Oblique incisions in hamstring tendon harvesting reduce iatrogenic injuries to the infrapatellar branch of the saphenous nerve

Purpose Iatrogenic injury to the infrapatellar branch of the saphenous nerve (IPBSN) is associated with many surgical interventions to the medial aspect of the knee, such as anterior cruciate ligament (ACL) reconstruction. Different types of surgical incisions during hamstring tendon harvesting for ACL reconstruction are related to a variable risk of IPBSN injury. This study aimed to evaluate the risk of iatrogenic IPBSN injury during hamstring tendon harvesting for ACL reconstruction with different incision techniques over the pes anserinus. Methods This study was performed on 100 cadavers. Vertical, horizontal, or oblique incisions were simulated on each cadaveric limb to determine the incidence of iatrogenic IPBSN injury. Results The vertical incision caused the IPBSN injury during hamstring tendon harvesting in 101 (64.7%), the horizontal incision in 78 (50.0%), and the oblique incision in 43 (27.6%) examined lower limbs. The calculated odds ratios (OR) for risk of injury in vertical versus horizontal and horizontal versus oblique incisions were 2.4 (95% CI 1.5–3.6) and 1.8 (95% 1.2–2.8), respectively. Conclusions The vertical incision technique over the pes anserinus should be avoided during hamstring tendon harvesting for ACL reconstruction. The adoption of an oblique incision, with the shortest possible length, will allow for the safest procedure possible, thus minimizing the risk of iatrogenic IPBSN injury, and improving patient outcomes and postoperative quality-of-life.