Protocol for a multi-centre pilot and feasibility randomised controlled trial with a nested qualitative study: rehabilitation following rotator cuff repair (the RaCeR study)

Background
Shoulder pain is a highly prevalent complaint and disorders of the rotator cuff, including tears, are thought to be the most common cause. The number of operations to repair the torn rotator cuff has risen significantly in recent years. While surgical techniques have progressed, becoming less invasive and more secure, rehabilitation programmes have remained largely like those initially developed when surgical techniques were less advanced and more invasive. Uncertainty remains in relation to the length of post-surgical immobilisation and the amount of early load permitted at the repair site. In the context of this uncertainty, current practice is to follow a generally cautious approach, including long periods of immobilisation in a sling and avoidance of early active rehabilitation. Systematic review evidence suggests early mobilisation might be beneficial but further high-quality studies are required to evaluate this.

Methods/design
RaCeR is a two-arm, multi-centre pilot and feasibility randomised controlled trial with nested qualitative interviews. A total of 76 patients with non-traumatic rotator cuff tears who are scheduled to have a surgical repair will be recruited from up to five UK NHS hospitals and randomly allocated to either early patient-directed rehabilitation or standard rehabilitation that incorporates sling immobilisation. RaCeR will assess the feasibility of a future, substantive, multi-centre randomised controlled trial to test the hypothesis that, compared to standard rehabilitation incorporating sling immobilisation, early patient-directed rehabilitation is both more clinically effective and more cost-effective. In addition, a sample of patients and clinicians will be interviewed to understand the acceptability of the interventions and the barriers and enablers to adherence to the interventions.

Discussion
Research to date suggests that there is the possibility of reducing the patient burden associated with post-operative immobilisation following surgery to repair the torn rotator cuff and improve clinical outcomes. There is a clear need for a high-quality, adequately powered, randomised trial to better inform clinical practice. Prior to a large-scale trial, we first need to undertake a pilot and feasibility trial to address current uncertainties about recruitment, retention and barriers to adherence to the interventions, particularly in relation to whether patients will be willing to begin moving their arm early after their operation.

Trial registration
ISRCTN Registry, 18357968. Registered on 10 August 2018.