A Rare Case: Ganglion Cysts in the Proximal Tibiofibular Joint Causes Lateral Side Knee Pain: A Case Report

INTRODUCTION: Proximal tibiofibular joint (PTFJ) ganglion cysts are very rare. The pathophysiology remains unclear. Lateral knee pain was present in dominant case, and some cases accompanied with common peroneal nerve symptoms. In cases of chronic trauma, it is sometimes confused with proximal tibiofibular joint instability. Thorough examination and investigations such as MRI are highly recommended. There is no consensus of management, but some studies indication that excision of the ganglion associated with low recurrences number. METHOD: We report a case of 28 yeara-old woman, with a chief complain of pain on the lateral side of her right knee. Pain increasing on one last year. She had a trauma on her knee in 5 years ago. She was diagnosis with Lateral Instability of her knee by a previous surgeon and refer to our clinic for second opinion. In physical exam we found, tenderness around fibula head, Lachman, McMurray, Lelli’s test was negative. Shuck test was not evident.. MRI was done and showing partial tear of anterior horn of lateral meniscus and partial tear of anterior proximal tibia fibula ligament also a fluid collection around the fibular head. We planned to repair the meniscus through arthroscopic and stabilize the Proximal tibiofibular joint with open surgery. RESULTS: Standard arthroscopic surgery was performed. Tear anterior horn meniscus was repair using inside out technique. In open surgery we found the anterior proximal tibiofibular ligament quite stable, and also we found a ganglion cyst around the PTFJ. We decided to leave the anterior PTFJ ligament, and excise the ganglion until its sac and follow up the case forward. CONCLUSION: Symptoms of pain caused by ganglion cysts in PTFJ, although rarely, can be very disturbing. The history of chronic trauma obscures this case with instability condition. There for careful diagnosis is required. Excision of the ganglion into the sac is the treatment of choice because of the very low recurrence rate. The complex anatomical composition of the lateral side of the knee can cause pain to arise from various components. The presence of PTFJ ganglion cysts should not be ignored