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 861
Topic: Knee Sports
A 25-year-old male sustains a severe knee dislocation resulting in an injury to the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and posterolateral corner (PLC). Following acute multiligament reconstruction, including the PLC, which of the following post-operative rehabilitation parameters is most critical to protect the PLC repair?
Correct Answer & Explanation
. Avoiding active isolated knee flexion against gravity for 6 weeks
Explanation
Active knee flexion against gravity isolates and activates the hamstrings. Hamstring contraction exerts a posterior and external rotatory force on the proximal tibia, placing severe stress on the newly reconstructed posterolateral corner (and PCL). Therefore, active hamstring contraction/knee flexion is typically avoided for the first 6 weeks postoperatively.
Question 862
Topic: Knee Sports
During arthroscopic posterior cruciate ligament (PCL) reconstruction, a surgeon is preparing the tibial tunnel. To prevent iatrogenic injury to the popliteal artery, it is critical to understand its anatomical relationship to the PCL. Where is the popliteal artery located in relation to the PCL tibial footprint?
Correct Answer & Explanation
. Directly posterior to the PCL tibial attachment
Explanation
The popliteal artery is at significant risk during tibial tunnel drilling for PCL reconstruction. It is located directly posterior to the PCL tibial attachment (the "facies poplitea"), separated only by the posterior capsule. Studies have shown the distance from the posterior capsule to the artery can be as little as 5 to 10 mm.
Question 863
Topic: Knee Sports
A 35-year-old male sustained a high-energy knee injury in a motor vehicle collision. Clinical examination reveals a gross posterolateral rotatory instability, a positive dial test at 30 and 90 degrees, a grade III posterior sag, and an absent posterior drawer. Foot drop is noted. MRI confirms avulsion of the PCL from the tibia, rupture of the fibular collateral ligament (FCL), and injury to the popliteus tendon. What is the most critical immediate concern that dictates the timing and approach to surgical management?
Correct Answer & Explanation
. Presence of a foot drop indicating common peroneal nerve injury.
Explanation
This patient has a multi-ligamentous knee injury involving the PCL and the posterolateral corner (PLC), a highly unstable injury. The key additional finding is 'foot drop,' which signifies injury to the common peroneal nerve. The common peroneal nerve courses superficially around the fibular head and is highly susceptible to injury in PLC disruptions and fibular head fractures. While all listed options represent valid concerns in multi-ligamentous knee injuries: Option A (post-traumatic arthritis) is a long-term complication but not an immediate concern dictating surgical timing. Option B (common peroneal nerve injury) is critical. Foot drop indicates significant nerve dysfunction, which needs to be addressed promptly. Surgical exploration and nerve repair or neurolysis may be necessary, and the presence of this neurological deficit often influences the timing and urgency of surgical intervention. Early diagnosis and management of nerve injuries are crucial for potential recovery. Option C (severity of PCL avulsion) is significant for surgical planning, but the nerve injury adds another layer of complexity and urgency. Option D (early mobilization to prevent stiffness) is important post-surgery but is not the most critical immediate concern pre-operatively, especially when compared to acute nerve injury. Option E (neurovascular compromise and compartment syndrome) is a critical immediate concern in any high-energy knee injury, especially dislocations. However, the question specifically states 'foot drop is noted,' identifying a definite neurological injury rather than just a potential for neurovascular compromise. If a popliteal artery injury was present, it would be the absolute highest priority, but a peroneal nerve injury is also very high priority. Given the options, the presence of an already identified foot drop makes the nerve injury the most critical factor listed that dictates the immediate approach to surgical management, potentially requiring specific nerve interventions concurrently with or preceding ligamentous reconstruction.
Question 864
Topic: Knee Sports
A 17-year-old female presents with a 1-year history of recurrent patellar dislocations after initial non-operative treatment failed. Physical examination reveals hyperlaxity and apprehension with lateral patellar translation. MRI of the knee (axial view shown) confirms severe trochlear dysplasia, patella alta, and a Tibial Tubercle-Trochlear Groove (TT-TG) distance of 18 mm.
Considering the comprehensive patellofemoral pathology, which combination of surgical procedures would BEST address the primary biomechanical deficiencies and reduce the risk of future dislocations?
This patient presents with multiple significant risk factors for patellofemoral instability: recurrent dislocations, severe trochlear dysplasia, patella alta, and a significantly increased Tibial Tubercle-Trochlear Groove (TT-TG) distance of 18 mm (normal is <15 mm). To address these comprehensive biomechanical deficiencies effectively, a multi-component surgical approach is typically required. MPFL reconstruction restores the primary medial soft tissue restraint. A tibial tubercle osteotomy (TTO) can address both the increased TT-TG distance (medialization) and patella alta (distalization). This combination comprehensively corrects the primary abnormalities and has shown superior outcomes for severe instability. Isolated MPFL or TTO would not fully address all factors. Trochleoplasty is reserved for severe dysplasia, and lateral retinacular release is rarely indicated as a standalone procedure.
