All portions of the extensor apparatus fused over a region ranging from 13 to 90 mm (mean 44 mm, SD +/− 21) proximal to the superior pole of the patella medial to the mid-line of the quadriceps tendon. The different components were structured in onion-like layers or similar to a husk of a corn. Superficial lateral and medial fibers in the proximal aspect of the thigh were piled in deeper inner layers at the level of the quadriceps tendon (Fig. 1). The thickness of the quadriceps tendon increased steadily as more aponeurotic layers of the extensor apparatus joined both medially and laterally. At the patella insertion the quadriceps tendon reached its maximal thickness of 79 mm (range 65 to 95 mm, SD +/− 0.9). Deep to the quadriceps tendon between the tendon and the femur, the muscle bundles of the articularis genus extended to the suprapatellar bursa, and the synovial membrane of the knee joint. The fibers of the articularis genus did not contribute to the architecture of the quadriceps tendon, but merely fused with the dorsal side of the aponeurosis of the vastus intermedius.