Recent findings support a beneficial role of hip abductor strength for disease modification and function and disability outcomes for knee osteoarthritis (OA). Participants in this study had knee OA (Kellgren-Lawrence ≥2) in at least 1 knee. Hip abductor strength was measured using Biodex Dynamometry. Participants underwent 3.0T MRI of both knees at baseline and 2 years later. Baseline-to-2-year cartilage damage progression, defined as any worsening of WORMS cartilage damage score, was assessed at each tibiofemoral and patellofemoral surface. Late-Life Function and Disability Instrument (LLFDI) and Chair-Stand-Rate were recorded at baseline and 5-year follow-up; outcomes analyzed using quintiles. Poor outcomes were defined as remaining in the same low-function quintiles or being in a worse quintile at 5-year follow-up. Researchers found:
- 275 knees from 164 persons [age=63.7 (SD=9.8) years, 79.3% women] comprised the structural outcome sample, and 187 persons [age=64.2 (9.7), 78.6% women] the function and disability outcomes sample.
- Greater baseline hip abductor strength was associated with reduced risks of baseline-to-2-year medial patellofemoral and lateral tibiofemoral cartilage damage worsening and with reduced risks of baseline-to-5-year poor outcomes for Chair-Stand-Rate and LLFDI Basic Lower-Extremity Function and Disability Limitation.
Chang AH, Chmiel JS, Almagor O, et al. Hip muscle strength and protection against structural worsening and poor function and disability outcomes in knee osteoarthritis. [Published online ahead of print February 27, 2019]. Osteoarthritis Cartilage. doi:10.1016/j.joca.2019.02.795.