Comparison of modified U-shaped and inverted L-shaped medial capsulorrhaphy in hallux vulgus surgery

Purpose: The distal soft tissue procedure is an integral component of bunion surgery to aid in hallux valgus angular (HVA) correction. There are some reports about the lateral soft tissue release, but rarely about medial capsular placation. 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. Methods: : A prospective analysis and review of 78 consecutive patients was performed between January 2018 and October 2021. All patients underwent chevron osteotomy and soft tissue procedure for hallux valgus (HV), and the patients were separated into 2 groups according to the implemented medial capsule closing technique. The modified U-shaped capsulorrhaphy was implemented for patients in group A, and the L-shaped capsulorrhaphy was done for patients in group B. All patients were followed for at least a year. The preoperative and follow-up data were collected for each patient, which include patient demographics, weightbearing radiographs of the foot, the active range of motion (ROM) of first metatarsophalangeal (MTP) joint and clinical results. Results: : In total, 75 patients with 80 feet met the inclusion criteria, there were 38 cases (41 feet) in group A and 37 cases (39 feet) in group B.Comparing the degrees of HVA and intramedullary angle (IMA) at 1 year after surgery, the statistical value of IMA was insignificant ( P =0.216), but a statistically significant difference in HVA was observed between the 2 groups ( P = 0.017). The degrees of ROM of the first MTP joint after 1 year in group A were better than group B ( P = 0.03). American Orthopaedic Foot and Ankle forefoot score (AOFAS, forefoot) was 53.37±7.66 preoperatively and 85.51±3.94 at one-year follow-up in Group A and 52.3±8 and 86.56±3.87 respectively in Group B. Significant improvement was achieved for both groups, but neither group showed any statistically significant differences ( P = 0.232). Conclusion: Compared to the inverted L-shaped capsulorrhaphy, the modified U-shaped capsulorrhaphy can provide a better ROM of the first MTP joint, and the modified U-shaped capsulorrhaphy can help maintain the normal HVA better 1 year following surgery; it could be a better choice for medial soft tissue reconstruction in HV surgery.