Results from the ACL SNNAP trial, a multi-centre study led by researchers at the University of Oxford reveal that, over 18 months, going straight to reconstructive surgery has a better outcome than a programme with rehabilitation first (and subsequent surgery if needed) for anterior cruciate ligament (ACL) injury. Published in The Lancet, the findings have significant implications for the long-term outcomes for patients as well as providing cost savings to healthcare providers.
Rupture of the ACL is a common knee injury that can have variable impacts on patients. Some recover successfully while others experience disabling effects of knee instability that can affect day to day activities, work, and recreation. The injury mainly affects young, active individuals, with an estimated 30,000 surgical reconstructions performed annually in the UK.
Despite being a common injury, existing management for ACL injury is based on insufficient evidence, which has led to a highly varied approach to management. With limited and conflicting evidence for the management and costs of ACL there is no guide to help decision making in long-standing injured but symptomatic patients. Treatment is either rehabilitation involving specialised physiotherapy exercises; or surgery which involves reconstructing the ligament.
David Beard, lead author and Professor of Musculoskeletal and Surgical Science at the Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS) said: "Although there is good evidence from previous (Scandinavian and Dutch) studies that rehab can be effective for newly injured patients, waiting lists in the NHS for assessment (and treatment) often mean that many patients are seen much further down the line and with a longer-standing injury. Despite my professional bias toward rehabilitation it became apparent (in my own clinic, and from others) that more longstanding ACL deficient patients did not improve or achieve sufficient knee stability with rehab alone. I was suspicious that these particular patients may be better served by undergoing reconstruction sooner, but a large rigorous trial was needed."
The clinical management study recruited 316 patients from 29 secondary care National Health Service orthopaedic units in the UK between 2017, and 2020. They were randomly assigned 1:1 to either a surgical reconstruction group or to a group undergoing initial rehabilitation with subsequent surgery, as required. Patients were followed up at 18 months and asked to report any pain, activity levels, secondary issues, satisfaction, and functionality of the knee. The study was run by SITU (the Surgical Intervention Trials Unit), one of the Royal College of Surgeons (Eng) specialist surgical trials units supported by the Rosetree's Trust, and in collaboration with the Oxford Clinical Trials Research Unit (OCTRU).
Dr Lottie Davies, co-applicant and Trial Manager at NDORMS said: "The trial had many challenges including the preference for specific treatment from both patients and clinicians and the problems in following up a young mobile population. Successfully completing the trial was the result of the much-valued effort and support of all involved without which these trials would not be possible."
The results showed that both groups improved over time but patients with non-acute ACL injury undergoing immediate surgical reconstruction without any further intervention having substantially better outcomes at 18 months after randomisation than did those undergoing non-surgical management (and any subsequent necessary surgery).
The secondary outcome measures, including patient satisfaction, also favoured surgical reconstruction over non-surgical management. The study also showed the devastating impact of ACL injury on activity and sport levels and, interestingly that in both groups, the return to pre-injury level of sport was very low at 18 months.
Professor Andrew Price, co-applicant and Consultant Knee Surgeon stated: "This study has significant implications for how we treat ACL injuries, especially the more longstanding injured patients with ongoing knee instability. Benefit can still be achieved with rehabilitation, and can be offered, but it appears that undergoing expedited reconstructive surgery is the best way forward to stabilise the knee and achieve better function."