Synovitis: a potential predictive factor of structural progression of medial tibiofemoral knee osteoarthritis -- results of a 1 year longitudinal arthroscopic study in 422 patients.

OBJECTIVE: To evaluate the prevalence of synovitis in painful medial tibiofemoral knee osteoarthritis (OA) and to evaluate correlation between synovitis and the structural severity and progression of tibiofemoral cartilage damage. STUDY: Multicenter, longitudinal, 1-year duration. PATIENTS: Primary painful knee OA (ACR criteria) of the medial tibiofemoral compartment, with pain of the signal knee on at least 30 days in the past 2 months, medial joint space width > or = 2mm, at least 10% of one cartilage surface of the medial compartment affected by superficial fibrillation or worse at baseline arthroscopy. ARTHROSCOPIC PARAMETERS: Knee arthroscopy under local anesthesia was performed and videorecorded at entry and after 1 year. Medial chondropathy was scored by using Societe Francaise d'Arthroscopie (SFA) score (0-100) and reader's overall assessment (VAS score, 100 mm). Progression of medial chondropathy was defined by a change in SFA and VAS scores over 4.5 and 8.0 mm after 1 year, respectively. Medial perimeniscal synovium was scored as normal (few translucent and slender villi, fine vascular network), reactive (proliferation of opaque villi), or inflammatory (hypervascularization and/or proliferation of hypertrophic and hyperemic villi). Medial chondropathy and synovitis were scored by a single reader blind to chronology of paired videotapes. RESULTS: Four hundred and twenty-two patients were enrolled (mean age: 61 years, females: 59%, body mass index: 31, mean disease duration: 4 years) and completed the 1-year study. Synovial abnormalities were present in 50% of the patients with reactive and inflammatory aspects in 29% and 21% of the patients, respectively. Patients with a reactive or inflammatory medial synovium had a more severe medial chondropathy. The worsening in medial chondropathy after 1 year was statistically more severe in the group of patients with an inflammatory perimeniscal synovial membrane at baseline compared to patients with normal and reactive aspects, with no difference between these two latter groups. The odds ratio for progression in VAS score after 1 year was 3.11 (95% CI [1.07, 5.69]) for patients with inflammatory synovium at baseline compared to patients with normal synovium. CONCLUSIONS: This study suggests that abnormalities of the medial perimeniscal synovium are a common feature of painful medial knee OA, associated with more severe medial chondropathy. It also suggests that an inflammatory aspect of the medial perimeniscal synovium could be considered as a predictive factor of subsequent increased degradation of medial chondropathy.

Arthroscopic evaluation of potential structure-modifying drug in osteoarthritis of the knee. A multicenter, randomized, double-blind comparison of tenidap sodium vs piroxicam.

OBJECTIVE: To test the hypothesis that tenidap has a structure-modifying effect in human knee osteoarthritis. STUDY: multicenter, prospective, randomized, double blind, 1 year duration. PATIENTS: primary painful knee osteoarthritis (ACR criteria) of the medial tibiofemoral compartment, medial joint space width > or =2mm, at least 10% of one cartilage surface of the medial compartment affected by superficial fibrillation or worse at baseline arthroscopy. STUDY MEDICATION: once daily dosage of either tenidap 40 mg, tenidap 120 mg or piroxicam 20mg. STUDY ENDPOINTS: bilateral extended weight-bearing X-rays and knee arthroscopy under local anaesthesia were done at entry and after 1 year. Joint space width was measured in millimeters at the narrowest point of the medial compartment. Chondropathy was scored by using reader's overall assessment (VAS score, 100mm) and Société Française d'Arthroscopie (SFA) score (0-100). RESULTS: Patients (665) were randomized and 494 completed the study. After 1 year, intra-group radiological changes and radiological difference between both tenidap groups and the piroxicam group did not reach statistical significance. The intra-group arthroscopic deterioration of chondropathy was low, but statistically significant in the three study groups. However, there was no statistically significant difference between both tenidap groups and the piroxicam group. CONCLUSIONS: This study failed to demonstrate any difference between the treatment arms with regard to the structural progression of medial knee osteoarthritis as measured by radiography and arthroscopy. Arthroscopy did, however, appears to be more sensitive in detecting disease progression than the weight-bearing radiographs with fully extended knees. This study shows that it is possible to complete a large international trial using arthroscopy as an outcome measure of articular cartilage.

Low-level increases in serum C-reactive protein are present in early osteoarthritis of the knee and predict progressive disease.

OBJECTIVE: To examine the role of low-grade inflammation in the etiology and progression of early osteoarthritis (OA) of the knee. METHODS: We used a new, high-sensitivity, automated monoclonal antibody immunoassay for the classic acute-phase protein, C-reactive protein (CRP), in serum. Anteroposterior radiographs of the knee with weight bearing were obtained on 845 women (ages 44-67) on entry into a population-based study of OA in Chingford, North London. In those defined radiologically as "cases," the knee radiographs were repeated after 4 years. RESULTS: Levels of CRP were higher in 105 women with knee OA defined radiologically as Kellgren-Lawrence grade 2+ (median 2.4 mg/liter, interquartile range [IQR] 1.0-5.1), compared with 740 women without OA (median 0.7 mg/liter, IQR 0.3-1.8) (P < 0.001). Median levels of CRP were higher in the 31 women whose disease progressed at least 1 Kellgren-Lawrence grade (median 2.6 mg/liter, IQR 1.9-4.6), compared with the 39 whose disease did not (median 1.3 mg/liter, IQR 0.6-2.4) (P = 0.006) . The significance of these differences persisted after adjustment for age, weight, height, smoking, knee pain, or injury. Classifying disease by the presence of joint space narrowing or osteophytes alone produced similar results. CONCLUSION: CRP levels are modestly but significantly increased in women with early knee OA, and higher levels predict those whose disease will progress over 4 years, suggesting that low-grade inflammation may be a significant aspect of early OA and may be amenable to therapeutic intervention and secondary prevention.