Minimally Invasive Chevron Akin for Hallux Valgus Surgery: A Prospective Observational Study With Mean 6.8-Year Follow-Up

Introduction Minimally invasive distal first metatarsal osteotomy with internal fixation has become an established technique for correction of hallux valgus deformities. Published data is limited to follow-up of 2–3 years. This study aimed to assess a large cohort of patients undergoing, MICA (Minimally Invasive Chevron and Akin), with minimum 5 year follow up. To evaluate the longer-term results of this procedure, patient reported outcome measures (PROMs) were used. Methods Five year PROM data was prospectively collected from consecutive patients who underwent primary MICA osteotomies performed by a single surgeon. The primary outcome measure was the Manchester-Oxford Foot Questionnaire (MOXFQ). Secondary outcome measures included visual analogue scale for pain (VAS-pain), and EuroQol-5 Dimensions Index (EQ-5D). Data were collected preoperatively, at 2 years and after a minimum of 5 years. Statistical significance was set at p< 0.05. Results 240 MICA were performed on 164 patients. Mean follow-up was 6.8±1.0 years with all patients completing minimum 5 year follow-up scores. The MOXFQ scores for all feet improved across all domains: from 44.6±20.9 preoperatively to 9.5±17.7 post-operatively for Pain (p < 0.001), from 37.7±23.6 to 8.0±17.5 for Walking and Standing (p < 0.001) and from 47.9±22.0 to 7.8±17.1 for Social Interaction (p < 0.001). VAS-pain & EQ-5D also improved. There was no statistically significant change in scores between minimum two- and five-year follow up PROMs. Conclusion This study reports the longest PROMs for minimally invasive hallux valgus surgery and demonstrates significant improvement which is maintained at minimum five-year follow up.