Orthopedic With Answers Review | Dr Hutaif General Orth -...

The patient has recurrent instability after multiple prior revisions with a dislocated constrained liner. This is likely a multifactorial problem that is challenging to manage. The prior AP pelvis shows the acetabular component to be horizontal, which is exacerbated by pelvic obliquity with the right hemipelvis lower. This is likely resulting in impingement in deep flexion, consistent with this patient’s mechanism of dislocation. Range of motion prior to impingement with constrained liners is also significantly reduced compared with nonconstrained bearings. The best option for definitive management is acetabular component revision with consideration of a dual mobility insert to increase impingement-free range of motion and jump distance. The femoral component should be evaluated and revised if contributing to the instability (retroverted) during trialing. Conversion to a lipped or dual-mobility liner is not indicated in the presence of a malpositioned acetabular component. Revision of a failed constrained liner to another without addressing the underlying mechanical factors would have a high risk of failure.

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The patient has sustained a herniated disk, which is likely causing his radicular symptoms. The patient does not have significant weakness or myelopathic symptoms, and initial treatment should be nonoperative. However, Hsu found that surgical treatment is shown to result in a better chance of returning to play in National Football League players. Regardless the treatment, the patient should not be allowed to return to play until he is asymptomatic with normal range of motion and a negative neurological examination.

Fractures of the hook of the hamate frequently are not identified in the acute phase. Because the fracture can be difficult to see on plain radiographs, the lack of findings can lead to a painful nonunion. A carpal tunnel view may show the fracture, but a CT scan will best detect the injury. Immobilization is the treatment of choice and will result in union in most patients unless the diagnosis is delayed. However, excision of the fragment may be necessary for patients who have nonunion, persistent pain, or ulnar nerve palsy.
REFERENCES: Carroll RE, Lakin JF: Fracture of the hook of the hamate: Acute treatment. J Trauma 1993;34:803-805.
Whalen JL, Bishop AT, Linscheid RL: Nonoperative treatment of acute hamate hook fractures. J Hand Surg Am 1992;17:507-511.

The patient has a surgical neck fracture with medial calcar comminution. In patients where this cannot be anatomically reconstructed to provide cortical support, a fibular allograft can be used to prevent varus collapse. A “push” screw can be seen in Figure 3, which was used to medialize the graft into a biomechanically favorable position for this fracture pattern. Although the allograft theoretically provides the other benefits listed, they are not the primary indication for this injury.

During the late acceleration phase of throwing, the triceps forcibly contracts, extending the elbow as the ball is released. Normally, this force is absorbed by the anterior capsule and the brachialis and biceps muscles. However, if the ulnar collateral ligament is insufficient, the elbow will be in a subluxated position during extension and cause impaction of the olecranon and the olecranon fossa posteromedially. Over time, osteophyte formation is likely to occur.
REFERENCES: Conway JE, Jobe FW, Glousman RE, Pink M: Medial instability of the elbow in throwing athletes: Treatment by repair or reconstruction of the ulnar collateral ligament. J Bone Joint Surg Am 1992;74:67-83.
Wilson FD, Andrews, JR, Blackburn TA, McCluskey G: Valgus extension overload in the pitching elbow. Am J Sports Med 1983;11:83-88.

Neer and associates focused on mechanical and nutritional factors as the etiology of rotator cuff arthropathy. McCarty and associates, in describing a similar syndrome known as Milwaukee shoulder, focused on an inflammatory cause in proposing the pathogenic role of hydroxyapatite, a basic calcium phosphate.
REFERENCES: Neer CS II, Craig EV, Fukuda H: Cuff-tear arthropathy. J Bone Joint Surg Am 1983;65:1232-1244.
McCarty DJ, Halverson PB, Carrera GF, Brewer BJ, Kozin F: Milwaukee shoulder: Association of microspheroids containing hydroxyapatite crystals, active collagenase, and neutral protease with rotator cuff defects. I: Clinical aspects. Arthritis Rheum 1981;24:464-473.

The MSIS definition of periprosthetic joint infection was updated in 2014 with two major and six minor criteria. The presence of one major criterion or three minor criteria is diagnostic for infection. The major criteria are two positive cultures with the same organism or a draining sinus tract. The current MSIS minor criteria are 1) an elevated ESR (more than 30 mm/hr) and CRP level (more than 10 mg/L), 2) an elevated synovial WBC count (more than 3,000 cells per/microliter), 3) an elevated synovial fluid polymorphonuclear count (more than 80%), 4) a positive histological analysis of periprosthetic tissue, and 5) a single positive culture.

