Baseline structural tissue pathology is not strongly associated with longitudinal change in transverse relaxation...

To evaluate whether baseline MRI-defined structural abnormalities are associated with subsequent change in laminar femorotibial cartilage transverse relaxation time (T2) of participants without radiographic signs, symptoms or risk factors for knee osteoarthritis (OA).

We studied all right knees with longitudinal MRI data of the refined Osteoarthritis Initiative Healthy Reference cohort. Baseline osteophytes, effusion-synovitis, Hoffa-synovitis, bone marrow lesions, cartilage lesions, and meniscus morphology and - extrusion were scored semiquantitatively from MR images by an expert reader. Deep and superficial layer cartilage T2 was computed in the medial and lateral femorotibial compartment (MFTC/LFTC) at baseline and at 1- and 4-year follow-up from multi-echo spin-echo MR images. Statistical analyses were performed using UNIANOVA.

82 participants (age 54.1 ± 7.2y, BMI 24.2 ± 3.0 kg/m²; 61% women, bilateral Kellgren-Lawrence 0) were studied. Number of baseline MRI pathologies was not significantly associated with longitudinal change in MFTC or LFTC cartilage T2 over 1 or 4 years. Feature-specific analyses suggested that presence of baseline MFTC osteophytes may be associated with prolongation in superficial MFTC cartilage T2 over one (0.8 vs. 0.0 ms, p = 0.02) and four years (2.3 vs. 0.9 ms, p = 0.01), and that MFTC meniscal damage or extrusion may be associated with prolongation in deep layer T2 times over the first year (0.7 vs. 2.1 ms, p = 0.02).

Our study does not provide evidence that, in knees without radiographic OA, baseline structural MRI abnormalities are strongly related to compositional progression during normal aging and/or the potentially earliest phases of the disease as measured by cartilage T2.