ORTHOPEDIC MCQS ONLINE BANK OITE 14B 

 

• Answer 04.50 # 2

• In the radiographs we have AP / lateral spinal xrays of a patient with known ankylosing spondylitis. Of note, there are bilateral total hip arthroplasties. There is marked thoracic kyphosis, and mild thoracolumbar scoliosis. No evidence of acute fx/ dislocations. Notice that the question specifically states… maximum correction of the sagittal decompensationcan be accomplished at a single levelby which of the following procedures? Surgical correction of the kyphosis deformity with osteotomy was first done in 1945. Since then, surgeons have tried several different approaches and techniques to correct the stiff kyphosis. The transpedicular wedge osteotomy was described by Thomasen (1985) for the correction of deformity secondary to ankylosing spondylitis. In this technique the spinous process of L2 and the upper part of L3 are removed; the laminae of the second and the upper part of the third lumbar vertebrae are also removed as well as the articular processes of L2-3 and the pedicles of L2. A wedge fracture is created on the posterior wall of the vertebral body of L2. Then, plates are fixed to the spinous processes of T12-L1 and L3-4. Thomasen osteotomy places the apex of correction anteriorly, serving to shorten the spine and avoid anterior column lengthening. Advantages include the prevention of neural compression by creation of a large, shared neural foramen through removal of the pedicles, limited stretch of anterior structures, and cancellous bone healing. This technique provides maximum correction of the deformity, and can be accomplished at a single level. You either know it, or you don’t.

 

Berven SH, Deriven V, Smith JA, Emami A, Hu SS, Bradford DS: Management of fixed sagittal plane deformity: Results of the transpedicular wedge osteotomy. Spine 2001;26:2036-2043.

Thomasen E: Vertebral osteotomy for correction of kyphosis in ankylosing spondylitis.

Clin Orthop 1985;194:142-152

1. An 18-year-old collegiate swimmer has bilateral shoulder pain for the past 6 months. She also notes frequent episodes of numbness throughout her dominant hand and prominent scapular winging on one side. Based on these signs and symptoms, examination

    

    

    

   will most likely reveal

   1. clinodactyly.

   2. negative ulnar variance.

   3. absent distal palmar crease.

   4. hypermobile patellae.

   5. tarsal coalition.

      • Answer 04.51 # 4

      • This a case of multidirectional instability (MDI) of the shoulder. Clues to dx include: young age, swimmer, bilateral shoulder pain, transient neurologic symptoms. For a complete dx is would have been nice to hear that the pt is able to dislocate or subluxate the glenohumeral joint in the three directions (anteriorly, inferiorly and posteriorly), but that we have to assume on our own. MDI include global shoulder laxity and it may be traumatic (acquired) or atraumatic (congenital). Most patients with congenital lax shoulders have generalized ligamentous laxity of many joints. Patients are typically young (late teens to early 30’s). Associated symptoms include pain, varying amounts of instability and transient neurologic symptoms. Common misdiagnoses include unidirectional instability, impingement, cervical disk disease, brachial plexitis, and thoracic outlet syndrome. Physical exam of patients undergoing surgery for shoulder MDI reveals 45-75% associated findings such as elbow hyperextension, MCP hyperextension, genu recurvatum, patellar hypermobility, positive thumb-to-forearm test. It is important to keep in mind the zebras (EhlersDanlos syndrome, Marfan syndrome) because these patients rarely benefit from softtissue instability repairs.

    

   Bonus… TUBS – Traumatic, Unidirectional, Bankart, Surgery

   AMBRII – Atraumatic, Multidirectional, Bilateral, Rehab, Inferior capsule, rotator Interval

    

   Schenk TJ, Brems JJ: Multidirectional instability of the shoulder: Pathophysiology, diagnosis, and management. J Am Acad Orthop Surg 1998;6:65-72

2. Which of the following is considered the best indication for use of extensile (extended iliofemoral) approach in the treatment of an acute acetabular fracture in an otherwise healthy 25-year-old patient?

   1. Associated posterior column and a posterior wall fracture

   2. Juxtatectal transverse fracture with an associated posterior wall fracture

   3. Anterior column and a posterior hemitransverse fracture

   4. Transtectal transverse fracture with roof impaction

   5. Extended posterior wall fracture

      • Answer 04.52 # 4

      • Transverse fractures separate the innominate bone, including the acetabulum, into two segments: a superior iliac and an inferior ischiopubic (i.e., the fracture runs across the acetabulum). Transverse fracture are sub-classified according to location relative to the weight bearing dome;

        • transtectal: fx courses through the weight-bearing dome (WBD);

        • juxtatectal: fx courses above the cotyloid fossa, so that a significant portion of the wt bearing dome is left intact;

        • infratectal: fx courses below the wt bearing dome;

   The extended iliofemoral approach gives excellent visualization of the outer table of the ilium, the superior dome, and posterior column. The anterior column can be visualized to the iliopectineal eminence. Thru this approach, the iliac fossa may also be exposed. Heterotopic ossification is more frequent with extensile approach compared to Kocher or Ilioinguinal approaches.

    

   Other common approaches include:

   Iliofemoral: mainly for fractures of the anterior column and anterior wall with no extension to the iliopectineal eminence.

   Ilioinguinal: this approach allows access to the anterior column as far as the symphysis pubis and the quadrilateral surface. This approach is also efficient for most both-column fractures.

   Kocher-Langenbech: indicated for isolated posterior wall and posterior column

    

   Judet R, Judet J, Letournel E: Fractures of the acetabulum: Classification and surgical approaches for open reduction. J Bone Joint Surg Am 1964;46:1615-1646.

3. Which of the following nerves supplies the extensor digitorum longus?

    

    

   1. Sural

   2. Tibial

   3. Posterior tibial

   4. Superficial peroneal

   5. Deep peroneal

      • Answer 04.53 # 5

      • Courtesy of remedial anatomy 101. EDL muscle is in the anterior compartment of the lower leg and is innervated by the Deep Peroneal nerve provides sensation to the first web space in the. DP branch is motor and sensory in nature. It extends and dorsiflexes the lesser toes and dorsum of the foot. Deep Peroneal nerve innervates all the muscles in the anterior compartment including: Tibialis Anterior (L4), Extensor hallucis longus (L5), and Peroneous tertius.

    

   Bonus…

   Lateral compartment (peroneous longus a

    

    

    

   Grant’s Atlas of Anatomy, ed 10. Philadelphia, PA, Lippincott William & Wilkins, 1999, pp 364-371

4. As a patient approaches skeletal maturity, the lesion shown in Figures 14a and 14b usually undergo what changes?

   1. Remained unchanged

   2. Increase in size

   3. Decrease in size and may heal after growth is complete

   4. Become malignant after growth is completed

   5. Affect growth of the affected bone

      • Answer 04.54 # 3

      • The radiographs are of a skeletally immature pelvis with wide open physis, no obvious fracture/ dislocation / no SCFE. There is a radiolucent lesion in the L proximal femur just inferior to the growth plate. This is a mostly lytic, centered lesion with thinned but otherwise intact cortices. This lesion represents a Unicameral Bone Cyst. Differential dx includes aneurysmal bone cyst and fibrous

    

    

    

   dysplasia.

   UBCs are benign, fluid-filled cavities generally seen in the metaphyseal areas of immature persons (<20 yrs). These lesions tend to expand and may weaken the area by thinning the adjacent cortices. They are most commonly diagnosed incidentally or they may present as a pathological fracture. UBC’s are associated with the “fallen leaf sign” which is a fractured cyst wall fragment. Most common sites for UBCs are proximal humerus and femur.

   If the lesion presents as a fracture, let the fracture heal first; then address the cyst. If found incidentally, just observe; unless it is a large cyst in the subtrochanteric femoral area, which needs prophylactive treatment to avoid a pathological fx. Definitive tx is resection or curettage & bone grafting. Some authors recommend cyst aspiration followed by steroid injection / normal saline. The most common complication is recurrence of lesion (~45%). Natural history of cysts is progression from active to quiescent to an involutional stage. The lesion progressively shrinks and may heal spontaneously after growth is complete.

