The feasibility of conducting a randomized controlled trial that compares immediate versus optional delayed surgical repair for treatment of acute Anterior cruciate ligament injury-results of the IODA pilot trial.

Background: Standard care for anterior cruciate ligament (ACL) injuries often includes surgical reconstruction of the ACL. However, two randomized controlled trials (RCT) concluded that conservative treatment does not result in inferior clinical outcomes compared to immediate ACL reconstruction. More research is needed to verify these results and to assess whether patient-specific parameters can predict whether a patient would benefit from immediate surgery or conservative treatment. However, before running such an RCT, we performed this pilot study to assess the feasibility of recruiting patients for such an RCT.

Methods: This is a pragmatic, multicenter, randomized, controlled pilot trial with two parallel groups funded by the Belgian Health Care Knowledge Centre (KCE trials). Patients with an acute ACL injury were recruited from two Belgian hospitals. They were randomized to either conservative treatment (e.g., rehabilitation with optional delayed surgery in case of persistent instability) or immediate surgery (< 12 weeks post-injury). The primary aim of this pilot study was to assess the feasibility of participant recruitment. Furthermore, we evaluated adherence to the protocol and the allocated treatment arm and the feasibility of recruiting a representative sample of ACL patients.

Results: Out of the initial 70 screened patients, 29 were included in the pilot study, 15 were randomized in the conservative treatment group, and 14 were in the surgical treatment group. This yielded a recruitment rate of 41%. However, the investigators could not screen many potential patients due to inadequate referrals within the recruiting hospitals. Seven cross-overs were observed between the treatment arms: 3 patients who were assigned to the conservative treatment group insisted on immediate surgery, while four patients allocated to immediate surgery chose not to undergo surgery. Of the initial 29 patients, 5 dropped out after randomization. The recruited sample confirmed the typically young and physically active sample of ACL patients.

Conclusions: This pilot study confirmed the challenging recruitment process for an RCT that compares a surgical and a non-surgical treatment option. While encountering substantial recruitment challenges, our pilot study revealed that transitioning to a full-scale RCT is feasible, with some essential modifications. Key adjustments encompassed augmenting the number of participating sites, optimizing patient recruitment processes, and extending the recruitment period. Furthermore, this study showed a high completion rate, affirming the feasibility of the study protocol. However, there was a high cross-over rate (7/29 patients) between treatment arms. This should be avoided when progressing to the full trial. The recruited sample reflects a young and active population, which represents the ACL population well.

Trial registration: ClinicalTrials.gov (NCT04408690) on 25/05/2020.