Future research should focus on larger sample size, standardization of treatment protocol and basic science evidence.

BackgroundOsteoarthritis is a progressive multifactorial condition of the musculoskeletal system with major symptoms including pain, loss of function, damage of articular cartilage and other tissues in the affected area. Knee osteoarthritis imposes major individual and social burden, especially with the cost and complexity of surgical interventions. Mesenchymal stem/stromal cells have been indicated as a treatment for degenerative musculoskeletal conditions given their capacity to differentiate into tissues of the musculoskeletal system.MethodsA systematic search will be conducted in Medline, Embase, Cochrane Library, Scopus and relevant trial databases of English, Japanese, Korean, German, French, Italian, Spanish and Portuguese language papers published or in press to June 2018, with no restrictions on publication year applied. References will be screened and assessed for eligibility by two independent reviewers as per PRISMA guidelines. Cohort, cross-sectional or case controlled studies will be included for the analysis. Data extraction will be conducted using a predefined template and quality of evidence assessed. Statistical summaries and meta-analyses will be performed as necessary.DiscussionResults will be published in relevant peer-reviewed scientific journals and presented at national or international conferences by the investigators.Trial registrationThe protocol was registered on the PROSPERO international prospective register of systematic reviews prior to commencement, CRD42018091763.Electronic supplementary materialThe online version of this article (10.1186/s13018-019-1070-8) contains supplementary material, which is available to authorized users.

SummaryBackground: rotator cuff tear affects many people. Natural history, and evidence for non-operative treatment remains limited. Our objective is to assess evidence available for the efficacy and morbidity of commonly used systemic medications, physiotherapy, and injections alongside evaluating any negative long-term effects.