Andreas Pappas, Alexander Hönning, Marc D. Schmittner, Axel Ekkernkamp, Denis Gümbel

• Introduction Hallux valgus (HV) is the most common forefoot deformity. Surgical correction of HV aims to reduce pain, preserve joints, and re-establish foot function while restoring the hallux valgus angle (HVA) and intermetatarsal angle (IMA). Many surgical procedures have been proposed, including open and minimally invasive (MI) techniques. This study aimed to compare the midterm outcomes of open vs. MI procedures and their impact on the duration of surgery, hospital stay, HVA, and IMA post-operatively. Materials and methods One hundred and twenty HV patients operated by open or MI surgery between October 2019 and October 2022 were included. One hundred three patients met the inclusion criteria and consented to the study. Patients were prospectively surveyed for foot functionality, post-operative pain, and complications using the AOFAS score. Radiographic measurements of HV angles, length of hospital stay, and surgery duration were analysed. Results MI surgery patients had significantly better AOFAS scores ( p  < 0.001) 12 months post-operatively compared to open surgery. Complication rates were lower in the MI group (3.8% vs. 33.3%, p  < 0.001). MI surgery patients also had shorter hospital stays (0.9 ± 0.3 days vs. 2.0 ± 0.0 days) and surgery duration (19.7 ± 2.3 min vs. 80.7 ± 6.8 min). MI surgery was more effective in correcting the IMA but equally effective as open surgery for HVA correction. Conclusion MI surgery resulted in better patient satisfaction, fewer complications, and more precise correction of IMA values. Moreover, the duration of surgery and hospital stay were significantly lower in patients undergoing MI surgery. Further research is needed to validate these findings in controlled, prospective randomised trials.