Popliteal Cyst Compressive Tibial Neuropathy and Venous Insufficiency: A Case Report

Popliteal cysts are a collection of synovial fluid found in the popliteal fossa that typically form in adults in association with traumatic injuries, degenerative conditions, or inflammatory arthritis of the knee. While often asymptomatic, popliteal cysts may become problematic as enlarging and ruptured cysts may compress surrounding neurovascular structures, resulting in lower extremity edema or peripheral neuropathy. We report a unique case of a symptomatic popliteal cyst in a patient with both compressive neuropathy and venous congestion in the setting of a non-ruptured popliteal cyst after a surgically repaired intraarticular injury. Magnetic resonance imaging (MRI) showed a synovial cyst abutting the posterior neurovascular bundle and evidence of avascular necrosis. An open posterior cyst decompression was done, and the patient was able to report significant symptomatic improvement over the course of two weeks postoperatively. The previously noted varicose veins also demonstrated noticeable resolution. While relatively common, popliteal cysts may require prompt surgical decompression in order to provide effective symptomatic relief.