This practice set contains high-yield board review questions covering key concepts in Knee Sports. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Question 1621
Topic: Knee Sports
A 16-year-old male with a history of systemic JIA is currently treated with Etanercept. He sustained an anterior cruciate ligament tear and is scheduled for reconstruction. What is the recommended perioperative management of his biologic medication?
Correct Answer & Explanation
. Withhold Etanercept for at least one to two dosing cycles prior to surgery
Explanation
Etanercept is a TNF-alpha inhibitor. To minimize the risk of postoperative infection, current guidelines recommend withholding biologic agents for one to two dosing intervals before an elective orthopedic surgery, resuming once wound healing is satisfactory.
Question 1622
Topic: Knee Sports
What is the primary pathophysiologic mechanism by which DEH causes joint pain and restricted range of motion?
Correct Answer & Explanation
. Intra-articular space occupation causing mechanical block and joint incongruity
Explanation
DEH produces an asymmetric, space-occupying cartilaginous mass within the joint. This leads directly to mechanical locking, joint incongruity, and resultant pain during motion.
Question 1623
Topic: Knee Sports
During a medial opening-wedge high tibial osteotomy (HTO), the surgeon aims to correct a varus deformity. If the osteotomy gap is opened disproportionately wider anteriorly than posteriorly, what is the most significant biomechanical consequence?
Correct Answer & Explanation
. Increased posterior tibial slope
Explanation
The normal proximal tibia has an inherent posterior slope. Opening the osteotomy wider anteriorly than posteriorly will increase the posterior tibial slope, which alters knee kinematics and places increased tension on the anterior cruciate ligament.
Question 1624
Topic: Knee Sports
A 9-year-old boy with poorly controlled JIA presents with a progressive unilateral knee deformity. The affected knee exhibits overgrowth and a fixed flexion contracture. Which phenomenon best explains the observed limb length discrepancy?
Correct Answer & Explanation
. Increased blood flow to the physes secondary to chronic synovitis
Explanation
Chronic synovitis in JIA causes intense local hyperemia. This increased regional blood supply stimulates the adjacent open physes, resulting in premature bone overgrowth and a limb length discrepancy.
Question 1625
Topic: Knee Sports
Which of the following statements regarding bioabsorbable screws is FALSE?
Correct Answer & Explanation
. Their strength typically exceeds that of metallic screws.
Explanation
Bioabsorbable screws are designed to degrade over time, eliminating the need for removal. They are indeed commonly used in soft tissue fixation (e.g., ACL reconstruction). However, their strength is generallylowerthan that of metallic screws, and they lose strength over time as they degrade. They can also cause inflammatory reactions (sterile effusions) and their degradation products can alter local pH. Therefore, the statement that their strength typically exceeds metallic screws is false.
Question 1626
Topic: Knee Sports
A 22-year-old male collegiate football player sustains a valgus and external rotation injury to his right knee. Physical examination reveals gross instability to valgus stress at 0 and 30 degrees of flexion, a positive Lachman test, and significant posterolateral rotatory instability (positive Dial test at both 30 and 90 degrees). Imaging confirms complete tears of the ACL, MCL, and injury to the posterolateral corner (PLC). What is the most appropriate initial surgical approach for this multi-ligamentous knee injury?
Correct Answer & Explanation
. Acute surgical repair or reconstruction of all injured ligaments (ACL, MCL, PLC) within 2-3 weeks of injury.
Explanation
This patient presents with a severe, multi-ligamentous knee injury involving the ACL, MCL, and PLC, along with significant rotatory instability. Such injuries, particularly those involving the PLC, are complex and lead to poor outcomes with non-operative management (E). Acute surgical intervention (within 2-3 weeks) to repair/reconstruct all damaged ligaments (D) is generally recommended. Delaying surgery for too long makes primary repair less feasible and increases the difficulty of reconstruction. ACL reconstruction alone (A) or MCL repair alone (B) will leave significant instability. Staged reconstruction (C) is often avoided if possible, as it can complicate rehabilitation and delay recovery, though sometimes necessary depending on swelling/patient factors. The current consensus generally favors addressing all significant instabilities simultaneously if conditions allow.
