Objective. The adduction moment at the knee during gait is the primary determinant of medial-tolateral load distribution. If the adduction moment contributes to progression of osteoarthritis (OA), then patients with advanced medial tibiofemoral OA should have higher adduction moments. The present study was undertaken to investigate the hypothesis that the adduction moment normalized for weight and height is associated with medial tibiofemoral OA disease severity after controlling for age, sex, and pain level, and to examine the correlation of serum hyaluronan (HA) level with disease severity and with the adduction moment in a subset of patients.Methods. Fifty-four patients with medial tibiofemoral OA underwent gait analysis and radiographic evaluation. Disease severity was assessed using the Kellgren-Lawrence (K-L) grade and medial joint space width. In a subset of 23 patients with available sera, HA was quantified by sandwich enzyme-linked immunosorbent assay. Pearson correlations, a random effects model, and multivariate regression models were used.Results. The adduction moment correlated with the K-L grade in the left and right knees (r = 0.68 and r = 0.60, respectively), and with joint space width in the left and right knees (r = -0.45 and r = -0.47,

PRP isolated from autologous blood may be useful as a source of anabolic growth factors for stimulating chondrocytes to engineer cartilage tissue.

We have developed an enzyme-linked immunosorbent-inhibition assay which makes use of a moinoclonal antibody specific for keratan sulfate to quaintify keratan sulfate present as single chains in adult hurnan serum. In adults hospitalized with conditions not thought to affect the turnover of keratan sulfate-contairiing tissues, the serum levels varied from individual to individual (53-1,009 ng/ml) but did not show significant differences with respect to age, sex, or disease category. There were no significant differences between the serum levels of adult hospitalized patients and those of nonhospitalized normal adults. In contrast, the concentration of keratan sulfate in the sera of children aged 5-12 was significantly higher. No keratan sulfate was detected in the sera of 3 adult patients with macular corneal dystrophy, an inherited disorder of the cornea. This may indicate that individuals with macular corneal dystrophy have no keratan sulfate-containing proteoglycans in their cartilage. Adult patients with osteoarthritis have significantly higher concentrations of circulating keratan sulfate. This suggests that the assay could prove valuable in monitoring increased cartilage catabolism in joint diseases.The majority of proteoglycans (PGs) in cartilage are large molecular weight macromolecules that endow cartilage with its ability to undergo reversible deformation (1). These complex carbohydrates consist of a core protein ( M , = 25&380 x lo3) to which glycosaminoglycans (GAGS) and both 0-and N-linked oligosaccharides are covalently attached (1). In humans and many other species, there are over 100 chondroitin sulfate (CS) and keratan sulfate (KS) GAG side chains in a single PG monomer.The rate at which cartilage PGs turn over ( 2 4 ) and the mechanisms involved in the degradation of PGs in normal and pathologic cartilage (1 3-7) remain in question. There have been numerous reports of both anabolic and catabolic alterations in cartilage in diseases such as osteoarthritis (OA), rheumatoid arthritis, disc degeneration, and other diseases in which these tissues are affected (8-10). The absence of significant amounts of partially degraded PGs in normal cartilage matrix (1 1) suggests that individual PG molecules normally are rapidly degraded into smaller