Surgical Anatomical Study of the Lateral Femoral Cutaneous Nerve in Direct Anterior Approach for Total Hip Arthroplasty to Minimize Neurological Complications.

Injury to the lateral femoral cutaneous nerve (LFCN) is a well-recognized complication of total hip arthroplasty (THA) performed via the direct anterior approach (DAA), largely due to the anatomical variability of the nerve and its proximity to surgical incision lines. The present cadaveric study aimed to quantitatively evaluate the anatomical relationship between the LFCN and commonly used skin incisions in the DAA, including the bikini and longitudinal incision lines, to identify incision-related risk patterns and potential safer zones. Seventy-three thighs from 50 fresh Korean adult cadavers were used. Prior to dissection, bony landmarks and DAA incision lines were marked on the skin using pins. Dissection was then performed to expose the fascia lata and the LFCN, after which the distance between the incision line and the nerve was measured and statistically analyzed. Two principal emergence patterns of the LFCN, stem and divided, were identified, with the divided pattern being slightly more prevalent. The bikini incision intersected the anterior branch of the LFCN in all specimens, whereas the posterior branch was spared in approximately one-quarter of cases. In contrast, longitudinal incisions rarely intersected the anterior branch but frequently overlapped with the posterior branch; this overlap was more pronounced when the incisions were placed closer to the anterior superior iliac spine. These findings indicate that the risk of LFCN injury varies according to incision type and may be reduced by lateral adjustment in both incision lines, as well as by distal adjustment in the longitudinal incision. This quantitative anatomical evidence provides a foundation for optimizing DAA incision strategies in THA and may contribute to reducing postoperative sensory complications related to LFCN injury.