5. Sports Medicine MCQs

Thirty-one patients who were unable to abduct the involved arm after reduction of a primary anterior dislocation of the glenohumeral joint were found to have a ruptured rotator cuff. In their series, the incidence of injury to the axillary nerve was 7.8% as compared with 100% for rupture of the rotator cuff.

The incidence of preimplantation positive cultures of musculoskeletal allografts used for anterior cruciate ligament reconstruction has varied between 4.8% and 13.3%. Interestingly, in none of the studies evaluating this issue did any of the patientsimplanted with a "contaminated" graft develop a clinical infection. The results of the current literature suggest that the treatment of low-virulence organisms is unnecessary if no evidence of clinical infection exists. Preimplantation cultures do not appear to correlate with clinical infection. Therefore, the routine culture of allograft tissue is not recommended.

DISCUSSIONMultiple studies have confirmed that CAM or pincer anatomy is commonly present in asymptomatic hips. According to a large systematic review, CAM deformities are present in approximately one-third of asymptomatic hips in young adults, and the proportion was higher than 50% in the subgroup of athletes.Ganz and associates proposed that femoral acetabular impingement is the root cause of osteoarthritis in the majority of nontraumatic, nondysplastic hips, and functional improvement with surgical correction of the deformity has been demonstrated. Despite the link between CAM deformity and hip osteoarthritis, a corresponding link between correction of the deformity and prevention of osteoarthritis has never been proven.Results of CAM deformity correction, typically including repair of the degenerative labral tear, are much poorer when there is significant joint space loss. A typical joint space cutoff of 2 mm or less is used to recommend against hip preservation surgery.

DISCUSSION: Randomized clinical trials comparing an early accelerated vs nonaccelerated rehabilitation have demonstrated no significant differences in long-term results. At 2 and 3 years postsurgically, there are no differences in laxity, number of graft failures, or KOOS scores.