The complication rate after routine wrist arthroscopy is between 2% and 5%.

The lowest reported rates of osteolysis involving cemented TKAs are associated with monolithic tibial components. 20
Modular components and cemented metal-backed patella components are associated with a high prevalence of backside tibial insert wear and osteolysis
.
Injury to the popliteal artery during total knee arthroplasty (TKA) is most likely to occur when placing a sharp retractor
A. directly posterior to the posterior cruciate ligament (PCL).
B. posteromedial to the PCL.
C. posterolateral to the PCL.
D. in the posteromedial corner of the knee.
Vascular complications during TKA are rare but do occur. Traditionally, it was taught that the popliteal artery was situated posterior to the PCL; however, more recent anatomic dissections have demonstrated that this artery is usually located posterolateral to the PCL.
Correct answer : C
A 70-year-old woman has severe stiffness of her knee following a primary total knee arthroplasty (TKA) 3 years ago. The patient has well-fixed femoral and tibial components, and a preoperative work-up for infection is negative. The decision is made to proceed with a revision TKA of both the femoral and tibial components. An extensile exposure is planned to facilitate removal of the components. What extensile exposure would require the least modification of postoperative rehabilitation with regards to weight bearing and range of motion?
A. Quadriceps snip
B. Lateral parapatellar approach
C. V-Y quadriceps turndown
D. Tibial tubercle osteotomy
Achievement of adequate exposure in revision TKA is critical as it reduces the surgical time, enhances the ability for both component removal and reconstruction, and avoids devastating complications such as extensor mechanism disruption. Numerous extensile exposures in revision TKA have been described.
21
A tibial tubercle osteotomy, V-Y tendon plasty, and V-Y quadriceps turndown all provide excellent exposure, but require a modification in postoperative rehabilitation as they often require a period of immobilization followed by limits in range of motion. In contrast, the quadriceps snip allows immediate weight bearing along with progressive range of motion; no modification of postoperative rehabilitation is required. Lateral parapatellar approach would offer no benefit for exposure.
Correct answer : A

- Coracoid transfer
PREFERRED RESPONSE: 1- Loss of external rotation PREFERRED RESPONSE: 1- Glenohumeral arthritis

Passive stretching is contraindicated during rehabilitation as it may potentiate the severity of the myositis ossificans. Electrical stimulation, iontophoresis, isometric exercise, and ice/heat contrast are not known to exacerbate this process.
REFERENCES: Brunet ME, Hontas RB: The thigh, in DeLee JC, Drez D (eds): Orthopaedic Sports Medicine. Philadelphia, PA, WB Saunders, 1994, pp 1086-1112.
Cushner FD, Morwessel RM: Myositis ossificans traumatica. Orthop Rev 1992;21:1319-1326.

DISCUSSION: A chronic patellar tendon rupture is a difficult complication to manage. Patients typically present with both inability to extend their leg and instability of the extremity, oftentimes associated with multiple falls.
Attempts at secondary repair have been associated with high failure rates whereas the use of an extensor mechanism allograft has been shown to more effectively restore active extension in a substantial percentage of patients. Important aspects of the technique include fully tensioning the graft in full extension and immobilization of the extremity for 6 to 8 weeks postoperatively to allow for graft healing. Nonsurgical management will not result in an acceptable outcome for a young patient, and attempted secondary repair is associated with a high rate of failure, even when augmented with local tissues. This patient has gross rotational
malalignment of the components and the surgeon faced with this problem should consider obtaining a CT scan to determine component rotation preoperatively.

REFERENCES: Burnett RS, Berger RA, Paprosky WG, et al: Extensor mechanism allograft reconstruction after total knee arthroplasty: A comparison of two techniques. J Bone Joint Surg Am 2004;86:2694-2699.
Nazarian DG, Booth RE: Extensor mechanism allografts in total knee arthroplasty. Clin Orthop Relat Res
1999;367-123-129. , „. H
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Figure 53

Reiter’s syndrome is a seronegative spondyloarthropathy characterized most commonly by a triad of asymmetric arthritis, urethritis, and uveitis. Tendon ensethopathies can also be present. It is most often seen in men and is associated with a positive HLA-B27 marker. Rheumatoid arthritis does not usually present with these features; more commonly it causes forefoot pain and synovitis of the metatarsophalangeal joints. A CBC count with differential would be helpful in a situation of possible infection. The urethral swab would help to diagnose a gonococcal infection which can cause a monoarticular septic arthritis. Antiphospholipid antibody is associated with a hypercoaguable state and increased risk of deep venous thrombosis.
REFERENCE: Coughlin MJ: Arthritides, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, vol 1, pp 560-650.

