Hamstring Harvest Technique for Anterior Cruciate Ligament Reconstruction

Abstract

Traditional hamstring harvest of the semitendinosis and/or gracilis tendons may typically be performed through a limited 2-3 cm anteromedial incision. After isolation and distal release of the individual tendon(s), careful mobilization is performed to remove adjacent attachments, particularly at the medial head of the gastrocnemius. Tendon stripping releases the tendon proximally, and graft preparation and sizing are undertaken for subsequent ligament reconstruction.

Keywords

ACL, gracillis, hamstring, harvest, pes anserine, semitendinosis

Keywords

ACL, gracillis, hamstring, harvest, pes anserine, semitendinosis

Technique of Hamstring Graft Harvest

The anatomy of the distal hamstring complex has been extensively described in the literature. Lipscomb et al. initially reported that the hamstring strength after autograft harvest was comparable to the contralateral side. However, while predictable tendon regeneration has been documented after Semitendinosis and gracilis (STG) harvest, weakness of knee flexion above 90 degrees has been reported. Consequently, several surgeons have exercised caution in recommending hamstring grafts for those athletes who require full, active knee flexion strength, such as sprinters, gymnasts, wrestlers, and martial artists. In order to offset postoperative flexion weakness, Gobbi et al. recommend preservation of the gracilis, whereas other authors dispute the relative advantages of single- versus double-tendon harvest. Similarly, increased rates of clinical failure and secondary revision anterior cruciate ligament (ACL) reconstruction have been associated with smaller hamstring graft diameter (i.e., <8 mm), which may also be predicted by the cross-sectional area on preoperative magnetic resonance imaging and/or patient height.

Skin Incision

The skin incision for hamstring harvest should be made with the knee flexed in the figure-four position ( Fig. 19.1 ). An oblique 3-cm skin incision is made 5 cm below the joint line over the palpable distal semitendinosus. The incision should start 2 cm medial to the tibial tubercle and then continue posteromedially. The oblique incision is preferable to the vertical incision for two reasons: it gives a greater exposure to the length of the tendon, and it also has less potential to injure the infrapatellar branch of the saphenous nerve. Plan to harvest the graft, and drill the tibial tunnel through this incision. Incise the subcutaneous fat, and strip the fat off the sartorial fascia with a sponge.

Exposure of the Tendon

Identify the semitendinosus by palpating the superior edge with your finger. Incise the fascia over the upper border of the semitendinosus. Lift up the tendon with a hook, and free it with the hook from the fascia proximally and distally. Use a Kocher to apply distal traction to the tendon.

The fascial bands to the gastrocnemius are visualized and cut with the scissors ( Fig. 19.2 ). The tendon should feel free proximally. There should be no dimpling of the skin over the gastrocnemius when distal traction is applied to the tendon.

Tendon Release

Free the distal end of the tendon with the scissors while ensuring that maximal length is maintained distally as the broad tendon end fans out. Grasp the released end with a Kocher, and pull it firmly into the incision, where optionally it can be sutured in situ for greater control, and any residual bands can be released with the traction and blunt finger dissection. The tendon should be able to be withdrawn to the lateral side of the tibial tubercle once adequately mobilized ( Fig. 19.3 ).