. lengthening) as well as transfer of the tibialis anterior insertion to the talar neck.

Advantages of the Chopart amputation include increased limb length and maintenance of heel proprioception that cannot be preserved with more proximal amputations.

Lieberman et al argue in patients with peripheral vascular disease, it is important to preserve as much tissue as possible to preserve maximum function. They recommend that with appropriate care, an amputation at the Chopart (calcaneocuboid-talonavicular) level can give a good functional result.

(OBQ05.145) Which of the following is the most appropriate clinical scenario to utilize locking plate and screw technology?

1. Intra-articular distal femur fracture

    

    

    

2. Oblique ulnar diaphyseal fracture

    

    

    

3. Comminuted metaphyseal distal femur fracture

    

4. Transverse tibial diaphyseal fracture

    

    

5. Spiral humeral diaphyseal-metaphyseal fracture PREFERRED RESPONSE ▼ 3

CORRECT

DISCUSSION: Conventional plating provides stable internal fixation when fractures are anatomically reduced. Stability of this type of fixation relies on the plate/bone interface and the friction that develops between this interface. Locked plates rely on the plate/screw interface, and each provides not only axial stability but also angular stability; each screw acts as a fixed angle device. Indications for locked plating for indirect reduction include: 1. metaphyseal/diaphyseal fractures 2. comminuted diaphyseal fractures

3. comminuted metaphyseal fractures. 4. short segment fixation. Locked plates are not indicated for displaced articular fractures unless anatomic rigid fixation of the articular surface is done first (locking technology cannot reduce fractures/lag segments together).

The referenced article by Gardner et al reviews locking technology and reminds us that compression technology using non-locking screws and plates is still needed for many fractures and is even required for proper treatment of some fractures.

The referenced article by Wagner is an instructional paper on how to use hybrid plating technology and reviews concepts such as the necessity of lag screw fixation before locking.

The referenced study by Egol et al is a review paper that notes that locked plates and conventional plates rely on completely different mechanical principles to provide fracture fixation and in so doing they provide different biological environments for healing. They report that locked plates are indicated for: indirect fracture reduction, diaphyseal/metaphyseal fractures in osteoporotic bone, and with bridging severely comminuted fractures.

(OBQ04.158) A 31-year-old male sustains an ipsilateral displaced transverse acetabular fracture, pubic rami fractures, and a sacroiliac joint dislocation. What structure should be reduced and stabilized first?

1. Pubic rami

    

    

    

2. Posterior column

    

    

    

3. Anterior column

    

    

    

4. Sacroiliac joint

    

5. Quadrilateral plate

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: In an ipsilateral unstable pelvic ring and acetabular fractures, the pelvic ring injury must be initially stabilized in order to reduce the acetabular fracture to a stable base.

The referenced article by Matta reviewed 259 patients with acetabular fractures treated within 21 days of injury and found that the hip joint can be preserved and post-traumatic osteoarthrosis can be avoided if an anatomical reduction is achieved.

(OBQ11.114) An 82-year-old nursing home resident falls out of his motorized wheelchair onto a flexed elbow. He has pain at the elbow, no gross instability, and is unable to extend his elbow against gravity. His radiographs show an osteoporotic, comminuted displaced olecranon fracture involving 20% of the articular surface. Which of the following treatment options has the greatest likelihood of a functional elbow outcome?

1. Cast immobilization in 90 degrees of flexion

    

    

    

2. Closed reduction and percutaneous pinning

    

    

    

3. ORIF with a tension band construct

    

4. ORIF with a locking plate

    

    

5. Fragment excision and triceps advancement PREFERRED RESPONSE ▼ 5

CORRECT

DISCUSSION: The patient in the scenario is a low-demand, osteoporotic, elderly patient with a comminuted olecranon fracture. The treatment of choice in this subset of patients with this fracture pattern is fragment excision and triceps advancement.

Hak et al reviewed the treatment of olecranon fractures, recommending ORIF for displaced intraarticular fractures, either via tension band wiring or plate osteosynthesis based on fracture pattern and associated ligamentous disruption. For elderly, low-demand, osteoporotic patients, triceps advancement and fragment excision is advocated in the case of severely comminuted, osteoporotic patients with a fracture involving <50% of the joint surface.

