Minimally Invasive Chevron Akin for Hallux Valgus Surgery: A Prospective Observational Study with Mean 6.7 year Follow Up

O Townsend, N Hill, A Reaney, T Koç, T Lewis, D Gordon

Introduction: Minimally invasive (percutaneous) distal first metatarsal osteotomy with internal fixation is an established technique for hallux valgus deformity correction. Published data is limited to 2-3 years follow-up. This study aimed to assess patients undergoing MICA (Minimally Invasive Chevron and Akin) with minimum 5-year follow up, to evaluate the longer-term results of this procedure using validated patient reported outcome measures (PROMs).

Methods: Five-year PROM data was prospectively collected from 117 patients who underwent 169 primary MICA osteotomies between July 2014 and April 2018, performed by a single surgeon. Primary clinical outcome measures included visual analogue scale for pain (VAS-pain), Manchester-Oxford Foot Questionnaire (MOXFQ) 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: 169 MICA were performed on 117 patients (112 females, 5 males). Mean follow-up was 6.7 years (standard deviation (SD) 0.96 years). All patients completed minimum 5-year follow-up scores. The MOXFQ scores (mean ± SD) for all 169 feet improved for all domains: from 44.5 ± 22.1 preoperatively to 10.3 ± 17.0 post-operatively for Pain (p<0.001), from 39.2 ± 24.5 to 9.3 ± 17.9 for Walking and Standing (p<0.001) and from 48.2 ± 22.8 to 8.7 ± 17.6 for Social Interaction (p<0.001). VAS-pain improved from 30.8 ± 22.7 to 12.9 ± 21. (p<0.001). EQ-5D Index improved from 0.74 ± 0.14 to 0.90 ± 0.12 (p<0.001).

Conclusion: This is the largest study at this time point presenting PROM data following minimally invasive distal first metatarsal osteotomy. It is also the longest in follow up for this technique. This study demonstrates significant improvement in PROMs at the mid-term and MICA can be considered as an effective and long-lasting option for the management of hallux valgus deformity.