    

   Wilkins RM: Unicameral bone cysts. J Am Acad Orthop Surg 2000;8:217-224

5. Which of the following techniques most efficiently strengthens skeletal muscle?

   1. Isotonic

   2. Isometric

   3. Plyometric

   4. Eccentric

   5. Concentric

      • Answer 04.55 # 4

      • The mentioned references are rather poor in info. The one study that mentions that… there is a significant difference between concentric and eccentric contractions in mean torque produced for shoulders for both internal and external rotation.

   Meaning eccentric contractions [training] produces higher mean torque. Miller review:

    

   muscle tension is constant through the range of motion while length changes Concentric; muscle shortens during contraction

    

   Eccentric; muscle lengthens during contraction

    

    

    

   muscle tension is generated while length remains unchanges muscle tension is generated as the muscle maximally contracts at a

    

   constant velocity over a full range of motion May be either concentricor eccentric

   Miller states that isokineticexercises are the best for maximizing strength, but need special equipment (cybex machine), and are a combination of concentric and eccentric.

    

   Sirota SC, Malanga GA, Eischen JJ, Laskowski ER: An eccentric- and concentricstrength profile of shoulder external and internal rotator muscles in professional baseball pitchers. Am J Sports Med 1997;25:59-64

6. A 25 year old man underwent an uneventful anteror crucuate ligament reconstruction with a bone-patella-bone autograft 4 months ago. Examination now reveals a painless knee, no effusion, and range of motion from 10 to 120 degrees. Results of a Lachman’s test are negative, and patella mobility is excellent. What is the most common cause for the loss of motion?

    

   1. Loss of graft fixation

   2. Femoral tunnel drilled too vertically

   3. Anterior femoral tunnel placement

   4. Anterior tibial tunnel placement 5- Posterior tibial tunnel placement

       

      back   answer

      Question 04.56 Answer = 4 (Sports Medicine )

       

      As someone who is interested in reconstruction, when I first read this question, I thought “10-120 degrees”, that not too bad. But according to Foo et al., 10-120 degrees is considered a failure status post ACL reconstruction. The most common reason for ACL failure is tunnel positioning. The femoral tunnel is most commonly misplaced (anteriorly with one incision technique). The table below describes to mode of failure of each malpositioning.

       

      Remember, anterior placements affect knee flexion and posterior placements affect extension. Let’s look at each answer

       

      1. (loss of fixation) is wrong because your knee is still stable (- Lachman)

      2. (vertical femoral) is wrong because they do not mention rotational instability (common outcome with vertical tunnels )

         So we’re left with the tibial tunnels

          

         5 (post tunnel) is incorrect because you will be tight in extension but really loose in flexion (better than 120 degrees)

         4 (ant tunnel) is correct b/c you’re tight in flexion and impinge trying to get into extension

         Reference(s)

          

          

          

         Allen Cr et al. Revision ant cruciate ligament recon Orthop Clinic North Am 2003:34 79-98

      3. (ant femoral) is incorrect because even though you will be tight in flexion (as described, you probably won’t impinge in coming back into full extension

    

   Howel Sm et al. Failure of reconstruc of the ACL due to impingement by the intercondylar roof. JBJS 1993:75:1044-1055

    

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7. A 24 year old man sustains the injury shown in figure 15a after a motor vehicle accident. Treatment consists of emergent open reduction and internal fixation as shown in Figure 15b. What is the most likely complication

    

   1. Infection

   2. Non-union

   3. Degenerative arthritis of the hip

   4. Chondrolysis

       

       

   5. Subtrochanteric femoral fracture at the screw insertion site

    

   back

    

   answer

   Question 04.57 Answer = 2 (Trauma

   )

    

   This is the old femoral neck fx question each year. Demographically, there is a bimodal group of these patients. Young <50 and old >50. The younger ones tend to be Garden 3&4 (higher energy) and usually have a poorer prognoses than the nondisplaced or minimally displaced Garden 1&2 seen in Bubby or Nana. The key numbers to remember in the prognosis of ORIF of these injuries is

    

   Garden 1&2: AVN 5% and Nonunion 10% Garden 3&4: AVN 15% and Nonunion 30%

   Notice that non-union is the MAJOR complication. Perfect reduction is the key to success (not screw number or apex distances). Valgus of 15 degrees and ant/post angulation of 10 degrees is acceptable. If indeed you get one of these Garden 3&4 in the 65 + patient, the acceptable treatment is endo vs total. According to Broos, if your patient is 70-80 and you think their going to live for a while (5+ years) go with the

   THA.

    

   3 perhaps insinuates that DJD happens after AVN and 4 I think is dealing with screw cut out seen with sliding hip screws (remember to keep tip apex on AP/Lateral less than 25mm). 5 happens if you start your screws as you would a sliding hip screw (135

   degrees) below the lesser troch. Remember to keep your angle more acute

   back to this question

   OKU Trauma 2 115-124 next question

   Broos PL et al. Unstable fem neck fx in young adults. J Orthop Trauma 1998:12:235-239

8. What is the mechanism of antimicrobial action of aminoglycoside antibiotics?

    

   1. Alteration of bacterial cell membrane permeability

   2. Inhibition of bacterial cell wall synthesis

   3. Inhibition of bacterial metabolism

   4. Inhibition of bacterial protein synthesis

   5. Interference with bacterial nucleic acid synthesis or activity

      back   answer

      Question 04.58 Answer = 4 (Orthopaedic Science )

       

      Ah…it was just yesterday that I was looking through “Microbiology Made Ridiculously Simple”

       

      1. Alteration of bacterial cell membrane permeability–

          

      2. Inhibition of bacterial cell wall synthesis

          

          

          

         -lactams (PCN/cephalosporin), vancomycin and bacitracin

          

      3. Inhibition of bacterial metabolism

          

          

          

          

          

      4. Inhibition of bacterial protein synthesis These are the –

          

      5. Interference with bacterial nucleic acid synthesis or activity

   Cipro (DNA changes in fetuses should jog your memory), Flagyl and Rifampin

   Ortho Basic Science 2000, pp239-259 Instr Course Lecture 2003:52:745-749 back to this question next question

9. A ballet student reports medial ankle pain with dorsiflexion of the hallux, particularly when en pointe and in a demi pointe position. Foot radiographs are normal. Despite rest and nonsurgical management, her symptoms persist. Treatment should now consist of

    

   1. 1st metatarsal cheilectomy

   2. gastrocnemius recession (strayer procedure)

   3. accessory navicular excision and posterior tibial advancement

   4. release of the flexor hallucis at the ankle

   5. peroneal tenosynovectomy

    

   back    answer Question 04. 59 Answer = 4 (Foot and Ankle)

    

   You have to know that she is having problems with her FHL before you can play this question

    

   5 can be thrown out right away because its on the lateral aspect of the ankle and just plain sucks as an answer for a medial ankle problem.

    

   1. is a viable option for painful/stiff hallux rigidus secondary to osteophytes, but her x-rays are normal and her pain is at the ankle, not the big toe

       

   2. is wrong because she does not have a gastroc contracture, cerebral palsy, or other condition requiring her gastrocnemius to be lengthened

   3. is wrong because its describing a procedure to correct a rigid pes planus (flat foot). This patient’s ankle pain can be confused with post tibial tendonitis though, so her big toe stiffness in conjunction with ankle pain are key to recognizing her condition

       

   4. was the right answer because dancers (pushing off of the forefoot) get a functional hallux rigidis secondary to a constriction of the FHL tendon underneath the sustenaculum tali in the fiberosseus tunnel. The pain is typically at the ankle and can be relieved by surgical release

   Reference(s)

   Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont,lL, American Academy of Qrthopaedic Surgeons, 2002, pp 547-564.

