The Pitfalls in Harvesting the Hamstring Tendons: Anatomic Considerations

Lee, Kwang Won; Sakane, Masataka; Fu, Freddie H

Abstract

The purpose of this study was to evaluate the anatomical relationships of hamstring tendons to adjacent structures, especially to the saphenous nerve, and to measure the length of the semitendinosus and gracilis tendons in order to determine whether they are of sufficient length to make multiple stranded grafts. Twenty-eight fresh frozen knees(mean ages: 67.9 years) were dissected. The tendons of the sartorius, gracilis, and semitendinosus were exposed. The lengths of the semitendinosus and the gracilis, the widths of the fused portion of each tendon were measured. Also we checked the bifurcation point, the presence of the accessory insertion, cross point of saphenous nerve. The average lengths of the semitendinosus and the gracilis tendons were 32.32+/-2.88cm (mean+/-SI) and 23.14+/-2.79cm, respectively. The upper border of the gracilis tendon was located an average of 1.53cm from the prominence of the tibial tuberosity. The tendons of the gracilis and semitendinosus fused average of 3.66cm from their insertion and firmly adherent to sartorius tendon. The width of conjoined tendon was 2.94cm. The average distance between the saphenous nerve at its cross-over point and the tibial tuberosity was 9.71cm. Several key anatomic points are useful in the harvest of these tendons. Their conjoined insertion site is medial and distal to the tibial tubercle. They become distinct structures at a point that is further medial and slightly proximal. Tendon harvest is facillitated by identifying the tendons proximal to this point. The superficial medial collateral ligament lies deep to the tendons in this area and should not be disturbed. The accessory insertion of the semitendinosus tendon should be identified and transected to avoid tendon damage at harvest. Knee flexion may reduce the risk of injury to the saphenous nerve as it crosses the gracilis tendon. These results should be helpful to surgeon considering using the hamstring tendons as for ligament reconstruction of the knee.