Rupture of the patellar tendon after use of its central third.

The authors, in performing anterior cruciate ligament reconstruction, have been using the central third of the patella tendon with a connected piece of patella for a transfer. In this paper they report a case in which the residual patella tendon itself ruptured and required a subsequent repair. The technique of repair is described. Diagnosis of the rupture was difficult. The authors also describe an experimental technique for assessing derangement of the knee.