Josephine Fox

Background: A balloon spacer is a relatively simple addition to an arthroscopic debridement procedure for irreparable rotator cuff tears. Objective: To evaluate the clinical and cost-effectiveness of a subacromial balloon spacer for individuals undergoing arthroscopic debridement for irreparable rotator cuff tears. Design: A multicentre participant-and assessor-blinded randomised controlled trial comparing arthroscopic debridement with the InSpace^® (Stryker, Kalamazoo, MI, USA) balloon to arthroscopic debridement alone, using a novel adaptive design. Pretrial simulations informed stopping boundaries for two interim analyses, using outcome data from early and late time points. Setting: A total of 24 NHS centres. Participants: Adults with a symptomatic, irreparable rotator cuff tear for whom conservative management had been unsuccessful. Interventions: Arthroscopic debridement of the subacromial space plus insertion of the InSpace balloon compared with arthroscopic debridement alone. Main outcome measures: Oxford Shoulder Score at 12 months. Results: A predefined stopping boundary was met at the first interim analysis. Recruitment stopped with 117 participants randomised. We obtained primary outcome data on 114 participants (97%). The mean Oxford Shoulder Score at 12 months was 34.3 in the debridement-only group (59 participants of 61 randomised) and 30.3 in the debridement with balloon group (55 participants of 56 randomised; mean difference: −4.2; 95% confidence interval −8.2 to −0.26; p = 0.037). There was no difference in safety events. In the cost-effectiveness analysis, debridement-only dominated with a probability of n = 17). Statistical methodology study: We applied the novel adaptive design approach to data from seven previous randomised controlled trials. The method would have been applicable to five of these trials and would have made substantial savings in time to recruitment, without compromising the main findings of the included trials. Interim analysis interpretation study: We asked potential data monitoring committee members to review interim analysis reports presented using Bayesian and frequentist frameworks. They did not always follow the stopping rules and would benefit from additional information to support decision-making. Limitations: The InSpace balloon could be beneficial in a different population although we are not aware of it being widely used for other purposes. As a result of the pandemic, we were not able to complete data collection for objective measures. Conclusions: In this efficient adaptive trial, clinical and cost-effectiveness favoured the control treatment without the InSpace balloon. Therefore, we do not recommend this device for the treatment of irreparable rotator cuff tears. Future work: There is an urgent need for high-quality research into interventions for people with irreparable rotator cuff tears as there is a lack of good evidence for all available treatment options at present. Trial registration: This trial is registered as ISRCTN17825590. Funding: This project (project reference 16/61/18) was funded by the Efficacy and Mechanism Evaluation (EME) Programme, a Medical Research Council and National Institute for Health and Care Research (NIHR) partnership. The trial is co-sponsored by the University of Warwick and University Hospitals Coventry and Warwickshire NHS Trust. This study will be published in full in Efficacy and Mechanism Evaluation; Vol. 10, No 3. See the NIHR Journals Library website for further project information.

Introduction Robotic-assisted knee replacement systems have been introduced to healthcare services worldwide in an effort to improve clinical outcomes for people, although high-quality evidence that they are clinically, or cost-effective remains sparse. Robotic-arm systems may improve surgical accuracy and could contribute to reduced pain, improved function and lower overall cost of total knee replacement (TKR) surgery. However, TKR with conventional instruments may be just as effective and may be quicker and cheaper. There is a need for a robust evaluation of this technology, including cost-effectiveness analyses using both within-trial and modelling approaches. This trial will compare robotic-assisted against conventional TKR to provide high-quality evidence on whether robotic-assisted knee replacement is beneficial to patients and cost-effective for healthcare systems. Methods and analysis The Robotic Arthroplasty Clinical and cost Effectiveness Randomised controlled trial-Knee is a multicentre, participant-assessor blinded, randomised controlled trial to evaluate the clinical and cost-effectiveness of robotic-assisted TKR compared with TKR using conventional instruments. A total of 332 participants will be randomised (1:1) to provide 90% power for a 12-point difference in the primary outcome measure; the Forgotten Joint Score at 12 months postrandomisation. Allocation concealment will be achieved using computer-based randomisation performed on the day of surgery and methods for blinding will include sham incisions for marker clusters and blinded operation notes. The primary analysis will adhere to the intention-to-treat principle. Results will be reported in line with the Consolidated Standards of Reporting Trials statement. A parallel study will collect data on the learning effects associated with robotic-arm systems. Ethics and dissemination The trial has been approved by an ethics committee for patient participation (East Midlands—Nottingham 2 Research Ethics Committee, 29 July 2020. NRES number: 20/EM/0159). All results from the study will be disseminated using peer-reviewed publications, presentations at international conferences, lay summaries and social media as appropriate. Trial registration number ISRCTN27624068.