The effect of intra-articular allogenic platelet rich plasma in Dunkin-Hartley guinea pig model of knee osteoarthritis.

Objectives: To investigate the pathway for disease modifying effect of the PRP in osteoarthritis of knee.

Design: Two experimental models (group I and II) of Twelve Dunkin-Hartley guinea pigs each were enrolled as a part of a prospective controlled experimental study. One knee was enrolled for intervention and the other knee of the same animal used as control, the intervention being three intra-articular allogenic PRP injections given at a weekly interval. Equal volume of isotonic saline injection were given simultaneously in the control knees. Six animals from each model (subgroup IA, IIA) were euthanized at three months and the remaining six (subgroup IB, IIB) at six months post intervention. Samples of synovial fluid were collected from each knee joint for COMP level analysis by ELISA and bilateral knee joints were harvested for histopathological assessment of articular cartilage and synovium at the time of euthanasia.

Results: Mean synovial fluid COMP concentration was significantly lower in PRP treated knees (p<0.05) at three months. On histological examination mean synovitis scores and synovial vascularity were significantly lower in PRP treated knees as compared to controls at both three and six months (p < 0.05). Additionally mean articular cartilage degeneration was significantly lower in PRP treated knees in group 1 only (p<0.05).

Conclusion: Our preliminary data from the study has shown some evidence of positive influence of PRP in knee OA, possibly due to its anti-inflammatory effect and disease modifying effect, shown by short-term chondro-protective effect in PRP injected knees.

Level of evidence: V.