Question 865
Topic: Knee Sports
A 28-year-old professional athlete suffers a high-energy knee injury during a football game. Clinical examination reveals gross instability in multiple planes, a positive Lachman test, positive posterior sag sign, and a positive varus stress test at 30 degrees of flexion. MRI confirms complete tears of the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and lateral collateral ligament (LCL), with associated posterolateral corner (PLC) injury.
What is the most critical principle guiding the surgical management of this acute multiligamentous knee injury?
Correct Answer & Explanation
. Perform a staged approach, addressing all posterolateral corner structures before cruciate ligaments.
Explanation
The image provided is a knee MRI, likely showing ligamentous pathology. This patient presents with an acute, complex multiligamentous knee injury involving the ACL, PCL, LCL, and PLC. The management of such injuries is complex, but the critical principle is to restore overall knee stability to prevent long-term functional deficits and post-traumatic arthritis. While some debate exists regarding single-stage versus staged procedures, the modern consensus for acute multiligament injuries (especially in high-demand athletes) favors a single-stage reconstruction of all torn ligaments. The primary goal is to re-establish the normal joint kinematics and prevent chronic instability.The posterolateral corner (PLC) is a crucial stabilizer. Unaddressed PLC injury can lead to failure of cruciate ligament grafts. Therefore, the PLC is often addressed first during reconstruction, or simultaneously with the other ligaments, to provide a stable foundation. Delaying surgery allows for significant scarring and increased difficulty in surgical repair/reconstruction, and may not lead to significant healing for completely torn ligaments.Rationale for options:A. Prioritizing only the ACL and staging others is generally not recommended for multiligament injuries, as the remaining instability will compromise graft integrity and overall knee function.B. Delaying surgery for 6-12 weeks foralltears is often not ideal. While some isolated collateral ligament injuries can be managed non-operatively, complete multiligament injuries benefit from early definitive surgical intervention to minimize scarring, improve outcomes, and facilitate rehabilitation. However, a 'staged' approach is sometimes used if soft tissues are severely compromised, or if the patient presents late. For acute injuries, a single stage is often preferred if possible.C. While many surgeons prefer to address all structures in a single stage, a staged approach for multiligament injuries is sometimes employed, especially for severe cases or if significant swelling/blistering is present. However, theprincipleof restoring stability is paramount. In acute repairs, the PLC structures are often addressed first or concurrently as their integrity is vital for success of cruciate reconstruction. This option specifically mentions addressing PLCbeforecruciate ligaments, which is a common practice in staged approaches, especially if there's severe soft tissue injury or the patient is not suitable for a single, lengthy procedure. Given the options, and the emphasis on PLC's importance, this points to a critical sequencing consideration.D. Reconstructing all torn ligaments in a single stage is the current trend for acute multiligament injuries in athletes to restore overall knee stability. This is generally preferred when feasible. However, option C highlights the importance of the PLC.E. This statement is incorrect. The ACL plays a significant role in knee stability, especially rotational stability, and its absence in a multiligamentous injury would lead to continued instability and poor long-term outcomes.
Question 866
Topic: Knee Sports
A 16-year-old female presents with persistent pain, instability, and a 'giving way' sensation in her right knee, 18 months after sustaining a multi-ligamentous knee injury (ACL, MCL, PCL tears) that was treated non-operatively due to initial missed diagnosis. Radiographs show early degenerative changes. MRI confirms chronic laxity of all three ligaments. What is the MOST appropriate next step in management?
Correct Answer & Explanation
. Consider a staged reconstruction, addressing the PCL and MCL first, followed by ACL.
