Relationship Between 2 Years of Muscle Strength Decrease and Volume Loss of Menisci and Cartilage According to Knee Pain in Mild and Moderate Knee Osteoarthritis.

Abstract

The aim of the study is to explore the relationship between 2-yr changes in muscle strength and cartilage according to knee pain in mild and moderate knee osteoarthritis. Two hundred seventy-nine participants were retrospectively obtained from the Osteoarthritis Initiative. Western Ontario McMaster University and Knee Injury and Osteoarthritis Outcome Score were used to assess pain and function. Five muscles strength (maximum extensor and flexor, normalized maximum extensor and flexor, and extensor/flexor ratio) were measured from isometric strength test. Menisci and cartilage volumes were measured from magnetic resonance imaging to assess 2 yr of osteoarthritis progression. Mild and moderate knee osteoarthritis progression was characterized by patellofemoral cartilage loss and meniscal degeneration. For WOMAC pain >2 participants, decrease in extensor strength and normalized extensor strength were positively correlated with medial meniscus volume loss (r = 0.261, P = 0.021; r = 0.232, P = 0.041, respectively). The extensor/flexor ratio changes were positively associated with Western Ontario McMaster University function changes (r = 0.291, P = 0.013) over 2 yrs. The study observed a positive correlation between quadriceps strength decrease and medial meniscus degeneration in mild and moderate knee osteoarthritis patients with Western Ontario McMaster University pain >2. These findings suggested quadriceps-hamstrings balance possibly plays a protective role in knee function for participants with weaker quadriceps and severe pain. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME. Upon completion of this article, the reader should be able to: 1): Determine the effect of knee extensor muscle strength changes on the medial and lateral meniscus, tibia, and medial and lateral femoral cartilage over 2 yrs in mild to moderate knee osteoarthritis patients; 2): Describe the correlation of knee extensor strength with the medial and lateral meniscus, tibia, and medial and lateral femoral cartilage at different WOMAC-pain levels; and 3): Discuss the relationship between changes in muscle strength and changes in meniscus and cartilage volume and WOMAC pain scores over 2 yrs in mild to moderate knee osteoarthritis patients. Advanced. The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s) ™. Physicians should only claim credit commensurate with the extent of their participation in the activity.