The reference by Morrey is a comprehensive review of fractures and fracture-dislocations about the elbow.

Incorrect answers:

Answer 1: Cast immobilization in 45-90 degrees of flexion is advocated for non-displaced fractures. Answer 2: Not the treatment in cases of severe comminution and osteoporosis. Answer 3: Not the treatment in cases of severe comminution and osteoporosis. Answer 4: Not the best option for a low-demand patient with severe comminution and minimal joint surface involvement.

(OBQ06.206) A 24-year-old female sustains a surgical neck proximal humerus fracture in an motor vehicle collision. She undergoes open reduction and internal fixation but heals in 30 degrees of varus and has significant limitation of shoulder range of motion despite 9 months of conservative treatments. What is the most appropriate treatment at this time?

1. Manipulation under anesthesia

    

    

    

2. Humeral head resurfacing

    

    

    

3. Shoulder hemiarthroplasty

    

4. Revision open reduction internal fixation with osteotomy

    

    

5. Reverse total shoulder arthroplasty PREFERRED RESPONSE ▼ 4

CORRECT

DISCUSSION: Malunions of the proximal humerus typically result in significant restrictions in range of motion. This young patient has sustained a proximal humeral malunion, and treatment should include a corrective osteotomy for improved outcomes, as she has failed conservative treatment.

The cited reference by Williams et al as well as the referenced article by Siegel et al explain various techniques in management of proximal humerus malunions. They state that the two primary indications for surgical management of proximal humerus malunion include 1) pain and 2) diminished function resulting from limited range of motion. Because this patient is young, you would attempt revision ORIF/osteotomy as opposed to humeral head arthroplasty.

(OBQ07.211) In the treatment of intra-articular calcaneal fractures, surgical reduction and fixation has been shown to have improved outcomes over nonoperative treatment in all of the following patient groups EXCEPT:

1. Sedentary job

    

    

    

2. Sanders IIb fractures

    

    

    

3. Women

    

    

    

4. Younger age (<29 years old)

    

5. Previous calcaneus fracture

PREFERRED RESPONSE ▼ 5 CORRECT

DISCUSSION: The referenced study by Buckley et al is a prospective study of intra-articular calcaneus fractures at several trauma centers. They found that overall, the outcomes after nonoperative treatment were not different from those after operative treatment. However, when stratifying groups, women who were managed operatively scored significantly higher on the SF-36 than did women who were managed nonoperatively. Also, patients who were less than twenty-nine years old, had a Böhler angle of 0 degrees to 14 degrees, a comminuted fracture, or a light workload did better after surgery compared with those who were treated nonoperatively.

(OBQ10.40) In an isolated ankle syndesmotic injury, the fibula is unstable in the incisura fibularis of the tibia. In what direction is the fibula most unstable?

1. Anterior-posterior

    

    

    

2. Medial-lateral

    

    

    

3. Proximal-distal

    

    

    

4. Rotational

    

5. Equivalent instability in all axes

PREFERRED RESPONSE ▼ 1 CORRECT

DISCUSSION: In an ankle syndesmosis injury, the fibula is most unstable in an anterior and posterior direction. This is whether or not there is an accompanying ankle fracture. Most commonly, the fibula will subluxate anterior in an ankle fracture model.

The first referenced article by Xenos et al found that stress lateral radiographs have more interobserver reliability than stress AP/mortise radiographs and that two syndesmotic screws are stronger than one.

The referenced article by Candal-Couto et al is a biomechanical study that found more anterior-posterior instability in a syndesmosis injury model, and more ankle instability is noted with syndesmosis injury and a concomitant deltoid injury. The referenced article by Zalavras et al is an excellent review article on ankle syndesmosis injuries.

(OBQ06.250) What is the most appropriate plating technique utilized for the medial malleolus fracture typically seen in a displaced supination-adduction ankle fracture?

