AAOS & ABOS MCQs: Knee Ligament & Meniscal Injuries

Question 1

A 15-year-old diver has had persistent, activity-related low back pain for the past 2 months. He denies any history of trauma. Examination reveals that the pain is localized to the lumbosacral junction, and there are no radicular symptoms. The pain is worse with back extension. Neurologic examination is normal, as are AP, lateral, and oblique radiographs of the lumbosacral spine. Further evaluation should include

Explanation

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.

Question 2

A 23-year-old college basketball player reports persistent lateral ankle pain after sustaining an inversion injury 6 months ago. Examination reveals pain over the anterolateral ankle, absence of swelling, and no clinical instability. Management consisting of vigorous physical therapy fails to provide relief, and a intra-articular corticosteroid injection provides only temporary relief. Radiographs obtained at the time of injury and subsequent AP and varus stress views are normal. A recent MRI scan fails to show any abnormalities. Management should now include

Explanation

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.

Question 3

Which of the following tissues used for anterior cruciate ligament (ACL) reconstruction has the highest maximum load to failure?

Explanation

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.

Question 4

Creatine is currently being used by athletes as a dietary supplement in an attempt to enhance performance. What is the physiologic basis for its use?

Explanation

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.

Question 5

A 16-year-old high school football player sustains an injury to the left hip. The avulsed fragment identified by the arrow in Figure 34 represents the origin of which of the following structures?

Explanation

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.

Question 6

Which of the following methods of meniscal repair has the highest load to failure strength?

Explanation

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.

Question 7

Figure 35 shows the lateral radiograph of a 15-year-old basketball player who felt a dramatic pop in his knee when landing after a lay-up. The patient reports that he cannot bear weight on the injured extremity. Management should consist of

Explanation

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.

Question 8

A 52-year-old man has pain in the sternal area after landing on his right shoulder in a fall from his bicycle. In addition, he reports that he had difficulty swallowing and breathing immediately after the fall, but the symptoms resolved. A CT scan reveals a posterior sternoclavicular dislocation. Initial management should include

Explanation

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.

Question 9

What nerve is at greatest risk of harm from the portal shown in Figure 36?

Explanation

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.

Question 10

In the majority of patients with chronic anterior cruciate ligament (ACL)-deficient knees, analysis of the gait pattern during level walking will most likely reveal which of the following changes?

Explanation

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.

Question 11

Glenohumeral inferior stability in the adducted shoulder position is primarily a function of the

Explanation

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.

Question 12

A 20-year-old football player has repeated episodes of heat cramps during summer training sessions. A deficiency of what electrolyte is most responsible for heat cramps?

Explanation

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.

Question 13

Figure 37 shows the radiograph of a 23-year-old football player who sustained a blow to the anterior aspect of his shoulder. Examination reveals pain and limited rotation. He is unable to flex the arm above the shoulder. Management should include which of the following studies?

Explanation

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.

Question 14

A 21-year-old football player had severe pain and immediate swelling in the left anteromedial chest wall while bench pressing near maximal weights several days ago. Examination at the time of injury revealed a mass on the anteromedial chest wall. Follow-up examination now reveals decreased swelling, and axillary webbing is observed. The patient has weakness to adduction and forward flexion. The injured muscle originates from the

Explanation

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.

Question 15

A 24-year-old baseball pitcher reports pain over the posterior aspect of his shoulder that occurs only during throwing. He notes that the discomfort is greatest during the late cocking and early acceleration phases. Examination reveals localized tenderness with palpation over the external rotators and posterior glenoid. Radiographs are shown in Figures 38a through 38c. What is the most likely diagnosis?

Explanation

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.

Question 16

What percent of the adult human meniscus is vascularized?

Explanation

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.

Question 17

A 30-year-old man who participates in recreational sports reports the spontaneous onset of intermittent pain and swelling about the right knee. Examination reveals a 3+ effusion, with a range of motion of 10 degrees to 60 degrees. He has mild diffuse tenderness but no instability. MRI scans and an arthroscopic view are shown in Figures 39a through 39c. Management should consist of

Explanation

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.

Question 18

Figure 40 shows the plain radiograph of a 30-year-old woman who has had a long history of standing bilateral anterior knee pain and a sense of patellar instability without frank dislocation. Nonsurgical management consisting of anti-inflammatory drugs and physical therapy has failed to provide relief. Examination reveals full range of motion of both knees, with moderate patellofemoral crepitance. Patellar apprehension and patellar grind tests are positive. The Q-angle measures 20 degrees. Management should now consist of

Explanation

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.

