Third-Generation Minimally Invasive Chevron and Akin Osteotomies (MICA) in Hallux Valgus Surgery Two-Year Follow-up of 292 Cases

Background: There is interest in hallux valgus deformity correction using internal fixation with the minimally invasive chevron and Akin osteotomies (MICA) technique. The objective of this study was to assess the correction measured on postoperative radiographs and clinical outcomes, using validated outcome measures, at 2 years following third-generation MICA. Methods: This is a prospective single-surgeon case series of 333 consecutive feet that underwent MICA surgery between July 2014 and April 2018. The primary clinical outcome measures included the Manchester-Oxford Foot Questionnaire (MOXFQ), EuroQol-5 Dimensions-5 Level (EQ-5D-5L) Index, EuroQol-visual analogue scale (EQ-VAS), and a VAS for pain (VAS-pain). Secondary outcome measures included radiographic parameters and complication rates. Results: Preoperative and 2-year postoperative patient-reported outcome measures (PROMs) were collected for 292 feet (87.7%). At a minimum 2-year follow-up, the MOXFQ scores (mean +/- standard deviation [SD]) had improved in each domain-i.e., reduced from 44.5 +/- 21.0 preoperatively to 9.4 +/- 15.8 postoperatively for pain (p < 0.001), from 38.7 +/- 23.4 to 6.5 +/- 14.6 for walking and standing (p < 0.001), and from 48.0 +/- 22.3 to 6.6 +/- 13.5 for social interaction (p < 0.001). The VAS-pain score improved from 31.4 +/- 22.7 preoperatively to 8.4 +/- 16.4 at the 2-year follow-up (p < 0.001), the 1-2 intermetatarsal angle was reduced from 15.3 degrees +/- 3.6 degrees preoperatively to 5.7 degrees +/- 3.2 degrees at the 2-year follow-up (p < 0.001), and the hallux valgus angle was reduced from 32.9 degrees +/- 10.2 degrees to 8.7 degrees +/- 5.2 degrees (p < 0.001). Conclusions: The third-generation MICA provided significant improvement in clinical outcome measures at the 2-year follow-up and can be successfully used for correction of a range of hallux valgus deformities with a low rate of symptomatic recurrence.