Bone Metabolic-Morphologic relation is Mediated by Gait; Cartilage Compositional-Morphologic relation isn’t: PET/MRI in Isolated PFJOA

Motivation: Whether the compositional, metabolic, and biomechanical relationships have a mediated effect on one another is the next crucial step toward decoding the isolated PFJOA mechanism. Goal(s): To investigate whether the relationship of morphological-joint-degradation with SUV-values from 18NaF-PET and cartilage-T2 in isolated-PFJOA are mediated by gait-biomechanics. Approach: Linear regression was performed between (i)WORMSBME(predictor) vs. Medial-SUVmax, Lateral-SUVmax (outcomes), and (ii) WORMSCartilage(predictor) vs. Mean-T2-Deep-Medial, T2-Superficial-Medial, T2-Deep-Lateral, T2-Superficial-Lateral (outcomes) patellar and trochlear. For significant correlations, mediation analyses were done to examine the role of Normalized-Mean-Peak vGRFIP as a mediator. Results: WORMSBME vs. Medial-SUVmax, Lateral-SUVmax relationships are mediated by gait; WORMSCartilage vs. Mean-T2-Deep-Medial, T2-Superficial-Medial, T2-Deep-Lateral, T2-Superficial-Lateral aren’t mediated. Impact: This is the first step towards understanding the flow of causalities and mediated interrelationships of bone remodeling (SUV), morphological degradation (WORMS), cartilage loss (T2), and gait biomechanics in a complex joint developing isolated PFJOA