A Posteromedial Approach to a Complex Multifragmentary Avulsion Fracture of the Posterior Cruciate Ligament :A Case Report

Pre-operative clinical examination revealed no neurovascular deficit, but was limited due to significant pain and patient reluctance to participate in range of motion. Radiographs showed an intraarticular fracture of the posterior aspect of the right tibial spine with the dominant fragment displaced approximately 1 cm posteriorly in the joint space. Computed Tomography (CT) verified a 1 cm fragment lateral to the posterior tibial plateau (Figure 1). Magnetic Resonance Imaging (MRI) of the knee showed a comminuted fracture involving the tibial plateau as seen on radiographs and CT, an attenuated Anterior Cruciate Ligament (ACL) without a full thickness tear, and an intact Posterior Cruciate Ligament (PCL) attached to the dominant posteriorly displaced fracture fragment (Figure 2). Other ligament pathology included a type I sprain of the fibular collateral ligament (FCL). Examination under anesthesia revealed restricted motion of the knee from 0 to 90 degrees, posterior sag was apparent and posterior drawer test with the knee flexed at 90 degrees showed grade III instability with a soft endpoint. The patient also had a slight increase in dial testing at 30 degrees and varus stress testing at 30 degrees demonstrated a slight laxity with firm endpoint. Based on the patient’s age and activity level, operative intervention was deemed appropriate.