AAOS & ABOS Sports Medicine MCQs (Set 4): Knee Ligament & Meniscal Injuries | Board Review

Spondylolysis may develop as a stress fracture resulting from repetitive hyperextension during athletic activities. In young people, the pars interarticularis is thin, the neural arch has not yet reached maximum strength, and the intravertebral disk is less resistant to shear. While clinical symptoms may lead to the suspicion of spondylolysis, radiographic confirmation may be difficult in early cases. Plain radiographs may be negative initially, and the plain MRI scan may not offer good visualization of the pars. A bone scan with SPECT is very sensitive initially. CT scans with regular axial and reverse-gantry angled cuts may help determine the type of fracture and the course of treatment. Congeni J, McCulloch J, Swanson K: Lumbar spondylolysis: A study of natural progression in athletes. Am J Sports Med 1997;25:248-253.

Because the patient has failed to respond to appropriate nonsurgical management and imaging studies are normal, the use of arthroscopy not only aids in the diagnosis of chronic ankle pain, but is also helpful in its treatment. In patients with this condition, typical findings include synovitis in the lateral gutter and fibrosis along the talofibular articulation; syndesmosis chondromalacia of the talus and ankle also may be found. In patients with anterior soft-tissue impingement, approximately 84% who have a poor response to nonsurgical management will have a good to excellent response after arthroscopic synovectomy and debridement. Ferkel RD, Fasulo GJ: Arthroscopic treatment of ankle injuries. Orthop Clin North Am 1994;25:17-32.

While the patellar tendon ligament is considered by many to be the tissue of choice for ACL reconstruction, more recent studies have shown that the quadruple semitendinosus and gracilis tendon graft has the greatest stiffness and offers the highest maximum load to failure. Hamner DL, Brown CH Jr, Steiner ME, Hecker AT, Hayes WC: Hamstring tendon grafts for reconstruction of the anterior cruciate ligament: Biomechanical evaluation of the use of multiple strands and tensioning techniques. J Bone Joint Surg Am 1999;81:549-557. Cooper DE, Deng XH, Burstein AL, Warren RF: The strength of the central third patellar tendon graft: A biomechanical study. Am J Sports Med 1993;21:8l8-823. Brown CH Jr, Steiner ME, Carson EW: The use of hamstring tendons for anterior cruciate ligament reconstruction: Technique and results. Clin Sports Med 1993;12:723-756.

Creatine is currently used as a nutritional supplement in an attempt to enhance athletic performance. The physiologic basis for its use is based on its conversion by CK to PCr, which acts as an energy reservoir in muscle cells for the production of ATP. A number of studies that examined the effect of creatine supplementation on performance concluded that while creatine does not increase peak force production, it can increase the amount of work done in the first few anaerobic short duration, maximal effort trials. The mechanism for this enhancement of work is unknown, but it is most likely secondary to the increase in the available PCr pool. Greenhaff PL: Creatine and its application as an ergogenic aid. Int J Sport Nutr 1995;5:S100-S110. Greenhaff PL, Casey A, Short AH, Harris R, Soderlund K, Hultman E: Influence of oral creatine supplementation on muscle torque during repeated bouts of maximal voluntary exercise in man. Clin Sci 1993;84:565-571. Trump ME, Heigenhauser GJ, Putman CT, Spriet LL: Importance of muscle phosphocreatine during intermittent maximal cycling. J Appl Physiol 1996;80:1574-1580.

The avulsed fragment represents the origin of the rectus femoris from the anterior inferior iliac spine and the brim of the acetabulum. Avulsion of the anterior inferior iliac spine is much less common than avulsion of the anterior superior iliac spine with its origin of the sartorius. The origin of the gluteus minimus is from the outer cortex of the iliac wing and has not been reported as a source of bony avulsion. The hip capsule is composed of the ischiofemoral and pubofemoral ligaments, in addition to the iliofemoral ligament. The pelvic attachment of the ischiofemoral ligament is from the ischial part of the acetabulum posteriorly, while the pubofemoral ligament attaches to the pubic portion inferiorly. Technically, ligaments do not have origins and insertions as muscle tendon groups do, but have attachment sites. Metzmaker JN, Pappas AM: Avulsion fractures of the pelvis. Am J Sports Med 1985;13:349-358.

