Pathological infrapatellar plica: a report of two cases and literature review.

In two cases of flexion contracture of knees, the vertical septum pattern of the infrapatellar plica was noted arthroscopically to be thickened, fibrotic, and to have lost its elasticity. The plicae were impinged to the intercondylar notch and trochlea at extension of the knees, blocking further extension. The pathological plicae were resected, followed by improvement in range of the knees. At 6 months postoperatively, the knees gained full extension. This is the first report showing that the infrapatellar plica caused a clinical symptom.