Anatomical distribution of synovitis in knee osteoarthritis and its association with joint effusion assessed on non-enhanced and contrast-enhanced MRI

Purpose: To describe the anatomical distribution of synovitis and its association with joint effusion on non-enhanced and contrast-enhanced (CE) MRI in patients with knee osteoarthritis (OA).Methods: Baseline MRI was performed at 1.5 T using axial proton density (PD)-weighted (w) fat suppressed (fs) and axial and sagittal T1-w fs CE sequences. Synovial enhancement was scored in nine articular subregions. Maximum synovial enhancement was grouped as absent (0), equivocal (1) and definite (2 and 3). Effusion was scored from 0 to 3 on the axial sequences. We described the anatomical distribution of synovitis, its association with effusion and compared assessment of effusion on T1-w fs CE and PD fs sequences.Results: 111 subjects were included and examined by MRI. 89.2% of knees exhibited at least one subregion with a minimum grade 2 and 39.6% at the maximum of a grade 3. The commonest sites for definite synovitis were posterior to the posterior cruciate ligament (PCL) in 71.2% and in the suprapatellar region in 59.5% of all knees. On T1-w fs CE, 73.0% of knees showed any effusion. Definite synovitis in at least one location was present in 96.3% knees with an effusion and in 70.0% without an effusion. Higher grades of effusion were scored on the PD fs sequence.Conclusion: Definite synovitis was present in the majority of knees with or without effusion with the commonest sites being posterior to the PCL and in the suprapatellar recess. Joint effusion as measured on PD fs images does not only represent effusion but also synovial thickening.<br/

Association of vitamin D status with knee pain and radiographic knee osteoarthritis

Objective: The objective of the present study was to explore the association of serum vitamin Dconcentration and polymorphism in the vitamin D receptor (VDR), with knee pain and radiographic kneeosteoarthritis (OA) among men and women in a large population-based UK cohort study.Methods: Seven hundred and eighty-seven participants in the Hertfordshire Cohort Study (399 men, 388women; mean age 65.6 ? 2.7 years) underwent a questionnaire on knee pain and radiographic kneeexamination. This study examined the association of Fok1, Cdx2 and Apa1 polymorphism in the gene forthe VDR and serum 25(OH)D concentration with knee pain and radiographic knee OA by a generalizedestimating equations population averaged logistic regression analysis in the Hertfordshire Cohort Study.Results: There were no associations of Fok1, Cdx2 and Apa1 polymorphisms of the VDR with knee OAexcept for Aa for Apa1 compared with AA [Odds ratio (OR) 0.59, 95% confidence interval (CI) 0.36e0.95,P¼ 0.031]. While, ff for Fok1 (OR 1.60, 95% CI 1.07e2.39, P¼ 0.022) and AA for Cdx2 polymorphism (OR2.21, 95% CI 1.07e4.56, P¼ 0.032) was significantly associated with higher prevalence of knee paincompared with FF for Fok1 and GG for Cdx2, respectively. None of these are statistically significant afteradjusting for the three polymorphisms tested. 25(OH)D level was not significantly associated withradiographic knee OA, while, low tertile of 25(OH)D level tended to be associated with knee paincompared with high tertile of 25(OH)D level.Conclusion: The present cross-sectional study using a large-scale population from the HertfordshireCohort study indicated that vitamin D may be associated with pain rather than radiographic change, butthe evidence for an association between vitamin D genetic variation and pain in knee OA is very weak inthe present study. Further replication of our results will be required to elucidate the association ofvitamin D and knee OA