Biochemical and Histological Evaluation of different intra-articular injections as therapy for Temporomandibular Joint Osteoarthritis in Rats

Abstract

Introduction: Temporomandibular joint (TMJ) osteoarthritis is usually treated by intra-articular injection of medications. Intra-articular hyaluronic acid (HA) injection reduces friction and stress on the joint cartilage through lubrication, chondro-protection and proteoglycans synthesis. Platelet Rich Plasma (PRP) with its high concentration of growth factors plays a great role in joint repair through enhancing osteo-inductivity, and chondrogenic differentiation. This study aims at comparing intra-articular injection of combination of hyaluronic acid and platelet rich plasma to intra-articular injection of each of them alone. Materials& Methods: 24 young adult male 250-300 grams albino rats were used in the current study divided randomly into 4 groups: Group 1 (control) in which animals were left without treatment. Group 2 which was subdivided into 3 study groups, in Group 2A: the animals received 2 doses of HA, in Group 2B: the animals received 2 doses of PRP, and in Group 2C: the animals received 2 doses of combined PRP and HA. After 28 days, the animals were sacrificed and histological analysis was performed. Synovial fluid Samples were extracted before each intra-articular injection, the concentration of vascular endothelial growth factor (VEGF) and fibroblast growth factor-2 (FGF-2) were detected and statistically analyzed. Results: Group 2C showed superior findings to the other 2 study groups regarding fibrocartilage and bone regeneration, while Group 2B was superior to group 2A regarding the study parameters. Conclusion: Intra-articular injection of combination of PRP and HA is superior to intra-articular injection of HA or PRP alone for the treatment of TMJ osteoarthritis in rats.