   Hamilton WG, Hamilton LH: Foot and ankle injuries in dancers, in Coughlin MJ, Mann RA (eds): Surgeryof the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 1225-1256.

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10. A 31 year old man fell while rock climbing and sustained the injury shown in Figure 16a. Six months later he can walk without discomfort. Current radiographs are shown in Figure 16b. What is the most appropriate management at this time?

     

    1. Continued observation

    2. Revision open reduction of the pubis symphysis

    3. Fusion of the pubis symphysis

    4. Sacroiliac joint fusion

    5. Removal of hardware

     

     

    back   answer

    Question 04.60

     

    Answer = 1( Trauma )

     

    It appears this man suffered a APC Ior II type of pelvic injury (“open book” or external

    widened

     

    more than 2.5 cm and the SI began to open anteriorly. There does not appear to be a vertical

    component (which tells us the posterior SI ligaments are still intact) If there was a vertical component, you would expect to have to fix the SI joint

     

    In the ORIF photo, despite the plate being broken, it appears the SI joints are closed down

    anteriorly and the pubic diastasis is <2.5 cm. Remember, at 2.5 cm, the anterior ligaments of the SI joint start to see the load from external rotation.

     

    From our choices, I think we can throw 4 out right away, the SI joints are not the problem ( posterior ligament disruption would make this a better answer )

     

    2 would be right if the SI joints were still open and the diastasis was wider.

    3 is wrong. I don’t think we ever fuse the pubis (at least not according to the references

    )

     

    1 and 5 are our best answers. This guy is doing fine though and not bothered by the palte.

    Granted, no one wants a piece of metal floating around their privates, but the conservative approach is usually the way of the OITE. 1 it is

    Reference(s)

    Kellam JF (ed): Orthopaedic Knowledge Update:Trauma 2.

    Trauma Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 255-275.

     

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11. Which if the following best characterizes the natural history of cervical spondylotic myelopathy

    1. Slow steady deterioration

    2. Rapid deterioration

    3. Stable over time

    4. Stable for long periods of time with stepwise deterioration 5- Improvement after an initial episode of severe symptoms

     

    back    answer Question 04.61 Answer = 4 (Spine)

     

    The natural history of this disorder is usually slow deterioration in a stepwise fashion, with worsening symptoms of gait abnormalities, weakness, sensory changes, and often pain. The diagnosis can usually be made on the basis of findings from the history, physical examination, and plain radiographs, but confirmation by magnetic resonance imaging or computed tomography and myelography is necessary. Minimal symptoms without hard evidence of gait disturbance or pathologic reflexes warrant nonoperative treatment, but patients with demonstrable myelopathy and spinal cord compression are candidates for operative intervention. Both anterior and posterior approaches have been utilized for surgical treatment of cervical myelopathy.

     

    Some key points to remember:

    • 12 mm canal diameter associated with spondylosis

    •Cervical myelopathy typically affects gait/motor of LE, sensation in UE. Proximal muscles affected more than distal (so foot drop uncommon)

    •Spondylosis predisposes neck to hyperextension injuries (central cord syndrome)

    -

    Emery SE: Cervical spondylotic myelopathy: Diagnosis and treatment. J Am Acad Orthop Surg 2001 ;9:376~388.

    Lees F, Turner JW: Natural history and prognosis of cervical spondylosis. Br Med J 1963;5373:1607-1610. Clarke E, Robinson PK: Cervical myelopathy:A complication of cervical spondylosis. Brain 1956;79:483-510.

     

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12. A 5-year old boy experiences complete growth arrest of the left proximal tibia after undergoing treatment of osteomyelitis 5 months ago. Which of the following procedures would best address the expected limb-length discrepancy

     

    1. A shoe lift on the left side

    2. Right femoral shortening

    3. Right tibial shortening

    4. Left tibial lengthening

    5. Epiphysiodesis of the distal femur and proximal tibia at age 8 years

     

    back    answer Question 04.62 Answer = 4 (Pediatrics)

    It seems this question occurs every year. Do you shorten/lengthen/both/nothing at all? Let’s state the key facts to help answer these questions Boys grow until 16 and girls until 14.. The distal femoral physis adds 10 mm/year while the proximal tibia adds 6 mm/year. Easy enough so far If their final limb length inequality will be 0-2 (do nothing or give a shoe lift).

    If their final discrepancy will be 2-6, shorten the effected side (epiphysiodesis or shortening)

     

    If their final discrepancy will be 6+, lengthen a side and possibly shorten the other also if needed

     

    This boy essentially loses his left tibia growth center at 5 years of age. He will be short 66 mm on this left by the time he reaches 16 (11 years

    * 6 mm/year = 66 mm). This is 6.6 cm. By the algorithm listed above, he will need to be lengthened on the effected side (left) and possibly shortened on the contra lateral side (right). The only choice that has lengthening in it is choice 4.

     

    Reference(s)

    Moseley CF: Assessment and prediction in leg-length discrepancy Orthopaedics Instr Course Lect 1989;38:325-330.

    Stanitski OF: Limb-length inequality:Assessment and treatment options.JAm Acad OrthopSurg 1999;7:143-153.

     

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13. The bending stiffness of a half pin is proportional to one half the radius of the pin to what power

     

    1- 2

    2- 3

    3- 4

    4- One third 5- One fourth

    back    answer Question 04.63 Answer = 3 (Trauma)

     

     

     

    -fix formaulas for success

     

    1. Half pins must be at less than 30% of your bone diameter (to decrease new fracture)

    2. Moment of Inertia of pin (which determines stiffness) is ½ * r4

    3. If applying two columns to frame (i.e. anterior and anteriormedial), apply each half pin at 45◦ to each other General Truths:

    Make your frame stronger by increasing pin diameter, number, separation and decreasing bone-rod distance Pin/bone failure is most common at the cortical entry point of the pin

     

    Reference(s)

    Buckwalter JA, Einhom TA, Simon SR (eds):Orthopaedic Basic .

    Trauma Science: Biology and Biomechanics of the Musculoskeletal System, ed 2. Rosemont, IL,American Academy of Orthopaedic Surgeons, 2000, pp 371-399.

     

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14. Figures 17a and 17b show the postoperative and current radiographs of a 76 year old woman who underwent revision total hip arthroplasty. She now reports acute hip pain and is unable to walk. Which of the following factors contributed most to the

     

     

    failure mechanism?

     

    1. Component malposition

    2. Abductor laxity

    3. Constrained articulation

    4. Skirted femoral head

        

        

    5. Inadequate liner locking mechanism

     

    back answer

    Question 04.64 Answer = 3 (Hip and Knee Reconstruction)

     

    In THA revision surgery, the constrained liner is the last straw for instability. Its used when people are recurrent dislocaters and you cannot figure

     

     

    in people who have had numerous

    procedures done and now you need extra stability because they’ve lost normal anatomy.

    To understand the question, you need to realize that the component pictured is constrained (see the ring on x-ray). A constrained component is a bipolar that basically snaps into the polyethylene and shell. Your asking the components to hold the hip in place rather than soft tissue and good mechanics. If this dissociates, you usually need to open reduce it.

     

    I think this question was somewhat tricky simply because a couple of these failure mechanisms look viable.

     

    1. is wrong because this component has good anteversion and inclination (though a high hip center )

        

    2. is wrong because the constrained liner is meant to deal with this exact problem (poor abductors )

        

       1. is wrong although a skirt can cause this problem. The one pictured is not significantly skirted to cause a dislocation (I assume). Skirts with constraint == BAD NEWS

           

       2. is incorrect because the locking liner did not fail. You still see the femoral head within the ring. What failed was the cemented liner dissociating from the shell/cage…which brings us to 3

    3. is correct because the constrained liner places high shear and strain on the articulation site and cause pull out as demonstrated in this example. Reference(s)

       Hip & Knee Shapiro GS, Weiland DE, Markel DC, Padgett DE, Sculco TP, Pellicci8. Reconstruction PM: The use of a constrained acetabular component for recurrent .dislocation. J Arthroplasty 2003;18:250-258.