A total shoulder arthroplasty (TSA) is indicated in the 72 year old male with debilitating shoulder pain and an intact rotator cuff on MRI. The other patient scenarios are examples of contraindications for TSA.A TSA involves replacement of the humeral head with a metal head and resurfacing of the glenoid to a cemented all-polyethylene surface. In order to achieve optimal results, patients must be selected carefully. Patients with an irreparable rotator cuff tear, non-functioning deltoid, inadequate glenoid bone stock and brachial plexopathy are poor candidates for TSA.Edwards et al. conducted a multicenter randomized controlled trial to compare TSA versus hemiarthroplasty in patients with primary osteoarthritis of the shoulder. They found that TSA provided better scores for pain, mobility, and activity than hemiarthroplasty at 2 year follow-up. Boileau et al. followed 45 consecutive patients who underwent reverse TSA ( rTSA) for cuff tear arthropathy (CTA), post-traumatic arthritis, and failure of revision arthroplasty. After a mean follow-up of 40 months, they found that the reverse prosthesis improved function and was able to restore active elevation in patients with incongruent cuff-deficient shoulders. They also found thatthe results were less predictable and complication and revision rates were higher in patients undergoing revision surgery as compared to those patients undergoing rTSA for CTA.Illustrations A and B show the preoperative and postoperative x-rays of a patient with characteristic OA of the glenohumeral joint that was treated with TSA.Incorrect Answers:Figure A is a glenoid CT 3D reconstruction of a 26-year-old accountant who has recurrent shoulder instability. His first dislocation occurred after a fall while skiing. He has now sustained his third dislocation, which was reduced in the emergency department prior to being sent to your office. What is the most appropriate definitive treatment?Immobilization in external rotation for 6 weeks Arthroscopic bony Bankart repairArthroscopic Remplissage procedureGlenoid augmentation using coracoid transfer Glenoid augmentation using tricortical iliac crest graftThis patient has recurrent shoulder instability with a small bony defect of the anterior glenoid and no previous surgery. The most appropriate definitive management in this patient would be arthroscopic bony Bankart repair.Older (>20 years old), recreational athletes with minor glenoid bone loss (<20 % of the glenoid surface area) may be treated with soft tissue stabilization procedures using suture anchors. Goals of this procedure include tightening and repairing the torn ligament and labrum to the glenoid.Younger, contact sports athletes with large glenoid defect (>20%) may require bony augmentation type of procedures.Lynch et al. review the clinical presentation, assessment and treatment algorithm for surgical management of bone loss associated with anterior shoulder instability. While defects larger than 25% of glenoid width should be managed with bony augmentation, they recommend soft-tissue stabilization in smaller defects.Balg et al. analyzed 131 patients following Bankart procedure and identified following risk factors for failure: age <=20, competitive participation in contact sports, shoulder hyperlaxity, Hill-Sachs on AP radiograph, glenoid bone loss of contour on AP radiograph.Using human cadaveric shoulders with various anterior glenoid defects sizes, The MOON Shoulder Group compared radiography, MRI and CT to determine the most reliable imaging modality for predicting bone loss. Three-dimensional CT, followed by regular CT were the most reliable and reproducible imaging modalities for predicting glenoid bone loss.Figure A shows an en face sagittal 3D reconstruction of a glenoid with 10% surface area loss. Incorrect Answers:A latissimus dorsi tendon transfer is a well established procedure for treatment of massive irreparable posterosuperior rotator cuff tears. All of the following factors have been shown to result in worse clinical outcomes after a transfer EXCEPT?Nonsynergistic action of the transferred muscle Fatty atrophy of the supraspinatus and infraspinatus Deficiency of the subscapularisAbsence of the coracoacromial ligament Deltoid weaknessA latissimus dorsi tendon transfer can be utilized in patients with a massive, irreperable rotator cuff tear involving the supraspinatus and infraspinatus. It has been reported to relieve pain and improve function in a carefully selected patient population. Those patients with deficiency of the deltoid or subscapularis, nonsynergistic muscle action after transfer, or fatty infiltration of the posterosuperior cuff have worse clinical outcomes. Absence of the CA ligament may allow anterosuperior escape in RC deficient shoulders but has not been shown to lead to worse outcomes after a tendon transfer.The paper by Warner, et. al demonstrated that poor tendon quality, stage 3/4 muscle fatty degeneration, and detachment of the deltoid insertion each had a statistically significant effect on the Constant score noting that salvage reconstruction of a previous cuff repair had more limited gains as compared to primary. The reference by Ianotti, et. al showed that synchronous in-phase contraction of the transferred latissimus dorsi is associated with a better clinical result while improved preoperative shoulder function and general strength also positively influence the clinical result.An active 68-year-old woman undergoes an uncomplicated rotator cuff repair with a double-row construct using biocomposite knotless anchors. At her two month follow up, she is noted to have increased shoulder pain, weakness and limited motion. Imaging reveals failure of the rotator cuff repair. What is the most likely mechanism of failure?Anchor fatigue and breakage Anchor pull out from boneSuture rupture secondary to anchor eyelet abrasion Suture pull out from the repaired tissueInfectionRotator cuff repair (RCR) failure most commonly occurs from a failure of the repaired tissue to heal with suture anchor pull out from the repaired tissue.The overall complication rate of arthroscopic RCR is roughly 10%. Failed RCR most commonly results from failure to heal (19-94%) secondary to poor rotator cuff tissue, insufficient vascularity or poor bone quality. Other causes of RCR failure include surgical complications (deltoid disruption, infection, foreign body reaction, stiffness, neurologic injury), diagnostic errors (missed lesions of the rotator interval, long head of biceps or subscapularis tear), and technical errors (excessive tension due to lack of proper tissue mobilization, anchor pull out secondary to improper anchor placement).George et al evaluated the causes of failed RCR and results of revision RCR. While results of revision RCR are inferior to primary RCR, arthroscopic repair yields > 60% good or excellent results. Risk factors for poor results following revision RCR include poor tissue quality, detachment of the deltoid origin and multiple previous surgeries.Diduch et al reviewed the design and composition of various anchors used in arthroscopic shoulder surgery. Current advancements in the field include highstrength polyethylene sutures, new biocompatible anchor materials (PEEK, biocomposite) and modified designs including knotless systems. With improved strength of the current anchors and repair constructs, the most common mode of arthroscopic RCR failure is now related to tissue failure occurring at the tissue-anchor interface.Cole et al discussed the different primary rotator cuff repair constructs, including single row, double row, transosseous and transosseous equivalent. The authors concluded that construct selection depends on tear acuity, size and tissue quality. For acute tears < 12mm in anteroposterior length, singlerow configuration likely has sufficient strength to maintain the repair and promote healing. For more chronic tears, poor tissue quality, or tears > 1215 mm in the anteroposterior dimension, the authors recommend double-row or transosseous-equivalent repair to better restore the anatomic footprint and provide optimal mechanical stability to achieve healing. Illustration A is an algorithm from George et al detailing the decision-making process when considering revision RCR for a symptomatic failed RCR.Incorrect ResponsesBiocomposite anchors exhibit high load-to-failure and result in fatigue failure less commonly than metal anchors.A 32-year-old cross-training athlete awakens with severe left neck and shoulder pain after a day of intense upper body training. Aside from a recent viral illness, he is otherwise healthy. His pain improves, but two weeks later he notes significant left shoulder weakness. Examination reveals weakness of shoulder abduction, forward elevation and external rotation with the arm at his side. Radiographs are normal. Electromyography demonstrates 2+ positive sharp waves and fibrillations. Sensory nerve conduction studies show reduced amplitudes. MRI of the brain, cervical spine and shoulder are shown in Figures A-D, respectively. Which of the following is true of his prognosis?Decompression will result in improved muscle strength and function.The patient can expect a gradual return of muscle strength without long term functional deficits. Immunomodulators may decrease the number and severity of his relapses. 4 . Arthroscopic repair will result in the best functional outcomes given the patient's high activity level.