Based on the mechanism of injury and findings of medial laxity, the most likely diagnosis is injury to either the growth plate or the medial collateral ligament. With the open physeal plate, this area of injury is presumed present until proven otherwise; therefore, stress radiographs should be obtained before implementing any treatment or ordering more extensive and expensive tests.
REFERENCES: DeLee JC: Ligamentous injury of the knee, in Stanitski CL, DeLee JC, Drez D Jr (eds): Pediatric and Adolescent Sports Medicine. Philadelphia, PA, WB Saunders, 1994,
vol 3, pp 406-432.
Clanton TO, DeLee JC, Sanders B, Neidre A: Knee ligament injuries in children. J Bone Joint Surg Am 1979;61:1195-1201.
Torg JS, Pavlov H, Morris VB: Salter-Harris type III fracture of the medial femoral condyle occurring in the adolescent athlete. J Bone Joint Surg Am 1981;63:586-591.

Spondylolisthesis can be classified into five types. Type I, dysplastic, occurs at the lumbosacral junction as a result of congenital abnormalities of the upper sacrum and/or the arch of L5.Type II, isthmic, refers to those involving a lesion in the pars interarticularis. Type IIA, lytic, represents fatigue fractures of the pars. Type IIB describes those with elongated, but intact pars. Type IIC describes those that are a result of an acute fracture of the pars. Type III, degenerative spondylolisthesis, results from longstanding intersegmental disease. Type IV, traumatic, refers to those resulting from fractures in regions other than the pars, such as the pedicles. Type V, pathologic, refers to spondylolisthesis resulting from generalized or local bone disease. The radiographs demonstrate type II, isthmic spondylolisthesis.

The normal porosity of cortical bone is 10% compared to trabecular bone, which is 50% to 90%. Cortical bone porosity occurs because of the Haversian and Volkman canals and, to a lesser extent, from the osteocyte lacunae and canaliculi.
Trabecular bone is arranged as a series of interconnecting small plates and rods. The porosity may vary between 50% to 90%. This porosity is secondary to the spaces between the trabecular pieces of bone rather than voids in the actual pieces of trabecular bone.

Maintenance of adequate hydration is the single most important factor affecting athletic performance. While carbohydrate loading may be beneficial for some endurance athletes, the consumption of carbohydrates during exercise does not appear to be beneficial for athletes engaged in events that last less than 1 hour. In general, athletes consuming a balanced diet do not need electrolyte supplementation.
REFERENCES: Maughan RJ, Noakes TD: Fluid replacement and exercise stress: A brief review of studies on fluid replacement and some guidelines for the athlete. Sports Med 1991;12:16-31.
Barr SI, Costill DL, Fink WJ: Fluid replacement during prolonged exercise: Effects of water, saline, or no fluid. Med Sci Sports Exerc 1991;23:811-817.

This patient is experiencing soreness over his medial (ulnar) collateral ligament. Valgus overload is likely to reproduce his symptoms and is most pronounced during the late cocking phase of the throwing cycle. In windup, very little elbow torque is required. In early cocking, the arm is getting loaded, and maximum valgus is not yet achieved at the elbow. In acceleration and deceleration, more force is _generated at the level of the shoulder joint._

The foot in a patient with tibial hemimelia does not resemble the other four conditions described; the foot is in equinus and varus.
C alcaneovalgus foot is dorsiflexed and everted through the axis of the ankle joint. A vertical talus has excessive forefoot dorsiflexion and valgus.
A patient with an L5 myelomeningocele may have this appearance due to activity of the dorsiflexors and evertors, with absent power in the plantarflexors and invertors.
Due to the posteromedial bow in the tibia, the foot may appear dorsiflexed and in valgus.

Activities of daily living such as dressing, eating, and bathing can all be performed with elbow motion through a 100 degrees arc of flexion and extension (30 degrees to 130 degrees) and a 100 degrees arc of forearm rotation (50 degrees pronation, 50 degrees supination). Some patients can accomplish these activities of daily living with 10 degrees less motion at each end point. This is referred to as the functional arc of motion.
REFERENCES: Kasser JR (ed): Orthopaedic Knowledge Update 5. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1996, pp 283-294.
Morrey BF, Askew LJ, Chao EY: A biomechanical study of normal functional elbow motion. J Bone Joint Surg Am 1981;63:872-877.

