Minimum 5-Year Follow-up Results: CROSSBAT (Combined Randomised and Observational Study of Surgery vs No Surgery for Type B Ankle Fracture Treatment)

Background:

Isolated Weber B, AO (Association for the Study of Internal Fixation) type 44B ankle fractures with no fracture to the medial side are the most common type of ankle fracture and may be treated with internal fixation or without surgery.

This study aimed to determine if surgery is superior to nonsurgical management for the treatment of these fractures after a minimum 5-year follow-up.

Methods:

Design: A pragmatic, multicenter, single-masked, randomized controlled trial with minimum 5-year follow-up. Setting/participants/interventions: Participants between 18 and 65 years with AO type 44B ankle fracture and minimal talar shift were recruited from 22 hospitals in Australia and New Zealand. Participants willing to be randomized were randomly allocated to undergo surgical fixation followed by mobilization in a walking boot for 6 weeks. Those treated nonsurgically were managed in a walking boot for 6 weeks. Outcome assessors were masked for the treatment allocation. Primary outcomes: Patient-reported ankle function using the American Academy of Orthopaedic Surgeons Foot and Ankle Outcomes Questionnaire (FAOQ) and the physical component summary (PCS) of the SF-12v2 General Health Survey at 12 months postinjury and at minimum 5 years post injury. Primary analysis was intention-to-treat.

Results:

Of the 160 (80 surgical, 80 nonoperative) randomized patients included in the CROSSBAT analysis, 77 (40 surgical, 37 nonoperative) were followed up for repeat analysis at minimum 5-year follow-up (mean 7.3 years, range 5.1-8.9). This cohort demonstrated that surgery was not associated with clinically or statistically significant differences compared to nonoperative management for the FAOQ (51.7 vs 49.6; mean difference 2.1, 95% CI –2.1 to 6.2, P = .95), or the PCS (51.5 vs 49.1; mean difference 2.3, 95% CI –2.0 to 6.7, P = .54). The surgical cohort had a higher rate of any adverse events (odds ratio 3.7, 95% CI 1.2-11.6, P = .04).

Conclusion:

The results of this study suggest that surgical management is not superior to nonsurgical management in type B ankle (fibula) fractures with minimal talar shift over a 5-year period and is associated with increased adverse events.

Level of Evidence:

Level II, randomized clinical trial.