[Ruptures of the extensor mechanism of the knee joint (author's transl)].

Ruptures of the quadriceps tendon and patellar ligament are rare among injuries of the extensor mechanism of the knee when compared to fractures of the patella. 39 cases of which 31 were re-examined are being discussed with regard to therapy and results. According to our findings, ruptures of the extensor mechanism are not exclusively an injury of higher age groups. Predisposing factors for ruptures of the quadriceps tendon and patellar ligament are preexisting disease or posttraumatic sequelae. Fresh or old injuries require different operative technics. Usually, fresh ruptures can be repaired by end-to-end sutures. Old injuries require plastic procedures. Different technics are being described. Postoperatively, cast fixation is mandatory. The post-operative period of remobilisation is largely depend upon preexisting degenerative joint changes as are the post-operative results. A significant increase in post-operative osteoarthritis did not occur. Early degenerative changes in the femoro-patellar joint as seen on tangential views by the Settegast technic lead to the conclusion that the operative reconstruction does not always take into consideration the biomechanics of the femoro-patellar articulation. Immediate operative reconstruction of the ruptured extensor mechanism of the knee joint seems mandatory.