Numerous experimental studies have shown that vertical suture techniques are superior to all of the other noted methods. In fact, vertical sutures have been shown to be twice as strong as several of these techniques. DeHaven KE: Meniscus repair. Am J Sports Med 1999;27:242-250. Dervin GF, Downing KJ, Keene GC, McBride DG: Failure strengths of suture versus biodegradable arrow for meniscal repair: An in vitro study. Arthroscopy 1997;13:296-300.

Tibial tubercle avulsion is an injury of the adolescent knee that most often occurs just before the end of growth. The fracture usually occurs with jumping, either at push-off or landing. This patient has a type III injury. In type III injuries, the articular surface is disrupted, and meniscal injury and compartment syndrome can occur. Open reduction is the treatment of choice, and anterior fasciotomy should be considered prophylactically at the time of surgery. Although the fracture heals with an anterior epiphysiodesis of the proximal tibia, little growth remains in this patient and no special handling of the physis is warranted. Ogden JA, Tross RB, Murphy MJ: Fractures of the tibial tuberosity in adolescents. J Bone Joint Surg Am 1980;62:205-215.

Posterior sternoclavicular dislocations require rapid treatment because of the proximity of major neurovascular structures and the airway. Initial management should consist of closed reduction under general anesthesia in the operating room with a chest surgeon available. A successful closed reduction is usually stable. Internal fixation of sternoclavicular injuries should be avoided because of the likelihood of hardware migration and possible injury to the mediastinal structures. If closed reduction is unsuccessful, open reduction is indicated. Treatment following reduction of the sternoclavicular joint includes the application of a figure-of-8 splint and a sling for 6 weeks, followed by stretching and strengthening exercises. Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont IL, American Academy of Orthopaedic Surgeons, 1999, pp 287-297.

The figure shows the anterolateral portal for elbow arthroscopy, and injury to the radial nerve has been reported in conjunction with this portal site. Studies have shown that closer proximity to the radial nerve is associated with more distal portal sites. The lateral and posterior antebrachial cutaneous nerves are both at less risk of injury. The ulnar and median nerves are both fairly remote to this location. Field LD, Altchek DW, Warren RF, O'Brien SJ, Skyhar MJ, Wickiewicz TL: Arthroscopic anatomy of the lateral elbow: A comparison of three portals. Arthroscopy 1994;10:602-607. Papilion JD, Neff RS, Shall LM: Compression neuropathy of the radial nerve as a complication of elbow arthroscopy: A case report and review of the literature. Arthroscopy 1988;4:284-286.

Patients with chronic ACL-deficient knees typically have lower than normal net quadriceps activity during the middle portion of the stance phase; the net moment about the knee reverses from one that demands quadriceps activity to one that demands increased hamstring activity. This type of gait is termed "quadriceps avoidance." This avoidance is believed to be a functional adaptation to reduce anterior tibial translation, and it is most prevalent as the knee moves from 45 degrees of flexion toward full extension, the arc of motion through which the ACL is most responsible for stability. Hurwitz DE, Andriacchi TP, Bush-Joseph CA, Bach BR Jr: Functional adaptations in patients with ACL-deficient knees. Exerc Sport Sci Rev 1997;25:1-20. Andriacchi TP, Birac D: Functional testing in the anterior cruciate ligament-deficient knee. Clin Orthop 1993;288:40-47.

When the arm is adducted, the superior structures, including the superior glenohumeral ligament, are responsible in limiting the inferior translation. With the arm abducted, the inferior glenohumeral ligament complex is responsible for limiting inferior subluxation. Rotator cuff activity can actually depress the humeral head and does not play a role in preventing inferior subluxation. The long head of the biceps and the posterior glenohumeral ligament do not play a role in protecting the shoulder from inferior instability. Warner JJ, Deng XH, Warren RF, Torzilli PA: Static capsuloligamentous restraints to superior-inferior translation of the glenohumeral joint. Am J Sports Med 1992;20:675-685.

Sodium deficiency is the cause of heat cramps. It is the principle electrolyte of sweat and is readily lost during training, especially in warmer temperatures. The condition can be avoided by adding extra table salt to food and maintaining good hydration before and after sports activities. Salt tablets are to be avoided when a patient has heat cramps because the high soluble load will cause gastric irritation. Bergeron MF, Armstrong LE, Maresh CM: Fluid and electrolyte losses during tennis in the heat. Clin Sports Med 1995;14:23-32.