        

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15. A carpenter sustains an avulsion injury to the dorsal aspect of the proximal phalanx of his thumb. Examination reveals a 2-cm * 2-cm defect with an exposed extensor tendon that is without its paratenon. Coverage should be accomplished by a

     

    1. full-thickness skin graft

    2. split-thickness skin graft

    3. cross-finger flap

    4. first dorsal metacarpal artery flap

    5. Moberg advancement flap

     

    back    answer Question 04.65 Answer = 4 (Hand)

     

    1. and 5 are the two answers used for thumb flaps. The size of the defect excludes the Moberg flap int his case

     

    4 Firs dorsal metacarpal artery flap is based in an arteriovenous system rising from the radial artery at the first web. It is a constant branch that is accompanied by sensitive branches from the radial nerve and superficial veins. The first dorsal metacarpal artery flap has several advantages over Moberg when the thumb tip defect is larger than 1.5 cm.

     

    3 the cross-finger flap is commonly used for volar-directed tip injuries with exposed bone or tendon when insufficient pulp for the volar V-Y flap is present. Generally, the flap is harvested from the finger radial to the injury, except when reconstructing the index.

     

    5 The Moberg flap, or the volar advancement flap is a rectangular volar flap based on both neurovascular bundles. The flap is undermined in the distal to proximal direction to the MCP crease superficial to the flexor pollicis sheath and advanced in the distal direction. This flap can usually be advanced 1.5 cm distally.

     

    1 and 2 Skin graft application is considered for distally located and volarly directed fingertip wounds without exposed bone or tendon.

    Controversy exists as to whether split- or fullthickness grafts are better. Advocates for split grafts maintain the take is earlier and more

    reliable and wounds contract more, resulting in a smaller defect, while others favor fullthickness grafts for earlier re-innervation and more reliable, durable coverage

    Reference(s)

    Chao JD, Huang JM, WiedrichTA: Localhand flaps.JASSH . 2001;1 :25-44.

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16. A 65 year old woman who underwent total shoulder arthroplasty on the left side 1 year ago now reports that she is unable to tuck in her shirt behind her back using the left hand. Examination reveals weakness with the bell-press on the left side. What is the most likely diagnosis?

 

1. Excessive glenoid retroversion

2. Excessive humeral head retroversion

3. Inadequate postoperative therapy

4. Subscapularis insufficiency

5. Axillary nerve injury with deltoid dysfunction

 

back   answer

Question 04.66

 

Answer = 5 (Shoulder/Elbow)

 

First, we know that her deficit is weakness in the sub-scapularis. So it seems like a gimme. But as we often see on the OITE, sometimes the obvious choice is like curtain # 3 on “Let’s Make a Deal”

So in reality, this is a total shoulder question and what during the procedure can affect internal rotation. To make matters worse, neither one of these articles answers the question well.

 

1 and 2 are wrong because version of your glenoid/humerus deals with stability. Since glenoid version is 0to -7◦ (retroverted) and humeral version is 30-40◦ (retroverted), you would expect excessive retroversion to result in posterior instability– not internal rotation deficiency

 

 

y man” would have affected her sooner than 1 year

 

5 is wrong because the axillary nerve controls deltoid function (elevation) while the upper and lower subscapularis nerve controls the subscap.

 

4 is correct because often in total shoulders, these people have internal rotation contractures and part of the procedure requires taking down the subscap and repairing/advancing it. If not advanced enough or repaired well, it can result in insufficiency/rupture of the subscap

 

Reference(s)

Miller SL, Hazrati Y, Klepps S, Chiang A. Flatow EL: Loss of . subscapularis function after total shoulder replacement: A seldom recognized problem. J Shoulder Elbow Surg 2003;12:29-34.

Cofield RH, Edgerton BC: Total shoulder arthroplasty: Complications . and revision surgery. Instr Course Lect 1990;39:449-462.

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• 67.04 A 16-year-old girl underwent treatment for severe slipped capital femoral epiphysis three years ago. She has no pain; however, she walks with asymmetric foot progression and finds it difficult to enter or sit in a car. Current radiographs are shown in Figures 18a and 18b. Treatment should now consist of

  1. - hip arthrodesis

  2. - total hip arthroplasty

  3. - proximal femoral resection arthroplasty

  4. - extension, external rotation, and varus producing osteotomy of the proximal femur.

  5. - flexion, internal rotation, and valgus producing osteotomy of the proximal femur.

• 67.04 Answer: 5.

• Primary upper femoral osteotomy to correct preexisting deformity have been discussed by many authors – the osteotomies include the Dunn (Subcapital), Kramer & Barmada (Base of neck), & Southwick (Intertrochanteric). The osteotomies are designed to correct extension/varus

  deformity with flexion/valgus/internal rotation. As we all know, these patients present in external rotation so answer 4 would only worsen their condition. Answer 1 is inappropriate since this patient is without pain. THA in a 16 year old pain female without pain is a recipe for a lawsuit. Answer 3 does not address the true underlying problem with her ambulation which is the rotation and angulation of her limb.

• 68.04 A 12-year-old boy sustains an injury to his knee while playing football. Examination reveals diffuse tenderness, a 2+ effusion, and restricted range of motion. He has 2+ laxity with valgus stress. Which of the following imaging studies will best aid in diagnosis?

   

  1. - Bone Scan

  2. - MRI

  3. - CT

  4. - Bone age radiographs

  5. - AP and lateral radiographs with and without stress

• 68.04 Answer: 5.

• As outlined in Orthop Clin N Am: Plain radiographs should always be obtained to assess for fractures, as well as acute ligamentous injury with the use of varus or valgus stress. It must be remembered that fractures at this age may occur at the origins or insertions of the collateral ligaments and that both fractures and ligamentous instability may be diagnosed through simple radiographs.

• 69.04 A 50 year-old man sustains the isolated injury shown in Figures 19a and 19b when his bicycle is struck by a motor vehicle. Examination reveals extensive softtissue injury on the anterolateral aspect of the leg, with loss of skin and muscle in the anterior and lateral

  compartment of the leg. Sensation is intact in the distribution of the tibial nerve but absent in the distribution of the peroneal nerve. Capillary refill in his toes is 2 seconds. In addition to irrigation and debridement of the limb, initial management should include

  1. - application of a long leg cast

  2. - skeletal traction

  3. - external fixation from the femur to the tibia (spanning fixator)

  4. - open reduction and internal fixation with medial and lateral plates.

  5. - transtibial amputation

• 69.04 Answer: 3.

• ORIF in the presence of extensive soft tissue injury has been shown to be fraught with many complications, including wound dehiscence, infection, articular collapse, nonunion, and mechanical axis malalignment. In this case, an external fixator that spans the knee joint provides

  immediate temporary stability. Repeat assessment of the wound should be done within 48 hrs of initial debridement. Amputation with an intact tibial nerve and good cap refill is also not advisable. Skeletal traction here would be difficult and quite morbid. Long leg casting is best left for toddler’s fx’s, not grade III open tibial plateaus.

• 70.04 Which of the following substances counteracts the proteolytic enzymes produced by chondrocytes?

  1. - Stromelysin

  2. - Cathepsin b

  3. - Zinc

  4. - Tissue inhibitor of metalloproteinase

  5. - Decorin

• 70.04 Answer: 4. Tissue inhibitor of metalloproteinase is an inhibitor of collagenase, stromelysin, and other proteolytic enzymes. Cathepsin b is a protease. Decorin regulates collagen fibrillogenesis. Zinc is a mineral.