Discussion: The MR images reveal a large cystic medial talar dome osteochondral lesion (OCL) in a patient who has failed nonsurgical treatment. Ankle fusion is inappropriate because the patient has an otherwise normal ankle. Arthroscopic debridement and drilling are appropriate for smaller (< 1.5 cm sq) noncystic lesions. Retrograde drilling and bone grafting is an option in the treatment of cystic OCL if the cartilage surface is intact; however, intraoperative arthroscopy images show that this patient's cartilage surface is unstable. Osteochondral allografts and autografts are effective in the treatment of large cystic talar dome OCLs but are not appropriate for the initial surgical treatment of smaller lesions like this one.

DISCUSSION: Disruption of the extensor mechanism is a rare but devastating complication of knee arthroplasty. Primary repair is associated with a high rate of failure. The results associated with using an extensor mechanism allograft are still variable overall, but the literature on the subject supports tensioning of the allograft in full extension. In studies conducted by Burnett and associates and Nazarian and Booth, the patellar remnant is excised. The use of a fresh-frozen nonirradiated allograft is recommended, and patellar resurfacing of the insensate patella is unnecessary and potentially weakens the allograft.

Subscapularis rupture is most likely, given weakness with the lift-off test. The injury is usually caused by either forceful hyperextension or external rotation of the adducted arm. Patients will complain of anterior shoulder pain and weakness of the arm when used above and below shoulder level. SLAP lesions usually occur with a fall onto an outstretched arm in abduction and slight forward flexion. No mention was made of shoulder instability or deltoid weakness.

DISCUSSIONProximal tibial osteotomy is the most appropriate intervention to correct varus malalignment and to decrease stress on the ACL. In some cases, proximal tibial osteotomy alone may address both pain and instability, but, if instability persists, particularly in the setting in which instability can be dangerous, subsequent ACL reconstruction can further stabilize the knee with less stress on the graft after correction of malalignment. Varus alignment places increased stress on the native or reconstructed ACL. ACL reconstruction should only be performed at the same time as or following proximal tibial osteotomy to correct alignment in the setting of varus malalignment. It is not appropriate to perform ACL reconstruction prior to proximal tibial osteotomy in this setting. Distal femoral osteotomy is not indicated to correct varus malalignment. Varus alignment places increased stress on the native or reconstructed ACL, and ACL reconstruction alone is not indicated for this patient.

A failed bony Bankart repair with multiple dislocations can further erode the anteroinferior glenoid, changing the sagittal morphology of the glenoid into an “inverted pear.” Quantitative bone loss is best evaluated by CT scan with 3-D reconstructions and subtraction of the humeral head. Bone loss >30% necessitates glenoid augmentation with either a Latarjet procedure or iliac crest bone grafting. A revision arthroscopic or open Bankart repair with capsular shift or remplissage do not address bone loss. The Latarjet procedure can effectively restore stability with glenoid bone loss and after failed stabilizing procedures.

The patient has a partial articular supraspinatus tendon avulsion (PASTA) lesion. Outcome studies suggest that articular-sided tears of this magnitude do well with arthroscopic decompression and debridement alone. Determination of lesion thickness is important in recommending treatment, and may be done with a variety of methods. Tears that involve exposure of less than 5 mm of the rotator cuff footprint likely measure less than half of the tendon thickness. In the absence of other associated pathology, bicipital tenotomy or synovectomy would be unnecessary. Completion of the tear or transtendinous repair would be considered for lesions of greater than 50% thickness.

The patient has a cyclops lesion. This is a nodule of fibroproliferative tissue that originates from either drilling debris from the tibial tunnel or remnants of the ACL stump; more rarely it is the result of broken graft fibers. The treatment of choice is excision of the nodule and, if needed, additional notchplasty. Marked improvements in function and symptoms have been noted after removal of the extension block and resumption of a rehabilitation program.

Medial dislocation of the biceps tendon in the shoulder is commonly associated with subscapularis tendon tears. Although type II SLAP tears can result in bicipital instability, type I SLAP lesions do not. Congenitally shallow grooves and tears of the transverse ligaments usually do not lead to dislocation of the biceps tendon. Supraspinatus tendon tears are associated with long head of the biceps tendon ruptures but do not cause biceps tendon dislocations.

