Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement
Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.
Peri-Articular Apparent Bone Volume Fraction Is Associated with Numerous Patient Characteristics in Knees with Osteoarthritis: Data From the Osteoarthritis Initiative.
Driban1, Jeffrey B., Price1, Lori Lyn, Tassinari1, Anna M., Lo2, Grace H., McAlindon1, Timothy E.
Recent evidence suggests that peri-articular bone changes are integral to knee osteoarthritis (OA) pathophysiology. Peri-articular trabecular morphology changes have been associated with radiographic knee OA severity and may identify individuals at risk for knee OA progression. However, it is unclear how patient characteristics are associated with peri-articular trabecular morphology in knees with OA. The purpose of this study was to evaluate the association between patient characteristics and apparent bone volume fraction (aBVF), one measure of trabecular morphology, in knees with OA.
The sample comprised 421 participants in the Osteoarthritis Initiative (OAI) progression cohort who at the 30- or 36-month OAI visit had 3-tesla magnetic resonance imaging (MRI) that included a coronal 3D Fast Imaging with Steady State Precession (FISP) trabecular morphometry sequences of one knee (right knee unless contraindicated). We used a trabecular morphometry program (calcDCN, University of California-San Francisco) to measure aBVF in the medial tibial plateau. aBVF was calculated in 20 consecutive central slices within a 15 mm × 3.75 mm region of interest placed in the peri-articular medial tibia and then averaged. Intra-tester reproducibility was high (ICC = 0.99). We used three multiple linear regression models to evaluate patient characteristics associated to aBVF: 1) individual-level model (sex, race, age at time of MRI, body mass index at time of MRI, college, income, and history of smoking), 2) individual-level model with history of knee injury/surgery model, and 3) model 2 with knee-specific variables of radiographic severity (joint space narrowing [JSN] and joint space width [JSW] at 300 mm).
Participant and knee-specific characteristics are reported in the table. Average (± s.d.) peri-articular aBVF was 0.10 ± 0.07. All three regression models were statistically significant (p < 0.001). Individual-level variables accounted for 12.0% of the variance in aBVF. The combination of individual-level and knee-specific variables accounted for 22.2% of the variance in aBVF. Females were characterized by lower aBVF in all three models. In contrast, Caucasians and patients with a higher body mass index had higher aBVF in all three models. History of knee injury/surgery and greater radiographic severity in the medial compartment (higher JSN score, lower JSW) were associated with higher aBVF. Age at the time of the MRI was only related to aBVF when radiographic severity was included in the model.
Among individuals with knee OA, peri-articular morphology is influenced by multiple individual-level (sex, race, body mass index) and knee-specific variables (knee injury/surgery, OA severity). Increases in aBVF were associated with individuals with higher body mass index and history of knee injury/surgery, Caucasians, and markers of local knee OA severity.
Table. Characteristics Associated with Peri-articular Apparent Bone Volume Fraction
To cite this abstract, please use the following information:
Driban, Jeffrey B., Price, Lori Lyn, Tassinari, Anna M., Lo, Grace H., McAlindon, Timothy E.; Peri-Articular Apparent Bone Volume Fraction Is Associated with Numerous Patient Characteristics in Knees with Osteoarthritis: Data From the Osteoarthritis Initiative. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :1998