• 71.04 A 40-year-old woman has a chronic boutonniere deformity of the proximal interphalantgeal (PIP) joint of her middle finger with a preserved joint space. She lacks 45º of active extension but has full passive extension of the PIP joint. Treatment should consist of

   

• 1 - central slip tenotomy

• 2 - volar plate release

• 3 - lateral band relocation

• 4 - arthrodesis of the PIP joint

• 5 - arthroplasty of the PIP joint

• 71.04 Answer: 3. Disruption of the central

  slip results in the classic boutonniere deformity with loss of extension at the PIP joint and hyperextension of the DIP joint. This occurs when the lateral band subluxates volarly and the biomechanics are significantly altered. The lateral bands become flexors of the PIP joint and by their shortening become extensors of the DIP joint.

   

• This question can be answered by simple process of elimination. The joint space is “preserved” thereby eliminating answers 4 & 5. Disrupting the central slip would only worsen a boutonniere deformity so answer 1 is wrong. Answer 2 is wrong because there is flexibility to the PIP joint which means that the volar plate is not contracted and therefore does not need to be released.

• 72.04 Strength training at a constant velocity using submaximal and maximal contraction describes what type of training?

  1. - Isometric

  2. - Isotonic

  3. - Isokinetic

  4. - Eccentric

  5. - Proprioceptive neuromuscular facilitation

• 72.04 Answer: 3. Isokinetic exercise involves movement at a constant speed. To ensure improvement in muscle performance across a spectrum of speeds, isokinetic training should be performed at a variety of contractile velocities. Inappropriate use of isokinetic exercise can be detrimental. During the earlier phases of rehabilitation, isokinetic exercise should be submaximal. Maximal isokinetic exercise should be reserved for the final stages of rehabilitation.

   

• Isometric exercises are a form of resisted exercise in which the muscle contracts without an appreciable change in the length of the muscle or visible joint motion. Isotonic exercises make use of movement against a constant external resistance

• 73.04 A 22-year-old woman sustains a grade 2 open tibial pilon fracture and undergoes emergent irrigation and debridement, followed by fracture stabilization. Postoperative radiographs are shown in Figures 20a and 20b. What is the most appropriate definitive management?

  1. - Application of a long leg cast

  2. - Revision fibular fixation and application of a hybrid fixator

  3. - Conversion of the transarticular fixator to a hybrid fixator construct

  4. - Open reduction and internal fixation of the distal tibia

  5. - Intramedullary nailing of the tibia

• 73.04 Answer: 4. The immediate goals of pilon fx treatment are to avoid complications, restore overall limb alignment, and reconstruct the articular surface. The ability to achieve these objectives is a function of the severity of the fx & associated soft-tissue injuries.

• By now, everyone is familiar with the two-stage protocol for soft tissue management in the treatment of complex pilon fx’s. This patient has already undergone stage I of the tx protocol, placement of a medial spanning external fixator and restoration of the fibular length with internal fixation. The second stage now consists of formal ORIF of the distal tibia once the soft tissues have a chance to cool down.

• 74.04 What is the most common genetic disorder caused by a new mutation of a single gene?

  1. - Homocystinuria

  2. - Neurofibromatosis type I

  3. - Gaucher’s disease

  4. - Marfan’s syndrome

  5. - Larsen’s syndrome

• 74.04 Answer: 2. As plainly indicated on the first line of the neurofibromatosis section of OKU 7 (page 210): NF1 is the

  most common disorder known to be caused by a mutation in a single gene, occurring in about 1 in 3,000 newborns.

• 75.04 Figures 21a and 21b show the radiographs of a 61 year-old man who has chronic pain in the right great toe. Nonsteroidal anti-inflammatory drugs and shoe modifications have failed to provide relief. Treatment should now consist of

  1. - interphalangeal joint fusion

  2. - cheilectomy

  3. - implant arthroplasty of the metatarsophalangeal joint

  4. - proximal phalangeal osteotomy

  5. - metatarsophalangeal joint fusion

• 75.04 Answer: 2. Cheilectomy, or

  excision of the dorsal exostosis of the metatarsal head is currently indicated for grades I and II hallux rigidus, in younger athletic patients, and for grade III hallux rigidus in older patients with advanced arthrosis who want to avoid the risk and morbidity of a more extensive procedure. A cheilectomy is a simple procedure that leaves a stable joint, has low morbidity, and preserves strength and joint motion. One of its prime indications is “extensive osteophyte formation” on xray as seen prominently on this patient’s lateral radiograph.

• 76.04 The adult human lumbar nucleus pulposus receives the majority of its nutrition from

  1. - blood vessels that penetrate into the annulus fibrosis.

  2. - blood vessels that cross the end plates.

  3. - diffusion from blood vessels within the end plates.

  4. - direct arterial blood supply.

  5. - blind-loop (cul-de-sac) arterioles that end near the junction of the nucleus pulposus and the annulus fibrosis.

• 76.04 Answer: 3. Most descriptive accounts of the intervertebral disc dismiss the subject of its vascular nutrition with a brief mention of the general agreement that the normal adult disc is avascular. This may give the impression that the substance of the disc is inert biologically. In fact, experimental evidence has indicated that the normal disc tissue is quite vital and has a demonstrable rate of metabolic turnover. The disc cannot receive the blood-borne nutrients through the mediation of synovial fluid, but must rely on a diffusional system with the vessels that lie adjacent to the disc within the end plates.

   

• The peripheral vascular plexus of the annulus and the vessels adjacent to the hyaline cartilage of the bone-disc interface provide the two sources for the diffusion of metabolites into the disc.

• 77 . Item Deleted

• Item Deleted but for educational purposes: What characteristic change appears in cartilage in latestage osteoarthritis?

  1. Swelling of the matrix

  2. Longer glycosaminoglycan side chains

  3. Increase in keratin sulfate concentration

  4. Increase in type ii collagen

  5. Clusters of chondrocytes

• Item Deleted but for educational purposes:

  What characteristic change appears in cartilage in late-stage osteoarthritis?

  Swelling of the matrix – there is DECREASED water content, increase in hyaluronan concentration Longer glycosaminoglycan side chains – no, smaller and more variable

  Increase in keratin sulfate concentration – YES! Contained in proteoglycans. Incidentally, chondroitin sulfate DECREASES (I feel next year’s question coming on)

  Increase in type ii collagen – not an absolute increase in type II collagen but there IS a relative DECREASE in type XI collagen Clusters of chondrocytes – the number of chondrocytes decreases from birth to maturity, but there is a relatively stable number of cells as one ages even in the presence of OA.

  Maybe this is the reason this question was thrown out

  79.04 A patient undergoes a hemiarthroplasty for a femoral neck fracture. Routine pathologic examination reveals lymphoma. Staging reveals that the proximal femur is an isolated lesion. What is the best course of action?

  1. Wide resection of the proximal femur

  2. Wide resection of the proximal femur and chemo

  3. Chemo and XRT to the femur

  4. Hip disarticulation

  5. Bone marrow transplant

  79.04 Answer 3

• emotherapy and radiation therapy is the treatment of choice for isolated lymphoma with or without the presence of the fracture and hardware.

• 80.04 A 35 year old woman sustains the injuries shown in Fig 22a and 22b as a result of a motor vehicle accident. Examination revels that the fractures are closed and the patient has normal sensation and perfusion in the leg and foot. Definitive management should consist of

  1. use of a cast brace until union

  2. open reduction and internal fixation of both the femur and tibia

  3. IM nailing of both femur and tibia

  4. IM nailing of the femur and external fixation of the tibia

  5. External fixation of both femur and tibia

      

      

      

      

     80.04 Answer 2

      

     The fractures depicted are intraarticular with metaphyseal displacement and therefore require anatomical fixation of their articular component with internal fixation with extension to the diaphysis. External fixation, although initially appropriate to manage the floating knee, is not definitive. IM nailing does not address the articular component of the fracture and is the wrong choice.