1. Tension band plating

    

    

    

2. Antiglide plating

    

    

    

3. Bridge plating

    

    

    

4. Neutralization plating

    

5. Submuscular plating

PREFERRED RESPONSE ▼ 2 CORRECT

DISCUSSION: A supination-adduction ankle fracture leads to a vertical fracture of the medial malleolus. Traditional fixation of the medial malleolus with oblique screws from the tip of the malleolus directed proximally will ineffectively protect against shear forces at the fracture site; these also are directed quite obliquely to the vertical fracture line, and therefore have poor biomechanical resistance to failure. An antiglide plate is used medially to prevent displacement of the fracture segment due to shear forces.

According to the referenced article by Toolan et al, placement of two horizontal (perpendicular to the fracture line) lag screws from medial to lateral are biomechanically the most important aspect of the construct whether a plate is used or not.

(OBQ05.192) When discussing treatment options with a 35 year-old healthy male with an isolated, closed tibial shaft fracture, the surgeon should inform him that in comparison to closed treatment, the advantages of intramedullary nail fixation include all of the following EXCCEPT?

1. Quicker time to union

    

    

    

2. Decreased risk of malunion

    

    

    

3. Decreased risk of compartment syndrome

    

4. Decreased risk of shortening

    

    

5. Quicker return to work

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: All of the answer choices are correct except #3. Intramedullary nailing can increase the risk of compartment syndrome.

In a study of 94 tibial fractures, Finkemeier reported 10 (11%) had compartment syndromes. Three of the 10 patients developed the compartment syndrome postoperatively.

In comparing IM nailing to non-op, Bone et al showed that IM nailing had a shorter time to union (mean, 18 vs 26 weeks; p = 0.02), lower non-union rate (2% vs 10%), decresed incidence of shortening (2% vs 27%), and quicker return to work (mean, 4 vs 6.5 months), but no difference in compartment syndrome (0% in both groups).

The classic article cited by Sarmiento el al. reported that closed treatment with use of a prefabricated functional below-the-knee brace was effective in a study of 1000 closed diaphyseal fractures of the tibia with an incidence of nonunion of only 1.1%. However, those authors had very strict criteria for use of the fracture-brace (exclusion criteria included intact fibular, shortening >2cm).

(OBQ07.265) Which of the following is an indication for surgical treatment of an acute humeral shaft fracture?

1. radial nerve palsy

    

    

    

2. long oblique fracture type

    

    

    

3. comminuted fracture

    

4. Holstein-Lewis fracture type

    

    

5. ipsilateral both bone forearm fracture PREFERRED RESPONSE ▼ 5

CORRECT

DISCUSSION: Humeral shaft fractures can be managed nonoperatively due to a high union rate with infrequent complications. Certain situations, however, favor operative osteosynthesis: failure of closed reduction, associated articular injury, vascular or brachial plexus injuries, associated ipsilateral forearm fractures, segmental fractures, and pathologic fractures. Open fractures should be irrigated and debrided if necessary with subsequent external or internal fixation. Polytrauma patients with multiple extremity or multi-system injuries may also be considered for operative stabilization. A relative indication also may be the transverse or short oblique fracture in an active patient since these fracture patterns are more prone to delayed union. An acute radial nerve palsy associated with a humeral shaft fracture is not an indication for surgery.

(OBQ05.98) Based on the Young and Burgess classification of pelvic ring injuries, an anterior-posterior compression type II injury does not result in disruption of which of the following?

1. pubic symphysis

    

    

    

2. anterior sacroiliac ligaments

    

    

    

3. posterior sacroiliac ligaments

    

    

    

4. sacrospinous ligament

    

5. sacrotuberous ligament

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: An APC type 1 involves slight widening of pubic symphysis and/or anterior sacroiliac (SI) joint. An APC II is a continuation of this force, and additionally involves a disrupted anterior SI joint, as

well as sacrotuberous and sacrospinous ligaments. An APC III also involves disrupted posterior SI ligaments, causing complete SI joint disruption with potential translational and rotational displacement.

The reference by Young et al is a classic article that describes the Young and Burgess classification of pelvic ring injuries. They retrospectively analyzed pelvic ring radiographs and discussed four patterns of injury: anteroposterior compression, lateral compression, vertical shear, and a complex/combined pattern.

