Intercondylar synovial septum in two patients with nail-patella syndrome.

This case report describes the arthroscopic findings in two patients with nail-patella syndrome (NPS). In both cases, a midline synovial septum was encountered that completely subdivided the knee into medial and lateral compartments. One patient required two subsequent arthroscopic procedures, and the synovial septum was found to have recurred even after it had been resected at the initial surgery. The etiology and clinical significance of this anatomic anomaly are unknown, however, surgeons should be aware of its existence and the potential difficulties it may present during knee arthroscopy in patients with NPS.