Small femoral offset is a risk factor for lateral femoral cutaneous nerve injury during total hip arthroplasty using a direct anterior approach

• Published in: Orthopaedics & traumatology, surgery & research Vol. 102; no. 8; pp. 1043 - 1047
• Main Authors: Ozaki, Y, Homma, Y, Sano, K, Baba, T, Ochi, H, Desroches, A, Matsumoto, M, Yuasa, T, Kaneko, K
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01-12-2016
• Subjects: Adult; Aged; Aged, 80 and over; Arthroplasty, Replacement, Hip - adverse effects; Arthroplasty, Replacement, Hip - methods; Case-Control Studies; Direct anterior approach; Fascia Lata - diagnostic imaging; Fascia Lata - pathology; Female; Femur - diagnostic imaging; Femur - innervation; Femur - pathology; Humans; Lateral femoral cutaneous nerve; Male; Middle Aged; Orthopedics; Peripheral Nerve Injuries - etiology; Retrospective Studies; Risk Factors; Surgery; Surveys and Questionnaires; Thigh - innervation; Tomography, X-Ray Computed; Total hip arthroplasty; Lateral femoral cutaneous nerve; Direct anterior approach; Total hip arthroplasty
• ISSN: 1877-0568; 1877-0568
• DOI: 10.1016/j.otsr.2016.08.019

Abstract Introduction Lateral femoral cutaneous nerve (LFCN) injury is a risk specific to the direct anterior approach (DAA) for total hip arthroplasty (THA). However, prevention strategies have not been established. This study aimed to identify the predisposing factors determining LFCN injury during THA via a DAA. Hypothesis Patients with LFCN injury after THA via DAA would demonstrate predisposing factors. Material and methods LFCN injury was identified using a patient questionnaire. Potential factors predisposing to LFCN injury were identified in four categories in patient records: patient factors (age, sex, BMI, diagnosis and range of hip motion), surgical factors (surgical time and surgeon's experience of the DAA), preoperative radiographic factors (neck-shaft angle, femoral offset, acetabular offset, total offset and length of muscle on computed tomography axial image) and radiographic changes (differences between each offset pre- and post-surgery). Multivariate analysis was performed to identify risk factors for LFCN injury during this surgery. Results After application of inclusion and exclusion criteria, 102 hips (28 with LFCN injury; 74 without) in 102 patients (17 males, 85 females; mean age 66.0 years [range, 26–88 years]) were included. Univariate analysis of patients with and without LFCN injury revealed that small preoperative femoral offset and short preoperative long axis of the tensor fascia lata were statistically significant risk factors for LFCN injury ( P = 0.004, and P = 0.01, respectively). Multivariate analysis showed that small preoperative femoral offset was the only independent risk factor for LFCN injury (odds ratio, 0.895; 95% Confidence Interval, 0.817–0.981; P = 0.0018). Discussion Smaller femoral offset was a significant risk factor for LFCN injury following THA via a DAA. Our recommendations are that careful attention should be paid to the skin-fascia incision and subcutaneous exposure, and that excessive retraction of the sartorius muscle and tensor fascia lata should be avoided, to reduce the risk of LFCN injury in patients with a small femoral offset. Level of evidence IV, retrospective historical cohort study.