Effect of Mean Platelet Volume on Platelet Rich Plasma Based Injection Therapy in Patients with Osteoarthritis of the Knee JointA Longitudinal Study

Introduction: There are different types of arthritis seen in elderly patients, of which Osteoarthritis (OA) is the most common. Platelet Rich Plasma (PRP), which is derived from blood, contains many growth factors. Platelet count and indices in PRP has association with pain score of OA, further study will prove its significance.

Aim: To find the correlation of platelet parameters like platelet count, Mean Platelet Volume (MPV) and Plateletcrit (PCT) with clinical OA improvement score in PRP-treated patients of OA.

Materials and Methods: The longitudinal study was done in the Department of Pathology, PDU Civil Hospital, Rajkot, Gujarat, India, from January 2021 to October 2021. Study was conducted on 40 patients, who were administered intra-articular injection of PRP prepared using double spin method. It was injected at the site of maximum pain in the knee joint. Platelet count, MPV and PCT were noted in the pre and post intervention. Patients were followed-up at two months and six months. The data was analysed using Friedman Analysis of Variance (ANOVA) and Pearson’s correlation test.

Results: The mean age of patients was 58.57±4.95 years and there were 26 (65%) females and 14 (35%) males. Increase in platelet count, MPV, PCT in PRP prepared by double spin method and improvement in Visual Analog Scale (VAS) (Before-8.38±0.63; After-4.28±0.85), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) (Before-63.30±4.99; After- 43.67±5.22) and International Knee Documentation Committee (IKDC) (Before-45.04±6.06; After-66.14±5.78) score were found to be statistically significant. Correlation of platelet parameters WOMAC with Platelet count (p-value=0.052, R-value=-0.310), VAS with MPV (p-value=0.005, R-value=0.436) and IKDC with PCT (p-value=0.032, R-value=0.339) were also statistically significant at six months follow-up.

Conclusion: Single dose intra-articular injection PRP in OA knee with KL Grade 1 and 2 is valuable, efficient and cost-effective treatment to reduce or delay in knee replacement. The study showed the significant correlation of platelet parameters with OA improvement scores.