Effect of minimally invasive distal first metatarsal osteotomy on blood flow of the metatarsal head

Abstract

BackgroundDistal first metatarsal osteotomy is an option for operative treatment of mild to severe hallux valgus (HV) deformities. Minimally invasive distal linear metatarsal osteotomy (DLMO) provides good outcomes without avascular necrosis (AVN) of the metatarsal head. However, no reports have described the in vivo blood flow changes in the metatarsal head after osteotomy. This study was performed to evaluate the in vivo blood flow of the pre- and post-osteotomy metatarsal head in patients with HV using laser Doppler flowmetry and thus clarify the effect of minimally invasive distal first metatarsal osteotomy on the change in blood flow. MethodsFrom April 2015 to October 2016, DLMO was performed on 13 feet with HV in 10 patients (2 men, 8 women). Blood flow measurements of the pre- and post-osteotomy first metatarsal head in all feet were performed by laser Doppler flowmetry. AVN was evaluated using plain radiographs at the final postoperative follow-up. ResultsThe median pre- and post-osteotomy blood flow was 1.5 (0.97–1.95) and 1.46 (0.98–1.77) ml/min/100 g, respectively (median change in blood flow, 0.00; 95% CI, −0.23–0.13; P = 0.72). The rate of change in the blood flow was 0.0% (95% CI, −11.9%–8.7%; range, −28.6%–64.7%), and only three patients (23.1%) showed a decrease of ≥10%. The median pre- and post-osteotomy systolic blood pressure was 90 (84.5–97) and 93 (84.5–95) mmHg, respectively (median change in blood pressure, 0.00; 95% CI, −3.0–2.0; P = 0.82). The rate of change in the systolic blood pressure was 0.0% (95% CI, −3.1%–2.2%; range, −9.1%–24.0%). No radiographic evidence of AVN was present at the final follow-up. ConclusionsNo significant difference was found in the rate of change in blood flow pre- and post-osteotomy, suggesting that minimally invasive distal first metatarsal osteotomy does not influence blood flow of the metatarsal head.