Objectives-To determine the prevalence of tibiofemoral radiographic knee osteoarthritis (OA) in people aged 35-54 years associated with chronic (> 3 months) knee pain using two diVerent radiographic grading systems. Methods-Population

A majority of the ACL injured knees had a cortical depression fracture, which was associated with larger BML volumes. This indicates strong compressive forces to the articular surface and cartilage at the time of injury, which may constitute an additional risk factor for later knee osteoarthritis development.

Serum concentrations of two extracellular matrix molecules were determined over a 3 yr period in individuals with chronic knee pain to investigate whether sequential serum measurements of cartilage- and bone-derived molecular fragments reflect early stages of osteoarthritis (OA) of the knee joints. Thirty-eight individuals with chronic knee pain (> 3 months at inclusion) with or without radiographic evidence of knee joint OA at the 3 yr follow-up radiographic examination were studied. Serum concentrations of cartilage oligomeric matrix protein (COMP) and bone sialoprotein (BSP) increased significantly (P < 0.001) in the 23 individuals with radiographic OA at follow-up, while remaining unchanged in the 15 individuals with normal radiographs at follow-up. The baseline concentrations of the two variables did not differ between the groups. These findings suggest that pathological processes in cartilage and subchondral bone coincide in OA, and appear to be reflected by circulating levels of macromolecules released from cartilage and bone. Changes in serum levels of COMP and BSP are potential tools in studies of knee joint OA in subjects with chronic knee pain.

Objective-To assess the correlation between the presence of radiographically diagnosed osteophytes in the tibiofemoral joint (TFJ) and (1) magnetic resonance (MR) detected cartilage defects and meniscal lesions in the same joint and (2) knee pain. Methods-Fifty nine people, 29 men and 30 women, with chronic knee pain (aged 41-58 years, mean 50 years) were examined with posteroanterior weightbearing radiograms in semiflexion of both TFJ. The presence and grade of marginal and central osteophytes were assessed. On the same day, an MR examination was performed of the signal knee with proton density and T2 weighted turbo spin-echo sequences on a 1.0 T imager. Cartilage defects and meniscal abnormalities in the TFJ were noted. The subjects were questioned for current knee pain for each knee. Results-Marginal osteophytes had a sensitivity of 77%, specificity of 83%, and positive predictive value of 87% for MR detected cartilage defects in the TFJ and a sensitivity of 71%, specificity of 68%, and positive predictive value of 71% for meniscal abnormalities. A correlation (p<0.05) between osteophytes at the medial tibial condyle and knee pain was found. Conclusions-With the presence of marginal osteophytes in the TFJ there is a high prevalence of MR detected cartilage defects in the same joint whether joint space narrowing (<3 mm) is present or not.