Longitudinal Relationship Between Tibiofemoral Contact Stress at Baseline and Worsening of Knee Pain Over 84 Months in the Multicenter Osteoarthritis Study

Abstract

Objective: The aim of the study was to determine whether tibiofemoral contact stress predicts risk for worsening knee pain over 84 ms in adults aged 50-79 yrs with or at elevated risk for knee osteoarthritis.

Design: Baseline tibiofemoral contact stress was estimated using discrete element analysis. Other baseline measures included weight, height, hip-knee-ankle alignment, Kellgren-Lawrence grade, and Western Ontario and McMaster Universities Osteoarthritis Index pain subscale. Logistic regression models assessed the association between baseline contact stress and 84-mo worsening of Western Ontario and McMaster Universities Osteoarthritis Index pain subscale.

Results: Data from the dominant knee (72.6% Kellgren-Lawrence grade 0/1 and 27.4% Kellgren-Lawrence grade ≥ 2) of 208 participants (64.4% female, mean ± SD body mass index = 29.6 ± 5.1 kg/m 2 ) were analyzed. Baseline mean and peak contact stress were 3.3 ± 0.9 and 9.4 ± 4.3 MPa, respectively. Forty-seven knees met the criterion for worsening pain. The highest tertiles in comparison with the lowest tertiles of mean (odds ratio [95% confidence interval] = 2.47 [1.03-5.95], P = 0.04) and peak (2.49 [1.03-5.98], P = 0.04) contact stress were associated with worsening pain at 84 mos, after adjustment for age, sex, race, clinic site, and baseline pain. Post hoc sensitivity analyses including adjustment for body mass index and hip-knee-ankle alignment attenuated the effect.

Conclusions: These findings suggest that elevated tibiofemoral contact stress can predict the development of worsening of knee pain.

Trial registration: ClinicalTrials.gov NCT03033238.

Figure 1:

Process for Tibiofemoral Articular Contact Stress Estimation. (A) Segmentation of magnetic resonance (MR) images of tibiofemoral joint. (B) Bone models generated from segmentation of MR images. (C) Alignment of bone models to standing radiograph. (D) Computation of contact stress via discrete element analysis.

Figure 2:

Participant Inclusion Diagram

Figure 3:

(A) Odds Ratios with 95% Confidence Intervals (CI) for Mean Contact Stress and all Covariates as Predictors for Worsening Knee Pain. (B) Odds Ratios with 95% Confidence Intervals for Peak Contact Stress and all Covariates as Predictors for Worsening Knee Pain. All analyses were completed with the lowest tertile of baseline contact stress as the referent group.