Early Radiological and Functional Outcomes of Fourth-Generation Minimally Invasive Surgery vs Open Surgery for Hallux Valgus Correction

Research Type: Level 2 - Prospective comparative study, Meta-analysis of Level 2 studies or Level 1 studies with inconsistent results Introduction/Purpose: Introduction: Fourth-generation minimally invasive surgery (MIS) is a promising technique for the treatment of hallux valgus (HV). There are few studies comparing the functional and radiological outcomes of fourth-generation MIS versus open surgery for HV correction. Objectives: To compare radiological and functional outcomes (PROMS) of patients undergoing fourth-generation MIS and open surgery. Methods: A prospective cohort study of patients who underwent HV surgery at a trauma center was performed. Convenience sampling was used. Inclusion criteria: patients aged ≥18 years with at least six-month of postoperative follow-up. The following groups were compared: a) Open surgery group: Chevron or Scarf and Akin osteotomy, or b) Fourth-generation MIS group: extra-articular metaphyseal transverse osteotomy and Akin (META). The decision to perform open or MIS surgery was based on the surgeon's preference. Patients with previous surgery or a history of first-ray trauma were excluded. The FAOS questionnaire (0-100 points), VAS, and quality of life (EQ-5D) were assessed. Two foot and ankle surgeons measured the following pre- and postoperative parameters: hallux valgus angle (HVA), 1-2 intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA), and first metatarsal shortening. Results: A total of 72 patients were included (mean age: 52 years, 96% women); 30 patients in the fourth-generation MIS group (45 feet) and 42 in the open surgery group (62 feet). The mean follow-up was 12 months in the open surgery group and 9 months in the MIS group. Both techniques resulted in significant reductions in the postoperative radiological parameters. When comparing groups, there were no differences in measurements except for first metatarsal shortening, which was greater in the open surgery group. Regarding FAOS, VAS, and EQ-5D scores, no significant differences were found, except for mobility, which was better in the fourth-generation MIS group [median 2 (range 1-3) vs. 1 (range 1-4)]; P = 0.04. Conclusion: At 6 months of follow-up, fourth-generation MIS is at least comparable to Chevron/Scarf + Akin osteotomy in terms of radiological and functional outcomes. Future studies with longer follow-up periods and larger sample sizes are needed to confirm these findings.