Incidence of lateral femoral cutaneous nerve neuropraxia after anterior approach hip arthroplasty.

BACKGROUND

Although injury to the lateral femoral cutaneous nerve (LFCN) is a known complication of anterior approaches to the hip and pelvis, no study has quantified its' incidence in anterior arthroplasty procedures.

QUESTIONS/PURPOSES: We therefore defined the incidence, functional impact, and natural history of LFCN neuropraxia after an anterior approach for both hip resurfacing (HR) and primary total hip arthroplasty (THA).

METHODS

We followed 132 patients who underwent an anterior hip approach (55 THA; 77 HR). We administered self-reported questionnaires for sensory deficits of LFCN, neuropathic pain score (DN4), visual analog scale, as well as SF-12, UCLA, and WOMAC scores at one year postoperatively. A subset of 60 patients (30 THA; 30 HR) was evaluated at two time intervals.

RESULTS

One hundred seven patients (81%) reported LFCN neuropraxia with a mean severity score of 2.32/10 and a mean DN4 score of 2.42/10. Hip resurfacing had a higher incidence of neuropraxia as compared with THA: 91% versus 67%, respectively. No functional limitations were reported on SF-12, WOMAC, or UCLA scores. Of the subset of 60 patients followed over an average of 12 months, 53 (88%) reported neuropraxia at the first followup interval with only three (6%) having complete resolution at second followup. Improvement in DN4 scores was observed over time: 3.6 versus 2.5, respectively.

CONCLUSIONS

Although LFCN neuropraxia was a frequent complication after anterior approach THA, it did not lead to functional limitations in our patients. A decrease in symptoms occurred over time but only a small number of patients reported complete resolution.

LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.