The patient has a posterior dislocation. The radiograph reveals marked internal rotation, but fails to show whether the humeral head is posteriorly displaced. Therefore, an axillary radiograph should be obtained to help confirm the diagnosis. Transverse view CT or MRI scans also may be useful. The other studies will not help confirm the diagnosis. In addition to a direct posterior blow, a shoulder dislocation may be caused by a seizure disorder or electrocution. Bloom MH, Obata WG: Diagnosis of posterior dislocation of the shoulder with the use of Velpeau axillary and angle-up roentgenographic views. J Bone Joint Surg Am 1967;49:943-949.

The patient has a pectoralis major rupture, an injury that occurs most commonly during weight lifting. Grade III injuries represent complete tears of either the musculotendinous junction or an avulsion of the tendon from the humerus, the most common injury site. Examination will most likely reveal ecchymoses and swelling in the proximal arm and axilla, and strength testing will show weakness with internal rotation and in adduction and forward flexion. Axillary webbing, caused by a more defined inferior margin of the anterior deltoid as the result of rupture of the pectoralis, can be seen as the swelling diminishes. Surgical repair is the treatment of choice for complete ruptures. Nonsurgical treatment is associated with significant losses in adduction, flexion, internal rotation, strength, and peak torque. The pectoralis major originates from the proximal clavicle and the border of the sternum, including ribs two through six. The pectoralis major inserts (rather than originates) on the humerus. The coracoid process is the insertion site for the pectoralis minor, as well as the origin for the conjoined tendon. The pectoralis major has no attachment or origin from the scapula. The anterior deltoid originates from the lateral one third of the clavicle and the anterior acromion. Miller MD, Johnson DL, Fu FH, Thaete FL, Blanc RO: Rupture of the pectoralis major muscle in a collegiate football player: Use of magnetic resonance imaging in early diagnosis. Am J Sports Med 1993;21:475-477.

The radiographs show a posterior glenoid osteophyte, often termed a "thrower's exostosis." These exostoses are best visualized on the Stryker notch view and may be missed on other more standard radiographic views of the shoulder. CT and MRI scans may be used, but usually add little information to the radiographic findings. Arthroscopic examination of patients with this condition commonly reveals undersurface tearing of the rotator cuff and posterior labrum. Treatment of this condition remains somewhat controversial, with avocation of both nonsurgical and surgical techniques. Meister K, Andrews JR, Batts J, Wilk K, Baumgarten T, Baumgartner T: Symptomatic thrower's exostosis: Arthroscopic evaluation and treatment. Am J Sports Med 1999;27:133-136. Ferrari JD, Ferrari DA, Coumas J, Pappas AM: Posterior ossification of the shoulder: The Bennett lesion. Etiology, diagnosis, and treatment. Am J Sports Med 1994;22:171-176.

The adult menisci are considered to be relatively avascular structures, with the peripheral blood supply originating predominately from the lateral and medial genicular arteries. Branches of these vessels form the perimeniscal capillary plexus, which supplies the peripheral border throughout its attachment to the joint capsule. Vascular penetration studies have shown that 10% to 30% of the peripheral portion of the medial meniscus and 10% to 25% of the lateral meniscus are vascularized. Arnoczky SP, Warren RF: Microvasculature of the human meniscus. Am J Sports Med 1982;10:90-95.

The patient has synovial chondromatosis. The MRI scans show multiple small proscribed areas of signal intensity in the gutters and suprapatellar pouch, suggesting very small loose bodies. The arthroscopic view shows the classic appearance of multiple small chondral loose bodies. Synovial chondromatosis is a condition in which the synovium undergoes metaplasia, producing multiple chondral loose bodies that can subsequently ossify. The treatment of choice, removal of the loose bodies and arthroscopic synovectomy, results in a lower incidence of recurrence than other treatment methods. Coolican MR, Dandy DJ: Arthroscopic management of synovial chondromatosis of the knee: findings and results in 18 cases. J Bone Joint Surg Br 1989;71:498-500.

