Effects of T 1p Characteristics of Load-Bearing Hip Cartilage on Bilateral Knee Patellar Cartilage Subregions: Subjects With None to Moderate Radiographic Hip Osteoarthritis

• Published in: Journal of magnetic resonance imaging
• Main Authors: Bhattacharjee, Rupsa, Thahakoya, Rafeek, Luitjens, Johanna, Han, Misung, Roach, Koren E, Jiang, Fei, Souza, Richard B, Pedoia, Valentina, Majumdar, Sharmila
• Format: Journal Article
• Language: English
• Published: United States 13.09.2023
• Subjects: knee; T1p; bilateral; statistical-modeling; Osteoarthritis; hip

The polyarticular nature of Osteoarthritis (OA) tends to manifest in multi-joints. Associations between cartilage health in connected joints can help identify early degeneration and offer the potential for biomechanical intervention. Such associations between hip and knee cartilages remain understudied. To investigate T associations between hip-femoral and acetabular-cartilage subregions with Intra-limb and Inter-limb patellar cartilage; whole and deep-medial (DM), deep-lateral (DL), superficial-medial (SM), superficial-lateral (SL) subregions. Prospective. Twenty-eight subjects (age 55.1 ± 12.8 years, 15 females) with none-to-moderate hip-OA while no radiographic knee-OA. 3-T, bilateral hip, and knee: 3D-proton-density-fat-saturated (PDFS) Cube and Magnetization-Prepared-Angle-Modulated-Partitioned-k-Space-Spoiled-Gradient-Echo-Snapshots (MAPSS). Ages of subjects were categorized into Group-1 (≤40), Group-2 (41-50), Group-3 (51-60), Group-4 (61-70), Group-5 (71-80), and Group-6 (≥81). Hip T maps, co-registered to Cube, underwent an atlas-based algorithm to quantify femoral and acetabular subregional (R -R ) cartilage T . For knee Cube, a combination of V-Net architectures was used to segment the patellar cartilage and subregions (DM, DL, SM, SL). T values were computed from co-registered MAPSS. For Intra-and-Inter-limb, 5 optimum predictors out of 13 (Hip subregional T , age group, gender) were selected by univariate linear-regression, to predict outcome (patellar T ). The top five predictors were stepwise added to six linear mixed-effect (LME) models. In all LME models, we assume the data come from the same subject sharing the same random effect. The best-performing models (LME-model ) selected via ANOVA, were tested with DM, SM, SL, and DL subregional-mean T . LME assumptions were verified (normality of residuals, random-effects, and posterior-predictive-checks). LME-model (Intra-limb) had significant negative and positive fixed-effects of femoral-R and acetabular-R T , respectively (conditional-R  = 0.581). LME-model (Inter-limb) had significant positive fixed-effects of femoral-R T (conditional-R  = 0.26). Significant positive and negative T associations were identified between load-bearing hip cartilage-subregions vs. ipsilateral and contralateral patellar cartilages respectively. The effects were localized on medial subregions of Inter-limb, in particular. 1 TECHNICAL EFFICACY: Stage 1.