Displaced clavicle fractures are associated with higher rates of nonunion.
Nonunion occurs in roughly 5-6% of clavicle fractures and can result in slower functional return, poor cosmesis and muscle fatigability. Clavicle fractures can be sub-classified using the Allman classification into medial, diaphyseal, and lateral injuries (Illustration A). The Neer classification for diaphyseal injuries describes fractures as "nondisplaced" (less than 100% displacement) and "displaced" (greater than 100% displacement).
Robinson et al. performed a prospective cohort study to identify risk factors for nonunion after nonoperative management of clavicle fractures. The overall nonunion rate was 6.2% and was highest in lateral third fractures (11.5%).
Diaphyseal fractures had the lowest nonunion rate (4.5%). Additionally, the authors found that the risk for nonunion was increased by advancing age, female gender, fracture displacement, and comminution.
Jorgensen et al. performed a systemic review of the literature looking for predictors of non-union and malunion in mid shaft clavicle fractures treated non-operatively. They found fracture comminution, displacement, older age, female gender, and the presence of smoking to be his factors for non-union. Of these, displacement was the most likely factor that can be used to predict nonunion.
Figure A demonstrates a displaced left clavicle diaphyseal fracture. Note that the medial fragment is displaced superiorly by the deforming force of the sternocleidomastoid. Illustration A represents the Allman classification.
Illustration B demonstrates the deforming forces acting on the clavicle.
Incorrect Answers:
Answer 1: Diaphyseal fractures were demonstrated to have the lowest rate of nonunion when compared to lateral third fractures and medial clavicle fractures.
Answer 3: Advancing age was found to be an independent predictor of nonunion.
Answer 4: Female gender was found to be an independent predictor of nonunion.
Answer 5: Injury to the dominant hand was not found to be associated with an increased risk of non-union.

The patient sustained a posterior wall fracture dislocation. For acetabular fractures, the position of the limb in space at the time of impact (in terms of the amount of flexion/extension, internal/external rotation, and adduction/abduction) will dictate the fracture pattern. For posterior wall fracture patterns, the limb is in some degree of flexion, adduction, and internal rotation. Other combinations are possible to contribute to an acetabular fracture but not likely to contribute to a posterior wall pattern.
This posterior wall fracture pattern can be addressed from a standard Kocher-Langenbeck approach for both fixation and arthroplasty. There is no significant cranial or anterior extension of the fracture that would necessitate a modified
posterior approach or greater trochanteric osteotomy. The other listed approaches would not be appropriate.
Indications for total hip arthroplasty are continuing to evolve and many patient-specific and fracture specific variables are involved. Several studies have investigated this issue and the common variables that influence the success of primary fixation are related to the age of the patient, greater than 50 years as well as associated bone quality and how these are affected with the fracture. The presence of marginal impaction suggests significant insult to the cartilage. In the presence of pre-existing cartilage wear, the likelihood of success with primary fixation is decreased. The presence of significant comminution of the fracture (greater than 3 fragments) also suggests decreased success with primary fixation. The other factors listed can contribute to perioperative morbidity but not as clearly when compared to the three listed in
. In the clinical setting of a patient older than 50 years old with a comminuted fracture, marginal impaction, and femoral head damage, there should be serious consideration for combined fracture fixation and acute total hip arthroplasty. Delayed arthroplasty can be an option in some patients, but clinical outcomes have not been as favorable as acute combined treatment.
Although urethral tears, rib fractures, and subdural hematoma are commonly involved with high-energy accidents and are routinely investigated through advanced trauma life support (ATLS) protocols, the ipsilateral knee has not received such focus. In a recent multi-center study, 15% of patients were found to have ipsilateral knee symptoms within a period of 1 year from the date of injury. The patterns of knee injury included 56 fractures (29%), 49 ligamentous lesions (25%), and 88 miscellaneous (46%) causes, including bone bruises, wounds, and swelling. Multi-ligamentous knee injuries can be occult and a detailed examination of the knee should be standard in these patients upon secondary and tertiary surveys.