Question 1627
Topic: Knee Sports
A 34-year-old male competitive athlete sustains an acute knee injury during a soccer match. He reports immediate pain, swelling, and a 'pop'. Lachman test is positive with a soft endpoint, pivot shift test is positive, and there is a mild varus thrust with stress testing. MRI confirms a complete ACL rupture and a Grade III posterolateral corner (PLC) injury involving the fibular collateral ligament (FCL), popliteofibular ligament (PFL), and posterior capsule. What is the most appropriate acute surgical management strategy for this combined injury?
Correct Answer & Explanation
. Simultaneous acute ACL reconstruction and surgical repair/reconstruction of the PLC.
Explanation
Combined ACL and high-grade Posterolateral Corner (PLC) injuries (Grade III) represent a severe knee injury with significant rotational and varus instability. Leaving a Grade III PLC injury untreated or delaying its repair/reconstruction often leads to persistent instability, failure of the ACL reconstruction, and progressive degenerative changes. Therefore, simultaneous acute (within 2-3 weeks of injury) surgical repair and/or reconstruction of both the ACL and the PLC is generally recommended to restore stability and optimize outcomes. Options A and B risk persistent instability and potential failure of the reconstructed ligament due to the unaddressed concomitant injury. Conservative management (Option D) is generally insufficient for high-grade combined injuries in an athlete. Option E describes repair, but often reconstruction is needed for full Grade III tears, and debridement of ACL is not primary treatment.
Question 1628
Topic: Knee Sports
A 28-year-old semi-professional athlete sustains a high-energy knee injury during a football game. Clinical examination reveals gross instability with a positive Lachman, posterior drawer, varus stress test at 0 and 30 degrees, and increased external rotation at 30 degrees, indicative of a combined ACL, PCL, posterolateral corner (PLC), and lateral collateral ligament (LCL) injury. He has no neurovascular deficits. What is the most appropriate surgical management strategy regarding timing and technique?
Correct Answer & Explanation
. Delayed, single-stage reconstruction of all torn ligaments at 3-6 weeks, allowing soft tissue swelling to subside.
Explanation
This patient has a severe, multiligamentous knee injury (combined ACL, PCL, PLC, LCL). Non-operative management is generally not recommended for such extensive injuries in athletes. Immediate repair within 24-48 hours is largely discouraged due to significant swelling, stiffness, and increased risk of arthrofibrosis. Staged reconstruction might be considered in very specific, complex cases, but generally increases morbidity, cost, and prolongs recovery without clear superiority. Open primary repair of the PLC/LCL followed by delayed ACL/PCL reconstruction could be an option for isolated PLC avulsions or specific repairable tears, but it is not the overall best strategy for all ligaments in a high-energy multiligamentous injury. The current consensus for most multiligamentous knee injuries in athletes, especially high-grade combined injuries, is delayed, single-stage reconstruction of all torn ligaments at 3-6 weeks, after the acute inflammatory phase has subsided and soft tissue swelling has decreased. This timing minimizes the risk of arthrofibrosis, allows for better surgical exposure, and optimizes the chances of good postoperative range of motion and functional recovery. Repairable ligaments are typically repaired, while non-repairable ligaments are reconstructed.
Question 1629
Topic: Knee Sports
A 40-year-old male presents with chronic posterolateral knee pain, giving way, and hyperextension recurvatum after a multi-ligamentous knee injury 6 months ago. Physical examination reveals increased external rotation recurvatum and a positive reverse pivot shift test. Stress radiographs confirm increased posterolateral tibial translation. Which surgical procedure is most indicated?
Correct Answer & Explanation
. Reconstruction of the posterolateral corner (PLC) with or without other ligamentous reconstructions depending on full assessment.
Explanation
The clinical presentation of posterolateral knee pain, giving way, hyperextension recurvatum, increased external rotation recurvatum, and a positive reverse pivot shift test are highly indicative of posterolateral corner (PLC) instability. Stress radiographs confirming increased posterolateral tibial translation further support this. Isolated ACL or PCL reconstruction would not address the PLC deficiency. While other ligaments (ACL/PCL) may also be injured in a multi-ligamentous knee injury, the specific signs point strongly to the PLC. Reconstruction of the posterolateral corner is crucial for knee stability in such cases, often combined with ACL/PCL reconstruction if those are also torn, as failure to address the PLC leads to high failure rates of other ligament reconstructions. High tibial osteotomy is for varus malalignment, not primary instability.
