Intra-articular Recombinant Human Growth Hormone Injection Compared with Hyaluronic Acid and Placebo for an Osteoarthritis Model of New Zealand Rabbits

PURPOSE: Up to now, there is no feasible solution for stopping or reversing the degenerative process of osteoarthritis (OA). Our study evaluated the effect of intra-articular injection of growth hormone (GH) in OA-induced rabbit knees compared to hyaluronic acid (HA) and placebo. MATERIALS AND METHODS: A total of 21 male, skeletally mature, New Zealand rabbits received an intra-articular type II collagenase injection for OA induction. Two weeks later, the rabbits were randomized into three groups based on the weekly intra-articular injection to be received: GH, HA, and saline. Injections were done for three consecutive weeks. Evaluation was done at 8 weeks after treatment, clinically using the lameness period, macroscopically using the Yoshimi score and microscopically using the Mankin score. RESULTS: The shortest period of lameness was found in the GH group (15.9±2.12 days), compared to the HA group (19.4±1.72 days) and placebo group (25.0±2.94 days). There was a statistically significant difference in macroscopic scoring between groups (p=0.001) in favor of the GH group. There was also significant difference in the microscopic score between groups (p=0.001) also in favor of the GH group. CONCLUSIONS: Intra-articular injection of GH showed better clinical, macroscopic and microscopic results as compared to HA and placebo.