Arthroscopic Treatment of Lateral Meniscal Cyst Causing Peroneal Nerve Injury.

Compression of the common peroneal nerve by lateral meniscal cysts is rare. We report a 29-year male patient who complained of a gradually enlarging mass in the right popliteal fossa. He was diagnosed with a lateral meniscal cyst and a common peroneal nerve injury. The patient underwent arthroscopic surgery, including lateral partial meniscectomy and cyst drainage. When followed up at 3 months, the dorsal extensor strength of the right foot recovered to grade 5, and sensation of the distal right lower limb returned to normal. No recurrence of the cyst was found at the last follow-up at 18 months. This is a rare case of common peroneal nerve paralysis caused by a lateral meniscal cyst. Key Words: Meniscal cyst, Common peroneal nerve, Nerve injury.