Question 1630
Topic: Knee Sports
A 30-year-old competitive soccer player is diagnosed with a symptomatic isolated International Cartilage Repair Society (ICRS) grade IV chondral defect (2.5 cm x 3.0 cm) on the medial femoral condyle. He has failed conservative management. Which of the following surgical options is generally considered most appropriate for this type and size of lesion in an active individual?
For large (>2-2.5 cm²), symptomatic, full-thickness (ICRS Grade IV) chondral defects in active patients, biological solutions like Autologous Chondrocyte Implantation (ACI) or Matrix-Induced Autologous Chondrocyte Implantation (MACI) are generally considered the most appropriate treatment options. These techniques aim to regenerate hyaline-like cartilage and are suitable for larger lesions. Arthroscopic debridement and lavage offer only temporary symptomatic relief. Microfracture is typically reserved for smaller lesions (<2 cm²) and often results in fibrocartilage formation. The Osteochondral Autograft Transfer System (OATS) is suitable for smaller to medium-sized defects, but donor site morbidity limits its application for larger lesions. Total knee arthroplasty is for end-stage osteoarthritis, not an isolated chondral defect.
Question 1631
Topic: Knee Sports
A 15-year-old female presents with recurrent patellar dislocations despite rigorous physical therapy. MRI shows severe trochlear dysplasia, patella alta (Caton-Deschamps index 1.5), and an increased tibial tubercle-trochlear groove (TT-TG) distance of 20 mm. What is the most appropriate surgical approach for definitive treatment?
Correct Answer & Explanation
. Tibial tubercle osteotomy (e.g., Elmslie-Trillat or Fulkerson) with MPFL reconstruction.
Explanation
This patient has multiple predisposing factors for patellofemoral instability: recurrent dislocations, severe trochlear dysplasia, patella alta, and a significantly increased TT-TG distance (normal < 15mm, >20mm is severe). For such complex instability with multiple anatomical risk factors, a combined procedure is usually necessary. Tibial tubercle osteotomy (e.g., medialization and/or distalization) addresses the increased TT-TG distance and patella alta, improving patellar tracking. MPFL reconstruction provides static medial restraint. Therefore, a combination of tibial tubercle osteotomy and MPFL reconstruction is the most appropriate and effective surgical approach to stabilize the patella and prevent recurrence. Isolated MPFL reconstruction is insufficient for severe dysplasia and TT-TG distance. Lateral release can exacerbate instability. Patellectomy is a salvage procedure. Femoral osteotomy might be considered for severe rotational malalignment, but the primary issues here are patellar height and tracking.
Question 1632
Topic: Knee Sports
Which ligament is primarily responsible for preventing anterior translation of the tibia on the femur?
Correct Answer & Explanation
. Anterior cruciate ligament (ACL)
Explanation
The anterior cruciate ligament (ACL) is the primary static stabilizer that prevents anterior translation of the tibia on the femur. It also resists internal rotation of the tibia. The PCL prevents posterior translation. The MCL and LCL provide varus/valgus stability.
Question 1633
Topic: Knee Sports
Which of the following ligaments is considered the primary static stabilizer against posterior translation of the tibia on the femur?
Correct Answer & Explanation
. Posterior cruciate ligament (PCL)
Explanation
The posterior cruciate ligament (PCL) is the primary static stabilizer against posterior translation of the tibia on the femur. It is a strong ligament that also limits tibial external rotation. The ACL primarily resists anterior translation.
Question 1634
Topic: Knee Sports
Which of the following physical examination findings is most indicative of a complete tear of the anterior cruciate ligament (ACL)?
Correct Answer & Explanation
. Positive Lachman test
Explanation
The Lachman test is considered the most sensitive and specific clinical test for an acute anterior cruciate ligament (ACL) rupture. It is performed with the knee in 20-30 degrees of flexion, which isolates the ACL better than the anterior drawer test in 90 degrees of flexion, where secondary restraints (menisci, hamstrings) can mask instability. A positive McMurray test indicates meniscal injury. A positive pivot shift maneuver is highly specific but can be difficult to elicit acutely due to pain.
