Knee osteoarthritis. Efficacy of a new method of contrast-enhanced musculoskeletal ultrasonography in detection of synovitis in patients with knee osteoarthritis in comparison with magnetic resonance imaging.

OBJECTIVE: To develop a new method of digital synovial vascularisation quantification by using contrast-enhanced musculoskeletal ultrasonography (MUS) in detecting synovitis in patients with knee osteoarthritis (OA) compared with healthy subjects and MRI. METHODS: Evaluation of 41 patients with painful knee OA and 6 healthy subjects. The severity of knee pain was evaluated. All patients and all 6 healthy subjects underwent contrast medium-enhanced (CE)-MUS with SonoVue, and 36 patients additionally underwent CEMRI with Magnevist. Joint effusion, synovial thickening and pain were assessed and compared with B-mode and Power Doppler sonography (PDS) as well as contrast medium enhancement. RESULTS: Pain evaluated by the visual analogue scale(VAS) hardly correlated with other markers of disease activity measured by ultrasound (US) in B-mode or MRI. US of the superior recess revealed an effusion or synovial thickening in 58%. PDS findings were positive in 63%, and CE-MUS in the superior knee recess was positive in 95%. MRI showed effusion in the superior recess in 61% and showed positive findings in 82% when using contrast medium. The kappa value was 0.48 between US and MRI with regard to the effusion in the superior recess, and 0.53 between PD signal in the superior recess and effusion in the superior recess by US. Using MRI as the reference standard, there was a sensitivity of 72% for assessing effusion in the superior recess and 81% for assessing effusion in the lateral recess. CONCLUSION: Assessment of disease activity (synovitis) in knee OA by VAS is not sufficient. US PDS was more sensitive than B-mode, and CE-MUS was more sensitive than PDS and CE-MRI in detecting synovitis in patients with painful knee OA. Also, CE-MRI was more sensitive in detecting inflammatory changes in the superior recess than without contrast medium. Using CE-MUS and performing time/intensity analysis has shown to be a good model for evaluation of an inflammatory process in the setting of knee OA in the superior recess.

Bone marrow abnormalities on magnetic resonance imaging are associated with type II collagen degradation in knee osteoarthritis: a three-month longitudinal study.

OBJECTIVE: Using radiography to assess the efficacy of a disease-modifying osteoarthritis (OA) drug on joint structure is challenging. Subchondral bone marrow abnormalities determined by magnetic resonance imaging (MRI) and urinary excretion of C-terminal crosslinking telopeptide of type II collagen (CTX-II) have recently been shown to be predictors of radiographic progression in patients with knee OA, suggesting that these may represent valuable biomarkers with increased sensitivity compared with findings on radiography. The aims of this investigation were to analyze, in patients with knee OA, whether the values associated with these 2 OA biomarkers can change within 3 months, and to investigate the relationships between bone marrow abnormalities and CTX-II. METHODS: Knee MRI scans were obtained in 377 patients with painful knee OA (76% women, mean age 63 years, mean disease duration 6.6 years) at both baseline and 3 months. The femoral and tibial condyles and the patella were divided into 8 sites for the scoring of bone marrow abnormalities. A bone marrow abnormality was defined as an area of increased signal on T2-weighted images of the subchondral bone. All scans were reviewed centrally and scored by a single trained radiologist using a validated 4-point scoring method. Fasting urine and serum samples were also collected from all patients at baseline, month 1, month 2, and month 3, in order to measure the levels of urinary CTX-II and serum CTX-I, a biochemical marker of bone resorption. RESULTS: At baseline, 82% of patients had MRI evidence of bone marrow abnormalities. Bone marrow abnormality scores correlated significantly with CTX-II levels (P < 0.0001). Within 3 months, the bone marrow abnormality score decreased in 37 patients (9.8%), increased in 71 patients (18.8%), and did not change in the majority of patients (71.4%). Patients with baseline urinary CTX-II levels in the highest tertile had a relative risk of 2.4 (95% confidence interval 1.1-5.0) of worsening bone marrow abnormalities at 3 months compared with patients with levels in the lowest tertile, after adjustment for age, sex, and body mass index. In patients who showed a decrease in the bone marrow abnormality score at 3 months, urinary CTX-II levels decreased significantly (mean -75 ng/mmole creatinine), whereas levels increased (mean +23 ng/mmole creatinine) in patients showing an increase in the bone marrow abnormality score (P = 0.01 between the 2 groups). No significant association between bone marrow abnormalities and serum CTX-I was observed. CONCLUSION: In patients with painful knee OA, bone marrow abnormalities on MRI can change within only 3 months in approximately 30% of patients. Reduction in the extent of bone marrow abnormalities is associated with a decrease in cartilage degradation.