     81.04 Which of the following conditions leads to recurrent ankle injuries in children and adolescents?

      

     1. tarsal coalition

     2. accessory navicular

     3. os trigonum

     4. osteochondral fracture

     5. physeal fracture

• 81.04 Answer 1

• Tarsal coalitions often make for a rigid hindfoot which makes the patient more susceptible to ankle injuries. Patients usually present with painful flat feet without arch reconstitution when they attempts to stand on their toes. Hindfoot may be in valgus. Peroneal spasm

  may be present. Posterior tibialis function may be weak. Most common coalition is calcaneonavicular which can be seen on oblique radiographs once there is ossification of the coalition (8-12y.o.). Multiple coalitions occur 20% of the time and patients can be investigated with a foot series, Harris heel view and CT scan. The fractures listed as answer choices can be the result of amkle injury but aren’t causative. Os trigonum is asymptomatic. Accessory navicular can be painful and require resection but does not predispose to injury.

• 82.04 A 59 year-old man is in the recovery room after undergoing total knee arthroplasty for predominantly lateral compartment arthritis with genu valgum. Examination reveals decreased sensation in the first web space and he is unable to dorsiflex or evert the foot. What is the best course of action?

   

  1. return to the operating room for exploration of the wound

  2. remove the dressings and flex the knee

  3. consult a neurologist

  4. obtain an electromyelogram

  5. elevate the limb and apply ice

     – 82.04 Answer 2

      

• Peroneal nerve palsy is a recognized complication of total knee (0.3-4%), particularly in the presence of genu valgum, pre-op flexion contracture, previous high tibial osteotomy. Recommendation for initial treatment is to remove circumferential dressings and to flex the knee. Operative decompression is not the

initial course of action, particularly in a partial nerve palsy, which generally spontaneously recovers. EMG 3 weeks later if symptoms persist.

83.04 In a growing child, what artery provides the principal blood supply to the femoral head?

 

1. medial femoral circumflex

2. lateral femoral circumflex

3. superficial iliac circumflex

4. first perforating branch of the profunda femoris

5. descending branch of the inferior gluteal

   83.04 Answer 1

   • You just need to memorize the answer to this one. The medial femoral circumflex branches into the superior retinacular artery, which has been found to lose patency particularly in unstable SCFEs and contribute to the development of avascular necrosis. The incidence of AVN in SCFEs is anywhere from 5% to 15%. Although some authors have reported an increase in AVN with surgical open reduction of slips or trochanteric osteotomy, newer data suggest that this may not be the case. Because this is an area of debate, they went with an

     anatomy question instead of addressing the controversy. Take home message: unstable slips are more likely to develop AVN. More info: Aspiration of hip joint to remove hematoma has not been found to reduce AVN; unlike adult femoral neck fractures. Superolateral placement of pins has been associated with higher incidence of AVN.

   • 84.04 A 63 year old woman with type II diabetes mellitus and peripheral neuropathy has a fullthickness ulceration plantar to the second metatarsal head. Radiographs are unremarkable. Examination reveals no wound drainage or surrounding cellulitis, and a strong dorsalis pedis pulse is present. Initial management should consist of

     1. culture-specific antibiotics

     2. total contact casting

     3. surgical debridement

     4. second ray amputation

     5. observation

        84.04 Answer 2

        Neuropathic ulcers are caused by pressure and/or shear so total contact casting is an appropriate treatment as it is the optimal off-loading device. The exception to this is in the presence of infection or peripheral vascular insufficiency. This is why the question stresses the normal vascular exam and absence of signs of infection. It also has been stressed in the literature that close observation and followup is imperative. If tendons had been visible or necrosis was present (also suggestive of ischemic process), surgical debridement would be indicated.

        85.04 A patient has difficulty with urination and numbness in her perineum. Examination reveals weakness in her plantar flexors. What is the next most appropriate step?

         

        1. epidural steroid injection

        2. physical therapy

        3. surgical exploration and decompression

        4. MRI

        5. CT

        85.04 . Answer 4

        Cauda equina syndrome. Urinary retention is most consistent and common finding in presentation. Common causes are trauma, disc herniation, tumor and abscess. Emergent decompression within six hours of onset of symptoms does not correlate with return of motor or bladder function although early decompression is recommended. People with insidious onset actually tend to have more complete recovery than acute. Before surgical intervention, it is important to diagnose the cause and anatomic level of the injury. This is best achieved with MRI which has been found to be superior to CT scan.

        86.04 Which of following best describes the anatomic relationship of the digital artery and nerve?

         

        1. nerve ulnar to artery

        2. nerve radial to artery

        3. nerve palmar to artery

        4. artery palmar to nerve

        5. artery lateral to nerve

        86.04 Answer 3

         

        The palmar nerve is palmar to the palmar digital arteries which arise from the superficial arch.

        87.04 What is the most important variable in determining the outcome of compartment syndrome in children?

         

        1. peak tissue pressure

        2. severity of fracture

        3. duration of compartment syndrome prior to treatment

        4. presence of associated nerve injury

        5. number of compartments affected

        87.04 Answer 3

   • The most important determinant of outcome in compartment syndrome in children is duration. This determines the extent of irreversible ischemia, ie, tissue necrosis. Peak tissue pressure and number of compartments involved doesn’t really affect outcome significantly if decompression is achieved quickly. The presence of nerve injury may make the compartment syndrome more difficult to diagnose. Fracture may be causative but isn’t the main determinant of outcome. The question is, what causes the most tissue death and the answer

     is duration of ischemia. Children’s metabolisms are faster than adults and they are therefore more susceptible to poorer outcomes after shorter periods of ischemia.

   • 88.04 A 25 year old woman sustained the injury shown in figures 23a and 23b when she fell off a skateboard. Open reduction and internal fixation is the treatment of choice for this fracture because there is

     1. incongruity of the articular surfaces

     2. displacement of the metaphysis

     3. medial collateral ligament injury

     4. condylar widening and subluxation of the knee joint

         

         

     5. proximal tibiofibular joint dissociation

         

         

         

        88.04 Answer 4

   • Absolute indications for surgical management of tibial plateau fractures are open fracture, acute compartment syndrome or vascular injury complicating fracture, lateral tibial plateau fracture the results in instability of the joint, most displaced medial tibial plateau fractures and most displaced bicondylar fractures. Joint irregularity less than 1.5mm is not associated with increased joint contact

pressures and thus, not affecting prognosis. Condylar widening or incongruity between tibial and femoral condyles (i.e., malalignment) tends to lead to post-trauma OA. Mechanical alignment of the knee within has also been found to be important. This question is asked often and the presence of articular step-off is not what they are looking for. It is widening of condyles and subluxation of the knee joint. The presence of the other characteristics alone do not push the fracture into the surgical category.

89.04

What structure in the shoulder is the primary restraint to anterior dislocation at 90 degrees of abduction?

1. Inferior labrum

2. Superior glenohumeral ligament

3. Middle glenohumeral ligament

4. Posterior band of inferior glenohumeral ligament 5- Anterior band of inferior glenohumeral ligament

 

back   answer

Question 89.04 Answer 5

 

This topic is visited frequently on the exam based upon review of old tests. Therefore, it is best to have an overall knowledge of all the supporting structural anatomy in the shoulder. Per Miller, the static restraints of the shoulder include the glenoid labrum, articular version, articular conformity, negative intra-articular pressure, the capsule, and the capsuloligamentous structures. The superior glenohumeral ligament (SGHL) and coracohumeral ligament (CHL) are reinforcing structures of the rotator interval, limiting inferior translation and external rotation when the arm is adducted and posterior translation when the arm is forward flexed, adducted, and internally rotated. The middle glenohumeral ligament (MGHL) acts to limit external rotation of the adducted humerus, inferior translation of the adducted and externally rotated humerus, and anterior and posterior translation of the partly abducted (45 degrees) and externally rotated arm. The inferior glenohumeral ligament (IGHL) serves as the primary restraint to anterior, posterior, and inferior GH translation for 45-90 degrees of GH elevation. Easy to remember,right?

