Anatomical evaluation of the rectus femoris tendon and its related structures.

Purpose: The purpose of this study was to evaluate the anatomical structure of the quadriceps tendon in detail for use as an anterior cruciate ligament (ACL) graft tendon.
Materials and Methods: Sixteen cadaveric knees with an average age of 78.8 were used. After careful dissection of skin and fascia, the muscle structure of each quadriceps was evaluated. In particular, the rectus femoris (RF) tendon was measured at its widest and narrowest width, the distance between widest or narrowest point and the proximal end of the patella, and the length.
Results: The quadriceps tendon consisted of three layers. At the surface layer, the RF tendon existed mostly independently. The middle layer consisted of the vastus lateralis (VL) and medialis (VM) tendons. The deep layer consisted of the vastus intermedius (VI) tendon. The VL and VI tendons overlapped and were firmly connected, constituting the strength and size of the quadriceps. The narrowest width of the RF was 15.3 mm, and the narrowest point existed 4.8 mm proximal to the upper end of the patella. The average length of the RF was 27.3 cm.
Conclusion: If the RF tendon only is used as an ACL graft, surgeons should be cautious of the fact that the narrowest point of the RF tendon is located close to the patella. The entire quadriceps tendon is big enough to be used as an ACL graft. However, since the direction of the VL and VI tendons is different, the suitability of the quadriceps tendon as an ACL graft is questionable.