ACL STARR - Anterior Cruciate Ligament Stratified Accelerated Repair or Reconstruction Single blind randomised control trial for patients with proximal ACL injuries treatment with ACL repair v ACL reconstruction.

Research question: Does acute ACL repair provide superior clinical outcomes (KOOS-4) and is it cost effective when compared to the more established ACL reconstruction in patients with recent proximal ACL ruptures? Background: The knee is the most injured joint. The ACL is key in maintaining knee joint stability, function, and confidence to undertake everyday activities and sports. Following injury, surgery has been shown to provide better functional outcome than a non operative pathway (1). Current surgical practice is to use a graft to reconstruct the ligament, but another option involves direct repair of the ligament. Repair involves re-attachment/suture of the damaged ligament back from where it has been avulsed. It is thought that approximately 40% of ACL tears may be repairable (2,3). The tear pattern and potential for repair is determined by MRI and intraoperative assessment of the ligament. Time is considered a key factor allowing for the potential repair, and so surgery needs to be undertaken as soon as practicable. The evidence to support repair is weak or biased and an independent RCT is needed. Aims and objectives: To test the hypothesis that, in patients with recent proximal ACL ruptures, ACL repair is superior to ACL reconstruction at 24 months post intervention. Methods: The study will be a multicentre, blinded, randomised trial for ACL repair and ACL reconstruction in acutely injured patients. A total of 286 patients with a proximal ACL tear will be recruited from across the UK in order to randomise 214 patients. Patients will be identified and recruited following a pre-intervention MRI scan which identifies the proximal tear pattern. Surgery will be undertaken as soon as clinically appropriate and possible. Randomisation will be performed intra-operatively following eligibility and suitability assessment. Surgeons will be in equipoise over surgery type; repair or reconstruction. Patients and research staff will be blinded to which surgical procedure a patient has undergone. Both groups will undergo post operative rehabilitation with criteria based progression over 9 months, leading to return to unrestricted activity and sport. Australian Sister Study: A mirror study will be undertaken in Australia co-ordinated within the NHMRC Clinical Trials Centre (CTC), Sydney, but involving interstate sites. The primary outcome is the KOOS-4 score (knee pain and function) measured at 24 months. Secondary outcome measures include KOOS-4 score over time at 6 and 12 months, complications, graft failure, re-operation, EQ-5D-5L, KQoL-26, post operative pain, patient satisfaction, and resource usage. Timelines for delivery: The study start date is March 2024 with a duration of 68 months (60 months in Australia), Phase 1:Trial set up (0-8 months) Phase 2: Internal pilot (9-18 months) Phase 3: Main Trial recruitment (months 19-38) Phase 4: Main trial follow up (35-62 months) Phase 5: Analysis and Dissemination (63-68 months) Anticipated impact and dissemination: ACL repair is a technique that is being increasingly used in current practice without proper evaluation. The impact of this study will provide a formal (IDEAL level 3 (4)) evaluation of the benefits of ACL repair compared to current practice (reconstruction). The new evidence will validate its use or help restrict indications and practice. The results will be disseminated via publication and orthopaedic specialist societies, BASK, BSCOS, and BOSTTA.