Question 19

A 24-year-old runner who underwent an allograft reconstruction of the anterior cruciate ligament (ACL) 3 years ago now reports anterior knee pain. Examination reveals no swelling or effusion, and the patient has full motion. A Lachman test and a pivot-shift test are negative. Palpation reveals tenderness on the patellar tendon and at the inferior pole of the patella. AP and lateral radiographs are shown in Figures 41a and 41b. Management should consist of

Explanation

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.

Question 20

What is the most common mechanism of injury that produces turf toe?

Explanation

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.

Question 21

A 68-year-old man embarks on a 24-week strength training program. He trains at 80% of his single repetition maximum for both the upper and lower extremities. Which of the following changes can be anticipated?

Explanation

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.

Question 22

A 26-year-old ballet dancer reports posterolateral ankle pain, especially with maximal plantar flexion. Examination reveals maximal tenderness just posterior to the lateral malleolus, and symptoms are heightened with forced passive plantar flexion. Radiographs are shown in Figures 42a and 42b. What is the most likely cause of the patient's symptoms?

Explanation

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.

Question 23

A 23-year-old soccer player sustains a grade III complete posterior cruciate ligament (PCL) tear after colliding with another player. In reconstructing the PCL, it is optimal to reconstruct the

Explanation

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.

Question 24

Figure 43 shows the lateral radiograph of a patient who underwent anterior cruciate ligament reconstruction. Based on the tunnel placement shown in the radiograph, evaluation of postoperative knee range of motion will most likely show

Explanation

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.

Question 25

A 10-year-old soccer player has bilateral heel pain and reports that the pain is worse during and immediately after sports. Examination reveals that the calcaneal tuberosities are painful to palpation bilaterally. What is the most likely diagnosis?

Explanation

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.

Question 26

A 10-year-old male Tanner stage 1 soccer player sustains a complete anterior cruciate ligament (ACL) tear. Which of the following surgical techniques minimizes the risk of iatrogenic growth arrest in this patient?

Explanation

In a Tanner stage 1 patient with significant remaining growth, an all-epiphyseal or physeal-sparing extra-articular reconstruction minimizes the risk of physeal arrest. Transphyseal techniques carry a higher risk of growth disturbance in prepubescent children.

Question 27

A 25-year-old male sustains an anterior knee dislocation. After closed reduction in the emergency department, his foot is warm with palpable dorsalis pedis pulses. His ankle-brachial index (ABI) is 0.8. What is the most appropriate next step in management?

Explanation

An ABI less than 0.9 after a knee dislocation is a strong indicator of an arterial injury. A CT angiogram is indicated to definitively evaluate for popliteal artery damage, which requires emergent surgical intervention if confirmed.

Question 28

A 45-year-old female experiences a popping sensation in her posterior knee while descending stairs. MRI demonstrates a complete medial meniscus posterior root tear. Biomechanically, this injury is most equivalent to which of the following conditions?

Explanation

A medial meniscus posterior root tear disrupts the circumferential hoop stresses of the meniscus. Biomechanically, this results in altered load transmission equivalent to a total meniscectomy, leading to rapid articular cartilage wear.

Question 29

A 22-year-old male presents with a knee injury after a tackling collision. The dial test demonstrates 15 degrees of increased external rotation at 30 degrees of knee flexion compared to the contralateral side, but symmetric external rotation at 90 degrees. This finding indicates an isolated injury to which structure?

Explanation

An increase of >10 degrees of external rotation at 30 degrees of flexion, with symmetric rotation at 90 degrees, indicates an isolated posterolateral corner (PLC) injury. If external rotation is increased at both 30 and 90 degrees, it suggests a combined PCL and PLC injury.

Question 30

Which type of medial collateral ligament (MCL) tear has the lowest intrinsic healing potential and most frequently requires surgical repair if conservative management fails?

Explanation

Distal tibial MCL avulsions have a poor intrinsic healing potential because the torn end often displaces superficial to the pes anserinus tendons, creating a Stener-like lesion. These injuries frequently require surgical repair, whereas proximal and mid-substance tears generally heal well nonoperatively.

Question 31

During an ACL reconstruction, arthroscopic evaluation of the posteromedial compartment reveals a longitudinal tear at the meniscocapsular junction of the posterior horn of the medial meniscus. This specific pathology is commonly referred to as a:

Explanation

A ramp lesion is a longitudinal tear of the peripheral meniscocapsular attachment of the posterior horn of the medial meniscus. It is highly associated with ACL tears and often requires posteromedial portal visualization for accurate diagnosis and repair.

Question 32

A 6-year-old child presents with a painless snapping knee. MRI demonstrates a lateral meniscus covering the entire tibial plateau. Arthroscopy reveals hypermobility of the posterior horn with an absent coronary ligament. Which discoid meniscus variant is this?

Explanation

The Wrisberg variant of a discoid lateral meniscus lacks normal posterior meniscotibial (coronary) attachments. The meniscus is attached posteriorly only by the meniscofemoral ligament of Wrisberg, leading to hypermobility and a symptomatic snapping knee in young children.

