Special Theme Article: Clinical Imaging and the Rheumatic Diseases
Association of Incident Symptomatic Hip Osteoarthritis With Differences in Hip Shape by Active Shape Modeling: The Johnston County Osteoarthritis Project
Article first published online: 24 DEC 2013
Copyright © 2014 by the American College of Rheumatology
Arthritis Care & Research
Volume 66, Issue 1, pages 74–81, January 2014
How to Cite
Nelson, A. E., Liu, F., Lynch, J. A., Renner, J. B., Schwartz, T. A., Lane, N. E. and Jordan, J. M. (2014), Association of Incident Symptomatic Hip Osteoarthritis With Differences in Hip Shape by Active Shape Modeling: The Johnston County Osteoarthritis Project. Arthritis Care Res, 66: 74–81. doi: 10.1002/acr.22094
- Issue published online: 24 DEC 2013
- Article first published online: 24 DEC 2013
- Accepted manuscript online: 7 AUG 2013 12:46PM EST
- Manuscript Accepted: 29 JUL 2013
- Manuscript Received: 8 MAR 2013
- NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases. Grant Numbers: K23-AR-061406, P60-AR-30701, P60-AR-30701
- CDC/Association of Schools of Public Health. Grant Numbers: S043, S3486
- NIH. Grant Numbers: K24-AR-04884, P50-AR-063043, P50-AR-060752
To investigate hip shape by active shape modeling (ASM) as a potential predictor of incident radiographic hip osteoarthritis (RHOA) and symptomatic hip osteoarthritis (SRHOA).
All hips developing RHOA from baseline (Kellgren/Lawrence [K/L] grade 0/1) to mean 6-year followup (K/L grade ≥2, 190 hips) and 1:1 control hips (K/L grade 0/1 at both times, 192 hips) were included. Proximal femur shape was defined on baseline anteroposterior pelvis radiographs and submitted to ASM, producing a mean shape and continuous variables representing independent modes of shape variation. Mode scores (n = 14, explaining 95% of shape variance) were simultaneously included in logistic regression models with incident RHOA and SRHOA as dependent variables, adjusted for intraperson correlations, sex, race, body mass index (BMI), baseline K/L grade, and/or symptoms.
We evaluated 382 hips from 342 individuals: 61% women and 83% white, with mean age 62 years and mean BMI 29 kg/m2. Several modes differed by sex and race, but no modes were associated with incident RHOA overall. Among men only, modes 1 and 2 were significantly associated (for a 1-SD decrease in mode 1 score: odds ratio [OR] 1.7 [95% confidence interval (95% CI) 1.1–2.5] and for a 1-SD increase in mode 2 score: OR 1.5 [95% CI 1.0–2.2]) with incident RHOA. A 1-SD decrease in mode 2 or 3 score increased the odds of SRHOA by 50%.
This study confirms other reports that variations in proximal femur shape have a modest association with incident hip OA. The observation of proximal femur shape associations with hip symptoms requires further investigation.