Explanation
This patient has a neglected, chronic multiligamentous knee injury with persistent instability and early degenerative changes. While physical therapy and bracing might offer some symptomatic relief, they will not address the underlying mechanical instability caused by the chronically torn ligaments. Arthroscopic debridement is insufficient.For chronic multiligamentous knee instability with functional limitations, surgical reconstruction is indicated. Given the significant number of ligaments involved, a staged approach is often preferred over a single-stage reconstruction, especially in chronic cases. This allows for soft tissue healing and rehabilitation between stages, reducing the risk of complications associated with a very long single-stage surgery and potentially improving outcomes. The posterior side (PCL/PLC) is often addressed first, as it sets the foundation for knee stability and allows subsequent ACL reconstruction to be performed on a more stable base. The MCL can often heal with non-operative treatment, especially if medial opening is less than 5mm; however, in this chronic, unstable context, MCL reconstruction might also be needed.Rationale for options:A. Physical therapy is always important but insufficient to correct chronic multi-ligamentous mechanical instability.B. A single-stage reconstruction of all three ligaments might be an option, but it's a very extensive procedure with higher risks in a chronic setting. A staged approach is often considered preferable for chronic cases.C. A hinged knee brace may provide some stability but does not correct the underlying pathology or prevent progression of degenerative changes.D. A staged reconstruction, typically addressing the PCL and MCL (or PLC) first to establish the posterior and medial stability, followed by the ACL, is a common and often preferred strategy for chronic multiligamentous knee injuries. This allows for recovery and rehabilitation between stages. This is the correct answer.E. Arthrodesis is a salvage procedure for end-stage arthritis or failed reconstructions, not for early degenerative changes where reconstructive surgery is still feasible.
Question 867
Topic: Knee Sports
A 38-year-old male competitive runner presents with chronic left knee pain, swelling, and mechanical symptoms (catching/locking) that are worse with pivoting activities. MRI reveals a complex tear of the posterior horn of the medial meniscus, extending to the meniscocapsular junction, with radial components, suggesting a meniscal root tear. There is extrusion of the medial meniscus.
Given the patient's age, activity level, and the nature of the tear, what is the MOST appropriate surgical management?
Correct Answer & Explanation
. Arthroscopic repair of the meniscal root tear.
Explanation
The image provided shows a knee MRI, likely demonstrating a meniscal root tear. The patient has a complex, radial meniscal root tear with extrusion of the medial meniscus. Meniscal root tears are functionally equivalent to a total meniscectomy because they disrupt the circumferential hoop stress mechanism of the meniscus, leading to increased contact pressures on the articular cartilage and accelerated osteoarthritis. For a young, active patient with mechanical symptoms, pain, and extrusion, surgical repair is indicated to restore meniscal function.Arthroscopic repair of a meniscal root tear involves reattaching the avulsed root to its anatomical insertion site, typically using a transosseous technique or suture anchors. This aims to restore the hoop stress function, reduce tibiofemoral contact pressures, and prevent or delay the onset of osteoarthritis. Partial meniscectomy for root tears has been shown to lead to poor long-term outcomes, similar to total meniscectomy.Rationale for options:A. Arthroscopic partial meniscectomy for a meniscal root tear is contraindicated as it removes more meniscal tissue and does not restore the hoop stress function, leading to accelerated osteoarthritis. It is essentially equivalent to a total meniscectomy in terms of biomechanical consequences.B. Arthroscopic repair of the meniscal root tear (e.g., using a pull-out suture technique) is the gold standard treatment for symptomatic, repairable meniscal root tears, especially in young, active patients, to restore meniscal function and prevent progression to osteoarthritis. This is the correct answer.C. Total meniscectomy is an outdated procedure for meniscal tears, known to cause early osteoarthritis, and is inappropriate for this patient.D. High tibial osteotomy (HTO) is considered for unicompartmental osteoarthritis with varus malalignment, often as an adjunct to meniscal repair in cases with significant malalignment, but not as the primary treatment for a meniscal root tear alone.E. Non-operative management is typically for asymptomatic tears or those in older, low-demand patients without mechanical symptoms, and is generally not recommended for a young, active patient with symptomatic root tear and extrusion.
Question 868
Topic: Knee Sports
A 12-year-old female presents with persistent, severe left knee pain following an athletic injury. Radiographs are unremarkable. MRI, however, reveals a large osteochondral lesion on the lateral aspect of the medial femoral condyle, consistent with Osteochondritis Dissecans (OCD). The lesion is stable but significantly large (2.5 cm x 2.0 cm) and the patient is skeletally immature. What is the MOST appropriate surgical management for this lesion?
Correct Answer & Explanation
. Transarticular drilling of the lesion.