Question 33

During a double-bundle posterior cruciate ligament (PCL) reconstruction, the anterolateral bundle is biomechanically optimized when tensioned and fixed at what angle of knee flexion?

Explanation

The PCL consists of a larger anterolateral bundle and a smaller posteromedial bundle. During double-bundle reconstruction, the anterolateral bundle is typically tensioned and fixed at 90 degrees of flexion, while the posteromedial bundle is tensioned in extension.

Question 34

A 22-year-old athlete presents with recurrent instability 1 year after an ACL reconstruction. Radiographs reveal that the femoral tunnel was placed vertically at the 12 o'clock position in the intercondylar notch. What is the most likely clinical consequence of this tunnel malposition?

Explanation

A vertically placed femoral tunnel in ACL reconstruction controls sagittal plane translation but fails to adequately restore rotational stability. Clinically, this manifests as a persistent positive pivot shift test despite a negative Lachman test.

Question 35

A 30-year-old runner presents with a palpable, tender mass along the lateral joint line of the knee. MRI shows a multiloculated cystic structure associated with the lateral meniscus. This condition is most strongly associated with which type of meniscal tear?

Explanation

Meniscal cysts most commonly present on the lateral side of the knee and are strongly associated with horizontal cleavage tears. The tear acts as a one-way valve, allowing synovial fluid to accumulate and form a parameniscal cyst.

Question 36

A 24-year-old female athlete tears her anterior cruciate ligament (ACL) while playing soccer. During surgical reconstruction, the surgeon specifically aims to restore the posterolateral (PL) bundle. Biomechanically, restoring the PL bundle is most critical for controlling which of the following specific motions?

Explanation

The ACL consists of two main bundles: the anteromedial (AM) and posterolateral (PL). The PL bundle is tightest in near full extension and is the primary restraint to anterior translation and rotatory loads (pivot shift) in this position.

Question 37

A 32-year-old male undergoes a posterior cruciate ligament (PCL) reconstruction. The surgeon opts for an open tibial inlay technique rather than a traditional transtibial tunnel technique. The primary biomechanical and anatomical advantage of the inlay technique is:

Explanation

The tibial inlay technique avoids the acute angle, or 'killer turn,' present at the posterior exit of a transtibial tunnel. This acute angle can lead to graft attenuation, abrasion, and ultimate failure over time.

Question 38

A 55-year-old woman feels a pop in her posterior knee while deep squatting. MRI reveals an extruded medial meniscus and a complete defect at the posterior horn root. Biomechanically, an unrepaired complete medial meniscus posterior root tear is equivalent to:

Explanation

A complete meniscal root tear disrupts the meniscus's ability to convert axial loads into circumferential hoop stresses. Biomechanical studies have shown this is functionally and kinematically equivalent to a total meniscectomy, leading to accelerated cartilage wear.

Question 39

A 22-year-old football player sustains an isolated grade III medial collateral ligament (MCL) injury. Which specific location or characteristic of the MCL tear has the highest risk of failing nonoperative management?

Explanation

Distal (tibial) avulsions of the MCL have a poorer healing potential compared to femoral avulsions and can become entrapped above the pes anserinus (a Stener-like lesion), increasing the likelihood that nonoperative treatment will fail.

Question 40

A 27-year-old male presents with chronic knee instability. Physical examination demonstrates 15 degrees of increased external rotation at 30 degrees of knee flexion compared to the contralateral side. At 90 degrees of flexion, the external rotation is symmetric bilaterally. This Dial test finding indicates an isolated injury to which structure?

Explanation

The Dial test evaluates for posterolateral corner (PLC) and PCL injuries. Increased external rotation at 30 degrees only indicates an isolated PLC injury, while increased rotation at both 30 and 90 degrees indicates combined PLC and PCL injuries.

Question 41

Radiographs of a 19-year-old skier's acutely injured knee show a Segond fracture. This pathognomonic avulsion fracture of the anterolateral proximal tibia is highly associated with an anterior cruciate ligament (ACL) tear. Which specific structure avulses to cause this fracture?

Explanation

The Segond fracture is a cortical avulsion off the anterolateral proximal tibia. It represents an avulsion of the anterolateral capsular structures, specifically the anterolateral ligament (ALL), and is a radiographic marker of an ACL tear.

Question 42

During arthroscopy on a 20-year-old patient, a longitudinal tear of the medial meniscus is identified. The healing potential of a meniscal repair depends heavily on vascular supply. In an adult, what portion of the medial meniscus is considered well-vascularized (the red-red zone)?

