THE EFFECTS OF HYALURONAN DURING THE DEVELOPMENT OF OSTEOARTHRITIS

Ninety-nine mature New Zealand White (NZW) rabbits underwent unilatera l anterior cruciate ligament transection (ACLT) and were divided into three groups. The contralateral non-operated knees served as controls. The first group (SA) received intra-articular injections of 0.3 ml hy aluronan (HA: MW; 8x10(5)) beginning 4 weeks after ACLT, once a week f or 5 weeks. The second group (SV) was injected with vehicle (carrier o f HA) in the same fashion as the SA group. The third group (SN) served as a nontreatment group post ACLT. All animals were killed 9 weeks po st-surgery and were assessed by gross morphology, histomorphometry and biochemical analysis. Gross morphologic changes on the femoral cartil age in the SA group were less severe than those in the SV and SN group s. Cartilage thickness, cartilage area, and thickness of synovial lini ng cell layer histomorphometric parameters were measured, showing a po sitive effect of HA on the preservation of articular cartilage and syn ovial tissue. Similarly, the cartilage and synovial tissues from knees injected with HA did not demonstrate significant alterations from con tralateral controls as measured by biochemical analysis [i.e., water c ontent, pyridinoline concentration, glycosaminoglycan (GAG) content fo r the cartilage, and DNA concentration for the synovial tissue].