BACKGROUND & OBJECTIVE
Features detected on MRI that are commonly present in knee osteoarthritis (OA) such as meniscal tears, cartilage defects, and bone marrow lesions (BMLs), are often interpreted as the cause of the patient’s pain and symptoms. These findings tend to guide and inform medical and surgical clinical decision making. However, the relationship between MRI features of OA and the patient’s symptoms is unclear. Therefore, the aim of this systematic review and meta-analysis was to determine the prevalence of, and factors contributing to, MRI features of OA in asymptomatic uninjured knees.
Imaging must be interpreted in the context of clinical presentations.
A search was conducted for studies reporting the prevalence of MRI features of knee OA in:
- Asymptomatic adult knees (i.e. mean age ≥18 years with no knee symptoms during any activity)
- No history of injury or surgery
- In the following databases: EMBASE, Medline, CINAHL, SPORTDiscus, Web of Science and Scopus
Primary outcomes: individual MRI features that were assessed semi-quantitatively, AND included in the definition of MRI-defined knee OA (e.g. cartilage defects, meniscal tears, osteophytes, etc.).
Secondary outcomes: other MRI features previously associated with knee OA (e.g. effusion-synovitis, subchondral cysts, ligament tears, subchondral sclerosis, etc).
46 cross-sectional studies and 17 longitudinal studies, with a total of 4751 individuals and 5397 knees, were included in this systematic review. Here is a summary of the results: