Comparison of the effect of Platelet Rich Plasma (PRP) with Hyaluronic Acid (HA) injections to treat chronic Jumper's knee

Abstract

Introduction: Patellar Tendinopathies (PT) represent a very frequent disorder which incidence can reach 30-50% among jumping sports. This trouble is often rebel to classical treatment. Objective: To compare the efficacy of a single injection of RPR to a double infiltration of HA at one week interval. Patients/Methods: Thirty-three patients suffering from PT were enrolled into the study and split into two randomized groups . Eighteen patients (Group 1) have received one PRP injection and the other fifteen subjects (Group 2) received two HA infiltrations. Pain and functionality of the knee were evaluated before injection (T0), 6 weeks (T2) and 3 months (T3) after injections: pain with VAS and pressure algometer, algofunctional scores with IKDC and VISA-P questionnaires, ultrasound, isokinetic evaluation (quadriceps contractions : concentric 60°/sec (C60), concentric 240°/sec (C240), excentric 30°/sec (E30) and VAS during testing). Results: At baseline, difference existed only between groups for algometer, tendon thickness and axial hypoechoic area. In both groups, VAS, algometer, IKCD, VISA-P, VAS for isokinetic testing C60, C240 and E30 were significantly improved at T2 and T3 compared to T0. Comparison between the 2 groups showed no difference excepted for algometer, tendon thickness (T2, T3) and axial hypoechoic area (T2). Discussion and conclusions: There existed a similar improvement of the symptoms in both groups. PRP has already shown its efficacy in PT. HA should probably be a new therapeutic opportunity in this indication. Nevertheless, it should better, for further studies, to include a more homogeneous population and a longer follow-up period of time