Background: Stiffness after open hallux valgus surgery affects 7% to 38% of patients. Minimally invasive surgery (MIS) is thought to decrease this rate by reducing soft tissue trauma. MIS, now in its third generation, is advertised as delivering results superior to open surgery. However, no studies have reported stiffness or range of motion (ROM).
Methods: Between January 2014 and December 2015, a total of 50 patients received open scarf-Akin surgery and 48 received minimally invasive Chevron Akin (MICA) surgery. The endpoints were American Orthopaedic Foot & Ankle Society (AOFAS) score, range of motion, visual analog scale for pain, scar length, and subjective foot value. The minimal follow-up time was 2 years.
Results: Moderate stiffness occurred in 3 cases in both groups. In MICA, extension increased by 10 degrees while it remained unchanged in scarf. Both groups showed similar improvements in AOFAS score, pain, and subjective foot value. Radiographic evidence of correction was comparable, except for an increased shortening of the first metatarsal by 3 mm in MICA. The scars were smaller in MICA (1.2 cm) than in scarf (5 cm). Wound problems included delayed healing in 10% in scarf and wound infections in 4% in MICA. The rate of recurrence and other complications were comparable, except for reoperations, which were higher in MICA (27% mainly for protruding screws) than in scarf (8% mainly for stiffness). In MICA, 14% were intraoperatively converted to open surgery.
Conclusion: MICA showed no advantages over scarf other than a shorter scar. The observed gain in extension could be related to the increased shortening of the first metatarsal because of the size of the burr.
Level of evidence: Level II, prospective cohort (nonrandomized, comparative) study.
Keywords: MICA; hallux valgus; minimally invasive; range of motion; scarf; stiffness.