This clinical scenario describes a patient with FAI attributable to pincer (acetabular) deformity. This form of FAI, which involves prominence of the anterosuperior acetabular lip, may be more common among women. Decreased range of motion and pain occur secondary to the abutment of the femoral head against the acetabular labrum and rim. Hip flexion, combined with adduction and internal rotation, recreates this contact and causes pain, but CAM or pincer etiology remains unknown. The differential diagnosis of hip pain in a young athlete includes femoral neck stress reaction/fracture, sacroiliac arthritis, intra-articular loose body, trochanteric bursitis, osteitis pubis, and hernia. No information presented in this scenario suggests any of these causes. Diagnosis of FAI is best performed via MR imaging, with an arthrogram increasing the sensitivity and specificity for labral pathology. Ultrasonography may be useful in the diagnosis of dysplasia or for dynamic assessment of a snapping hip, but ultrasonography is not commonly used to diagnose labral pathology. Although concomitant chondral lesions of the femoral head are uncommon, the forced leverage of the anterosuperior femoral neck upon the anterior acetabulum may result in a “contra-coup” chondral injury on the posteroinferior acetabulum. This is the most common location of chondral lesions in this scenario. Without bony resection to prevent further impingement, this patient will continue to experience symptoms. Because there is no evidence of femoral neck prominence (CAM lesion), there is no indication for osteoplasty of the femoral neck; resection of the pincer lesion is necessary. This will often require take-down of the labrum in this location. If possible, iatrogenic or traumatic labral tears should subsequently be repaired after pincer debridement because the labrum hasimportant functions for hip stability and maintenance of the suction seal of the joint.

Plate and screw fixation of allograft is associated with the highest incidence of union but also the highest prevalence of allograft fracture. Conversely, intramedullary fixation is associated with a higher incidence of nonunion but fewer fractures. Step-cut osteotomies are not associated with a higher incidence of union.

Retrieval studies of well-fixed bulk allografts reveal that the junction site heals with bridging external callus and there is persistence of callus perpendicular to the junction site. External callus is annealed to the surface of the allograft. There is very little penetration of the allograft and the bone graft is not remodeled. Direct osteonal penetration of the allograft with haversian remodeling defines primary bone healing seen in fractures, which does not occur with allografts. Fibrovascular tissue is seen early in the healing phase of the cancellous portion of the allografts.

Os acromiale represents a failure of fusion of the anterior acromial apophysis and has been reported in approximately 8% of the population. Patients with a symptomatic os acromiale often report impingement-type symptoms with pain over the superior acromion, especially with overhead activities or sleeping. When nonsurgical management is unsuccessful, surgical options include excision, open reduction and internal fixation, and arthroscopic decompression.

p.579: “The Putti-Platt procedure is contraindicated in multidirectional instability (AMBRI); tightening the front of the shoulder will only increase the likelihood of posterior instability. In traumatic instability (TUBS) the data suggest that such a procedure, which limits external rotation is not necessary if the Bankart lesion is solidly repaired.”p. 577: “A vigorous effort to stabilize the shoulder with exercises is particularly indicated in patients with multidirectional or posterior instability and in athletes requiring a completely normal or supranormal range of motion.”p. 989: “If the [swimmer] has symptoms of subluxation, a conservative program that strengthens the external rotators is warranted. Surgery is seldom indicated.”

The images illustrate a large unstable osteochondral lesion of the medial femoral condyle. Radiographs and MR images clearly show deep subchondral bone involvement. The appropriate choice of surgery is OCA transplantation, which is indicated for primary treatment of large cartilage lesions, osteochondral lesions, and salvage procedure from failed prior cartilage surgery. Correction of mechanical axis malalignment, ligamentous insufficiency, and meniscal deficiency should also be addressed. ACI alone or an arthroscopic microfracture procedure would not address the bone defect, leaving an uneven articular surface. Although an osteotomy may be a viable choice, a distal femoral varus osteotomy would increase the contact pressure in the medial compartment and worsen the situation. The histologic anatomy of articular cartilage is well described. The superficial layer or lamina splendens contains a small amount of proteoglycan with collagen fibrils arranged parallel to the articular surface. In contrast, the deep zone contains the largest-diameter collagen fibrils, oriented perpendicular to the joint surface, and the highestconcentration of proteoglycans.

If the graft becomes tighter with knee flexion, the femoral attachment is too proximal. This error is referred to as “high and tight,” meaning that a high or proximal femoral attachment produces a graft that is too tight with knee flexion. If graft tension increases with increasing knee flexion, the result is loss of knee flexion or graft failure, increased contact forces resulting in patella femoral chondrosis, and possibly medial subluxation.