Comparison of modified U-shaped and inverted L-shaped medial capsulorrhaphy in hallux valgus surgery: a prospective, randomized controlled trial of 75 patients

PURPOSE: The purpose of this study was to report a modified U-shaped medial capsulorrhaphy and compare its clinical and radiological differences with an inverted L-shaped capsulorrhaphy in hallux valgus (HV) surgery. METHODS: A prospective study of 78 patients was performed between January 2018 and October 2021. All patients underwent chevron osteotomy and soft tissue procedures for HV, and the patients were randomly separated into 2 groups according to the medial capsule closing techniques: a modified U-shaped capsulorrhaphy (group U) and an L-shaped capsulorrhaphy (group L). All patients were followed for at least a year. The preoperative and follow-up data were collected for each patient and included patient demographics, weight-bearing radiographs of the foot, the active range of motion (ROM) of the first metatarsophalangeal (MTP) joint and the American Orthopedic Foot and Ankle Society (AOFAS) forefoot score. Mann–Whitney U test was used for the comparison of the postoperative measures between the groups. RESULTS: In total, 75 patients with 80 affected feet met the inclusion criteria, with 38 patients (41 feet) in group U and 37 patients (39 feet) in group L. One year after surgery, the mean hallux valgus angle (HVA), intermetatarsal angle (IMA), and AOFAS score in group U improved from 29.5 to 7.1, from 13.4 to 7.1, and from 53.4 to 85.5, respectively. The mean HVA, IMA, and AOFAS score in group L improved from 31.2 to 9.6, from 13.5 to 7.9, and from 52.3 to 86.6, respectively. Comparing the 1-year postoperative measures between the 2 groups, a significant difference was found in HVA (P = 0.02), but not found in IMA and AOFAS score (P = 0.25 and P = 0.24, respectively). The mean ROM of the first MTP joint was 66.3 degrees preoperatively and 53.3 degrees at the 1-year follow-up in group U, while 63.3 and 47.5 in group L. The degrees of ROM after 1 year in group U were better than those in group L (P = 0.04). CONCLUSION: Compared to the inverted L-shaped capsulorrhaphy, the modified U-shaped capsulorrhaphy provided a better ROM of the first MTP joint; at 1 year following surgery, the modified U-shaped capsulorrhaphy maintained the normal HVA better.