Per OKU 7, the SGHL functions primarily as a restraint to inferiorly directed forces while the shoulder is in the adducted position. The MGHL is highly variable and is poorly defined or absent in 40% of the population. This ligament functions as a restraint to translation and rotation in the middle and lower ranges of abduction. The IGHL consists of a thick anterior band, a thinner, less consistent posterior band, and the thin interposed axillary pouch. This complex acts as a restraint to translation and rotation with the arm abducted 90 degrees; translation is restrained when the arm is abducted, extended, and externally rotated. The labrum is a fibrous ring that functions to deepen the glenoid fossa, helping center the humeral head in the glenoid; it also provides the attachment site for the GH ligaments.

 

Now back to the question. Based on the above info (OKU is a little easier to remember than Miller), options 1-2-3 are ruled out based on the position of the arm. This leaves 4-5 to choose from, and 5 is correct because the anterior band is thick and consistently present.

Reference(s)

 

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Question 89.04 Answer 5

 

 

 

 

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90.04

 

A 23-year-old man with an idiopathic cavovarus foot has a painful callus over the lateral border of the fifth metatarsal. Examination reveals that the hindfoot corrects to slight valgus with

Coleman block testing. Surgical management should consist of

1. Achilles tendon lengthening and posterior capsulotomy

2. dorsiflexion osteotomy of the first metatarsal

3. Lapidus procedure (first tarsometatarsal arthrodesis)

4. Dwyer lateral closing wedge osteotomy 5- triple arthrodesis

 

back    answer Question 90.04 Answer 2

 

Per OKU 7, the Coleman block test is used to differentiate fixed from flexible deformities by having the patient stand with the lateral border of the foot on a 1-cm block. If the heel tilts out of varus, then this is evidence of a flexible deformity that can be treated with primarily forefoot surgery. Per the cited reference article, cavovarus is a complex deformity of the foot that occurs typically from muscle imbalance due to an underlying neurologic disorder, but can occur in the absence of a neurologic process. When defining the cavovarus foot, the relationship of the forefoot to the hindfoot in the weight-bearing position must be considered. Fixed plantarflexion of the first ray can contribute to hindfoot varus. With varus shifting of the talus of 1mm, the contact area is decreased by 42%, and the contact stress is doubled in the joint. When the calcaneal tibial axis corrected from its varus position with a block beneath the lateral border of the foot, a dorsiflexion first metatarsal osteotomy in conjunction with a calcaneal osteotomy was performed with good results (in the cited reference).

Based on the above, options 1 and 4 do not address the forefoot. Option 3 does not correct potential fixed plantarflexion of the first ray. Option 5 is too extreme for the limited description given of this patient. Option 2 is correct.

 

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Question 90.04 Answer 2

 

Reference(s)

 

 

 

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91.04

 

A 42-year-old man has a chronic anterior cruciate ligament-deficient knee. What variable has the greatest correlation with the future development of arthritis?

1. Patient age

2. Medial collateral ligament injury

3. Meniscal integrity

4. Quadriceps atrophy of more than 25% compared with the opposite extremity 5- Isokinetic muscle deficit of more than 15% compared with the opposite extremity

 

back    answer Question 91.04 Answer 3

 

The articles cited all discuss the trend toward accelerated degenerative changes in the ACL deficient knee. There is convincing evidence that an active individual with a nonfunctional ACL is susceptible to meniscus injury. There is also the risk of more tears occurring with time. This indicates that, if the meniscus cannot be repaired and requires partial meniscectomy or worse, the articular surface will deteriorate. Satku et al showed only 11% incidence of radiographic changes in patients with ACLdeficient knees with no evidence of meniscus tears compared with 100% in those having meniscectomy more than 5 yearspreviously.

According to Fu, evidence clearly implicates meniscectomy as a primary factor in the premature development of OA of the knee joint. Although data demonstrate the ability of the menisci to transmit load, they do not contribute to the primary stability of the knee. In the absence of the ACL, the menisci have been shown to enhance the knee's stability in vitro. Clinically, the argument that the menisci are important secondary stabilizers is less clear. The restraining capacity of the menisci to AP translation is much smaller than the forces the knee is subjected to in vivo during activities of daily living. Additionally,these forces can increase as much as threefold during strenuous athletics. It becomes apparent, on review of the literature, that the menisci clearly are not designed to participate as a significant restraining mechanism for the ACL-deficient knee.

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Question 91.04 Answer 3

 

Although age (1), associated injuries (2), activity level, and rehabilitation status (4,5) may correlate to some extent with future arthritis, the meniscal integrity (3) is consistently found to be more important.

 

Reference(s)

 

 

 

92.04

 

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The mechanism of osteolysis around total joint components is caused by

1. macrophage activation secondary to particulate debris

2. stress shielding secondary to stiff components

3. direct osteoclast activation secondary to particulate debris

4. T cell-mediated inflammatory response to metal ions

5. polymorphonuclear leukocyte activation secondary to complement cascade

    

   back   answer

   Question 92.04 Answer 1

    

   Per Miller, osteolysis at this time remains the most vexing problem in total joint arthroplasty. The process begins with wear sources that generate particulate debris, which initiates the osteolytic reaction. As a result of particle ingestion by the macrophages, the activated

   macrophage liberates osteolytic factors, including osteoclast-activating factor, oxide radicals, hydrogen peroxide, acid phosphatase, interleukins, and prostaglandins. These factors together assist in the dissolution of bone from around the prosthesis, allowing for prosthetic micromotion that leads to further generation of wear debris. Additional lysis of bone allows for prosthetic macromotion, loosening, and pain. Based upon this knowledge, answer 1 is the correct choice.

   Reference(s) 93.04

    

   A 38-year-old man sustains the injury shown in Figures 24a through 24c. In the system of Letournel and Judet, the fracture of the acetabulum would be classified as what pattern?

   1. Anterior wall plus posterior hemitransverse

   2. Associated both column

   3. Posterior column

   4. T-shaped

   5. Transverse plus posterior wall

 

 

 

 

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Question 93.04

 

 

 

 

Question 93.04

 

 

 

 

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Question 93.04 Answer 3

 

Answering this question correctly first requires a knowledge of Letournel and Judet’s system. The five elemental fracture patterns consist of posterior wall, posterior column, anterior wall, anterior column, and transverse. The five associated fracture types consist of posterior column/posterior wall,transverse/posterior wall, T-shaped, anterior column/posterior hemitransverse, and both column. These must be committed to memory as this is a frequently tested topic based upon review of old exams. Based on this, one can rule out option 1 as it is not even part of the system.

 

In looking at the figures, one can immediately see the fracture of the inferior ramus. This quick observation narrows the possible solutions down to those types that involve the ramus - posterior column, anterior column, posteriorcolumn/posterior wall, T-shaped, anterior column/posterior hemitransverse, and both column. This rules out option 5 leaving us to decide between 2-3-4.

Next one must follow the five lines of the pelvis used to evaluate all acetabular/pelvic fractures – the iliopectineal line (anterior column), ilioischial line (posterior column), anterior lip, posterior lip, and line that depicts the superior weight-bearing surface of the acetabulum terminating as the medial tear drop; follow these lines on figure a. The Judet views are also included requiring the following knowledge –obturator oblique shows posterior wall and anterior column (OOPWAC) – figure c, the iliac oblique shows anterior wall and posterior column – figure b.

 

In this example, the iliac oblique shows a fracture line exiting through the posterior column and the obturator oblique shows the anterior column to be intact. This eliminates options 2 and 4, leaving 3 as the correct answer.

