Evaluation of sodium hyaluronate therapy in induced septic arthritis in the horse

This study was conducted to determine the efficacy of sodium hyaluronate (SH) with antibiotic therapy and joint lavage for reducing acute inflammatory and degenerative changes induced by septic arthritis. Septic arthritis was induced in six adult horses by inoculating the tarsocrural joints with 1 x 10(4) colony-forming units of Staphylococcus aureus. When clinical signs appeared, trimethoprim-sulphamethoxazole (30 mg/kg bodyweight [bwt] daily) and phenylbutazone (4.4 mg/kg bwt sid) were administered and continued until termination of the study (Treatment Day 18). Twenty-four hours post inoculation, all joints were lavaged with sterile lactated Ringer's solution. Following lavage, one joint of each horse was injected with 10 mg of SH, and the contralateral joint served as the control. Sodium hyaluronate treated joints showed significant reductions in lameness, tarsal circumference and synovial fluid protein and WBC concentrations. The synovial membrane of the SH-treated joints contained less cellular infiltrate, less granulation tissue formation and retained a more normal villous structure compared with controls. The total glycosaminoglycan loss from the articular cartilage in the SH treated joints was consistently less than that from the control joints; however, this difference was not statistically significant. Sodium hyaluronate with joint lavage appears to be more beneficial than lavage alone for treatment of septic arthritis.