Symptomatic Accessory Medial Meniscus Associated With Popliteal Pterygium Syndrome

Anomalies of the meniscus are uncommon. These anomalous formations have been predominately described in the lateral compartment of the knee. Congenital abnormalities of the medial meniscus are rare.

Chart and radiographic review of a single patient with a symptomatic congenital abnormality of the medial meniscus.

The patient was a 5-year-old boy with popliteal pterygium who developed painful snapping in the medial knee after anterior hemiepiphyseodesis to improve his knee extension. The patient had achieved full-knee extension from a preoperative 45-degree flexion contracture. The newly developed snapping was attributed to the hemiepiphyseodesis implants. After implant removal, the snapping persisted and was localized at the medial joint line. Through an arthrotomy, a medial meniscus abnormality was identified and excised with resolution of symptoms.

This report describes a symptomatic congenital abnormality of the medial meniscus in a child with popliteal pterygium. The patient was treated with excision of the anomalous structure with complete resolution of the symptoms. This is the first report of an intra-articular knee anomaly associated with popliteal pterygium syndrome.