Purpose

Background:Platelet Rich Plasma (PRP) has emerged as the forerunner amongst disease modifying treatment options of early osteoarthritis of knee. However there is no consensus on optimum dosing schedules.

Purpose: To determine whether multiple injections of PRP (Three) are better than single injection of PRP in a guinea pig knee OA model in short and long term.

Study Design: Controlled Laboratory Study

Methods and Materials

Methods:36 Dunkin Hartley guinea pigs (weighing ~600-800g) were chosen for this study. They were divided into group DC (disease control group), group G1 (single PRP group) and group G2(multiple PRP group) containing 10, 10 and 12 animals respectively. Four animals were used for preparation of allogeneic PRP. Groups G1 and G2 received one and three injections of PRP (at weekly interval) respectively. No intervention was done in group DC.Half of the animals from each group (subgroup DC.3, G1.3 and G2.3) were euthanized at three months and the remaining half (subgroup DC.6, G1.6 and G2.6) at six months post intervention. Histologic assessment for articular cartilage and synovium was done.

Results

Results: Mean synovial scores of single PRP group and multiple PRP group were significantly better than disease control group at 3 months. There was no difference between single and multiple PRP group at 3 months. At 6 months, the multiple PRP group was significantly better than single PRP and disease control groups in terms of mean synovial scores. The mean articular cartilage scores in multiple PRP group were significantly better than disease control groups at 3 months. However, at 6 months there was no significant difference amongst any of the groups in terms of mean articular scores.

Conclusion

Conclusion:Multiple injections are better than single injection at long term in terms of anti-inflammatory effect. multiple injections also exert chondroprotectice effect at short term