Comparison of Clinical Outcomes Between Ligament Repair and Reconstruction After Excision of Large Os Subfibulare With Diameter ≥10 mm: A Propensity Score–Matched Analysis

Abstract

Background:

Large os subfibulare (LOS; diameter ≥10 mm) is sometimes identified in patients with chronic lateral ankle instability or pain; thus, ossicle excision with lateral ligament stabilization is commonly performed. However, whether ligament repair or reconstruction yields superior outcomes remains controversial, and comparative studies are lacking.

Purpose:

To compare clinical outcomes between ligament repair (modified Broström-Gould procedure) and reconstruction after LOS excision and to identify factors influencing ligament repair outcomes.

Study Design:

Retrospective cohort study; Level of evidence, 3

Methods:

The medical records of patients undergoing LOS excision with ligament repair or reconstruction between May 2020 and April 2023 were retrospectively reviewed. After 1:1 propensity score matching by age, sex, side, body mass index, symptom duration, preoperative Tegner score, and Beighton score, 68 patients were included (34 per group). Preoperative imaging parameters, including ossicle diameter, signal-to-noise ratio (SNR) of the anterior talofibular ligament (ATFL), and joint degeneration, were evaluated. Intraoperative lesions, including osteochondral lesion of the talus and calcaneofibular ligament injuries, were recorded. Primary outcomes included patient-reported outcomes (PROs): visual analog scale (VAS) score for pain, Karlsson score, Tegner score, and Foot and Ankle Outcome Score (FAOS). Secondary outcomes included return-to-sport time and overall satisfaction. Complications, such as recurrent sprains and incisional numbness, were also recorded. Univariate analyses were conducted to evaluate the impact of preoperative imaging parameters and intraoperative lesions on ligament repair outcomes.

Results:

The mean follow-up times were 44.7 ± 9.3 months (repair) and 44.8 ± 7.3 months (reconstruction) (P = .914). Both groups showed significant improvements in VAS, Karlsson, Tegner, and FAOS values (all P < .05). Postoperative PROs showed no intergroup differences between the repair and reconstruction groups (VAS score: 0.8 ± 1.4 and 0.7 ± 0.8; Karlsson score: 87.9 ± 11.8 and 88.5 ± 8.4; Tegner score: 4.7 ± 1.1 and 4.2 ± 1.2; total FAOS: 90.1 ± 7.7 and 91.2 ± 6.7, respectively). Return-to-sport time, incidence of recurrent sprains, incision numbness, and overall satisfaction were comparable. In the repair group, ATFL-SNR negatively correlated with postoperative FAOS values (r = −0.707; P < .001), and patients with ATFL-SNR >11.8 had mean postoperative FAOS values lower than those of the reconstruction group (91.2 ± 6.7).

Conclusion:

Both procedures yielded satisfactory outcomes after LOS excision. However, ligament reconstruction may offer superior results when there is a high preoperative ATFL-SNR.