NATA-BOC Lower Extremity Injury Assessment 2 — Questions and Answers
Question 1: An athlete presents with pain at the anterolateral ankle that worsens with dorsiflexion and external rotation of the foot. Which injury should the athletic trainer suspect?
- Lateral ankle sprain
- Syndesmotic (high) ankle sprain (Correct answer)
- Achilles tendinopathy
- Peroneal tendon subluxation
Correct answer: Syndesmotic (high) ankle sprain
Pain at the anterolateral ankle that increases with dorsiflexion and external rotation (positive squeeze test or external rotation test) is characteristic of a syndesmotic or high ankle sprain, involving the anterior inferior tibiofibular ligament.
A syndesmotic (high) ankle sprain involves injury to the ligaments connecting the distal tibia and fibula: the anterior inferior tibiofibular ligament (AITFL), posterior inferior tibiofibular ligament (PITFL), interosseous membrane, and transverse ligament. The mechanism typically involves dorsiflexion with external rotation. Key clinical tests include the squeeze test (compressing the tibia and fibula at mid-calf produces distal pain), the external rotation test, and the Cotton test. These injuries are more debilitating and have significantly longer recovery times than lateral ankle sprains. The AITFL is the most commonly injured structure. A lateral ankle sprain involves the ATFL and CFL with an inversion mechanism, which is distinctly different.
Question 2: Which special test is used to assess the integrity of the posterior cruciate ligament?
- Lachman test
- Posterior drawer test (Correct answer)
- Pivot shift test
- Dial test
Correct answer: Posterior drawer test
The posterior drawer test is the primary special test for assessing the posterior cruciate ligament. It is performed with the knee at 90 degrees of flexion, applying a posterior force to the proximal tibia.
The posterior drawer test is performed with the patient supine, hip flexed to 45 degrees, and knee flexed to 90 degrees. The athletic trainer sits on the patient's foot to stabilize it and applies a posteriorly directed force to the proximal tibia. Increased posterior translation compared to the contralateral side indicates PCL insufficiency. The examiner should first check the tibial step-off (the anterior tibial plateau should project approximately 10mm anterior to the femoral condyles; loss of this step-off suggests PCL injury). The Lachman test assesses the ACL. The pivot shift test also assesses the ACL (rotatory instability). The dial test assesses the posterolateral corner structures.
Question 3: A distance runner presents with gradually worsening medial tibial pain that is relieved by rest. Palpation reveals diffuse tenderness along the posteromedial border of the tibia. What is the most likely diagnosis?
- Tibial stress fracture
- Medial tibial stress syndrome (shin splints) (Correct answer)
- Compartment syndrome
- Deep vein thrombosis
Correct answer: Medial tibial stress syndrome (shin splints)
Medial tibial stress syndrome presents with diffuse tenderness along the posteromedial tibial border, typically in the middle to distal third. The gradual onset, relationship to activity, and relief with rest are characteristic features.
Medial tibial stress syndrome (MTSS) is an overuse condition characterized by periostitis along the posteromedial tibial border, typically affecting the middle to distal third. Key differentiators: MTSS presents with DIFFUSE tenderness over a broad area (>5cm), while a stress fracture presents with FOCAL point tenderness. MTSS pain occurs during activity and resolves with rest; compartment syndrome pain increases during activity and may persist after cessation, often with numbness. DVT typically presents with calf swelling, warmth, and tenderness unrelated to activity patterns. Risk factors for MTSS include training errors (too much too soon), hard running surfaces, worn footwear, overpronation, and increased BMI. Treatment includes relative rest, ice, addressing biomechanical factors, and gradual return to activity.
Question 4: During a lateral pivot shift test, the athletic trainer feels a clunk as the knee moves from flexion to extension. What does this positive finding indicate?
- Meniscal tear
- PCL insufficiency
- ACL insufficiency with anterolateral rotatory instability (Correct answer)
- MCL laxity
Correct answer: ACL insufficiency with anterolateral rotatory instability
A positive pivot shift test indicates ACL insufficiency with anterolateral rotatory instability. The clunk occurs as the laterally subluxed tibial plateau spontaneously reduces as the knee moves from flexion to extension.
The pivot shift test is considered the most specific clinical test for ACL insufficiency. It replicates the giving-way phenomenon that patients experience. With the patient supine, the examiner applies a valgus stress and internal rotation to the tibia while moving the knee from full extension to flexion. In an ACL-deficient knee, the lateral tibial plateau subluxes anteriorly near extension (due to the pull of the iliotibial band); as the knee is flexed past approximately 20-30 degrees, the IT band moves posterior to the axis of rotation, and the tibial plateau spontaneously reduces with a palpable clunk. The test can be difficult to perform on a conscious, guarded patient and is most reliable under anesthesia. It is highly specific (98%) but has lower sensitivity in the awake patient.
Question 5: An athlete complains of lateral knee pain that worsens during downhill running. Tenderness is localized over the lateral femoral condyle. Which condition is most likely?
- Lateral meniscal tear
- Lateral collateral ligament sprain
- Iliotibial band syndrome (Correct answer)
- Popliteus tendinopathy
Correct answer: Iliotibial band syndrome
Iliotibial band syndrome presents with lateral knee pain localized to the lateral femoral condyle that worsens with repetitive flexion/extension activities. Downhill running increases friction of the IT band over the condyle.
Iliotibial band syndrome (ITBS) is one of the most common causes of lateral knee pain in runners. The IT band repeatedly crosses over the lateral femoral condyle during flexion and extension, creating friction and inflammation. Pain typically occurs at approximately 30 degrees of knee flexion (the 'impingement zone'). Downhill running increases the angle of knee flexion at footstrike, exacerbating the condition. Noble compression test (direct pressure over the lateral femoral condyle at 30 degrees of flexion reproducing pain) and Ober test (assessing IT band tightness) are key clinical tests. Risk factors include training errors, leg length discrepancy, excessive pronation, tight IT band, and weak hip abductors. A lateral meniscal tear would be on the joint line, not the condyle.
Question 6: Which test is most appropriate for assessing a suspected Achilles tendon rupture in an acute setting?
- Anterior drawer of the ankle
- Thompson (Simmonds) test (Correct answer)
- Tinel sign at the posterior ankle
- Homan sign
Correct answer: Thompson (Simmonds) test
The Thompson test is the primary clinical test for Achilles tendon rupture. The examiner squeezes the calf with the patient prone; absence of passive plantar flexion indicates tendon discontinuity.
The Thompson (Simmonds) test is performed with the patient prone or kneeling on a chair with the feet hanging over the edge. The examiner squeezes the calf musculature of the affected leg. A normal response is passive plantar flexion of the foot. If the Achilles tendon is ruptured, there is no plantar flexion (positive test). The test has high sensitivity (96%) and specificity (93%) for complete rupture. Additional findings suggesting Achilles rupture include: a palpable gap in the tendon, excessive passive dorsiflexion compared to the uninvolved side, inability to perform a single-leg heel raise, and positive calf squeeze test. The anterior drawer tests ankle ligaments, Tinel sign tests nerve irritation, and Homan sign (calf pain with passive dorsiflexion) is an outdated DVT screening test.
NATA-BOC Lower Extremity Injury Assessment 2
An athlete presents with pain at the anterolateral ankle that worsens with dorsiflexion and external rotation of the foot.
Which injury should the athletic trainer suspect?