The reference by Burgess et al is a validation of the aforementioned classification and study, as they reviewed 210 consecutive patients who sustained a pelvic ring injury. They validated the classification scheme and found that overall blood replacement averaged: lateral compression, 3.6 units; anteroposterior compression, 14.8 units; vertical shear, 9.2 units; combined mechanical, 8.5 units. Overall mortality was: lateral compression, 7.0%; anteroposterior, 20.0%, vertical shear, 0%; combined mechanical, 18.0%.

Incorrect answers:

1,2,4,5: An APC - 2 pelvic ring injury involves injury to all of these structures.

(OBQ11.73) When utilizing the pectoralis major tendon as a reference for restoring humeral height during shoulder hemiarthroplasty, at what level cephalad to the proximal edge of the tendon should the top of the prosthesis sit?

1. 1.0 cm

    

    

    

2. 2.4 cm

    

    

    

3. 3.8 cm

    

    

    

4. 5.6 cm

    

5. 6.5 cm

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: The pectoralis major tendon is a reproducible structure from which the humeral height during shoulder arthroplasty can be based upon, even in fracture situations where the anatomy is distorted. The superior edge of the pectoralis major tendon at its insertion on the humerus is 5.6 cm below the top of the humeral head.

The referenced study by Torrens et al is a cadaveric evaluation of the pectoralis major tendon and proximal humeral anatomy. They reported that the top of the head sits 5.6cm proximal to the superior border of the pectoralis major tendon.

The referenced study by Greiner et al is a retrospective review of shoulder hemiarthroplasty; improved radiographic and clinical outcomes were reported when the pectoralis major tendon was used as a reference for humeral height. Improved outcomes were also reported with successful tuberosity healing and centering of the humeral head in the glenoid.

The referenced study by Murachovsky et al is another cadaveric study that found the pectoralis major tendon is a reproducible means from which to base the humeral height. The distance reported was 5.6

+/- 0.5 cm in 40 shoulders.

(OBQ04.141) What percentage of normal circulating blood loss is needed for a patient to become tachycardic with a narrowed pulse pressure?

1. 5%

2. 10%

3. 25%

4. 40%

5. 50%

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: Hemorrhagic shock is divided into four classes - class I is <15% loss and shows compensation for the blood loss (no tachycardia/hypotension) and is treated with crystalloid replacement as necessary. Class II is a loss of 15-30% and is the target of this question. In this class, vasoconstriction leads to maintenance of perfusion pressure and tachycardia helps maintain cardiac output in the face of a decreased overall volume. The vasoconstriction leads to an elevated diastolic pressure, which is the cause of the narrowed pulse pressure (the difference between systolic and diastolic). Treatment remains control of ongoing bleeding and crystalloid replacement. Class III is a 30-40% loss, and is the first stage where hypotension is present. Signs of end organ hypoperfusion, such as confusion and decreased urine output, is seen. Treatment is crystalloid replacement and blood product replacement. Class IV is a loss of >40% and is often fatal.

Hak reviews the ATLS classification of hemorrhage in his review article on pelvic fractures and bleeding.

(OBQ09.182) In an uninjured proximal tibia which statement best describes the shape and position of the medial tibial plateau relative to the lateral tibial plateau?

1. More concave and more proximal

    

    

    

2. More convex and more proximal

    

    

    

3. More concave and more distal

    

4. More convex and more distal

    

    

5. Symetric in conture and more distal PREFERRED RESPONSE ▼ 3

CORRECT

DISCUSSION: The medial tibial plateau is more concave and more distal relative to the lateral tibial plateau.

Watson et al report "the medial tibial plateau has a more concave shape and is larger in both length and width than the lateral tibial plateau, which has a slightly convex shape. The lateral tibial plateau lies proximal to the medial plateau. The convexity of the lateral plateau helps differentiate it from the medial plateau on a lateral radiograph of the proximal tibia."

