A population-based study of the association between hip bone marrow lesions, high cartilage signal, and hip and knee pain.

The objective of this study was to describe the cross-sectional and longitudinal relationship between hip bone marrow lesions (BMLs), high cartilage signal, and hip and knee pain. One hundred ninety-eight participants in the Tasmanian Older Adult Cohort Study with right hip MRI conducted at two time points, approx. 2.3 years apart, were included. Short T1 Inversion Recovery MR images were used to quantitatively measure hip BML size and determine high cartilage signal presence. Hip and knee pain were individually assessed using the Western Ontario and McMaster Universities Osteoarthritis index pain score. Fifty-five participants (28%) had either femoral and/or acetabular BMLs. Cross-sectionally, the presence of large femoral, acetabular, or any hip BMLs was associated with higher odds of hip pain (OR = 4.42, 95% CI = 1.37-19.7; OR = 5.23, 95% CI = 1.17-22.9; OR = 4.43, 95% CI = 1.46-13.2, respectively). High cartilage signal was strongly associated with hip BMLs (OR = 6.45, 95% CI = 3.37-12.6), but not with pain. Longitudinally, incident acetabular (Mean diff = +5.90, 95% CI = +3.78 to +8.15) and femoral BMLs (Mean diff = +1.18, 95% CI = 0.23-1.94) were associated with worsening hip pain, while resolving femoral BMLs were associated with a decrease in knee pain (Mean diff = -3.18, 95% CI = -5.99 to -0.50). The evidence is consistent for hip, but not knee pain, and strongly suggests that large hip BMLs are associated with hip pain. Furthermore, high cartilage signal is asymptomatic, but strongly associated with hip BMLs. These findings suggest that hip BMLs play an important role in hip osteoarthritis.