Session Information
Date: Tuesday, November 7, 2017
Title: Osteoarthritis – Clinical Aspects Poster II: Observational and Epidemiological Studies
Session Type: ACR Poster Session C
Session Time: 9:00AM-11:00AM
Background/Purpose:
Relative local knee periarticular bone mineral density (paBMD) as measured by dual x-ray absorptiometry (DXA) has been associated with static alignment cross-sectionally, but not longitudinally; we postulated that there would be an association. We evaluated the association of paBMD with femur-tibial angle (FTA) within the Osteoarthritis Initiative (OAI).
Methods:
We performed a longitudinal study of a subgroup of the incidence subcohort of the OAI who had right knee DXA scans from both the 72-month and 96-month visits, generating knee medial:lateral paBMD ratios focused on the tibial plateau. Also, participants had to have radiographs read for FTA at the 72- and 96- month visits (negative value = greater varus) and 48-month readings of Kellgren and Lawrence (KL) grade, where grade ≥ 2 was considered as having ROA. Stratified by ROA status, we performed Spearman’s correlations of: 72- month paBMD ratio and FTA, as well as the 72- to 96- month change in paBMD ratio and FTA.
Results: 400 participants, 54% female, were included with a mean age of 65.0 (8.2) years and BMI of 28.3 (4.9) kg/m2.
Among those with no ROA based on the 48 month radiographs, n = 168, mean 72- month paBMD ratio was 1.09 (0.09) and FTA was -5.26 (1.66) (varus). Mean change from 72- to 96- month paBMD ratio was 0.00 (0.05) and FTA was -0.04 (0.83) (varus). Spearman correlations are presented in table 1.
Among those with ROA based on the 48 month radiographs, n = 232, mean 72- month paBMD ratio was 1.12 (0.13) and FTA was -5.43 (2.77) (varus). Mean change from 72- to 96- month paBMD ratio was 0.00 (0.06) and FTA was -0.04 (0.80) (varus). Spearman correlations are presented in table 2.
Table. Spearman’s Correlations of paBMD and Static Alignment
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No ROA
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paBMD Ratio
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FTA
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paBMD Ratio Difference
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FTA Difference
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paBMD Ratio
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FTA
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paBMD Ratio Difference
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FTA Difference
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ROA
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paBMD Ratio
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FTA
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paBMD Ratio Difference
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FTA Difference
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For each cell correlation coefficients are provided with the p-values below. |
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Conclusion: Baseline paBMD was associated with change in static alignment in those without and with OA. However, baseline static alignment was not associated with change in paBMD and change in paBMD was not associated with change in static alignment. Perhaps this is evidence that change in paBMD precedes altered static alignment in the natural history of OA. These findings support the idea that paBMD changes occur early in the natural history of OA and holds the promise of being a good marker for early disease.
To cite this abstract in AMA style:
Lo GH, Driban JB, Strayhorn MT, Price LL, Eaton C, McAlindon TE. Baseline Periarticular Tibial Knee Bone Mineral Density Is Associated with Change in Static Alignment [abstract]. Arthritis Rheumatol. 2017; 69 (suppl 10). https://acrabstracts.org/abstract/baseline-periarticular-tibial-knee-bone-mineral-density-is-associated-with-change-in-static-alignment/. Accessed .« Back to 2017 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/baseline-periarticular-tibial-knee-bone-mineral-density-is-associated-with-change-in-static-alignment/