Electrophysiological Assessment of Injury to the Infra-patellar Branch(es) of the Saphenous Nerve during Anterior Cruciate Ligament Reconstruction Using Medial Hamstring Auto-grafts: Vertical versus Oblique Harvest Site Incisions

Abstract

Background It was suggested that the direction of incision for medial hamstring tendons harvesting influences the incidence of injury to the infrapatellar branch of the saphenous nerve (IPBSN), a common complication following arthroscopically-assisted anterior cruciate ligament reconstruction (ACLR).

Objectives The main purpose of current study was to compare the incidence of IPBSN injury between vertical and oblique incisions utilizing electrophysiological evaluation.

Patients and Methods There were 60 patients underwent arthroscopically-assisted ACLR assigned to two equal vertical or oblique incision groups, randomly. One year postoperatively, the patients were electrophysiologically examined to detect whether IPBSN is injured. The Lysholm score was completed. The patients' satisfaction with surgical outcomes determined utilizing visual analogue scale (VAS). Finally, two groups were compared and the effect of IPBSN injury on function and satisfaction was investigated.

Results The incidence of IPBSN injury was higher in the vertical group (4 patients vs. 10 patients), but the difference was not statistically significant. The mean of Lysholm and VAS scores were the same. Also, the mean of Lysholm score was the same in patients with and without IPBSN injury. However, patients without IPBSN injury were more satisfied (8.9 ± 9 vs. 7.4 ± 1.1; P < 0.001).

Conclusions IPBSN injury is a common complication following arthroscopically-assisted ACLR and, if not significant, oblique direction of the incision is associated with decreased incidence of the injury. IPBSN injury has no effect on the function but because of the disturbance with patients' satisfaction, authors believe the oblique incision is preferable to avoid the nerve injury during medial hamstring tendons harvesting.