Changes in proximal femoral mineral geometry precede the onset of radiographic hip osteoarthritis: The study of osteoporotic fractures

• Published in: Arthritis and rheumatism 2009-07, Vol.60 (7), p.2028-2036
• Main Authors: Javaid, M. K., Lane, N. E., Mackey, D. C., Lui, L.‐Y., Arden, N. K., Beck, T. J., Hochberg, M. C., Nevitt, M. C.
• Format: Article
• Language: English
• Subjects: Absorptiometry, Photon; Aged; Biological and medical sciences; Bone Density - physiology; Cohort Studies; Disease Progression; Diseases of the osteoarticular system; Female; Femur Neck - diagnostic imaging; Femur Neck - physiopathology; Hip Fractures - epidemiology; Hip Fractures - physiopathology; Humans; Injuries of the limb. Injuries of the spine; Logistic Models; Medical sciences; Osteoarthritis; Osteoarthritis, Hip - diagnostic imaging; Osteoarthritis, Hip - epidemiology; Osteoarthritis, Hip - physiopathology; Osteophyte - diagnostic imaging; Osteophyte - physiopathology; Osteoporosis - complications; Osteoporosis - physiopathology; Osteoporosis. Osteomalacia. Paget disease; Phenotype; Prevalence; Risk Factors; Traumas. Diseases due to physical agents
• ISSN: 0004-3591; 1529-0131
• DOI: 10.1002/art.24639

Objective Radiographic hip osteoarthritis (RHOA) is associated with increased hip areal bone mineral density (aBMD). This study was undertaken to examine whether femoral geometry is associated with RHOA independent of aBMD. Methods Participants in the Study of Osteoporotic Fractures in whom pelvic radiographs had been obtained at visits 1 and 5 (mean 8.3 years apart) and hip dual x‐ray absorptiometry (DXA) had been performed (2 years after baseline) were included. Prevalent and incident RHOA phenotypes were defined as composite (osteophytes and joint space narrowing [JSN]), atrophic (JSN without osteophytes), or osteophytic (femoral osteophytes without JSN). Analogous definitions of progression were based on minimum joint space and total osteophyte score. Hip DXA scans were assessed using the Hip Structural Analysis program to derive geometric measures, including femoral neck length, width, and centroid position. Relative risks and 95% confidence intervals for prevalent, incident, and progressive RHOA per SD increase in geometric measure were estimated in a hip‐based analysis using multinomial logistic regression with adjustment for age, body mass index, knee height, and total hip aBMD. Results In 5,245 women (mean age 72.6 years), a wider femoral neck with a more medial centroid position was associated with prevalent and incident osteophytic and composite RHOA phenotypes (P < 0.05). Increased neck width and centroid position were associated with osteophyte progression (both P < 0.05). No significant geometric associations with atrophic RHOA were found. Conclusion Differences in proximal femoral bone geometry and spatial distribution of bone mass occur early in hip OA and predict prevalent, incident, and progressive osteophytic and composite phenotypes, but not the atrophic phenotype. These bone differences may reflect responses to loading occurring early in the natural history of RHOA.