(OBQ05.274) A 45-year-old homeless hemophiliac male presents with chronic tibial osteomyelitis. Which of the following factors has been shown to predict a better prognosis?

1. Polymicrobial infection

    

    

    

2. Use of external fixation

    

    

    

3. Infection with Staphylococcus

    

4. Metaphyseal infection

    

    

5. Contralateral lower extremity amputation PREFERRED RESPONSE ▼ 4

CORRECT

DISCUSSION: Success in the treatment of chronic tibial osteomyelitis is dependant on various factors including patient factors (immunocompetency of patient, nutritional status), injury factors (severity of injury as demonstrated by segmental bone loss), and infection factors (the extent and location of infection – metaphyseal infections heal better than mid-diaphyseal infections).

Cierny’s article states that factors affecting prognosis and treatment include: residual foreign materials and/or ischemic and necrotic tissues, host compromise, inappropriate antibiotic coverage, and the lack

of patient cooperation or desire.

The second referenced article by Cierny reviews the significant increase in success over the last 20 years in treating infected tibial nonunions, due to pharmalogical and technological advances.

(OBQ09.70) Following operative repair of lower extremity long bone and periarticular fractures, what is the time frame for patients to return to normal automobile braking time?

1. 6 weeks after initiation of weight bearing

    

    

    

2. 4 weeks postoperatively

    

    

    

3. 8 weeks from the date of injury

    

    

    

4. Once full range of motion of the ankle and knee exist

    

5. At the time of bony union

PREFERRED RESPONSE ▼ 1 CORRECT

DISCUSSION: According to the first referenced study by Egol et al, appropriate braking time returns at a point 6 weeks after initiation of weightbearing after treatment of lower extremity long bone and periarticular fractures, as examined with a driving simulator. No differences were seen in return of braking time between periarticular fractures and long bone injuries.

The second reference by Egol studied only operatively treated ankle fractures and found that time to appropriate braking returns at 9 weeks postoperatively. Interestingly, no significant association was found between the functional scores and normalization of total braking time.

(OBQ09.207) Varus malalignment after a talar neck fracture with medial comminution causes a decrease in what motion?

1. Tibiotalar dorsiflexion

    

    

    

2. Tibiotalar plantarflexion

    

    

    

3. Subtalar eversion

    

    

    

4. Subtalar inversion

    

5. Internal rotation

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: Varus alignment at the talar neck results in a decrease in subtalar eversion before impingement occurs. Varus talar neck alignment can cause a fixed internal rotation position of the midfoot as the navicular follows the talar head. This can lead to a more rigid hindfoot which is specifically manifested as a decreased eversion range of motion.

Herscovici et al review the appropriate management of complex ankle and hindfoot injuries in this instructional course lecture.

Daniels et al performed a cadaveric study where they osteotomized the talar neck and then studied ankle motion with and without removal of a medially based wedge of bone. They found that subtalar eversion was specifically decreased.

Sanders et al found that secondary reconstructive procedures following talar neck fractures were most commonly performed to treat subtalar arthritis or misalignment.

(OBQ05.150) With comparison to a below the knee amputation, each of the following are disadvantages of a through the knee amputation EXCEPT:

1. Slower self-selected walking speeds

    

    

    

2. Worse performance on the Sickness Impact Profile (SIP)

    

    

    

3. Physicians were less satisfied with the cosmetic recovery

    

    

    

4. More severe pain at amputation site

    

5. Require more dependence with patient transfers

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: Through-the-knee amputation level is associated with the worst functional result 2 years after injury (compared to transmetatarsal, Symes, AKA, or BKA)

The cohort study by MacKenzie et al prospectively followed 161 patients that were part of the Lower Extremity Assessment Project (LEAP). These patients underwent an above-the-ankle amputation at a trauma center within 3 months following the injury and followed for 2 years. This study revealed that through-the-knee amputations had significantly worse scores for the objective performance measures of self-selected walking speed, independence in transfers, walking, and stair-climbing. Through-the-knee amputees also had worse SIP scores than AKA and BKA patients. Physicians were also less satisfied with both the clinical and the cosmetic recovery of the patients with a through-the-knee amputation. It should be noted that patients with a BKA had a faster walking speed than those with an AKA. Despite the worse SIP scores for through-the-knee amputations, patients actually reported less pain than those with an AKA or BKA, though this wasn't statistically significant.