Explanation

In an adult, only the peripheral 10% to 30% of the medial meniscus (and 10% to 25% of the lateral meniscus) is vascularized by the perimeniscal capillary plexus. Tears in this peripheral zone have the highest healing potential.

Question 43

A patient complains of a severe loss of terminal knee extension 4 months after an anterior cruciate ligament (ACL) reconstruction. A lateral radiograph in full extension shows the entire tibial tunnel is placed anterior to the Blumensaat line. This non-anatomic placement is most likely to result in:

Explanation

A tibial tunnel placed too anteriorly (anterior to the Blumensaat line on a fully extended lateral radiograph) causes the graft to impinge against the roof of the intercondylar notch during terminal extension, leading to loss of extension and potential graft failure.

Question 44

A 30-year-old male sustains a knee dislocation (KD-III) in a high-velocity accident. After closed reduction, distal pulses are palpable but the ankle-brachial index (ABI) is measured at 0.8. What is the most appropriate next step in management?

Explanation

In the setting of a knee dislocation, an Ankle-Brachial Index (ABI) less than 0.9 is indicative of a potential vascular injury and mandates advanced vascular imaging, most commonly a CT angiogram, to rule out a popliteal artery intimal tear or occlusion.

Question 45

A 29-year-old runner presents with a palpable, firm mass along the lateral joint line of the knee. MRI reveals a multiloculated parameniscal cyst. This finding is most strongly associated with which type of meniscal tear?

Explanation

Parameniscal cysts occur when joint fluid is pumped through a meniscal tear into the surrounding parameniscal soft tissues. They are most commonly associated with horizontal cleavage tears of the lateral meniscus.

Question 46

Surgical reconstruction of the posterolateral corner (PLC) of the knee aims to restore its three primary static stabilizers. These structures include the lateral collateral ligament, the popliteus tendon, and the:

Explanation

The three primary static stabilizers of the posterolateral corner (PLC) are the lateral collateral ligament (LCL), the popliteus tendon, and the popliteofibular ligament (PFL). Anatomical reconstruction techniques focus on restoring these specific structures.

Question 47

A 9-year-old boy (Tanner stage 1) sustains a mid-substance anterior cruciate ligament (ACL) tear and experiences recurrent instability. To minimize the risk of iatrogenic growth arrest, which surgical management is most appropriate?

Explanation

In a pre-pubescent child with significant growth remaining (Tanner stage 1), an all-epiphyseal (physeal-sparing) ACL reconstruction is recommended to avoid drilling across the open physes and thereby minimizing the risk of growth arrest or angular deformity.

Question 48

Following an anterior cruciate ligament (ACL) reconstruction using a hamstring autograft, the graft undergoes a biological process known as ligamentization. During this process, the graft is mechanically at its weakest during which postoperative timeframe?

Explanation

The ligamentization process consists of incorporation, necrosis/revascularization, and remodeling. The graft is mechanically weakest during the revascularization and necrosis phase, which typically occurs between 6 and 12 weeks postoperatively.

Question 49

The posterior cruciate ligament (PCL) consists of two functional bundles. What is the tensioning pattern of these bundles throughout the knee's range of motion?

Explanation

The PCL has a larger anterolateral (AL) bundle and a smaller posteromedial (PM) bundle. The AL bundle is taut in flexion, whereas the PM bundle is taut in extension.

Question 50

A 10-year-old girl presents with painless snapping in her lateral knee. MRI reveals a complete discoid lateral meniscus without any evidence of tearing. What is the most appropriate management for this patient?

Explanation

An asymptomatic (painless), intact discoid meniscus is an incidental finding and requires no surgical intervention. Observation and reassurance are the recommended treatments, as surgical intervention in asymptomatic patients increases the risk of early osteoarthritis.

Question 51

The posterior oblique ligament (POL) is a key static stabilizer of the posteromedial corner of the knee. The POL is most effective at resisting valgus stress and internal tibial rotation at what degree of knee flexion?

Explanation

The posterior oblique ligament (POL) tightens in extension. It acts as a primary restraint to internal rotation and provides significant resistance to valgus stress when the knee is in full extension (0 degrees).

Question 52

Proponents of double-bundle anterior cruciate ligament (ACL) reconstruction argue that it more accurately restores native knee kinematics compared to single-bundle reconstruction. Specifically, biomechanical studies suggest double-bundle reconstruction provides superior control of:

Explanation

Double-bundle ACL reconstruction anatomically reconstructs both the anteromedial and posterolateral bundles. The addition of the posterolateral bundle specifically provides superior control of rotatory laxity, manifested clinically by a reduction in the pivot-shift phenomenon.

Question 53

A 40-year-old male undergoes a subtotal medial meniscectomy for an irreparable bucket-handle tear. Biomechanically, the loss of the medial meniscus primarily leads to which of the following alterations in knee joint contact mechanics?

