Comparison of Open Scarf-Akin Osteotomy and Minimally Invasive Chevron and Akin (MICA) Osteotomy for Severe Hallux Valgus Deformity: A Retrospective Study.

BACKGROUND

Minimally invasive surgery (MIS) for hallux valgus, particularly the minimally invasive chevron and Akin (MICA) technique, is gaining popularity. However, comparative studies between open scarf-Akin osteotomy (SA) and MICA remain limited, particularly for severe cases (ie, hallux valgus angle [HVA] ≥ 40° or intermetatarsal angle [IMA] ≥ 16°). This study aimed to compare the clinical and radiographic outcomes between SA and MICA for severe hallux valgus.

METHODS

We retrospectively reviewed 56 consecutive feet (SA = 33; MICA = 23) treated between January 2019 and January 2023 at a single institution in Hong Kong. Clinical outcomes were evaluated using the American Orthopaedic Foot & Ankle Society (AOFAS) score, Self-Reported Foot and Ankle Score (SEFAS), and visual analog scale (VAS) for pain. Radiographic parameters included the HVA, IMA, distal metatarsal articular angle (DMAA), first metatarsal pronation, and first metatarsal length.

RESULTS

Baseline characteristics were broadly comparable, with deformity severity trending higher in MICA. MICA had shorter total operative time and hospital stay (P = .002 and P < .001), although the SA group had a higher frequency of concomitant lesser-toe procedures (85% vs 61%, P = .056), and MICA showed greater improvements in AOFAS and SEFAS (P = .006 and P = .032). In exploratory 2-predictor sensitivity regression adjusting for concomitant lesser-toe procedure, MICA remained associated with shorter operative time (beta = -40.0 min, 95% CI -66.3 to -13.7; P = .003) and shorter length of stay (beta = -2.35 days, 95% CI -3.52 to -1.17; P < .001). After this adjustment, AOFAS improvement was greater in MICA (beta = +6.40, P = .008), whereas SEFAS and VAS improvements were not statistically different. For pronation, SA achieved superior apparent correction: severe postoperative pronation (Wagner 3) was 0% after SA vs 48% after MICA, and baseline-adjusted ordered logistic regression similarly favored SA (MICA vs SA OR 3.75, 95% CI 1.08-13.03; P = .037).

CONCLUSION

Both procedures reliably corrected severe HV deformity. MICA was associated with shorter total operative time and reduced length of stay. In exploratory covariate-adjusted sensitivity models, MICA maintained advantages in operative time and AOFAS scores, whereas between-group differences in SEFAS and angular radiographic outcomes were attenuated or nonsignificant. In contrast, SA demonstrated stronger correction of apparent first-metatarsal pronation, with no apparent residual severe pronation at follow-up compared with MICA.

LEVEL OF EVIDENCE: Level III, retrospective cohort study.