Dr. Wirth has received consultant fees, speaking fees, and/or honoraria (less than $10,000) from Merck Sorono, and owns stock and/or stock options in Chondrometrics.
Thigh Muscle Cross-Sectional Areas and Strength in Advanced Versus Early Painful Osteoarthritis: An Exploratory Between-Knee, Within-Person Comparison in Osteoarthritis Initiative Participants
Article first published online: 1 JUL 2013
Copyright © 2013 by the American College of Rheumatology
Arthritis Care & Research
Volume 65, Issue 7, pages 1034–1042, July 2013
How to Cite
Ruhdorfer, A., Dannhauer, T., Wirth, W., Hitzl, W., Kwoh, C. K., Guermazi, A., Hunter, D. J., Benichou, O., Eckstein, F. and For The Osteoarthritis Initiative Investigators (2013), Thigh Muscle Cross-Sectional Areas and Strength in Advanced Versus Early Painful Osteoarthritis: An Exploratory Between-Knee, Within-Person Comparison in Osteoarthritis Initiative Participants. Arthritis Care Res, 65: 1034–1042. doi: 10.1002/acr.21965
- Issue published online: 1 JUL 2013
- Article first published online: 1 JUL 2013
- Accepted manuscript online: 11 FEB 2013 10:07AM EST
- Manuscript Accepted: 17 JAN 2013
- Manuscript Received: 3 JUL 2012
- Osteoarthritis Initiative (OAI). Grant Numbers: N01-AR-2-2258, N01-AR-2-2259, N01-AR-2-2260, N01-AR-2-2261, N01-AR-2-2262
- NIH, a branch of the Department of Health and Human Services
- OAI Study Investigators
- Merck Research Laboratories
- Novartis Pharmaceuticals Corporation
- Pfizer Inc.
- Foundation for the NIH
- Paracelsus Medical University Research Fund
- Australian Research Council Future Fellowship
To compare cross-sectional and longitudinal side differences in thigh muscle anatomic cross-sectional areas (ACSAs), strength, and specific strength (strength/ACSA) between knees with early versus advanced painful radiographic osteoarthritis in the same person.
Forty-four of 2,678 Osteoarthritis Initiative participants (31 women and 13 men) met the inclusion criteria of bilateral frequent knee pain, medial joint space narrowing (JSN) in 1 knee, and no medial (or lateral) JSN in the contralateral knee. Thigh muscle ACSAs of the quadriceps, hamstrings, adductors, and individual quadriceps heads at consistent locations were determined using magnetic resonance imaging. Isometric muscle strength was determined in extension/flexion (Good Strength Chair). Baseline quadriceps ACSAs and strength were considered primary end points, and longitudinal changes of these factors were considered secondary end points (by paired t-tests).
No significant side differences in quadriceps (or other thigh muscle) ACSAs, strength, or specific strength were observed between medial JSN knees versus knees without JSN, or between specific medial JSN knee strata and contralateral knees without JSN, either in men or women. Two-year longitudinal changes in thigh muscle ACSAs and strength were small (≤5.2%) and did not differ significantly between medial JSN knees and knees without JSN.
In the context of previous findings that side differences in pain are associated with side differences in quadriceps ACSAs, the current results suggest that quadriceps (and other thigh muscle) properties are not independently associated with radiographic disease status (JSN) once knees have reached frequent pain status. Further, our longitudinal findings indicate that a more advanced radiographic stage of knee osteoarthritis is not necessarily associated with a longitudinal decline in muscle function.