ACL SNNAP Trial: ACL Surgery Necessity in Non Acute Patients

The ACL SNNAP study is a pragmatic multi-centre randomised controlled trial with two-arm parallel groups and 1:1 allocation ratio to compare non-surgical management (Rehabilitation) and surgical management (Reconstruction) options for patients with a symptomatic non-acute ACL deficient knee.

The objective is to determine, in patients with non-acute Anterior Cruciate Ligament Deficiency (ACLD), whether non-surgical treatment (with the option for later ACL reconstruction if required) is more effective than surgical ACL reconstruction (as measured by the Knee Injury and Osteoarthritis Outcome Score [KOOS4] at 18 months from randomisation).

Target sample size is 320 patients recruited from approx. 30 NHS orthopaedic units.

An internal pilot will be conducted with clear progression criteria regarding recruitment.

Both interventions are routine NHS treatments. Intervention content is based on a minimal set of pre-established criteria in order to ensure the integrity of the comparison while allowing for varying in practice in delivering the interventions between both surgeons and physiotherapists. This largely pragmatic approach will allow clinical management to reflect current practice and resource use within the NHS thus aiding generalisation.

Other than the allocated intervention, both groups will be followed-up in the same way to exclude bias. Follow up for study purposes will be by patient self-reported questionnaire completed using an electronic data capture collection system (a postal option will also be available). The questionnaire will include the outcomes indicated in section 4 and will be completed by participants at baseline, 6, 12 and 18 months. Non-response will be minimised through use of multiple reminders such as web based, phone and text.

Neither participants nor health care practitioners (surgeons and physiotherapists) can be blinded to receipt of the intervention.