The influence of obesity and gender on outcome after reversed L-shaped osteotomy for hallux valgus

BACKGROUND: Hallux valgus deformity (HV) affects around every fourth individual, and surgical treatment is performed in every thousandth person. There is an ongoing quest for the best surgical management and reduction of undesirable outcomes. The aim was to explore associations of obesity and gender with radiological and clinical outcome after reversed L-shaped osteotomy (ReveL) for HV. MATERIALS AND METHODS: This study was carried out in a retrospective cohort design at a single University Hospital in Switzerland between January 2004 and December 2013. It included adult patients treated with ReveL for HV. The primary exposure was body mass index (BMI) at the time of ReveL. The secondary exposure was gender. The primary outcome was radiological relapse of HV (HV angle [HVA] > 15 degrees [°]) at the last follow-up. Secondary outcomes were improvable patient satisfaction, complication, redo surgery, and optional hardware removal. Logistic regression analysis adjusted for confounders. RESULTS: The median weight, height, and BMI were 66.0 (interquartile range [IQR] 57.0–76.0) kilograms (kg), 1.65 (IQR 1.60–1.71) metres (m), and 24.0 (IQR 21.3–27.8) kg/m(2). Logistic regression analysis did not show associations of relapse with BMI, independent of age, gender, additional technique, and preoperative HVA (adjusted odds ratio [OR(adjusted)] = 1.10 [95% (%) confidence interval (CI) = 0.70–1.45], p = 0.675). Relapse was 91% more likely in males (OR(adjusted) = 1.91 [95% CI = 1.19–3.06], p = 0.007). Improvable satisfaction was 79% more likely in males (OR(adjusted) = 1.79 [CI = 1.04–3.06], p = 0.035). Hardware removal was 47% less likely in males (OR(adjusted) = 0.53 [95% CI 0.30–0.94], p = 0.029). CONCLUSIONS: In this study, obesity was not associated with unsatisfactory outcomes after ReveL for HV. This challenges the previous recommendation that preoperative weight loss may be necessary for a successful surgical treatment outcome. Males may be informed about potentially higher associations with unfavourable outcomes. Due to the risk of selection bias and lack of causality, findings may need to be confirmed with clinical trials.