Oral Questions Lateral: Ankle Instability Exam Prep
Key Takeaway
Here are the crucial details you must know about Oral Questions Lateral: Ankle Instability Exam Prep. Lateral ligament instability, often discussed in orthopedic oral questions lateral, involves injury to the ankle's anterior talofibular and calcaneofibular ligaments, typically from rotational trauma. Diagnosis includes the anterior drawer and talar tilt tests, assessing for excess anterior translation or tilt compared to the uninjured ankle. Management begins with physiotherapy concentrating on peroneal strengthening and proprioception, with bracing and further imaging like MRI for persistent symptoms.
A 24-year-old semi-professional soccer player presents with recurrent right ankle "giving way" sensation after multiple inversion injuries over 18 months. He has failed a comprehensive 6-month physiotherapy program including bracing and proprioceptive training. On examination, he has tenderness over the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) regions.
The following anatomical diagram illustrates the lateral ligamentous complex. Identify the primary static stabilizer of the ankle that is taut in plantarflexion, and describe the physical examination maneuver used to isolate it.
Candidate: The primary static restraint in plantarflexion is the ATFL. I would perform an anterior drawer test with the ankle in slight plantarflexion to isolate it. A positive test shows excessive anterior translation and/or a "clunk" compared to the contralateral side, indicating mechanical instability.
Candidates often confuse the ATFL and CFL. Failing to mention the specific position of the ankle (plantarflexion for ATFL, dorsiflexion for CFL) indicates a lack of biomechanical understanding. Furthermore, omitting the "contralateral comparison" is a major error as laxity is subjective without a baseline.
The ATFL is the primary static restraint to anterior translation in plantarflexion. To test it, I perform the Anterior Drawer test with the ankle in 10-20 degrees of plantarflexion, stabilizing the tibia and applying an anterior force to the calcaneus. A positive test is defined by an increase in anterior translation (>3mm difference) or a palpable "clunk," indicating mechanical insufficiency. I would then perform the Talar Tilt test in dorsiflexion to assess the CFL.
Given the patient has failed conservative management and now requires surgical intervention, describe your decision-making process for selecting the procedure, and specifically, what you would look for on the pre-operative workup that might change your surgical plan?
Candidate: I would consider an anatomical repair, most commonly a Modified Brostrom-Gould procedure. Before surgery, I check for a cavovarus foot deformity on radiographs or clinical exam. If present, I might need to perform a calcaneal osteotomy alongside the repair because the varus alignment will overload the repair and cause failure.
Candidates often forget to mention "Concomitant Pathology." Failing to mention an MRI to rule out Osteochondral Lesions (OCLs) of the talus or peroneal tendinopathy is a significant oversight, as these require specific treatment (debridement/repair) at the same time.
My decision-making follows a structured approach: 1. Patient Factors: Demands and ligamentous quality (Beighton score). 2. Deformity Factors: Evaluating for a cavovarus foot (if present, add calcaneal osteotomy). 3. Joint Factors: Using MRI to rule out intra-articular pathology (OCLs, impingement, or peroneal tears) which I would address arthroscopically or through the same incision. If the patient has high demands or generalized laxity, I would discuss anatomical reconstruction using an autograft/allograft rather than a primary repair.
