Increased Risk of Lateral Femoral Cutaneous Nerve Injury in Patients With Previous Hip Arthroscopy Who Underwent a Direct Anterior Approach Total Hip Arthroplasty.

PURPOSE: To evaluate the rates of lateral femoral cutaneous nerve (LFCN) injury in patients who underwent a direct anterior approach (DAA) total hip arthroplasty (THA) with and without previous hip arthroscopy.

METHODS: We retrospectively investigated consecutive DAA THAs performed by a single surgeon. These cases were grouped into patients with and without a history of previous ipsilateral hip arthroscopy. LFCN sensation was assessed during the initial follow-up (6 weeks) and 1-year (or most recent) follow-up visits. The incidence and character of LFCN injury was compared between the 2 groups.

RESULTS: In total, 166 patients underwent a DAA THA with no previous hip arthroscopy, and 13 had a history of previous arthroscopy. Of the 179 total patients who underwent THA, 77 experienced some form of LFCN injury at initial follow-up (43%). The rate of injury for the cohort with no previous arthroscopy was 39% (n = 65/166) on initial follow-up, whereas the rate of injury for the cohort with a history of previous ipsilateral arthroscopy was 92% (n =12/13) on initial follow-up ( P < .001). In addition, although the difference was not significant, 28% (n = 46/166) of the group without history of previous arthroscopy and 69% (n = 9/13) of the group with a history of previous arthroscopy had continued symptoms of LFCN injury at most recent follow-up.

CONCLUSIONS: In this study, patients who underwent hip arthroscopy before an ipsilateral DAA THA were at increased risk of LFCN injury compared with patients who underwent a DAA THA without a previous hip arthroscopy. At final follow-up of patients with initial LFCN injury, symptoms resolved in 29% (n = 19/65) of patients with no previous hip arthroscopy and 25% (n = 3/12) of patients with previous hip arthroscopy.

LEVEL OF EVIDENCE: Level III, case-control study.