The history, physical examination, and radiographs indicate that the patellofemoral pain is most likely caused by excessive lateral patellar pressure and patellar maltracking. Because the radiographs reveal the lateral tilt of the patella and lateral subluxation, the treatment of choice is bilateral lateral releases with anteromedialization of the tibial tubercles. This procedure corrects not only the excessive lateral patellar pressure, but also the lateral subluxation. The use of patella-stabilizing braces or taping may provide temporary relief, but these implements are not well-tolerated and they will not change the underlying biomechanics of the knee. Simple lateral release is indicated for isolated lateral tilt, but it does not correct the lateral subluxation. The use of thermal capsular shrinkage for the medial retinaculum has not been proven to provide long-term correction of the deformity. Boden BP, Pearsall AW, Garrett We Jr, et al: Patellofemoral instability: Evaluation and management. J Am Acad Orthop Surg 1997;5:47-57.

The radiographs show tunnel enlargement, which is seen after ACL reconstruction, particularly with allografts. Occasionally, there will be formation of an associated subcutaneous pretibial cyst. It has been proposed that the tunnel enlargement and cyst are the result of incomplete incorporation of allograft tissues within the bone tunnels. There may be residual graft necrosis, allowing synovial fluid to be transmitted through the tunnel to collect in the pretibial area, manifesting as a synovial cyst. In the absence of cyst formation, the presence of tunnel enlargement does not appear to adversely affect the clinical outcome. Based on studies by Fahey and associates, continued tunnel expansion does not occur. Victoroff and associates report good results with curettage and bone grafting of the tibial tunnel if a pretibial cyst is present. Because this patient does not have a pretibial cyst, observation with activity modification is the preferred treatment. Fahey M, Indelicato PA: Bone tunnel enlargement after anterior cruciate ligament replacement. Am J Sports Med 1994;22:410-414.

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. Clanton TO, Ford JJ: Turf toe injury. Clin Sports Med 1994;13:731-741.

Consistent, long-term exercise training in older athletes has proven very beneficial in reversing both endurance and strength losses that traditionally have been seen with aging. This patient's program will lead to a significant increase in the strength, cross-sectional area, and capillary density of the trained muscles. No major changes in aerobic capacity are anticipated. Strength improvements of up to 5% per day, similar to those for younger athletes, have been identified in this population in one study. Kirkendall DT, Garrett WE Jr: The effects of aging and training on skeletal muscle. Am J Sports Med 1998;26:598-602.

The patient has a symptomatic os trigonum caused by impingement that occurs with maximal plantar flexion of the ankle in the demi-pointe or full-pointe position. Patients frequently report posterolateral pain localized behind the lateral malleolus that may be misinterpreted as a disorder of the peroneal tendon. Pain with passive plantar flexion (the plantar flexion sign) indicates posterior impingement, not a problem with the peroneal tendon. The symptoms are not characteristic of a stress fracture, nor do the radiographs show a stress fracture or an osteochondritis dissecans lesion. The os trigonum is modest in its dimensions. The incidence or magnitude of symptoms does not correlate with the size of the fragment. Large fragments may be asymptomatic, while small lesions may create significant symptoms. Marotta JJ, Micheli LJ: Os trigonum impingement in dancers. Am J Sports Med 1992;20:533-536.

The PCL is a nonisometric structure with nonuniform tension during knee motion, with maximum tension at 90 degrees of flexion. While the posteromedial PCL fibers have been found to be the most isometric, the anterolateral fibers represent the bulk of the ligament. Studies have suggested that anterior placement of the femoral tunnel is superior to placement in an isometric position. The anterolateral bundle tightens as the knee flexes; therefore, it is optimal to tension the graft at 90 degrees of flexion. Harner CD, Xerogeanes JW, Livesay GA, et al: The human posterior cruciate ligament complex: An interdisciplinary study. Ligament morphology and biomechanical evaluation. Am J Sports Med 1995;23:736-745.

The radiograph shows the correct tibial tunnel and anterior femoral tunnel; therefore, range of motion will most likely show loss of flexion. Brown CH Jr, Carson EW: Revision anterior cruciate ligament surgery. Clin Sports Med 1999;18:109-171.

Calcaneal apophysitis (Sever's disease) is a common cause of heel pain in children who are active in sports. The symptoms are most commonly bilateral and will often respond to a gastrocnemius-soleus complex stretching program. In addition, rest, anti-inflammatory drugs, and heel pads for the shoe may be prescribed. There is no effect on the long-term growth of the calcaneus. Micheli LJ, Ireland ML: Prevention and management of calcaneal apophysitis in children: An overuse syndrome. J Pediatr Orthop 1987;7:34-38.