A retrospective radiographic comparative study of 113 feet undergoing joystick-assisted minimally invasive surgery (MIS) vs. minimally invasive Chevron-Akin (MICA) for hallux valgus correction.

Introduction: Minimally invasive surgery (MIS) is often used to treat hallux valgus deformities, as it is associated with few wound complications and shorter recovery times. Minimally invasive chevron and Akin (MICA) osteotomy is a common minimally invasive treatment for hallux valgus. However, effective and precise three-dimensional correction of hallux valgus is difficult to achieve. The aim of this study was to introduce and evaluate the radiographic effectiveness of a novel joystick-assisted MIS technique for hallux valgus.

Materials and methods: A retrospective study of 113 patients with hallux valgus undergoing MICA (49 feet) or joystick-assisted MIS (64 feet) between August 2019 and July 2024 was conducted.

Inclusion criteria: failure of conservative management, age 18-60 years, HVA > 20° on weight-bearing radiographs, minimum 6-month follow-up.

Exclusion criteria: prior surgery, rheumatic disease, neuropathy, vascular insufficiency, incomplete data/radiographs. Radiographic parameters were compared between groups.

Results: The mean age of the MICA group was 40.3 ± 11.3 years, and the joystick-assisted MIS group was 39.2 ± 13.5years. In the MICA group, the mean preoperative HVA, IMA, and DMAA were 32.1°±6.5°, 13.6°±2.8°, and 10.2°±3.6° respectively, decreasing postoperatively to 7.6°±4.2°, 5.3°±2.1°, and 2.4°±1.8°. In the joystick-assisted MIS group, corresponding values were 32.3°±10.0°, 14.3°±2.9°, and 10.9°±3.0° preoperatively, decreasing to 7.4°±4.3°, 5.1°±2.3°, and 2.2°±1.4° postoperatively. No significant intergroup differences were observed in pre- or postoperative HVA, IMA, DMAA, or TSP. The joystick-assisted MIS group demonstrated statistically superior metatarsal alignment and pronation correction compared to the MICA group (p < 0.001 for both).

Conclusions: Both the MICA technique and joystick-assisted MIS can correct HVA, IMA, TSP and first metatarsal pronation for moderate and severe hallux valgus. Compared with the MICA technique, joystick-assisted MIS has advantages in controlling the three-dimensional position of the metatarsal head.