The majority of stress fractures are treated with rest and protected weight-bearing. When the patient rests, strain on the affected bone is reduced and formation exceeds resorption, leading to bone healing.
A tension-sided femoral neck stress fracture is most at risk for progression to a complete fracture and displacement. Correct Answe Tension-sided femoral neck

Reduction, either open or closed, with internal fixation (pinning) is the recommended treatment for the majority of these injuries. Closed reduction with pinning is most often performed for acute injuries. Open reduction with pinning is performed for those injuries that cannot be reduced by closed means or those with a delayed presentation. Four cases of successful closed reduction and splinting, all performed upon presentation in the emergency department, have been described by Storken and associates, but the authors note that their review of three prior reports uncovered cases of secondary dislocation, which required surgical stabilization. One of the dislocations occurred 4 months after the reduction. They assert that an indication for primary ORIF is a CMC dislocation associated with major fractures. Primary arthrodesis can be considered in cases with severe intra-articular comminution, but this procedure substantially limits the ability of the hand to increase and decrease the transverse metacarpal arch, which is an important functional movement. It can also lead to osteoarthritis of the triquetrohamate joint. Suspension arthroplasty has been described for old fracture-dislocations of the fifth CMC joint, using a partial slip of the extensor carpi ulnaris.

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The hallux varus seen in this patient is most likely the result of a combination of causes. Based on the degenerative changes and the significant shortening of the first metatarsal relative to the second metatarsal, a metatarsophalangeal arthrodesis is the treatment of choice. The other surgical approaches are not expected to provide a satisfactory result.
REFERENCES: Coughlin MJ, Mann RA: Adult hallux valgus, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby-Year Book, 2000, pp 150-269.
Skalley TC, Myerson MS: The operative treatment of acquired hallux varus. Clin Orthop 1994;306:183-191.

- Corona mortis

- Ankle distraction arthroplasty_

Uneven resection of bone, typically leaving a retained posterolateral corner of the distal clavicle, can lead to failure of arthroscopic distal clavicle excision. The amount of bone resected, the gender of the patient, or the diagnosis (osteoarthritis versus osteolysis) does not appear to affect the results.
REFERENCE: Flatow EL, Duralde XA, Nicholson GP, Pollock RG, Bigliani LU: Arthroscopic resection of the distal clavicle with a superior approach. J Shoulder Elbow Surg 1995;4:41-50.

The forearm contains the anterior, dorsal, and mobile wad. The following muscles are located in each compartment: Mobile wad
Brachioradialis
Extensor carpi radialis brevis
Extensor carpi radialis longus
Volar compartment
Flexor carpi ulnaris
Flexor digitorum profundus Flexor digitorum superficialis Palmaris longus
Flexor carpi radialis
Flexor pollicis longus

The patient has posttraumatic arthritis of the elbow; therefore, the treatment of choice is hardware removal and soft-tissue releases with splinting to avoid recurrence of contractures. The combination of pain and stiffness in an elbow that has sustained significant joint surface damage renders it unresponsive to simple soft-tissue releases and heterotopic bone excision. Joint distraction and interposition arthroplasty offer the possibility of maintaining motion and relieving pain as a later salvage procedure. Joint replacement should not be performed in young, active, strong individuals because the prosthesis will fail quickly and complications will develop. Synovectomy and radial head excision are not indicated.
REFERENCES: Morrey BF: Distraction arthroplasty: Clinical applications. Clin Orthop 1993;293:46-54.
O’Driscoll SW: Elbow arthritis: Treatment options. J Am Acad Orthop Surg 1993;1:106-116.

The MRI scan shows a C7 burst fracture. A CT scan of the cervical spine will allow for optimal evaluation of this C7 burst fracture. Specifically, it will provide additional osseous detail and will assist with the detection of additional fractures,
including those of the posterior elements. Additional CT imaging of the thoracic and lumbar spine is required to rule out concommitant injuries (which may be present in 10% to 15% of patients). Anteroposterior and lateral cervical spine radiographs would be a good option for further evaluation but are not included in the available choices here.
Cervical spine flexion and extension radiographs should not be obtained in a patient who is known to have a relatively unstable spine and a neurologic deficit. Electromyography and nerve conduction velocity studies are best used to evaluate for cervical radiculopathy secondary to degenerative abnormalities and are usually not indicated in the acute trauma setting.

Although the Holstein-Lewis fracture, described as an oblique distal one third fracture, is best known for its association with neurologic injury, radial nerve palsy is most commonly associated with middle one third humeral fractures. Most nerve injuries are neurapraxias or axonotmeses, with up to 90% resolving in 3 to 4 months.
REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 271-286.
Pollock FH, Drake D, Bovill EG, Day L, Trafton PG: Treatment of radial neuropathy associated with fractures of the humerus. J Bone Joint Surg Am 1981;63:239-243.