(SBQ06.2) A 21-year-old male presents to the emergency department after sustaining a gun shot wound to his back. Subsequent radiographs reveal a bullet in the L2 vertebral body. Physical exam shows no neurologic deficits. He undergoes emergent laparotomy and is found to have a small bowel laceration. What would be the preferred treatment following his exploratory laparotomy and small bowel repair?

1. Intravenous antibiotic coverage for Gram negative bacteria for 7 days

    

    

    

2. Surgical decompression and bullet fragment removal

    

    

    

3. Observation

    

    

    

4. Broad-spectrum oral antibiotic coverage for 7 days

    

5. Broad-spectrum intravenous antibiotic coverage for 7 days

PREFERRED RESPONSE ▼ 5 CORRECT

DISCUSSION: The clinical presentation is consistent with a GSW with bowel perforation and a retained bullet in the vertebral body. Because the patient is neurologically intact broad-spectrum intravenous antibiotic coverage for 7 days is the most appropriate treatment.

Gunshot wounds to the spine present relatively little risk of infection in most cases. When there has been an injury to the small bowel, the risk of infection can be minimized with a 7-day course of broad-spectrum antibiotics. Indications for surgery include when a neurological deficit is present that correlates with imaging findings of neurological compression by the missile, or when the missile is in contact with the CSF posing a risk for metal toxicity.

Roffi et al performed a Level 4 study of 42 patients that sustained a gunshot wound that perforated the stomach or bowel and then entered the spinal column. They found that an extended regimen of broad spectrum antibiotics combined with bedrest appeared to significantly reduce the risk of spinal or paraspinal infection, whereas early bullet removal did not significantly prevent the occurrence of infection.

Velmahoos et al performed a Level 4 study including 24 patients that sustained a gunshot wound to the spine with associated colonic injury. They found that the incidence of sepsis was 8.4% (compared to 5% in non-bowel injuries) and concluded that retainment of the bullet did not increase the rate of sepsis.

Incorrect Answers:

Answer 1: The patient needs coverage for both Gram+ and Gram- organisms. Answer 2: There are no indications for surgery at this point. Answer 3: Antibiotics are indicated to decrease the risk of infection. Answer 4: Intravenous antibiotic has been found to be more effective than oral antiobiotics.

(OBQ07.141) Treatment of an atrophic nonunion of the radial diaphysis should include which of the following?

1. Ilizarov fixation

    

    

    

2. Electrical stimulation

    

    

    

3. Ultrasound bone stimulator

    

    

    

4. Plate exchange with autogenous cancellous grafting

    

5. Plate exchange with ulnar shortening osteotomy

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: Atrophic nonunions of the radius and ulna are fairly rare with modern techniques of fixation; the few reports that have been published have discussed the use of structural corticocancellous bone grafts for the treatment of atrophic nonunions. The referenced study by Ring et al noted a 100% healing rate and improved patient reported outcomes with 3.5-mm plate-and-screw fixation and autogenous cancellous bone-grafting for atrophic forearm nonunions.

(OBQ07.153) Anterior perforation of the distal femur from antegrade femoral nailing has been attributed to what factor?

1. Non-anatomic reduction

    

    

    

2. Mismatch of the radius of curvature of implant and bone

    

    

    

3. Usage of too large an implant

    

    

    

4. Lateral patient positioning

    

5. Lateral proximal starting point

PREFERRED RESPONSE ▼ 2 CORRECT

DISCUSSION: Anterior perforation of the femur has been attributed to a simple mismatch in the radius of curvature of implants and the apex anterior bowed femur.

The radius of curvature is generally smaller (114-120 cm) than many earlier generation femoral nails (up to 300 cm), and the referenced article by Ostrum et al describes a case series of 3 such patients with subtrochanteric fractures. He noted that the difference in femoral anteroposterior bow between the bone and the implant is a contributing factor to distal femoral anterior cortex penetration in intramedullary nailing of subtrochanteric fractures.

