Disparities in Rotator Cuff Tear Progression Definitions and Rates: A Systematic Review.

Background: While rotator cuff tears are prevalent in the general population, the natural history of this disease is unclear. Understanding rotator cuff tear progression is crucial for refining surgical indications and evaluating the necessity of early interventions. This study presents an in-depth analysis of the existing literature on the definitions and progression rates of rotator cuff tears, aiming to enhance clinical decision making and patient outcomes. Methods: A systematic literature search was conducted based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, using Medline (PubMed), Embase (Elsevier), and Web of Science databases on January 12, 2023. Articles were identified as relevant to the natural history and progression of asymptomatic and symptomatic partial-thickness (PT) and full-thickness (FT) rotator cuff tears. Those written in English reporting rotator cuff progression rates of tears in adults, based on magnetic resonance imaging (MRI) or ultrasound, were included. After reviewing the articles, the data on the rates of tear progression and associated risk factors were extracted, compiled, and analyzed. The risk of bias was determined using the Newcastle-Ottawa Scale. Results: Twenty-one articles met the inclusion criteria, with 1,831 tears included. The progression rate for all partial thickness tears was 26.7% ± 12.8% at an average follow-up of 2.2 ± 0.9 years, with 5 definitions for tear progression. For FT tears, the progression rate was 54.9% ± 18.6% at a follow-up time of 3.0 ± 2.0 years, with 8 definitions for tear enlargement. A significant difference (p < 0.0001) was found between the progression rates of PT and FT tears. Patients who were initially asymptomatic and became symptomatic had higher progression rates (33%-63%) than those who remained asymptomatic (4%-38%). Conclusion: Further research would benefit by identifying a clinically relevant and standardized definition of rotator cuff tear progression, to describe the natural history of rotator cuff disease, making results more comparable and optimizing treatment planning. Level of Evidence: Level II. See Instructions for Authors for a complete description of levels of evidence.