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Key information


Sub-acromial spacer for Tears Affecting Rotator cuff Tendons: a Randomised, Efficient, Adaptive Clinical Trial in Surgery (START:REACTS)

Chief Investigator: Mr Andrew Metcalfe FRCS(Tr&Orth) PhD, Associate Professor in Trauma and Orthopaedics

Sponsor: University Hospitals Coventry and Warwickshire and University of Warwick (co-sponsors)

Funder: This project is funded by the Efficacy and Mechanism Evaluation (EME) Programme, an MRC and NIHR partnership.

Funders disclaimer: The views expressed in this publication are those of the author(s) and not necessarily those of the MRC, NHS, NIHR or the Department of Health and Social Care.

*The EME Programme is funded by the MRC and NIHR, with contributions from the CSO in Scotland and Health and Care Research Wales and the HSC R&D Division, Public Health Agency in Northern Ireland.

Registration Number: ISRCTN17825590;


Within the shoulder there are a group of muscles and tendons called the rotator cuff. Tears of the rotator cuff tendons are very common. They can be very painful and it can be difficult to move the shoulder normally. Many tears of the tendons can be repaired but some tears cannot. When a tear cannot be repaired, one common treatment is a keyhole operation to clear space around the tendons and remove the painful tissue. This is called an arthroscopic debridement. It is low risk and is thought to benefit most people with rotator cuff tears.

A new device has recently been introduced in the UK with the aim of improving outcomes from surgery for this condition. It is a balloon made out of a biodegradable synthetic material (free of animal products), called the InSpace balloon. It is inserted at the end of an arthroscopic debridement operation and is filled with water. It is thought to act as a cushion inside the joint. It dissolves after about three months, by which time the patient has had a chance to strengthen the other muscles to give a longer lasting effect. It is not yet known whether this balloon device is any better or worse than the standard arthroscopic debridement operation.

The aim of this study is to find out whether it is better to have an arthroscopic debridement operation, or the same operation with the addition of the InSpace balloon, in patients with a tear of the rotator cuff muscles that cannot be repaired.

The National Institute of Health and Care Excellence (NICE) has studied the balloon and decided that it should only be used in research to determine if it works. The study will determine which operation is best at reducing pain and improving movement, strength, and quality of life, and whether the balloon is worth the additional cost.

Sample size:

Adaptive study (variable sample size), maximum sample size 221

Primary outcome:

Oxford Shoulder Score


2 years recruitment

The trial is now complete, results can be accessed here