A randomized blinded placebo controlled trial was conducted to assess the clinical, biochemical and histological effects of a hyaluronan, sodium chondroitin sulfate and N-acetyl-d-glucosamine combination (PG) administered through an intra-articular (IA) route for the treatment of osteoarthritis (OA) at the time of injury. OA was induced in one carpal joint of each of 16 horses. Horses were designated placebo or IA PG treated. All horses were treated with 125 mg amikacin sulfate IA and 5 mL physiological saline in the middle carpal joint bilaterally on study Days 0 (after induction of OA), 7, 14 and 28, except the OA affected joint of the IA PG horses, which received 5 mL PG plus 125 mg of amikacin sulfate on similar days. Evaluations included clinical and radiographic, synovial fluid analysis, gross and histological examinations, as well as histochemical and biochemical analyses.
The model induced a significant pathology that resulted in clinical disease. No adverse treatment-related events were detected in any of the horses. Intra-articular treatment of OA-affected joints with PG resulted in a transient 16% improvement in clinical pain (lameness scores) and evidence of improvement trends in bone proliferation radiographically as well as in the degree of full thickness articular cartilage erosion seen grossly when compared to placebo treated OA affected joints, although the vast majority of outcome parameters were not significantly different than controls. The findings support some potential clinical sign or disease modifying action of this compound administered IA at the tested dose and frequency.