Evaluating the Impact of Platelet-Rich Plasma Injections on Knee MRI Imaging and Pain Severity in Patients with Knee Osteoarthritis: A Comparative Before-After Study

Abstract

Objectives: Knee osteoarthritis affects 40% of people over 70 years old worldwide, making non-surgical treatments like platelet-rich plasma (PRP) injections an essential focus. Recognizing that osteoarthritis impacts all joint components, magnetic resonance imaging (MRI) has become crucial for monitoring treatment effectiveness. Our study examines changes in pain intensity and knee MRI imaging of patients with knee osteoarthritis following PRP injections, contributing to the advancement of non-surgical interventions and improved patient outcomes.
Methods and materials: This interventional before-after study recruited patients with knee osteoarthritis who were referred to physical medicine and rehabilitation and orthopedics clinics at Shahid Rahnamoun and Shahid Sadoughi hospitals in Yazd and were considered suitable candidates for platelet-rich plasma (PRP) injections by specialists. Participants received PRP injections on two separate occasions, spaced one month apart. The study examined three time points: before the PRP injection, one month post-injection, and six months post-injection. MRI findings were assessed before the injection and six months afterward. Patients' pain intensity was evaluated based on Visual Analog Scale (VAS). The collected data were analyzed using SPSS software version 26 with a paired t-test for statistical analysis. The statistical significance threshold was set at p < 0.05 for all criteria.
Results: The study involved 25 patients with 36 affected knees (14 patients with one affected knee and 11 patients with two affected knees). The mean age of the participants was 64.27 years, with 3 male patients (12%) and 22 female patients (88%). Comparison of MRI findings six months post-PRP injection to pre-injection revealed no significant changes for most parameters. However, a statistically significant difference was observed in the mean pain intensity score when comparing measurements one month post-injection to pre-injection, six months post-injection to pre-injection, and after the second injection (six months post-injection) to the first injection (one month post-injection) based on the utilized criteria (p<0.05).
Conclusion: In conclusion, the findings of this study indicate that platelet-rich plasma (PRP) injections effectively reduce pain intensity in patients with knee osteoarthritis. However, the treatment does not lead to significant changes in the MRI findings for these patients. Therefore, while PRP injections can be a beneficial therapeutic option for managing symptoms and enhancing patients' daily lives, they may not alter the underlying structural pathology of knee osteoarthritis as visualized on MRI.