Explanation
The patient has a large, stable osteochondral lesion (OCD) in a skeletally immature patient. The treatment of OCD depends on skeletal maturity, stability, and size. In skeletally immature patients, stable lesions are initially treated non-operatively with activity modification and bracing. However, if symptoms persist, or the lesion is large, surgical intervention is considered.For stable OCD lesions in skeletally immature patients that fail conservative management, or are deemed unlikely to heal spontaneously (e.g., large size), transarticular or retroarticular drilling is often the first-line surgical treatment. The goal of drilling is to stimulate blood flow and healing across the cartilage-bone interface without violating the articular cartilage surface (if transarticular drilling is used, care is taken not to penetrate the cartilage surface in multiple passes). Retroarticular drilling allows multiple drilling sites from outside the joint without disrupting the articular surface. The image is not provided, so the stability is based on the question text.Rationale for options:A. While initial non-operative management is standard for stable OCD, the 'persistent, severe pain' and 'significantly large' size after failure of 6 months non-operative care makes continued non-op less appropriate as thenextstep.B. Arthroscopic debridement and microfracture are typically for unstable lesions, loose bodies, or focal chondral defects without a significant underlying bone defect, not for stable OCD with intact cartilage overlying the lesion.C. Transarticular drilling (or retroarticular drilling) is the most appropriate surgical management for large, stable OCD lesions in skeletally immature patients that have failed conservative management, as it promotes healing of the lesion while preserving the articular cartilage. This is the correct answer.D. Osteochondral autograft transplantation (OATs) is used for unstable or loose OCD lesions, or full-thickness chondral defects, typically in the adult or near-skeletally mature patient. It is more invasive than drilling and involves harvesting cartilage and bone from a non-weight-bearing area.E. Autologous chondrocyte implantation (ACI) is also for large, full-thickness chondral defects, usually in adults, and is a two-stage procedure; it is not typically used for stable OCD lesions in skeletally immature patients.
Question 869
Topic: Knee Sports
In native knee kinematics, 'femoral rollback' is the posterior translation of the femoral contact point on the tibia during deep flexion, which increases clearance and allows greater flexion. Which structure is the primary anatomic driver of this obligatory posterior rollback?
Correct Answer & Explanation
. Posterior cruciate ligament (PCL)
Explanation
Femoral rollback is the posterior translation of the femur on the tibia during knee flexion, which shifts the contact point posteriorly, increases the quadriceps moment arm, and prevents posterior impingement, allowing deep flexion. This kinematic mechanism is primarily guided and driven by the posterior cruciate ligament (PCL).
Question 870
Topic: Knee Sports
A 22-year-old collegiate football player sustains a valgus and twisting injury to his knee. MRI confirms a complete proximal tear of the medial collateral ligament (MCL) and an anterior cruciate ligament (ACL) rupture. What is the most appropriate initial management protocol?
Correct Answer & Explanation
. Hinged knee bracing for 4-6 weeks followed by delayed ACL reconstruction
Explanation
Combined ACL and proximal MCL tears are typically best managed by initially allowing the MCL to heal nonoperatively in a hinged knee brace. Once the MCL has healed and full knee range of motion is restored (usually 4-6 weeks), delayed ACL reconstruction is performed. This approach minimizes the significant risk of postoperative arthrofibrosis associated with acute multi-ligament surgery.
Question 871
Topic: Knee Sports
The anterior cruciate ligament (ACL) consists of two distinct functional bundles: the anteromedial (AM) and posterolateral (PL) bundles. Which of the following best describes the biomechanical function and tensioning of these bundles during knee range of motion?
Correct Answer & Explanation
. The AM bundle is tight in flexion and controls anterior translation, while the PL bundle is tight in extension and controls rotatory stability.
Explanation
The ACL has two main bundles named for their tibial insertions. The Anteromedial (AM) bundle is tight in flexion and is the primary restraint to anterior tibial translation. The Posterolateral (PL) bundle is tight in extension and provides the primary restraint to rotatory loads (preventing the pivot shift). This biomechanical differentiation is critical for understanding anatomic ACL reconstructions.
Question 872
Topic: Knee Sports
A 16-year-old female undergoes medial patellofemoral ligament (MPFL) reconstruction for recurrent lateral patellar instability. To ensure proper graft isometry during knee flexion, where must the femoral attachment of the graft be placed anatomically?
Correct Answer & Explanation
. In the saddle region, proximal and posterior to the medial epicondyle, and distal to the adductor tubercle.
Explanation
The anatomic femoral footprint of the MPFL (often radiographically localized by Schรถttle's point) is situated in a "saddle" region between the adductor tubercle and the medial epicondyle. Specifically, it lies proximal and posterior to the medial epicondyle, and just distal and anterior to the adductor tubercle. Accurate placement is essential to ensure the graft remains appropriately tensioned (isometric) throughout the knee arc of motion.
Question 873
Topic: Knee Sports
A 28-year-old male sustains a knee injury during a soccer tackle. Physical examination reveals a positive dial test at 30 degrees of knee flexion with 15 degrees of increased external rotation compared to the contralateral side. At 90 degrees of knee flexion, the external rotation is symmetric bilaterally. Which of the following structures is most likely injured?