Explanation

Total or subtotal medial meniscectomy removes the structure responsible for load distribution, resulting in a 50% to 70% reduction in contact area. This geometrically concentrates the forces, leading to a 200% to 300% increase in peak contact stresses and accelerated articular cartilage wear.

Question 54

Female athletes demonstrate a significantly higher incidence of noncontact anterior cruciate ligament (ACL) injuries compared to males. Which of the following is an established intrinsic risk factor for ACL tears in the female athletic population?

Explanation

Established intrinsic risk factors for ACL tears in females include a narrow intercondylar notch, increased generalized laxity, an increased Q-angle, quad-dominant muscle activation (decreased hamstring-to-quad ratio), and landing from jumps with decreased knee and hip flexion (stiffer landing posture).

Question 55

During a traumatic knee dislocation, the popliteal artery is exceptionally vulnerable to traction injury due to its rigid tethering within the popliteal fossa. Proximally, it is tethered by the adductor hiatus. Distally, the artery is tightly anchored by which anatomical structure?

Explanation

The popliteal artery is relatively immobile because it is securely tethered proximally at the adductor hiatus (Hunter's canal) and distally by the tendinous arch of the soleus muscle. This rigid fixation makes it highly susceptible to stretch and intimal tearing during severe knee dislocations.

Question 56

A 12-year-old female soccer player with wide-open physes sustains a complete anterior cruciate ligament (ACL) rupture. She experiences recurrent instability despite bracing and physical therapy. When planning surgical reconstruction, which of the following techniques minimizes the risk of growth arrest and angular deformity?

Explanation

In skeletally immature patients with significant remaining growth, physeal-sparing techniques such as an iliotibial band extra-articular tenodesis (MacIntosh or modified Kocher) are preferred to avoid growth arrest. Transphyseal techniques crossing open physes carry a higher risk of angular deformity or limb length discrepancy.

Question 57

A 24-year-old professional football player sustains a direct blow to the proximal tibia with the knee flexed, resulting in a posterior cruciate ligament (PCL) injury. Which bundle of the PCL is the primary restraint to posterior tibial translation at 90 degrees of knee flexion?

Explanation

The PCL consists of two main bundles: the anterolateral (AL) and posteromedial (PM) bundles. The AL bundle is larger, tighter in flexion, and serves as the primary restraint to posterior translation at 90 degrees of flexion.

Question 58

A 30-year-old skier sustains a twisting injury to his knee. On physical examination, the dial test demonstrates 20 degrees of increased external rotation at 30 degrees of knee flexion compared to the contralateral side. At 90 degrees of flexion, the external rotation is symmetric to the normal knee. What is the most likely diagnosis?

Explanation

An increase in external rotation of more than 10 degrees at 30 degrees of flexion, but not at 90 degrees, indicates an isolated posterolateral corner (PLC) injury. If asymmetry is present at both 30 and 90 degrees, it indicates a combined PLC and PCL injury.

Question 59

A 22-year-old athlete presents with a locked knee after a deep squat. MRI reveals a "double PCL sign" on the sagittal T2-weighted sequence.

What is the most appropriate management for this pathology?

Explanation

The "double PCL sign" is highly specific for a bucket-handle tear of the medial meniscus, where the displaced meniscal fragment flips into the intercondylar notch parallel to the intact PCL. Management requires arthroscopy to either repair or excise the unstable meniscal fragment.

Question 60

When comparing bone-patellar tendon-bone (BPTB) autografts and hamstring autografts for primary ACL reconstruction, patients receiving a BPTB autograft have a statistically higher risk of which of the following postoperative complications?

Explanation

Multiple studies demonstrate that BPTB autografts are associated with a higher incidence of donor-site morbidity, specifically anterior knee pain and kneeling pain, compared to hamstring autografts. Rates of graft rupture and infection are not definitively higher for BPTB.

Question 61

An 18-year-old high school hockey player sustains an acute, isolated Grade III medial collateral ligament (MCL) tear during a game. Physical examination reveals gapping in 30 degrees of flexion with a firm endpoint in full extension. What is the most appropriate initial management?

Explanation

Isolated Grade III MCL injuries typically heal well with nonoperative management. A hinged knee brace allowing early range of motion, combined with functional rehabilitation, is the gold standard of treatment and promotes strong collagen healing.

Question 62

A 22-year-old football player sustains a direct blow to the proximal tibia while his knee is flexed. Exam shows a posterior sag sign and +2 posterior drawer at 90 degrees of flexion, but no varus/valgus instability. Dial test is symmetric at 30 and 90 degrees. What is the most appropriate initial management?

Explanation

Isolated Grade I and II PCL tears are managed non-operatively with a brace locked in extension (or a dynamic PCL brace) to prevent posterior tibial subluxation. Early hamstring strengthening is contraindicated as it exacerbates posterior translation.