The radiographs show nonunion of both the greater and lesser tuberosities. Tuberosity pull-off and nonunion remain among the most common causes of failed humeral head arthroplasty for fracture. Strict attention to securing the tuberosities to each other and to the shaft, and autogenous bone grafting from the excised humeral head will decrease the incidence of pull-off and improve healing rates. Active-assisted range-of-motion and strengthening exercises should be delayed until tuberosity healing is noted radiographically, usually at 6 to 8 weeks postoperatively.
REFERENCES: Hartsock LA, Estes WJ, Murray CA, et al: Shoulder hemiarthroplasty for proximal humeral fractures. Orthop Clin North Am 1998;29:467-475.
Hughes M, Neer CS: Glenohumeral joint replacement and postoperative rehabilitation.
Phys Ther 1975;55:850-858.
Compito CA, Self EB, Bigliani LU: Arthroplasty and acute shoulder trauma. Clin Orthop 1994;307:27-36.

Figure 61 reveals transient osteoporosis of the left hip. This is a T1-weighted image of the pelvis with generalized low-intensity signal of the bone marrow in the left femoral head. A T2-weighted
image would show high-intensity signal in a similar distribution. These changes signify an increase in bone marrow edema. On occasion, a subchondral insufficiency fracture is seen, but collapse of the femoral head should not occur with transient osteoporosis of the hip. It is seen most commonly in healthy middle-age men and in women during the third trimester of pregnancy. Hip pain is the most common symptom, and this typically lasts 6 to 8 months. Complete resolution of symptoms without long-term sequelae is the rule with few exceptions.
Figure 62 shows chondrosarcoma of the pelvis. This is a T1-weighted image that reveals a large soft-tissue mass of low-signal intensity, signifying destruction of the left acetabulum with medial protrusion of the left femoral head into the pelvis. These tumors occur typically in adults and are usually located in the proximal femur, ilium, or the periacetabular regions.
Figure 63 shows a superior acetabular labral tear. This is a T2-weighted image of the left hip after administration of intra-articular contrast. The distension of the joint with contrast shows the separation of the superior labrum from the bony acetabular rim.
Figure 64 shows end-stage osteonecrosis of the left femoral head. This is a T1-weighted image of the left hip with low-intensity signal, signifying bone marrow edema and femoral head collapse. There is a bandlike low signal intensity line that is characteristically seen on T1-weighted images. This represents the zone of demarcation between the viable and necrotic bone. The most common risk factors for osteonecrosis are heavy alcohol intake and chronic glucocorticoid use.
Figure 65 shows a T1-weighted image of a dysplastic right hip. A shallow acetabulum is present with approximately 40% uncoverage of the right femoral head. A shallow fovea on the femoral head and a hyperplastic superior labrum also are seen.
Figure 66 shows a T1-weighted image of a nondisplaced right femoral neck fracture. The fracture line is seen in the subcapital region of the femoral neck, and there is low-signal intensity signifying surrounding bone edema. Plain radiographs are negative in 8% of femoral neck fractures, and MRI has been shown to be 99% sensitive.
RECOMMENDED READINGS
1. [Korompilias AV, Karantanas AH, Lykissas MG, Beris AE. Transient osteoporosis. J Am Acad Orthop Surg. 2008 Aug;16(8):480-9. Review. PubMed PMID: 18664637. ](http://www.ncbi.nlm.nih.gov/pubmed/18664637)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/18664637)
2. [Hartley KG, Damon BM, Patterson GT, Long JH, Holt GE. MRI techniques: a review and update for the orthopaedic surgeon. J Am Acad Orthop Surg. 2012 Dec;20(12):775-87. doi: 10.5435/JAAOS-20-12-775. Review. PubMed PMID: 23203937. ](http://www.ncbi.nlm.nih.gov/pubmed/23203937)[View Abstract at PubMed](http://www.ncbi.nlm.nih.gov/pubmed/23203937)
3. Potter HG, Sou IT. Magnetic resonance imaging. In: Callaghan JJ, Rosenberg AG, Rubash HE, eds. _The Adult Hip_. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2007:409-422.

In the absence of any severe progressive neurologic deficits or other red flags, the most appropriate management for an acute lumbar disk herniation is nonsurgical care. Conservative treatments such as limited bed rest, anti-inflammatory medications, and judicious use of pain medications are appropriate in this clinical situation. Up to 90% of patients will experience a resolution of symptoms without the need for surgical intervention within a 3-month window. In the acute setting, with no neurologic deficits, immediate MRI of the lumbar spine is neither beneficial nor warranted. Likewise,without signs of an acute deficit, emergent surgical intervention and caudal epidural steroid injections are not needed.

