This prospective comparative cohort study asked whether third-generation minimally invasive Chevron-Akin (MICA) surgery reduces MTP joint stiffness and improves ROM compared to open scarf-Akin for mild-to-moderate hallux valgus. It is the first study to report stiffness and ROM outcomes specifically for MICA, with minimum 2-year follow-up in 98 patients.
MICA was developed specifically to reduce the 7-38% stiffness rate seen after open hallux valgus surgery by minimizing soft tissue trauma. Prior to this study, no published data on stiffness or ROM after MICA existed — advocates were claiming superiority without evidence.
When a patient asks about minimally invasive bunion surgery to avoid stiffness, this paper gives you the answer: stiffness rates are identical at 2 years (6% each), and the only proven benefit is a shorter scar (1.2 cm vs. 5 cm). Weigh that against a reoperation rate of 27% vs. 8%. Almost entirely for hardware problems. And a 14% intraoperative conversion rate even in experienced hands.
The 10-degree extension advantage seen with MICA is a mechanical consequence of greater metatarsal shortening from the burr, not a soft tissue benefit. Patients should not be counseled that MICA protects against stiffness.
This prospective comparative cohort study asked whether third-generation minimally invasive Chevron-Akin (MICA) surgery reduces MTP joint stiffness and improves ROM compared to open scarf-Akin for mild-to-moderate hallux valgus. It is the first study to report stiffness and ROM outcomes specifically for MICA, with minimum 2-year follow-up in 98 patients.
MICA was developed specifically to reduce the 7-38% stiffness rate seen after open hallux valgus surgery by minimizing soft tissue trauma. Prior to this study, no published data on stiffness or ROM after MICA existed — advocates were claiming superiority without evidence.
When a patient asks about minimally invasive bunion surgery to avoid stiffness, this paper gives you the answer: stiffness rates are identical at 2 years (6% each), and the only proven benefit is a shorter scar (1.2 cm vs. 5 cm). Weigh that against a reoperation rate of 27% vs. 8%. Almost entirely for hardware problems. And a 14% intraoperative conversion rate even in experienced hands.
The 10-degree extension advantage seen with MICA is a mechanical consequence of greater metatarsal shortening from the burr, not a soft tissue benefit. Patients should not be counseled that MICA protects against stiffness.