Illustration A shows an example of a nail penetrating the anterior femoral cortex.

(OBQ10.203) When placing a percutaneous retrograde pubic rami screw for fixation of an acetabular fracture, which of the following radiographic views can best ensure that the screw does not exit the posterior aspect of the superior pubic ramus?

1. AP pelvis

    

    

    

2. Outlet obturator oblique view

    

    

    

3. Inlet iliac oblique view

    

    

    

4. Iliac oblique view

    

5. Obturator oblique view

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: As reviewed in the referenced article by Starr et al, when placing a retrograde pubic rami screw, the pelvic inlet iliac oblique view will best determine the anteroposterior placement of the screw in the pubic ramus. To ensure placement outside of the joint, the outlet obturator oblique is best, but all other views should be incorporated into determination of the position of fixation, as the corridor for this screw placement is quite narrow.

(OBQ12.56) During surgical treatment of the most common variation of distal femoral "Hoffa" fractures, which of the following orientations for screw fixation should be used?

1. Medial to lateral screw placement across lateral femoral condyle

    

    

    

2. Anterior to posterior screw placement across medial femoral condyle

    

    

    

3. Medial to lateral screw placement across medial femoral condle

    

    

    

4. Anterior to posterior screw placement across lateral femoral condyle

    

5. Anterior to posterior screw placement across intercondylar notch

PREFERRED RESPONSE ▼ 4 CORRECT

DISCUSSION: The most common variation of a Hoffa fracture is a coronal fracture of the lateral femoral condyle. The most appropriate screw placement of the above answer choices in the treatment of the most common Hoffa fracture variant would be anterior to posterior screws across the lateral condyle for fixation.

Hoffa fractures are coronally oriented fractures of the femoral condyles, with most occurring in the lateral condyle. They are commonly associated with high-energy fractures of the distal femur and can often be overlooked during the assessment and treatment of distal femur fractures. Hoffa fractures are best evaluated using CT scans.

Nork et al. studied the association of supracondylar-intercondylar distal femoral fractures and coronal plane fractures. Of 202 supracondylar-intercondylar distal femoral fractures, they found coronal plane fractures were diagnosed in 38%. A coronal fracture of the lateral femoral condyle was involved more frequently than the medial condyle. Eighty-five percent of these coronal fractures involved a single lateral femoral condyle.

Holmes et al. looked at five cases of coronal fractures of the femoral condyle. All cases received open reduction and internal fixation with lag screws through a formal parapatellar approach. They reported good results with all fractures healing within 12 weeks without complications with final range of motion at least 0 degrees to 115 degrees.

(OBQ09.188) During an open reduction internal fixation of a humerus fracture using the posterior approach, a surgeon can identify the posterior antebrachial cutaneous nerve and trace it proximally to which of the following nerves?

1. Ulnar

    

    

    

2. Musculocutaneous

    

    

    

3. Radial

    

4. Median

    

    

    

5. Axillary

PREFERRED RESPONSE ▼ 3 CORRECT

DISCUSSION: The posterior antebrachial cutaneous nerve branches from the radial nerve in the axilla. It extends distally to innervate the skin on the back of the arm. Gerwin et al recommended identifying the nerve first when approaching the humerus from the posterior shaft. It can be traced proximally to safely identify the radial nerve before any proximal exposure of the shaft is done. Gerwin et al in their review also found that the radial nerve crossed the posterior aspect of the humerus an average of 20.7 +/- 1.2 centimeters proximal to the medial epicondyle to 14.2 +/-

0.6 centimeters proximal to the lateral epicondyle. In their review, Zlotolow et al. review the multiple surgical approaches to the humerus.

(OBQ11.110) Which of the following is an advantage of computer-assisted navigation used to place medullary nail interlocking screws compared to a freehand techinque?

1. Reduced fluoroscopy time

    

    

    

2. More reliable placement of interlocking screws through the nail

    

    

    

3. Reduced procedure time

    

4. Increased quality of fluoroscopic images

    

    

5. Improved accuracy of screw length