Feasibility Study for COSMIC Study - Comparing Open SCARF Osteotomy and Minimally Invasive Chevron Osteotomy for Hallux Valgus Correction

Category: Bunion; Other Introduction/Purpose: Minimally invasive surgery for hallux valgus deformity is gaining popularity over the traditional Open scarf osteotomy. Emerging evidences are showing similar clinical outcomes but further studies are needed to ascertain this. The aim of this study was to assess the feasibility of conducting a randomised controlled trial to compare the patient recorded and clinical outcomes for the surgical management of Hallux Valgus between open scarf osteotomy (OS) and minimally invasive chevron osteotomy (MICA). Methods: Patients suitable for surgical correction were invited to participate. Post op rehabilitation was standardised for both groups. Patients completed a validated questionnaire (Manchester Oxford Foot questionnaire and EQ-5D) preoperatively and post operatively at 6 months and 1 year. Radiological parameters and range of motion were measure pre and post operatively. A total of 41 patients were eligible for the study, 31 were successfully recruited and operated between Dec 2017 and June 2022. Results: 17 patients were randomised to MIS (15 female, mean age 51 years) and 14 to OS (13 female, mean age 51 years). Both groups have a significant improvement in the MOXFQ parameters (walking, pain and social) at 6m and 12m, as well as radiological parameters. VAS improved for OS at 6m (p=0.048) and 12m (p=0.025) but only improvement at 6m was seen for MICA (p=0.059 and p=0.054 at 12m). There was no improvement in EQ-5D in either group at 12 months and no difference in surgical time (p=0.53).There was a higher number of complication in the MICA group with 5 removal of metalwork (29.4%) and 2 superficial infections (11.8%) vs none in the OS group. Conclusion: Both surgical options show similar clinical results but higher complication rate was seen with MICA. A larger study is needed to evaluate further.