Posterior cruciate ligament recess

The posterior cruciate ligament recess is located behind the PCL and communicates with the medial femorotibial compartment. It is often distended during knee flexion.[2]It is a synovial recess that extends distally along the popliteus tendon. The SPR is characterized by its length, which averages approximately 22.64 ± 11.38 mm from the upper end of the lateral tibial condyle to the lower end of the depression.[1]

The SPR is closely associated with the popliteus muscle and tendon, and its morphology can be classified into three types based on its relationship with the popliteus muscle. Types 2 and 3, where the SPR extends to the proximal tibiofibular joint, may contribute to knee joint instability.[1] Additionally, the presence of the fabellofibular ligament can significantly increase the length of the SPR.[1]

Communication between the SPR and the proximal tibiofibular joint has been observed in approximately 27.5% of anatomical specimens, typically due to a defect in the posterior ligament of the fibular head.[2] This anatomical feature is important for understanding potential pathways for joint fluid distribution and implications for knee joint stability and injury.