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Thigh Muscle Cross‐Sectional Areas and Strength in Advanced Versus Early Painful Osteoarthritis: An Exploratory Between‐Knee, Within‐Person Comparison in Osteoarthritis Initiative Participants
Author(s) -
Ruhdorfer Anja,
Dannhauer Torben,
Wirth Wolfgang,
Hitzl Wolfgang,
Kwoh C. Kent,
Guermazi Ali,
Hunter David J.,
Benichou Olivier,
Eckstein Felix
Publication year - 2013
Publication title -
arthritis care and research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.032
H-Index - 163
eISSN - 2151-4658
pISSN - 2151-464X
DOI - 10.1002/acr.21965
Subject(s) - medicine , osteoarthritis , isometric exercise , thigh , physical therapy , knee pain , context (archaeology) , knee joint , longitudinal study , cross sectional study , magnetic resonance imaging , physical medicine and rehabilitation , anatomy , surgery , radiology , pathology , paleontology , alternative medicine , biology
Objective 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. Methods 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). Results 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. Conclusion 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.