COSMIC FEASIBILITY STUDY: COMPARING OPEN SCARF OSTEOTOMY AND MINIMALLY INVASIVE CHEVRON OSTEOTOMY FOR HALLUX VALGUS CORRECTION

Objectives Minimally invasive surgery (MIS) has gained popularity for hallux valgus, compared to the traditional scarf osteotomy (OS). Though evidence suggests similar clinical outcomes, there is paucity of randomised controlled studies. This study aimed to assess the feasibility of conducting a randomised controlled trial comparing the patient recorded and clinical outcomes for the surgical management of Hallux Valgus between OS and MIS Chevron Akin (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-5L) pre-operatively and post-operatively at 6 months and 1 year. Radiological parameters and range of motion were measured pre-and post-operatively. Results 31 patients were recruited between Dec 2017 and June 2022. 17 patients were randomised to MICA (15 female, mean age 51) and 15 to OS (14 female, mean age 51). Both groups had a significant improvement in all MOXFQ parameters at 6m and 12m, as well as radiological parameters. VAS improved for OS (p=0.048) and for MICA (p=0.059) at 6m. There was no significant improvement in EQ-5D in either group at 12 months and no significant difference in operative time (p=0.53). There was a higher number of complications in the MICA group with 5 removal of metalwork (29.4%) and 2 superficial infections (11.8%) versus none in the OS group. The dorsiflexion significantly improved in the OS group at 6months (p=0.04). Recruitment rate dipped during COVID. No patients were lost at follow up. Conclusion Both surgical options show similar clinical results, but higher complication rates were seen with MICA. This study illustrates the feasibility to conduct a randomised control trial for the comparison between the two techniques. Challenges to recruitment included surgeon equipoise, patient preference, training requirement and the pandemic which could be mitigated in a larger study.