The patient sustained a comminuted extra-articular distal humeral diaphyseal fracture. In isolation, this fracture would still be amenable to an attempt at closed treatment. His radial nerve palsy alone does not warrant open management, as early exploration has not shown a significant benefit in a closed fracture. In addition, despite the comminution and distal extent of the fracture, it is still amenable to closed treatment, though it may be at higher risk for malunion. However, in this patient with multiple lower extremity injuries, fixation of the humerus can facilitate
early mobilization and weight-bearing with his right upper extremity, representing a relative indication for surgical management.
The posterior triceps-reflecting approach described can be extended proximally to the level of the axillary nerve. The radial nerve must be found and protected, but the dissection can be carried well proximal to it and the medial triceps origin. The anatomic neck of the humerus cannot be visualized through this approach.
The plate functions as a neutralization plate, as multiple lag screws are seen placed outside of the plate, suggesting anatomic reduction and fixation of the fracture prior to applying the plate.
The working length of the plate is the distance between the proximal and distal screws closest to the fracture. The length of screw purchase in bone represents the working length of the screw, not the plate. The other answer choices describe dimensions of the plate and the fixation construct, not its working length.

Arthrodesis and resection arthroplasty of the hallux MP joint are indicated in the presence of arthritis of the hallux MP joint. A tendon transfer is preferred, and the extensor hallucis brevis tendon is an effective transfer. Use of the extensor hallucis longus tendon with arthrodesis of the hallux IP joint is indicated when there is a fixed deformity of the hallux IP joint.

This patient describes swelling of the toe, which is not associated with an interdigital neuroma. The pain, swelling, and clinical findings suggest a rupture of the plantar plate with early instability and second metatarsophalangeal synovitis.

- MRI

Low plate positioning with a prominent screw head in the most distal hole of the plate was shown to be correlated with peroneal tendon lesions. Distal plate placement in the absence of prominent screws was not associated with tendon lesions. Trimmed plates, locked plates, and uncontoured plates have not been shown to increase the risk of peroneal tendon pathology.

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First metatarsophalangeal joint replacement in this prospective comparative study performed poorly compared to arthrodesis. Patients with arthroplasties had greater pain and little improvement in range of motion.

A chronic mallet finger results in proximal retraction of the extensor mechanism and overpull of the central slip. Isolated central slip rupture does not cause this deformity. Rupture of the flexor digitorum sublimis can cause Swan-neck deformity. MP arthroplasty is not associated with this deformity. The sequalae of dorsal proximal interphalangeal joint dislocation (e.g., volar plate laxity or deficiency) leads to Swan-neck deformity.

The area indicated by the arrow represents gadolinium contrast extending into a separation between the lateral labrum and its acetabular attachment. This can be a traumatic detachment, but occasionally a cleft may be present as a normal variant of the labral morphology. The capsular attachment of the iliofemoral ligament is peripheral to the labrum. The pulvinar is the common name applied to the fat and overlying synovium contained within the acetabular fossa above the ligamentum teres. The zona orbicularis is a circumferential thickening of the capsule around the femoral neck, and the retinacular vessels travel within the capsular synovium up the femoral neck to supply the femoral head.
REFERENCES: Petersilge CA, Haque MA, Petersilge WJ, Lewin JS, Lieberman JM, Buly R: Acetabular labral tears: Evaluation with MR arthrography. Radiology 1996;200:231-235.
Czerny C, Hofmann S, Neuhold A, et al: Lesions of the acetabular labrum: Accuracy of MR imaging and MR arthrography in detection and staging. Radiology 1996;200:225-230.
Byrd JWT: Indications and contraindications, in Byrd JWT (ed): Operative Hip Arthroscopy. New York, NY, Thieme, 1998, pp 7-24.

The MRI scan shows a rupture of the Achilles tendon. The substantiated advantages of repair are less risk of re-rupture and greater plantar flexion strength. Dorsiflexion strength is not influenced. Motion, pain, and period of recovery are not specifically improved as a consequence of surgery.
REFERENCES: Bhandari M, Guyatt GH, Siddiqui F, et al: Treatment of acute Achilles tendon ruptures: A systematic overview and meta-analysis. Clin Orthop 2002;400:190-200.
Schepsis AA, Jones HE, Haas AL: Achilles tendon disorders in athletes. Am J Sports Med 2002;30:287-305.