Question 1635
Topic: Knee Sports
A 15-year-old male presents with chronic knee pain and mechanical symptoms. An MRI reveals an osteochondritis dissecans (OCD) lesion with fluid surrounding the fragment, indicating instability. What is the most common anatomic location for a pediatric knee OCD lesion?
Correct Answer & Explanation
. Lateral aspect of the medial femoral condyle
Explanation
The classic and most common location for osteochondritis dissecans (OCD) of the knee is the lateral (intercondylar) aspect of the medial femoral condyle, accounting for roughly 70-80% of all knee OCD lesions.
Question 1636
Topic: Knee Sports
A 16-year-old male competitive swimmer presents with 8 months of worsening posterior knee pain, especially with knee flexion and descending stairs. Physical exam reveals a posterior sag of the tibia, positive posterior drawer test at 90 degrees of flexion, and a positive quadriceps active test. What is the MOST likely diagnosis and a key consideration for surgical reconstruction?
Correct Answer & Explanation
. Posterior cruciate ligament (PCL) tear; double-bundle reconstruction to restore normal kinematics.
Explanation
The patient's symptoms (posterior knee pain, pain with flexion/stairs), mechanism (competitive swimmer, often associated with hyperextension or direct blows), and physical exam findings (posterior sag, positive posterior drawer at 90 degrees, positive quadriceps active test) are pathognomonic for a Posterior Cruciate Ligament (PCL) tear.Option A (ACL tear) presents with anterior instability, pivoting symptoms, and a positive anterior drawer/Lachman test.Option B (Meniscal tear) can cause pain and mechanical symptoms (locking, catching) but the specific PCL-related instability signs are not characteristic.Option C (Posterior cruciate ligament (PCL) tear; double-bundle reconstruction to restore normal kinematics) is the correct diagnosis and a key consideration for surgical reconstruction. PCL reconstruction aims to restore posterior stability. While single-bundle reconstruction is an option, double-bundle reconstruction is often preferred in high-demand athletes and chronic injuries, as it aims to reproduce the two functional bundles of the PCL (anterolateral and posteromedial) to better restore normal knee kinematics, especially rotational stability and posterior tibial translation throughout the range of motion.Option D (Patellofemoral pain syndrome) causes anterior knee pain, often worse with stairs or prolonged sitting, but does not present with posterior sag or posterior instability signs.Option E (Osteochondritis dissecans) can cause pain and mechanical symptoms but typically localized to the affected condyle and lacks the specific instability findings.
Question 1637
Topic: Knee Sports
A 30-year-old male sustains a high-energy knee injury during a skiing accident. Physical examination reveals a positive posterior drawer test and sag sign, indicating a PCL injury. Radiographs reveal a large bony avulsion fracture of the PCL insertion from the tibia, involving a significant fragment (>1 cm) and resulting in demonstrable posterior instability. The patient has no other associated ligamentous injuries. What is the most appropriate surgical management for this injury?
Correct Answer & Explanation
. Open reduction and internal fixation of the avulsion fracture.
Explanation
A PCL avulsion fracture from the tibia that is significantly displaced (often >5 mm or >1 cm fragment size, as in this case) and causes demonstrable posterior instability is an indication for surgical management. Unlike mid-substance PCL tears, which often involve reconstruction, PCL avulsion fractures typically allow for direct repair or fixation of the bony fragment. Open reduction and internal fixation (ORIF) of the avulsion fracture (Option C) is the gold standard for displaced PCL avulsion fractures. This approach allows for anatomical reduction and stable fixation, restoring the PCL's native biomechanics. Arthroscopic techniques can also be used, but the principle is fixation of the bone fragment. Non-operative management (Option A) is reserved for non-displaced or minimally displaced avulsions. PCL reconstruction (Option B) is performed for mid-substance tears, not for bony avulsions where the ligament itself is intact. Primary repair of the PCL substance (Option D) is rarely successful for mid-substance tears and is not applicable to a bony avulsion. Dynamic posterior tibialization (Option E) is an outdated technique and not indicated for acute avulsion fractures.
Question 1638
Topic: Knee Sports
A 45-year-old high-level amateur athlete sustains a complex knee injury involving tears of the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL, Grade III), and a lateral meniscal tear. Initial examination reveals significant instability in multiple planes. After initial evaluation and stabilization, what is the most appropriate timing and sequence for definitive surgical management of this multiligamentous knee injury (MLKI)?
