Post-traumatic Medial Meniscal Cyst in young: A case report

Meniscal cysts are rare, in that cysts of lateral meniscus are 3 times to 10 times more common than those of medial meniscus. Etiology of meniscal cysts includes trauma which results in contusion and haemorrage within the substance of meniscus leading to mucoid degeneration. Degeneration with age results in local necrosis and mucoid degeneration into a cyst, developmental inclusion of synovial cells within the substance of the meniscus and often are a result of extrusion of synovial fluid through a tear of the meniscus, resulting in a one-way valve effect of the tear. Arthroscopic partial menisectomy followed by cyst decompression is currently recommended for treatment of a meniscal cyst. We present a case of 18-year-old female with c/o pain and swelling in right knee had h/o trauma 3 yrs back. On examination, swelling 1x2 cm on medial tibial condyle, firm in consistency fixed to bone. MRI suggests grade 3 horizontal tear in posterior horn of medial meniscus and parameniscal cyst adjacent to medial meniscus. In this report, medial parameniscal cyst was resected using an arthroscopic posterior trans-septal approach. There have been no recurrences to date, and patient returned to her previous level of activity. A posterior trans-septal approach is useful for resection of a meniscal cyst arising from the posterior horn of the medial meniscus.