Question 63

Biomechanical studies have demonstrated that a complete radial tear of the medial meniscus posterior root results in contact pressures most similar to which of the following conditions?

Explanation

A complete tear of the meniscal root disrupts hoop stresses, causing extrusion of the meniscus. Biomechanically, this results in tibiofemoral contact pressures equivalent to those seen after a total meniscectomy.

Question 64

A 28-year-old woman is 6 months status post anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone autograft. She complains of anterior knee pain and a painful clunk at terminal extension. She lacks 10 degrees of full extension compared to the contralateral knee. What is the most likely cause of her symptoms?

Explanation

A Cyclops lesion is a localized nodule of fibrovascular tissue anterior to the ACL graft, leading to a painful loss of terminal extension. It often presents with a clunk as the nodule impinges in the intercondylar notch during terminal extension.

Question 65

During clinical examination of a knee with a suspected multiligamentous injury, the dial test demonstrates 20 degrees of increased external rotation compared to the contralateral side at 30 degrees of knee flexion. At 90 degrees of knee flexion, the external rotation is symmetric to the normal side. This physical examination finding is most consistent with:

Explanation

An isolated posterolateral corner (PLC) injury results in increased external rotation at 30 degrees of flexion but not at 90 degrees. If external rotation is increased at both 30 and 90 degrees, it indicates a combined PCL and PLC injury.

Question 66

A 30-year-old skier sustains an acute grade III medial collateral ligament (MCL) tear at its tibial insertion. Which of the following factors is most strongly associated with failure of non-operative management for this specific injury pattern?

Explanation

Distal (tibial-sided) MCL tears can flip superficial to the pes anserinus tendons, creating a "Stener-like" lesion that prevents spontaneous healing. Proximal MCL tears typically heal well with non-operative bracing.

Question 67

When evaluating the vascular supply of the menisci for potential repair, the peripheral blood supply predominantly arises from which of the following arteries?

Explanation

The medial and lateral inferior genicular arteries provide the primary blood supply to the peripheral 10-30% of the menisci (the red-red zone) via the perimeniscal capillary plexus. The middle genicular artery primarily supplies the ACL and PCL.

Question 68

A 24-year-old male presents to the emergency department after a high-speed motorcycle accident. His knee is grossly unstable in multiple planes, and a knee dislocation is suspected. The Ankle-Brachial Index (ABI) is calculated to be 0.85. What is the most appropriate next step in management?

Explanation

An ABI < 0.90 is highly sensitive for vascular injury in the setting of a knee dislocation. CT angiography is the gold standard next step to precisely delineate the location and extent of the popliteal artery injury before surgery.

Question 69

A 12-year-old boy (Tanner stage II) sustains a midsubstance ACL rupture. He has significant growth remaining. Which of the following surgical techniques is most appropriate to minimize the risk of growth arrest or angular deformity?

Explanation

In a skeletally immature patient with significant growth remaining (Tanner stage I or II), physeal-sparing techniques like all-epiphyseal reconstruction or iliotibial band over-the-top procedures are indicated. Drilling large tunnels across open physes increases the risk of premature closure and deformity.

Question 70

The anterior cruciate ligament (ACL) consists of two main functional bundles. Which of the following best describes the biomechanical behavior of the anteromedial (AM) and posterolateral (PL) bundles during knee range of motion?

Explanation

The anteromedial (AM) bundle of the ACL is primarily tight in flexion and provides anterior-posterior stability. The posterolateral (PL) bundle is primarily tight in extension and provides critical rotational stability.

Question 71

A 32-year-old male presents for evaluation of a failed ACL reconstruction. Imaging reveals widening of the femoral and tibial bone tunnels, measuring 16 mm and 15 mm, respectively. What is the most appropriate surgical approach?

Explanation

When significant tunnel widening is present (typically > 14 mm), a two-stage revision is recommended. The first stage involves hardware removal and bone grafting of the tunnels, followed by a second stage for definitive ACL reconstruction once the grafts incorporate.

Question 72

A 10-year-old child presents with a painful clunking lateral knee. MRI demonstrates a Wrisberg variant of a discoid lateral meniscus. This specific variant is characterized by which of the following anatomical features?

Explanation

The Wrisberg variant of a discoid lateral meniscus lacks the normal posterior capsular attachments (coronary ligaments). Its only posterior attachment is the meniscofemoral ligament of Wrisberg, leading to extreme hypermobility and the classic snapping knee syndrome.

Question 73

An AP radiograph of a 22-year-old skier's acutely injured knee demonstrates an elliptic bony avulsion fragment just distal to the lateral tibial plateau. This finding is highly pathognomonic for an injury to which structure, and what associated major ligamentous tear is likely present?

