Photo Credit: TefiM

The following is a summary of “Association of thigh intramuscular fat infiltration with incident knee and hip osteoarthritis: a longitudinal cohort study,” published in the March 2025 issue of American College of Rheumatology by Weng et al. 

Researchers conducted a retrospective study on thigh intramuscular fat infiltration (IMFI) and its link to incident knee and hip osteoarthritis, finding that IMFI was associated with metabolic inflammation and muscle dysfunction, potentially contributing to osteoarthritis development. 

They conducted a cohort study using UK Biobank data, including participants with baseline IMFI in thigh muscle assessed by MRI and no history of knee or hip osteoarthritis. Analyses included 24,224 and 24,221 participants for anterior and posterior thigh IMFI with knee osteoarthritis and 24,767 and 24,764 for hip osteoarthritis. Cox Proportional-hazard models estimated hazard ratios for incidents clinically diagnosed knee or hip osteoarthritis, adjusting for potential confounders. 

The results showed that during a mean follow-up of 4.8 years, 472 developed knee osteoarthritis, and 387 developed hip osteoarthritis. IMFI in the anterior thigh was associated with knee osteoarthritis, with adjusted HRs of 1.78 (1.19-2.65), 2.00 (1.34-2.99), and 2.34 (1.53-3.59) across the second to fourth quartiles (P for trend <0.01). Both anterior and posterior thigh IMFI were linked to hip osteoarthritis (both Ps for trend <0.01). Dose-response relationships were observed, and analyses confirmed the effect was independent of body mass index and sex. 

Investigators found that elevated thigh IMFI was associated with a higher incidence of knee and hip osteoarthritis. Reducing IMFI may help prevent osteoarthritis and lessen its impact. 

Source: acrjournals.onlinelibrary.wiley.com/doi/abs/10.1002/art.43159