Osteoarthritis of the knee: comparison of MR imaging findings with radiographic severity measurements and pain in middle-aged women

Abstract

Purpose: To prospectively compare magnetic resonance (MR) imaging-defined abnormalities of osteoarthritis (OA) of the knee with radiographic severity measurements of OA of the knee and self-reported pain.

Materials and methods: This study was approved by the institutional review board of University of Michigan. Informed consent was obtained for this HIPAA-compliant study. Knee MR imaging was performed in 117 women (mean age, 46 years; range, 32-56 years) from a community-based arthritis study (n = 1053) with 30 women in each of four categories: (a) no pain and no OA of the knee, (b) no pain and OA of the knee, (c) pain and no OA of the knee, and (d) pain and OA of the knee. OA of the knee was defined from radiographs. Two hundred thirty-two eligible knees had Kellgren-Lawrence scores for OA of the knee as follows: grade 0, 115 (49.6%); grade 1, 33 (14.2%); grade 2, 66 (28.4%); grade 3, 17 (7.3%); and grade 4, one (0.4%). MR images were assessed for location and severity of defects of cartilage, bone marrow edema (BME), osteophytes, subchondral cysts, sclerosis, meniscal and/or ligamentous tears, joint effusion, synovial cysts, and synovitis. MR imaging findings were compared with radiographic severity of OA of the knee (Kellgren-Lawrence scale) and self-reported pain with analysis of variance, t tests, and contingency table analyses.

Results: Defects of cartilage (higher than grade IIA) were found in 75% of knees; BME was found in 57% of knees (<1 cm, 41%; >1 cm, 16%). Large BME lesions were common in the pain and OA of the knee group (P = .001); this group was significantly more likely to have defects of cartilage (P = .001); meniscal tears (P = .001); and osteophytes, subchondral cysts, sclerosis, joint effusion, and synovitis (P < .001). Defects of cartilage, osteophytes, sclerosis, meniscal or ligamentous tears, joint effusion, and synovitis were strongly related to increasing Kellgren-Lawrence grade (P < .001).

Conclusion: In middle-aged women, there were significant associations between pain, radiographic severity of OA of the knee, and seven MR imaging-identified parameters.