Correct Answer & Explanation
. Delayed reconstruction of all ligaments (4-6 weeks after injury) once swelling has subsided and range of motion has improved, with primary repair of the MCL during the same setting.
Explanation
For multiligamentous knee injuries, a delayed reconstruction (4-6 weeks after injury) is generally preferred over immediate surgery. This allows for soft tissue swelling to resolve, improved range of motion, and decreased arthrofibrosis rates. For Grade III MCL tears in MLKI, primary repair or reconstruction within the delayed reconstruction setting is typically performed, often with a combined ACL/PCL reconstruction. Immediate surgery (Option A) has higher rates of arthrofibrosis and worse outcomes. Staged reconstruction (Option B) can be considered, but often the MCL is best addressed concurrently with cruciate reconstruction if a repair or reconstruction is planned. Option D and E advocate for non-operative management of a Grade III MCL in an athlete with MLKI, which is often insufficient for stability and return to high-level function. The evidence supports a delayed, single-stage or possibly staged approach for comprehensive reconstruction of MLKI.
Question 1639
Topic: Knee Sports
A 16-year-old male presents with recurrent episodes of patellar instability. He has a history of prior conservative management with bracing and physical therapy. Physical exam reveals a positive J-sign, increased Q-angle, and patellar apprehension. Radiographs show a trochlear dysplasia (Dejour type B) and a Tibial Tubercle-Trochlear Groove (TT-TG) distance of 20mm. What is the most appropriate surgical intervention to stabilize the patella?
Correct Answer & Explanation
. Trochleoplasty combined with MPFL reconstruction.
Explanation
The patient's presentation includes significant risk factors for recurrent patellar instability: trochlear dysplasia (Dejour type B) and a markedly increased TT-TG distance (20mm, normal < 15mm). Isolated MPFL reconstruction (Option A) is often insufficient when significant bony abnormalities like trochlear dysplasia and increased TT-TG distance are present. A tibial tubercle osteotomy (TTO) (Option B) addresses the increased TT-TG distance by medializing the patellar tendon insertion. However, a TTO alone does not correct severe trochlear dysplasia, which is a major contributor to instability. A trochleoplasty (Option C) directly addresses the trochlear dysplasia by deepening the trochlear groove, and when combined with MPFL reconstruction, provides comprehensive stabilization for severe cases with both trochlear dysplasia and patellar maltracking. Lateral retinacular release (Option D) is rarely indicated as an isolated procedure. Proximal realignment (Option E) is less effective in the presence of bony abnormalities. For a Dejour type B trochlear dysplasia and TT-TG of 20mm, trochleoplasty combined with MPFL reconstruction (and potentially TTO if TT-TG is still a major concern after trochleoplasty planning) provides the most robust solution for long-term stability. Given the options, trochleoplasty with MPFL reconstruction is the most comprehensive and effective approach for this complex case.
Question 1640
Topic: Knee Sports
The presence of microfractures in the subchondral bone is hypothesized to contribute to the progression of osteoarthritis (OA) primarily by:
Correct Answer & Explanation
. Altering the mechanical properties of the subchondral bone, leading to increased stiffness and altered load transmission to cartilage
Explanation
Microfractures and other pathologies in the subchondral bone are increasingly recognized as critical factors in OA progression. Damage to the subchondral bone, including microfractures and bone marrow lesions, often leads to increased bone stiffness and sclerosis. This altered mechanical environment beneath the cartilage results in abnormal load transmission to the overlying articular cartilage, subjecting chondrocytes to excessive or abnormal mechanical stress. This stress can initiate or accelerate chondrocyte catabolism, leading to cartilage degeneration. Furthermore, changes in subchondral bone can affect nutrient supply to the cartilage. Direct stimulation of chondrocyte proliferation is not a primary effect. While inflammation is involved in OA, microfractures primarily cause local rather than systemic inflammation in this context. They typically increase intraosseous pressure, not decrease it. Type I collagen synthesis in articular cartilage is indicative of fibrocartilage repair, not typically a direct result of subchondral microfractures in OA progression.
Test Yourself
Switch to an interactive, timed exam simulation to truly master this topic.