Functional and Radiographic Outcomes of Minimally Invasive Intramedullary Nail Device (MIIND) for Moderate to Severe Hallux Valgus

BACKGROUND: This study was aimed at assessing clinical and radiographic outcomes of the Minimally Invasive Intramedullary Nail Device (MIIND) to correct moderate to severe hallux valgus (HV) and the long-term persistence of its effects.METHODS: This case series study involved 100 patients, 84 women and 16 men (mean age, 59 years), who underwent the MIIND procedure with a mean follow-up of 97 months. Assessment was performed preoperatively, postoperatively, at 6 and 12 months, and at last follow-up. Clinical outcomes were evaluated with American Orthopaedic Foot & Ankle Society (AOFAS) scores, visual analog scale (VAS), and patient satisfaction. Intermetatarsal angle (IMA), metatarsophalangeal hallux valgus angle (HVA), distal metatarsal articular angle (DMAA), and tibial sesamoid position were assessed. Statistical analysis was performed.RESULTS: The mean AOFAS score improved from 57.9 to 90.5 points, VAS scale was 1.5 ± 2.0, and patients' satisfaction was 8.7 ± 1.4. The mean correction of the HVA and IMA showed a significant correction; however, the effect of time was not statistically significant on DMAA. Sex (P = .047), severity (P = .050), associated procedures (P = .000), and preoperative angle (P = .000) showed significant association with HVA correction and its persistence over time. Age was not statistically significant. Complications were 9 cases of superficial wound infection and 6 recurrences.CONCLUSIONS: The MIIND technique proved a viable procedure to correct moderate to severe HV with a low rate of complications and recurrence, producing significant correction of most radiographic parameters assessed and their persistence, even at long term.LEVEL OF EVIDENCE: Level IV, case series study.