Patients with primary elbow osteoarthritis tend to be active and are often involved in manual occupations that place greater demands on a total elbow implant. Such patients are most often treated with nonprosthetic options because of concerns about prosthetic longevity. As a result, few cases of primary osteoarthritis are included in published studies. However, complications such as stem fracture and aseptic loosening appear to be more common in this population than in any other subgroup, including revision patients. The poor soft-tissue quality associated with rheumatoid arthritis leads to a high-risk ligamentous attenuation and is a general contraindication to use of an unlinked implant. The same poor soft tissue leads to a higher rate of triceps insufficiency and wound dehiscence.

Various options exist to treat thumb CMC arthritis: trapezial resection alone, trapezial resection with ligament suspensionplasty or tendon interposition, trapezial resection with both ligament suspensionplasty and tendon interposition, CMC fusion, and CMC replacement. MCP hyperextension can develop in long-standing CMC arthritis, contributing to CMC instability as well as thumb pain and weakness. In patients with concomitant MCP hyperextension that exceeds 30°,
correction of the deformity of the MCP joint must also be addressed and can be done with MCP capsulodesis, extensor pollicis brevis tendon transfer, or MCP fusion. Fusion of both the thumb CMC and MP joints is not recommended as this would result in marked stiffness and dysfunction.

The three articular cartilage collagens that form cross bands are types II, IX, and XI. Of particular note:
Type XI binds to type II.
Type IX binds to the cross-banded fibrils in the superficial layer. Type VI attaches to the matrix around the chondrocytes.
Type X is near the calcified layer and is probably involved in mineralization of the calcified layer.

The most common mechanism of injury for turf toe is a hyperextension injury to the MTP joint. The foot is typically in a dorsiflexed position with the heel raised when an external force drives the MTP joint into further dorsiflexion. The joint capsule usually tears at the metatarsal neck because its attachment is weaker there than at the proximal phalanx. Some compression injuries to the dorsal articular surface of the metatarsal head can result from extension or hyperextension.
REFERENCES: Clanton TO, Ford JJ: Turf toe injury. Clin Sports Med 1994;13:731-741.
Rodeo SA, O’Brien S, Warren RF, et al: Turf toe: An analysis of metatarsophalangeal joint sprains in professional football players. Am J Sports Med 1990;18:280-285.

This patient has cam-type femoroacetabular impingement. Decreased internal rotation and a positive impingement test (forced flexion, adduction, and internal rotation) are classic findings. The lack of pain with resisted hip flexion makes hip flexor strain unlikely, and the lack of tenderness at the greater trochanter renders trochanteric bursitis unlikely. Although athletic pubalgia can be a source of longstanding groin pain, he lacks the pain with a resisted sit-up and tenderness along the pubic ramus that is frequently noted in patients with pubalgia. His radiographs reveal a focal femoral neck prominence consistent with cam impingement, although pistol grip deformities and flattening of the lateral femoral head are often present as well. His MRI scan shows a labral tear, which is common in cam impingement. Surgical treatment for cam impingement can be effective for symptomatic patients. Even among high-level athletes, open surgical dislocation of the hip has been shown to have good results. Most patients with cam impingement can be treated with arthroscopic osteoplasty and achieve results comparable with those realized with open surgical dislocation. The literature describes success in terms of athletes returning to sports (even professional athletes) to be approximately 90% after arthroscopic treatment. Byrd and Jones described five patients who developed transient neurapraxias that resolved uneventfully. The patients in his series who had concomitant microfracture had a 92% return to sports within the follow-up period. Cam impingement has long been thought to be associated with a history of a slipped capital femoral epiphysis. The capitis in these patients is displaced posteriorly, resulting in a prominent anterior femoral neck and decreased hip internal rotation. Pincer impingement is associated with a deep acetabulum, such as protrusion acetabula and acetabular retroversion. A patient who underwent a _periacetabular osteotomy can develop a more retroverted acetabulum as well._

This patient likely is experiencing failure of the UKA secondary to poor patient selection. In this young, heavy man, the component likely loosened due to the ongoing varus alignment of the knee and his elevated
weight. Despite this likely scenario, the next step is determining whether an infection is the cause of his pain. Prior to obtaining an aspiration, the surgeon can order ESR and CRP studies to determine whether aspiration is warranted. If the laboratory studies are unremarkable, the surgeon likely can forgo the
aspiration and proceed to a revision TKA with possible augments on standby.