Special Theme Article: Clinical Imaging and the Rheumatic Diseases
Is the Severity of Knee Osteoarthritis on Magnetic Resonance Imaging Associated With Outcome of Exercise Therapy?
Article first published online: 24 DEC 2013
Copyright © 2014 by the American College of Rheumatology
Arthritis Care & Research
Volume 66, Issue 1, pages 63–68, January 2014
How to Cite
Knoop, J., Dekker, J., van der Leeden, M., van der Esch, M., Klein, J. P., Hunter, D. J., Roorda, L. D., Steultjens, M. P. M. and Lems, W. F. (2014), Is the Severity of Knee Osteoarthritis on Magnetic Resonance Imaging Associated With Outcome of Exercise Therapy?. Arthritis Care Res, 66: 63–68. doi: 10.1002/acr.22128
- Issue published online: 24 DEC 2013
- Article first published online: 24 DEC 2013
- Accepted manuscript online: 27 AUG 2013 03:27PM EST
- Manuscript Accepted: 13 AUG 2013
- Manuscript Received: 26 MAR 2013
- Dutch Arthritis Association
To evaluate associations between severity of knee osteoarthritis (OA) on magnetic resonance imaging (MRI) and treatment outcomes in knee OA patients treated with exercise therapy in an exploratory study.
Ninety-five participants with knee OA in a 12-week exercise program had obtained 3.0T MRI scans of the knee joint prior to treatment. MRI data were systematically assessed for OA severity of multiple features (cartilage integrity, bone marrow lesions, osteophyte formation, effusion/synovitis, and meniscal abnormalities) according to the Boston Leeds Osteoarthritis Knee Score method. Regression analyses were performed to analyze associations between OA severity on MRI (for the tibiofemoral and patellofemoral [PF] compartments) and outcome of exercise therapy, i.e., changes in activity limitations (Western Ontario and McMaster Universities Osteoarthritis Index physical function; primary outcome), pain and upper leg muscle strength, and treatment response (Outcome Measures in Rheumatology/Osteoarthritis Research Society International criteria).
Improvements of 24%, 34%, and 21% on average in activity limitations, pain, and muscle strength, respectively, after 12-week exercise therapy were found (P < 0.001). Severity of abnormalities in PF cartilage integrity was significantly associated with fewer improvements in both activity limitations (P = 0.01) and muscle strength (P = 0.04). Severity of PF osteophyte formation was significantly associated with fewer improvements in muscle strength (P < 0.01). All other features on MRI were not associated with treatment outcome.
Effectiveness of exercise therapy seems to be independent of OA severity on MRI, except for abnormalities in cartilage integrity and osteophyte formation, both in the PF compartment. Our study suggests that all grades of OA severity on MRI can benefit from professionally supervised exercise therapy, although the effects might be reduced in patients with advanced PF OA.