Comparison of surgical or non-surgical management for non-acute anterior cruciate ligament injury: the ACL SNNAP RCT

Background: Anterior cruciate ligament injury of the knee is common and leads to decreased activity and risk of secondary osteoarthritis of the knee. Management of patients with a non-acute anterior cruciate ligament injury can be non-surgical (rehabilitation) or surgical (reconstruction). However, insufficient evidence exists to guide treatment. Objective(s): To determine in patients with non-acute anterior cruciate ligament injury and symptoms of instability whether a strategy of surgical management (reconstruction) without prior rehabilitation was more clinically and cost-effective than non-surgical management (rehabilitation). Design: A pragmatic, multicentre, superiority, randomised controlled trial with two-arm parallel groups and 1:1 allocation. Due to the nature of the interventions, no blinding could be carried out. Setting: Twenty-nine NHS orthopaedic units in the United Kingdom. Participants: Participants with a symptomatic (instability) non-acute anterior cruciate ligament-injured knee. Interventions: Patients in the surgical management arm underwent surgical anterior cruciate ligament reconstruction as soon as possible and without any further rehabilitation. Patients in the rehabilitation arm attended physiotherapy sessions and only were listed for reconstructive surgery on continued instability following rehabilitation. Surgery following initial rehabilitation was an expected outcome for many patients and within protocol. Main outcome measures: The primary outcome was the Knee Injury and Osteoarthritis Outcome Score 4 at 18 months post randomisation. Secondary outcomes included return to sport/activity, intervention-related complications, patient satisfaction, expectations of activity, generic health quality of life, knee-specific quality of life and resource usage. Results: < 0.001). The incremental cost-effectiveness ratio for the surgical management programme versus rehabilitation was £19,346 per quality-adjusted life-year gained. Using £20,000-30,000 per quality-adjusted life-year thresholds, surgical management is cost-effective in the UK setting with a probability of being the most cost-effective option at 51% and 72%, respectively. Limitations: Not all surgical patients underwent reconstruction, but this did not affect trial interpretation. The adherence to physiotherapy was patchy, but the trial was designed as pragmatic. Conclusions: Surgical management (reconstruction) for non-acute anterior cruciate ligament-injured patients was superior to non-surgical management (rehabilitation). Although physiotherapy can still provide benefit, later-presenting non-acute anterior cruciate ligament-injured patients benefit more from surgical reconstruction without delaying for a prior period of rehabilitation. Future work: Confirmatory studies and those to explore the influence of fidelity and compliance will be useful. Trial registration: This trial is registered as Current Controlled Trials ISRCTN10110685; ClinicalTrials.gov Identifier: NCT02980367. Funding: ; Vol. 28, No. 27. See the NIHR Funding and Awards website for further award information.