The 2026 ESSKA-ESA formal consensus on partial-thickness posterosuperior rotator cuff tears (Part 1): Definitions, classifications, etiologies, natural history and diagnosis

To establish evidence-based consensus recommendations regarding the diagnosis and treatment of partial-thickness posterosuperior rotator cuff tears (PT-PS-RCTs). This part addresses the definition, classification, natural history and diagnosis of these controversial conditions in shoulder surgery. This official European Society of Sports Medicine, Knee Surgery and Arthroscopy-European Shoulder Associates (ESSKA-ESA) Formal Consensus was conducted according to the ESSKA Formal Consensus Methodology. A Steering Group developed 33 questions, followed by a standardized literature search and evidence review. For each question, a consensus statement was drafted and assigned recommendation grades (A-D) according to the level of evidence. An independent Rating Group evaluated all statements until strong agreement was achieved. Twelve recommendations were generated with three Grade A, three Grade B, two Grade C, five Grade D and strong agreement. Grade A was found for the use of multiple classification systems in unison to characterize these injuries and for the distinction between acute and chronic tears. Scientific presumption level (Grade B) was found for the increased incidence of articular injuries in overhead and contact athletes and for the absence of a link between calcifying tendinitis and PT-PS-RCTs. Grade C was found to define the risk and timeframe of tear progression and the ideal imaging modality. This ESSKA-ESA Formal Consensus recommends that PT-PS-RCTs should be classified according to tear location, depth and tendon involvement. The aetiology of these injuries is multifactorial, and their progression is unpredictable. Current imaging modalities have limitations in characterizing these lesions. The present consensus provides clinicians with a practical evidence-based framework for the diagnosis and classification of PT-PS-RCTs while identifying key priorities for future clinical research. Level I formal consensus.