Radiographic and Clinical Results of Minimally Invasive Transverse Distal 1st Metatarsal and Akin Osteotomies for Symptomatic Hallux Valgus

Category: Bunion; Other Introduction/Purpose: Minimally invasive techniques for surgical treatment of hallux valgus (HV) has gained popularity over the past few years. Most published reports involve combined minimally invasive Chevron and Akin osteotomies (MICA) performed by a single surgeon. This study reports radiographic and clinical results on patients who underwent minimally invasive transverse distal 1st metatarsal and Akin osteotomies by 3 fellowship trained Foot & Ankle orthopedic surgeons. Methods: 192 consecutive patients (213 feet) between 2019 and 2022 with symptomatic hallux valgus without 1st tarsometatarsal or metatarsal phalangeal joint arthritis or TMT joint instability were followed for at least one year. The average age was 56.5, average final follow-up of 13.4 months, and 86.5% (166) of patients were women. Primary radiographic outcomes include pre- and post-operative HV (HVA), inter-metatarsal (IMA), and proximal inter-metatarsal angles (pIMA). Foot and Ankle Ability Measure (FAAM) scores were used to determine functional outcomes. Pain relief was measured by Visual Analog Scale (VAS) scores. Complication, re-operation and radiographic recurrence rates were also determined. Radiographic recurrence was defined as a change in HVA >10 degrees. Results: Additional procedures were performed on 83 feet (39%), the most common being lesser metatarsal osteotomies, which was performed in 88% of those patients. Among corrected bunions, 8.5% were classified as severe (HVA >40 degrees) and 79% were moderate (HVA >20 and < 40 degrees). Average pre-op HVA and IMA were 28.4 and 12.8 degrees and improved to 8.4 and 4.2 degrees (p < 0.001). Statistically significant increases in FAAM-ADL, FAAM-Sports and VAS scores were observed (p < 0.001). There were no cases of superficial or deep infections. There were 10 radiographic recurrences, 3 symptomatic recurrences and 2 non-unions requiring re-operation, and 13 (6%) hardware removals. Conclusion: The fourth-generation MIS HV surgery has demonstrated promising results in treating moderate and severe hallux valgus (HV), exhibiting favorable clinical and radiographic outcomes over an average follow-up period of 12.4 months. This technique has showcased remarkable safety and efficacy, with our cohort experiencing minimal recurrence, revision, and complication rates. Both instances of non-unions achieved successful union following re-operation.