NATURAL HISTORY OF LATERAL FEMORAL CUTANEOUS NERVE NEUROPRAXIA AFTER ANTERIOR APPROACH TOTAL HIP ARTHROPLASTY: A FIVE-YEAR FOLLOW-UP

The incidence of lateral femoral cutaneous nerve (LFCN) neuropraxia after anterior approach total hip arthroplasty has been reported to occur in up to 50% of patients. In the vast majority of cases there has been no functional impact it is unknown if symptoms persist or diminish over time. The aim of this study was to examine the natural history LFCN neuropraxia in a previously reported cohort of individuals after anterior approach total hip arthroplasty. One hundred and forty three consecutive patients underwent direct anterior hip approach (DAA) between September 2006 and February 2009 of which 107 had been identified with LCFN neuropraxia. These 107 patients (39 THA; 68 HR; 44 Female & 63 male; mean age 55.4 (38.4–88.8)), were provided a self-reported questionnaire for sensory deficits associated with LFCN as well as severity of symptoms on a 10 point visual analogue scale (VAS). These were done at initial assessment and latest follow-up. Sixty of the 107 patients (56%) completed their questionnaires at a mean follow-up of 5.4 years (24 THA; 36 HR). Twenty-two percent (13 of 60: 8 men & 5 women) had complete resolution of their symptoms (9 HR and 4 THR). Of the 47 patients (78%) still reporting symptoms of LFCN neuropraxia, the mean score on VAS decreased from a mean of 2.32 (SD:2.11) to 1.74 (SD:1.99). No limitation in activities was reported for 90% of patients (54 out of the 60). Of the 6 patients (10%) with limited activity they reported a mean VAS score of 4.4 (SD: 3.6 range of 0–8.4). The LFCN symptoms did not appear to be directly related to their activity limitation. While LFCN neuropraxia can be a common complication following direct anterior approach hip replacement, almost a quarter of patients will have complete resolution of symptoms and the majority will have a decrease in their symptomatology. LFCN neuropraxia following DAA hip arthroplasty does not appear to lead to any functional limitations and is associated with a low score on VAS.