Explanation

The Segond fracture is a cortical avulsion of the anterolateral capsule (specifically the anterolateral ligament) from the proximal lateral tibia. It is highly pathognomonic (up to 75-100% association) for an underlying anterior cruciate ligament (ACL) tear.

Question 74

During a medial patellofemoral ligament (MPFL) reconstruction for recurrent patellar instability, the surgeon uses fluoroscopy to identify the femoral attachment point (Schöttle's point). This radiographic landmark is located:

Explanation

Schöttle's point is an essential radiographic landmark for anatomical femoral MPFL graft placement. It lies just anterior to the posterior femoral cortical line and proximal to the most posterior point of Blumensaat's line.

Question 75

A surgeon is performing a PCL reconstruction and chooses an open tibial inlay technique over a transtibial tunnel technique. The primary biomechanical advantage of the tibial inlay technique is:

Explanation

The transtibial PCL reconstruction creates an acute angle (the "killer turn") at the posterior aperture of the tibial tunnel, which can cause graft abrasion and attenuation. The open tibial inlay technique secures the graft directly to the posterior tibia, bypassing this sharp angle.

Question 76

A 35-year-old runner presents with a palpable, firm mass on the lateral joint line of the knee. The mass fluctuates in size and is tender to palpation. MRI confirms a lateral parameniscal cyst. The most appropriate definitive surgical management involves:

Explanation

Parameniscal cysts are almost universally associated with horizontal cleavage tears of the adjacent meniscus. Effective treatment requires addressing the underlying pathology via arthroscopic partial meniscectomy and intra-articular decompression of the cyst.

Question 77

A 4-strand hamstring autograft used in anterior cruciate ligament (ACL) reconstruction has which of the following biomechanical characteristics compared to the native ACL?

Explanation

A quadruple-stranded hamstring graft has an ultimate load to failure of approximately 4090 N and a stiffness of 776 N/mm. Both of these values are significantly higher than those of the native ACL (2160 N and 242 N/mm, respectively).

Question 78

A 24-year-old football player sustains a direct blow to the anteromedial aspect of his knee. Examination shows a positive dial test with 15 degrees of increased external rotation at 30 degrees of knee flexion, but symmetric external rotation compared to the contralateral knee at 90 degrees. Which structure is most likely injured?

Explanation

Increased external rotation at 30 degrees of flexion with normal rotation at 90 degrees indicates an isolated posterolateral corner (PLC) injury. Combined PLC and PCL injuries demonstrate increased external rotation at both 30 and 90 degrees of knee flexion.

Question 79

A 55-year-old woman presents with acute medial knee pain after a deep squat. MRI reveals a medial meniscal extrusion of 4 mm and a hyperintense signal separating the posterior horn from its tibial attachment. What is the most appropriate management for an active patient with no significant osteoarthritis?

Explanation

Medial meniscus posterior root tears disrupt hoop stresses, resulting in meniscal extrusion and altered joint kinematics functionally equivalent to a total meniscectomy. Transtibial pull-out repair is indicated to restore mechanics and halt rapid progression to osteoarthritis.

Question 80

A 28-year-old skier sustains an isolated grade III medial collateral ligament (MCL) tear. MRI demonstrates an avulsion of the MCL from its distal tibial attachment with the torn end retracted superficial to the pes anserinus. What is the most appropriate treatment?

Explanation

Distal MCL avulsions with retraction over the pes anserinus create a "Stener-like" lesion of the knee that prevents anatomic healing. Unlike proximal MCL tears which often heal nonoperatively, these specific distal lesions require primary surgical repair.

Question 81

Six months following an uncomplicated bone-patellar tendon-bone ACL reconstruction, a patient complains of a painful "clunk" and an inability to achieve terminal knee extension. MRI shows a nodular mass anterior to the ACL graft. What surgical error is the most common cause of this complication?

Explanation

A cyclops lesion (localized anterior arthrofibrosis) causes loss of terminal extension and a painful clunk. It is strongly associated with an anteriorly placed tibial tunnel, leading to graft impingement in the intercondylar notch during extension.

Question 82

A 32-year-old male presents with a grossly deformed knee after a motorcycle crash. Following closed reduction of an anterior knee dislocation, his pedal pulses are palpable and symmetric. His Ankle-Brachial Index (ABI) is calculated as 0.85. What is the most appropriate next step in management?

Explanation

An ABI of less than 0.9 in the setting of a knee dislocation is highly suspicious for an occult vascular injury, even if pedal pulses are palpable. CT angiography is immediately indicated to rule out a popliteal artery intimal tear or occlusion.

