To study the effects of aging and cartilage degeneration of the proximal tibiofibular- and femorotibial joint (PTFJ, FTJ) on the cartilage of the PTFJ using T(1)ρ and T(2) mapping.
We performed sagittal T(1)ρ and T(2) mapping of the PTFJ and FTJ on 55 subjects with knee disorders. We placed 3 regions of interest (ROIs) on images of the cartilage in the PTFJ, medial femoral condyle (MFC), and medial tibia plateau (MTP). Correlation analysis was performed for the T(1)ρ and T(2) values of each ROI and the patient age and the osteoarthritic grade of the PTFJ and FTJ.
The T(1)ρ and T(2) values of the PTFJ were affected neither by aging nor the osteoarthritic grade of the FTJ. Values of the FTJ normalized to PTFJ values were correlated with the osteoarthritic grade of the FTJ in the MFC (r=0.851 and 0.779, respectively) and the MTP (r=0.635 and 0.762, respectively). There was a significant difference in the T(1)ρ but not the T(2) value of the PTFJ and MFC between normal and mildly osteoarthritic cartilage of each joint.
We document that the T(1)ρ and T(2) values of PTFJ cartilage were not affected by aging or cartilage degeneration in the FTJ. The T(1)ρ value of the PTFJ may represent a useful internal standard reference for evaluating early degeneration of the FTJ.