Influence of Anesthesia on harvesting the semitendinosus tendon for ACL replacement

Objective: Semitendinosus (ST) tendon is a commonly used graft for anterior cruciate ligament (ACL) repair. The longer the tendon, the more often can it be folded, yielding a bigger diameter and better stability. We aimed to investigate if the kind of anaesthesia is a relevant factor influencing the length of the harvested semitendinosus tendon.

Methods: This prospective, non-randomized study included patients undergoing ACL replacements at a single unit. The patients chose between spinal and general anaesthesia. If general anaesthesia was chosen, a short relaxation period was applied while harvesting the ST tendon. The data for tendon length, the folding factor, and the diameter of the graft was collected. Except for redo procedures and repairs with allograft, all patients undergoing an ACL replacement were included.

Results: 31 patients with general anaesthesia (GA) and 14 patients with Spinal Anaesthesia (SA) were examined. The ST tendon length was 29.03 cm ± 2.6 cm in the GA group and 25.4 cm ± 2.70 in the SA group (p=0.0001). The ST tendon could be quadrupled in 23 patients in the GA and 6 patients in the SA group (χ2=4.13, p=0.04). The graft diameter obtained was 8.53 mm ± 0.62 mm in the GA group and 7.71 mm ± 0.47 mm in the SA group (p<0.0001).

Conclusion: GA with short time relaxation while harvesting the ST tendon for ACL grafting allows to harvest longer ST tendons and consequently yields better results regarding the graft dimensions and should be offered to patients as a first choice.