Chronic Ankle Instability, Surgical Repair: Open Versus Closed

Rationale: Lateral ankle ligament injuries may be a result of ankle sprains. In 10-30% of patients with lateral ankle ligament injuries, chronic lateral ankle instability may be present. If conservative treatment fails, instability is treated surgically. Anatomic repair (also known as the Bröstrom procedure) is the current golden standard for surgical treatment of chronic ankle instability. The Bröstrom started out as an open technique and is now also performed arthroscopically. Both approaches are considered standard care and provide good results. Which approach is best, has not yet been researched. In this study it is hypothesized arthroscopic repair provides better functional outcome compared to open repair during short term follow-up.

Objective: The main objective of this study is to compare the functional outcome after arthroscopic and open anatomic repair in patients with chronic lateral ankle instability, and secondly to assess ankle stability and ankle Range of Motion (ROM) after arthroscopic and open ligament repair.

Study design: A Non-Blinded Prospective Randomized Controlled Trial Study population: All patients willing to participate, from an age of 18 years old, with persisting ankle instability for at least 6 months, eligible for anatomic repair.

Intervention: Both groups of patients are surgically treated with anatomic repair of the anterior talofibular ligament (ATFL). One group is treated arthroscopically and the other by the open approach.

Main study parameters/endpoints: The primary outcome measure is functional outcome 6 months after surgery measured using the Foot and Ankle Outcome Score. The main study parameter is a difference of ≥10 2 points per FAOS subscale between both treatment groups (Minimal Important Change = 10 points; 2 per subscale).