Hip shape as a predictor of osteoarthritis progression in a prospective population cohort
METHODS: Baseline dual-energy X-ray absorptiometry (DXA) images of the left hip of 831 subjects from the Tasmanian Older Adult Cohort (TASOAC) were analyzed using an 85-point statistical shape model. Hip pain was assessed by WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) and muscle strength was measured by a dynamometer. Hip structural changes were assessed using MRI and Radiographic OA (ROA) using plain radiographs.
RESULTS: Six shape modes described 68% of shape variation. At baseline, modes 1, 2, 4 and 6 were associated with hip ROA, modes 1, 3, 4 and 6 correlated with hip cartilage volume and all except mode 2 with muscle strength. Higher mode 1, and lower mode 3 and 6 scores at baseline predicted hip pain at follow-up and higher mode 1 and mode 2 scores were associated with hip effusion-synovitis. Greater scores for mode 2 (decreasing acetabular coverage) and lower mode 4 (non-spherical femoral head) at baseline predicted 10-year total hip replacement (THR); while mode 4 alone correlated with bone marrow lesions (BMLs), effusion-synovitis, and increased cartilage signal.
CONCLUSIONS: Hip shape is associated with ROA, THR, hip pain, effusion-synovitis, BMLs, muscle strength and hip structural changes. These data suggest that different shape modes reflect multiple facets of hip osteoarthritis. This article is protected by copyright. All rights reserved.
Publication titleArthritis Care & Research
Department/SchoolMenzies Institute for Medical Research
PublisherJohn Wiley & Sons, Inc.
Place of publicationUnited States
Rights statementCopyright 2016 American College of Rheumatology