Reference(s)

 

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Question 93.04 Answer 3

 

 

 

 

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94.04

 

The use of mini-incision total hip arthroplasty versus conventional total hip arthroplasty can be expected to result in

1. reduced operating room time

2. equivalent hip function 1 year after surgery

3. an increased length of hospital stay

4. a reduced rate of postoperative complications

5. increased surgical blood loss

    

   back   answer Question 94.04 Answer 2

    

   This question is based upon one reference article from the Journal of Arthroplasty 2003. In the cited study, 33 mini-incision THA patients were matched by diagnosis, gender, average age, and preoperative Harris Hip scores to 33 traditional posterior approach THA patients. In this

   study, blood loss was significantly lower in the miniincision group (rule out 5), the average length of surgical time was 2 hrs for the miniincision group and 1hr 40 min for the traditional incision group (rule out 1), the difference in length of hospital stay was not significant (3.8 to 3.9 days) (rule out 3), and no postoperative complications (defined in this study as dislocation or nerve injuries) occurred in the one year follow up period (rule out 4). Although the mini-incision group displayed significantly better Harris Hip scores at 3 and 6 months post op, the results at one year were the same for both groups making option 2 the correct choice.

    

   Reference(s)

   95.04

    

   What is the primary function of 1,25-dihydroxyvitamin D?

   1. Inhibits osteoclast bone resorption

   2. Promotes urinary excretion of phosphate

   3. New osteoblast bone formation

   4. Increases calcium and phosphate absorption from the gastrointestinal tract

   5. Decreases serum calcium

 

 

 

 

 

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back   answer Question 95.04 Answer 4

 

Quick physiology review: Vitamin D is a naturally occurring steroid activated by UV irradiation from sunlight or utilized from dietary intake. It is hydroxylated to 25hydroxyvitamin D in the liver and is hydroxylated a second time in the kidney to 1,25dihydroxyvitamin D. Conversion to the 1,25-dihydroxyform activates the hormone, whereas conversion to 24,25-dihydroxy inactivates the hormone. This conversion occurs in the renal tubular cell based upon PTH,serum Ca, and phosphorus levels. Increased PTH, decreased serum Ca, and decreased serum phosphorus stimulate production of the 1,25 form. As a result of activation, the 1,25 form acts at the bone and intestinal levels. It strongly stimulates osteoclastic resorption of bone and intestinal absorption of calcium and phosphorus leading to increased calcium and phosphorus levels in the serum. According to Miller, it has an unknown effect on the kidney.

 

Based on this knowledge, option 4 is the correct answer. The other answers either directly violate the above review (1,5) or lead to lower levels of serum calcium and phosphorus (2,3).

Question 95.04 Answer 4

 

Reference(s)

 

 

 

96.04

 

A 24-year-old man sustained multiple upper extremity injuries in a motorcycle accident. Six months after injury, the patient has significant pain and gross motion in the midportion of his arm. Radiographs are shown in Figures 25a and 25b. What is the most appropriate management at this time?

1. Continued observation

2. Application of an electrical stimulator

3. Bone grafting of the fracture site

4. Revision intramedullary nailing

5. Removal of the intramedullary nail and compression plating with bone grafting

 

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Question 96.04

 

 

 

Question 96.04 Answer 5

 

Most surgeons agree that humeral shaft fractures should unite within four months. Review of the figures shows a nonunion of the humeral shaft previously treated with an intramedullary nail. One should also take a brief moment to admire the apparent nipple ring on the radiographs, although it is a male patient, which isn’t nearly as cool. Anyway, in case you do not notice the nonunion area, the question also notes that there is gross motion in the midportion of his arm. All one has to do at this point is choose the answer that best describes the standard of care for humeral nonunion, as all of the answer choices are justifiable pending upon the situation.

 

On a side note, the cited references include OKU – Trauma 2 and Skeletal Trauma. The OKU reference discusses initial treatment options (functional brace vs. IM nailing vs. ORIF with plate/screws) but does not discuss options for nonunion. The Skeletal Trauma reference is out of the second edition from 1998, not the most recent third edition from 2003.

The following is taken from the most recent Skeletal Trauma: nonunion developed in less than 5% of patients treated with plating vs. 10% in those treated with IM nails, not to mention the 20% incidence of shoulder pain with the antegrade nail group. Back to the question – at the pathologic level, a nonunion is a fracture bridged with soft tissue. The characteristics of this tissue reflect the local mechanical and nutritional factors that predominate in the early weeks after injury. Nonunion is classified as either hypertrophic or atrophic based on its ability to incite a biologic reaction. Hypertrophic nonunion, with a predominance of fibrocartilage in the gap, can be effectively managed by stabilization alone. However, atrophic nonunion, with a fibrous tissue gap (as seen in the figures), often requires bone grafting. This eliminates options 1,2, and 4. Option 3 does not address the gap that remains as a result of the proximal and distal interlocking screws in the nail. Per Skeletal trauma, “compression plating with bone grafting is probably the most effective method for the treatment of established nonunion” – option 5 is correct.

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Question 96.04 Answer 5

 

 

 

 

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97.04

 

A 30-year-old construction worker sustains a traumatic amputation of his ring finger at the level of the proximal interphalangeal joint. Treatment the day of injury consists of primary closure after the flexor digitorum profundus tendon is first sutured over the end of the remaining middle phalanx. What is the most likely complication?

1. Lumbrical-plus deformity to the ring finger

2. Intrinsic-plus deformity to the hand

3. Extrinsic-plus deformity to the hand

4. Extrinsic-minus deformity to the hand

5. Quadregia effect to the hand

 

back   answer Question 97.04 Answer 5

 

To answer this question correctly, one must first have an understanding of the answer choices. A lumbrical plus finger is characterized by paradoxical extension of the IP joints while attempting to flex the finger. It is most often caused by laceration of the FDP tendon distal to the lumbrical origin. When the FDP contracts to flex the finger, it pulls on the lumbrical, which inserts on the radial lateral band of the extensor expansion. Therefore the IP joints paradoxically extend. This problem is treated by repair of the FDP or release of the lumbrical tendon. An intrinsic plus position is characterized by MCP joint flexion and IP joint extension. An intrinsic minus position yields MCP hyperextension and IP joint flexion. The quadregia effect involves an active flexion lag in fingers adjacent to a digit with an injured, adhesed, or improperly repaired FDP tendon. It results from tethering of the normal FDP tendons by the injured or repaired FDP, because they all share a common muscle belly. As the injured digit reaches its maximum flexion, the FDP tendons in adjacent digits can have no further proximal excursion because all forces of the common muscle belly are being expended on the injured or tethered digit. I have no idea what an extrinsic plus or minus hand entails.

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Question 97.04 Answer 5

 

 

Based on this explanation, on can assume that 5 is the correct answer option. On a side note, the question states that the amputation occurred at the level of the PIP joint, but the repair is “over the end of the remaining middle phalanx.” How can you repair a tendon over the middle phalanx if the amputation occurred proximal to the middle phalanx at the PIP joint? Reference(s)

 

 

 

 

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98.04

 

What is the site of the primary abnormality in hereditary motor sensory neuropathy?

1. Muscle

2. Peripheral nervous system

3. Anterior horn cells

4. Spinocerebellar system 5- Motor end plate-synapse

 

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Per OKU 7, the features of a polyneuropathy causing weakness and wasting of the legs and feet initially and subsequent wasting of the hands (Charcot-Marie-Tooth) is presently referred to as hereditary motor-sensory neuropathy (HMSN). There are at least seven types, and the most common variety has an autosomal dominant pattern of inheritance. Two broad categories of HMSN are recognized, the hypertrophic, demyelinating (types I and III), and the rarer, axonal (neuronal) type II. The genetics are being established but it is known that the defects involve genes controlling myelination (peripheral myelin protein and myelin protein zero). In the hypertrophic form, secondary to demyelination, nerve conduction velocities are uniformly decreased, with nerve biopsy showing “the onion bulb” hypertrophy of the myelin sheath. In the neuronal variant, the nerve conduction velocities may be only slightly slowed but the compound muscle action potential is decreased. Muscle biopsy shows atrophy of fiber groups. In order to answer this question correctly, you basically have to know that the HMSN process affects the peripheral nerves giving answer 2.

 

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Question 98.04 Answer 2

 

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99.04