Two Year Follow-Up of Patient Reported Outcomes Following Third Generation Minimally Invasive Chevron Akin Osteotomies (MICA) in Hallux Valgus Surgery

Abstract

Category: Bunion Introduction/Purpose: The aim of this study was to explore the 2 year results of third generation (using screw fixation) Minimally Invasive Chevron and Akin osteotomies (MICA) for hallux valgus correction. There is a paucity of published data regarding the outcomes of this relatively new technique. We present the largest series in the literature, using three separate validated patient-reported outcome measures (EQ-5DL, VAS Pain and Manchester Oxford Foot Questionnaire (MOXFQ), for this time point. Methods: A single surgeon case series of patients with hallux valgus underwent primary third generation minimally invasive chevron and akin osteotomies for hallux valgus correction. Between August 2015 and January 2018, 290 MICAs were performed in 203 patients that were eligible for 2 year follow up. Baseline and 2 year post-operative patient reported outcomes were collected for 164 feet in 130 patients (124 females; 6 males). Paired t-tests were used to determine the statistical significance of the difference between pre- and post-operative scores. Results: The mean age was 56.6 (range 29.5-81.0, standard deviation (s.d.) 10.9). At two year follow up, mean MOXFQ scores improved for each domain: Pain; baseline 40.6 (range 0-100, s.d. 22.8), reduced to 11.3 (range 0-75, s.d. 16.0, p<0.001); Walking; 36.0 (range 0-100, s.d. 25.9) reduced to 8.2 (range 0-75.0, s.d. 16.0, p<0.001); Social interaction; 46.7 (range 0-100, s.d. 24.3), reduced to 7.7 (range 0-75.0, s.d. 13.9, p<0.001). Mean VAS Pain score improved from 30.4 (range 0.0-90.0, s.d. 23.6) to 9.4 (range 0.00-70.0, s.d. 15.6, p<0.001). Mean EQ-5D index score improved from 0.750 (range 0.066-1.000, s.d. 0.148) to 0.892 (range 0.410-1.000, s.d. 0.135, p<0.001). Mean EQ-5D VAS score did not significantly improve from 81.9 (range 0-100, s.d. 17.1) to 83.0 (range 0-100, s.d. 18.0, p=0.559). Conclusion: This is the largest prospective case series of short-term patient reported outcomes using a validated assessment method for hallux valgus, following third generation MICA to date. These data show that this technique is effective at improving foot and ankle specific patient reported outcomes at 2 years. This cohort is being followed over the longer term.