Correct Answer & Explanation
. Posterolateral corner (PLC) and PCL
Explanation
An isolated injury to the posterolateral corner (PLC) results in a positive dial test at 30 degrees but not at 90 degrees. If both the PLC and PCL are torn, the dial test will be positive at both 30 and 90 degrees.
Question 874
Topic: Knee Sports
A 22-year-old collegiate soccer player undergoes primary ACL reconstruction using a bone-patellar tendon-bone (BTB) autograft. Six months postoperatively, she complains of anterior knee pain and a palpable click when extending the knee from 30 degrees to full extension. What is the most likely etiology?
Correct Answer & Explanation
. Cyclops lesion
Explanation
A Cyclops lesion (localized anterior arthrofibrosis) typically presents with an extension deficit and a terminal extension click or clunk after ACL reconstruction. Patellar clunk syndrome is classically associated with posterior stabilized total knee arthroplasty, not ACL reconstruction.
Question 875
Topic: Knee Sports
A 21-year-old female soccer player undergoes primary anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone autograft. Six months postoperatively, she complains of anterior knee pain and a hard block to terminal knee extension at 10 degrees of flexion. What is the most likely surgical etiology of this complication?
Correct Answer & Explanation
. Anterior placement of the tibial tunnel
Explanation
A hard block to terminal knee extension following ACL reconstruction is a classic presentation for intercondylar roof impingement. This is most commonly caused by placing the tibial tunnel too anteriorly, causing the graft to impinge against the notch in extension.
Question 876
Topic: Knee Sports
A 25-year-old athlete sustains a multi-ligament knee injury. Physical examination reveals a negative posterior drawer test but a dial test that shows 20 degrees of increased external rotation at 30 degrees of flexion, which reduces to symmetric rotation at 90 degrees of flexion compared to the uninjured side. Which structure or combination of structures is most likely injured?
Correct Answer & Explanation
. Posterior Cruciate Ligament (PCL) and Posterolateral Corner (PLC)
Explanation
An isolated posterolateral corner (PLC) injury presents with increased external rotation at 30 degrees of flexion but symmetric rotation at 90 degrees on the dial test. If external rotation is increased at both 30 and 90 degrees, a combined PCL and PLC injury should be suspected.
Question 877
Topic: Knee Sports
A 25-year-old male presents with a painful, swollen knee following a twisting injury while playing soccer. There is a large effusion, and he has limited range of motion. Aspiration of the knee joint yields frank blood. Which of the following injuries is most likely?
Correct Answer & Explanation
. Anterior cruciate ligament (ACL) tear.
Explanation
Hemarthrosis (frank blood in the joint) after acute knee trauma, especially a twisting injury, is highly indicative of a significant intra-articular injury with rich blood supply. The most common cause is an Anterior Cruciate Ligament (ACL) tear, which involves disruption of the highly vascular ACL. Other causes include osteochondral fractures, peripheral meniscal tears (less common to cause frank hemarthrosis on their own), and patellar dislocations. Isolated meniscus tears or MCL sprains, prepatellar bursitis, and patellar tendinitis typically do not cause frank hemarthrosis. An MCL sprain is extra-articular.
Question 878
Topic: Knee Sports
The primary blood supply to the anterior cruciate ligament (ACL) is derived from which artery?
Correct Answer & Explanation
. Middle genicular artery
Explanation
The middle genicular artery, a branch of the popliteal artery, provides the primary vascular supply to the ACL. It pierces the posterior capsule to supply the cruciate ligaments.
Question 879
Topic: Knee Sports
During deep flexion of the normal knee joint, femoral rollback on the tibial plateau is primarily driven by the tension in which structure?
Correct Answer & Explanation
. Posterior cruciate ligament
Explanation
The PCL is responsible for the posterior translation of the femur on the tibia (femoral rollback) during deep knee flexion. This mechanism optimizes the extensor mechanism's moment arm and prevents posterior impingement.
Question 880
Topic: Knee Sports
Which of the following describes the anatomical structure primarily responsible for resisting valgus stress at the knee joint?
Correct Answer & Explanation
. Medial collateral ligament (MCL).
Explanation
The Medial Collateral Ligament (MCL) is the primary static stabilizer that resists valgus stress (forces pushing the knee inward) at the knee joint. The LCL resists varus stress. The ACL resists anterior translation of the tibia, and the PCL resists posterior translation. The popliteus tendon has a role in posterolateral stability and external rotation but is not the primary valgus restraint.
Test Yourself
Switch to an interactive, timed exam simulation to truly master this topic.
