Anatomical relationship between the distal lateral femoral cutaneous nerve and the quadriceps tendon autograft harvest site: a cadaveric study with implications for acl reconstruction surgery.

PURPOSE: The lateral femoral cutaneous nerve (LFCN) is a sensory nerve providing cutaneous sensation to the anterolateral thigh. Injury to the LFCN is a known complication of quadriceps tendon (QT) autograft harvest during anterior cruciate ligament (ACL) reconstruction. While the proximal course of the LFCN is well described, its distal anatomy relative to the QT remains poorly defined. This study evaluated the distal course of the LFCN to identify zones of reduced iatrogenic injury during QT harvest. METHODS: Twenty-nine lower extremity specimens from 17 formalin-embalmed cadavers were dissected to expose the LFCN and define its distal anatomy relative to the QT. Distances from the endpoint to five predefined QT landmarks were measured, and univariate linear regression assessed associations between donor height and LFCN-QT clearance. Group comparisons evaluated differences by height and sex. RESULTS: Twenty-nine lower extremities (16 female, 13 male) were analyzed. Mean LFCN-QT clearance was smallest at the superior QT border (37.4 ± 34.6 mm) and greatest at the inferior QT border (101.9 ± 46.2 mm). Donor height was positively associated with clearance at all landmarks (all p < 0.05). Female donors demonstrated reduced clearance on unadjusted analysis; however, these differences were no longer significant following adjustment for height. CONCLUSION: The LFCN is at greatest risk of injury near the superior QT border, where LFCN-to-QT clearance is lowest. Shorter individuals demonstrated reduced clearance distances overall, suggesting height may be a more relevant predictor of LFCN-QT clearance than sex. These findings support individualized surgical planning during QT autograft harvest to minimize iatrogenic LFCN injury.