MRI and knee OA

Osteoarthritis of the knee and MRI (1,2)

• in a study (2) 710 patients over the age of 50 with normal x-rays of the tibiofemoral joint underwent an MRI scan of the knee
  • of the 710, 206 (29%) reported knee pain in the preceding month
    • 631 (89%) had some abnormality characteristic of OA
    • osteophytes were the most common finding, in 524 (74%) patients
    • 492 (69%) patients had articular cartilage defects
    • prevalence of abnormalities increased with age, as might be expected
  • abnormalities were almost universal in patients reporting knee pain (90-97%, depending on definition of pain) but still remarkably high in patients not reporting knee pain (86-88%), calling into question the clinical significance of MRI findings
    
    
  • this study casts doubt on the usefulness of MRI in the decision making regarding management of knee OA
    • "..so the pictures may be better and certainly more interesting, but whether imaging will lead to more effective treatment seems doubtful based on the findings of this study.." (1)

Reference:

• 1) ARC. Synovium 2012; 37:1-2.
• 2) Guermazi A, Niu J, Hayashi D et al. Prevalence of abnormalities in knees detected by MRI in adults without knee osteoarthritis: population based observational study (Framingham Osteoarthritis Study). BMJ 2012 Aug 29;345:e5339.