Determination of Effect of Platelet Rich Plasma Injection on Improving Pain and Function in Young Healthy Athletes with Isolated Grade 2 or 3 Knee Medial Collateral Ligament Sprains

Background: Knee medial collateral ligament (MCL) sprain is common in athletes, which keeps them away from trainings. Platelet-rich plasma (PRP) injection is used as an adjunct for treatment of musculoskeletal injuries. This study was supposed to define effect of PRP injection on high-grade MCL sprain healing, in comparison to rehabilitation alone. M aterials and Methods: This study was performed on 46 healthy athletes with high-grade MCL sprains who came to sports medicine clinic of Taleghani Hospital, Tehran over a one-year period (2017-2018). In first visit injury grade, its location, baseline pain, Lysholm score and joint stability was determined. Participants randomly allocated to 2 groups (n=23), “group A” had 12-week functional rehabilitation and “group B” had the same rehabilitation plus a single PRP injection. At 4-week intervals valgus stress testing, pain and Lysholm scores was reassessed. The scores of 4 th , 8 th and 12 th weeks was compared to the baseline scores. R es ults: Mean baseline pain score in control and intervention group was 5.09±0.949 and 5.26±0.810 respectively that in the fourth week of study reduced to 1.30±0.765 and 2.43±0.507 (p<0.001). In intervention group, fourth week pain was significantly reduced while stability and Lysholm scores of the groups had no significant difference. C onclusion: PRP injection had a short-term statistically significant pain reduction effect that may assist in faster rehabilitation progress, shorter return to play and less detraining which is crucial to professional athletes.