Definitions and reporting of ‘failure’ after rotator cuff repair: A systematic review of level I and level II evidence and proposal for standardisation

Background: Failure is widely reported in randomised controlled trials assessing rotator cuff repair (RCR), yet the term lacks a consensus definition and reported rates vary widely. This systematic review characterised how RCR failure is defined and reported in Level I and II studies and proposes a reporting standard. Methods: MEDLINE, Embase and Cochrane were searched for English-language Level of Evidence I and II studies published between January 2003 and April 2025 reporting on failure following RCR. Data on definitions, parameters and etiologies of failure were extracted and summarised through descriptive statistics. Results: Twenty-two studies met the inclusion criteria. Ten (45.5%) provided a formal definition of failure; the remainder described specific etiologies. Imaging-based assessment of tendon integrity was the most common parameter among formal definitions (7 of 10), and re-tear was the most common etiology among studies without one (9 of 12). Reported failure rates tracked closely with the parameter used, exceeding 50% under imaging-based definitions and reaching 0% under a patient-reported outcome measure (PROM)-based definition. Discussion: RCR trials lack a uniform definition of failure. We propose a multi-domain reporting standard incorporating structural, patient-reported and clinical outcomes, with thresholds to be established through expert consensus.