Is 6 Weeks Immobilization for a Chopart Injury Still State of the Art? Comparison Between Cast Immobilization Versus Functional Treatment

Treatment Arms for Randomization

1. Restrictive treatment: Immobilization in a cast or VACOped boot (lower leg boot with ankle immobilzation) for 6 weeks.

* Advantage: Provides stable conditions for fracture healing. * Disadvantage: Risk of muscle atrophy and ankle joint stiffness due to prolonged immobilization. 2. Functional treatment: Weightbearing as tolerated using a rigid-sole shoe.

* Advantage: Allows early mobilization, reduces muscle atrophy, and helps maintain ankle mobility. * Disadvantage: Potential concern regarding pain, insufficient fracture stabilization, or pseudarthrosis Study Objectives This research project focuses on the treatment of Chopart fractures. In recent years, the number of diagnosed fractures following ankle sprains has increased. This rise is likely due to improved awareness of these injuries and the more frequent use of advanced imaging techniques such as CT scans (Computed Tomography). However, the optimal treatment strategy for these fractures remains unclear.

Current treatment approaches range from operative management to conservative treatment with 6-8 weeks of immobilization, and more recently to functional treatment protocols. Most of the available evidence consists of case series, representing a low level of evidence. High-quality comparative studies are currently lacking.

As a public hospital, Hospital Cantonal Fribourg (HFR) manages a large number of regional trauma cases, including Chopart injuries, with an incidence of approximately 50 cases per year. At present, treatment at HFR is predominantly conservative, involving 8 weeks of immobilization in a cast or a VACOped boot. While immobilization allows sufficient time for fracture healing, it may result in muscle atrophy and ankle joint stiffness. Recent literature suggests that a more functional treatment approach may lead to promising results. However, it remains unclear whether earlier weightbearing and functional rehabilitation improve overall outcomes or result in prolonged pain and increases the risk of complications. Therefore, the aim of this study is to compare different non-operative treatment strategies using both patient-reported outcome measures and objective gait analysis.

The primary objective of this study is to evaluate patient-reported outcomes following different non-operative treatment strategies for Chopart fractures. In addition, the study will assess differences in gait patterns between the two study arms and correlate these findings with patient-reported outcomes and quality of life. The study also aims to determine the timeline required to regain a normal gait pattern after injury.

Outcome Measures The primary outcome will be patient-reported functional outcome and quality of life, assessed using a 22-item questionnaire combining the EFAS Score (European Foot and Ankle Society) and the Short Form-12 health survey. The secondary outcome will be objective gait analysis parameters.