Question 83

A 9-year-old boy (Tanner stage I) with widely open physes sustains a mid-substance ACL tear. His parents wish to proceed with surgical management due to recurrent instability episodes. Which surgical technique is most appropriate?

Explanation

In prepubescent patients with widely open physes (Tanner stage I), a physeal-sparing technique like the IT band extra-articular tenodesis or an all-epiphyseal reconstruction is recommended. Transphyseal techniques carry an unacceptably high risk of growth arrest or angular deformity in this age group.

Question 84

During an ACL reconstruction, a systematic arthroscopic evaluation is performed. Viewing from the anterolateral portal through the intercondylar notch reveals a tear at the meniscocapsular junction of the posterior horn of the medial meniscus. What is this specific lesion called?

Explanation

A meniscal "ramp" lesion is a tear at the peripheral meniscocapsular junction of the posterior horn of the medial meniscus. It is frequently associated with acute ACL tears and is best visualized through a posteromedial portal or via an intercondylar trans-notch view.

Question 85

To address residual anterolateral rotatory instability during an ACL reconstruction, an anterolateral ligament (ALL) reconstruction is planned. Which of the following describes the correct anatomic origin and insertion of the ALL?

Explanation

The anterolateral ligament (ALL) originates slightly posterior and proximal to the fibular collateral ligament (FCL) on the lateral femoral epicondyle. It inserts on the proximal anterolateral tibia, approximately midway between Gerdy's tubercle and the fibular head.

Question 86

A 21-year-old athlete complains of the knee "giving way" 1 year after an ACL reconstruction, despite having no new trauma. On physical exam, the Lachman test is negative, but the pivot-shift test is markedly positive. Radiographs reveal the femoral tunnel is positioned at the 12 o'clock position in the coronal plane. What is the primary cause of this clinical presentation?

Explanation

A vertical femoral tunnel (placed high in the intercondylar notch, near 12 o'clock) provides adequate anterior-posterior stability, resulting in a negative Lachman test. However, it fails to control rotational forces, leaving the patient with a residual positive pivot-shift test.

Question 87

When comparing the tibial inlay technique to the transtibial tunnel technique for posterior cruciate ligament (PCL) reconstruction, the tibial inlay technique specifically avoids which of the following biomechanical issues?

Explanation

The tibial inlay technique secures the bone block directly to the posterior tibial facet, avoiding the acute angle or "killer turn" at the proximal tibial aperture. This reduces the risk of graft abrasion and attenuation frequently seen in transtibial PCL reconstructions.

Question 88

A 24-year-old athlete reports persistent loss of terminal knee extension 6 months following an anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone autograft. Radiographs demonstrate that the tibial tunnel is positioned anterior to the Blumensaat line with the knee in full extension. What is the most likely cause of his restricted motion?

Explanation

A tibial tunnel placed too anteriorly results in graft impingement against the intercondylar roof (Blumensaat line) during extension. This typically presents with a loss of terminal extension, anterior knee pain, and recurrent effusions.

Question 89

A 48-year-old woman experiences a sudden "pop" in the posterior aspect of her knee while squatting. MRI reveals a posterior medial meniscal root tear with 4 mm of meniscal extrusion. Which of the following best describes the biomechanical consequence of this injury if left untreated?

Explanation

A posterior root tear of the medial meniscus disrupts the hoop stresses, rendering the meniscus functionally incompetent. This results in altered knee kinematics and contact pressures that are biomechanically equivalent to a total medial meniscectomy.

Question 90

A 26-year-old soccer player sustains a twisting injury to his knee. On examination, the dial test reveals 15 degrees of increased external rotation of the tibia at 30 degrees of knee flexion compared to the contralateral side. At 90 degrees of flexion, the side-to-side difference in external rotation is less than 5 degrees. Which of the following injuries is most likely present?

Explanation

The dial test evaluates for PLC and PCL injuries. Increased external rotation (>10 degrees compared to the normal knee) at 30 degrees of flexion only indicates an isolated PLC injury, whereas increased rotation at both 30 and 90 degrees indicates combined PLC and PCL injuries.

Question 91

A 31-year-old male is brought to the emergency department after sustaining a traumatic knee dislocation during a rugby match. The knee was reduced on the field. On examination, the foot is warm, but the dorsalis pedis and posterior tibial pulses are palpable but asymmetric compared to the uninjured limb. The ankle-brachial index (ABI) is 0.85. What is the most appropriate next step in management?

Explanation

An ankle-brachial index (ABI) of less than 0.90 or asymmetric pulses following a knee dislocation raises high suspicion for a popliteal artery injury. A CT angiogram is indicated to definitively evaluate the vascular status before proceeding with surgical intervention.

AAOS Orthopedic MCQs (Set 1): Kienbock's Disease & Wrist Disorders | 2026 Board Review

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

Key Takeaway

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

Chapter Index