Person:

Lu, Bing

Background: Accelerated knee osteoarthritis may be a unique subset of knee osteoarthritis, which is associated with greater knee pain and disability. Identifying risk factors for accelerated knee osteoarthritis is vital to recognizing people who will develop accelerated knee osteoarthritis and initiating early interventions. The geometry of an articular surface (e.g., coronal tibial slope), which is a determinant of altered joint biomechanics, may be an important risk factor for incident accelerated knee osteoarthritis. We aimed to determine if baseline coronal tibial slope is associated with incident accelerated knee osteoarthritis or common knee osteoarthritis. Methods: We conducted a case–control study using data and images from baseline and the first 4 years of follow-up in the Osteoarthritis Initiative. We included three groups: 1) individuals with incident accelerated knee osteoarthritis, 2) individuals with common knee osteoarthritis progression, and 3) a control group with no knee osteoarthritis at any time. We did 1:1:1 matching for the 3 groups based on sex. Weight-bearing, fixed flexion posterior-anterior knee radiographs were obtained at each visit. One reader manually measured baseline coronal tibial slope on the radiographs. Baseline femorotibial angle was measured on the radiographs using a semi-automated program. To assess the relationship between slope (predictor) and incident accelerated knee osteoarthritis or common knee osteoarthritis (outcomes) compared with no knee osteoarthritis (reference outcome), we performed multinomial logistic regression analyses adjusted for sex. Results: The mean baseline slope for incident accelerated knee osteoarthritis, common knee osteoarthritis, and no knee osteoarthritis were 3.1(2.0), 2.7(2.1), and 2.6(1.9); respectively. A greater slope was associated with an increased risk of incident accelerated knee osteoarthritis (OR = 1.15 per degree, 95 % CI = 1.01 to 1.32) but not common knee osteoarthritis (OR = 1.04, 95 % CI = 0.91 to 1.19). These findings were similar when adjusted for recent injury. Among knees with varus malalignment a greater slope increases the odds of incident accelerated knee osteoarthritis; there is no significant relationship between slope and incident accelerated knee osteoarthritis among knees with normal alignment. Conclusions: Coronal tibial slope, particularly among knees with malalignment, may be an important risk factor for incident accelerated knee osteoarthritis.

Objectives: We examine the prospective association of soft drink consumption with radiographic progression of knee osteoarthritis (OA). Design: Prospective cohort study. Setting: This study used data from the osteoarthritis initiative (OAI). Participants: In OAI, 2149 participants with radiographic knee OA and having dietary data at baseline were followed up to 12, 24, 36 and 48 months. Measures The soft drink consumption was assessed with a Block Brief Food Frequency Questionnaire completed at baseline. To evaluate knee OA progression, we used quantitative medial tibiofemoral joint space width (JSW) based on plain radiographs. The multivariate linear models for repeated measures were used to test the independent association between soft drink intake and the change in JSW over time, while adjusting for body mass index and other potential confounding factors. Results: In stratified analyses by gender, we observed a significant dose–response relationship between baseline soft drink intake and adjusted mean change of JSW in men. With increasing levels of soft drink intake (none, ≤1, 2–4 and ≥5 times/week), the mean decreases of JSW were 0.31, 0.39, 0.34 and 0.60 mm, respectively. When we further stratified by obesity, a stronger dose–response relationship was found in non-obese men. In obese men, only the highest soft drink level (≥5 times/week) was associated with increased change in JSW compared with no use. In women, no significant association was observed. Conclusions: Our results suggest that frequent consumption of soft drinks may be associated with increased OA progression in men. Replication of these novel findings in other studies demonstrating the reduction in soft drink consumption leads to delay in OA progression is needed.