Effectiveness of the intra-articular injection of platelet rich plasma in the treatment of patients with primary knee osteoarthritis

Osteoarthritis (OA) is the most prevalent form of arthritis in the world.Aim of the workTo evaluate the effect of 6-monthly intra-articular injection of platelet rich plasma (PRP) on the functional status of knee joint measured by the International Knee Document Committee scale (IKDC), the visual analogue scale for pain (VAS) on the ultrasonographic findings of OA knee. Assessment of its safety as a new line of treatment was taken into consideration.Patients and methodsThe study was carried out on 20 patients with mild to moderate primary knee OA. They were injected intra-articularly with 5 ml PRP for each affected joint, at 1 month intervals for 6 injections. Clinical examination, VAS, IKDC score and diagnostic Doppler ultrasonography were performed before and after PRP treatment.ResultsAfter 6 months of PRP, there was a significant improvement in the duration of inactivity stiffness (8.3 ± 2.4 min), VAS score (3.9 ± 1.1) and IKDC score (74.3 ± 10.2) compared to baseline values (18.7 ± 6.5 min, 5.9 ± 1.3 and 40.9 ± 10.4 respectively; p < 0.001). A significant improvement in Doppler activity (p = 0.04) and synovial thickening (p < 0.001) was found after 6 months of PRP. A significant correlation was found between age of patients, body mass index and disease duration with the VAS (r = 0.55, p < 0.001 and r = 0.29, p = 0.03 and r = 0.71, p < 0.001) and a negative correlation with the IKDC score (r = −0.32, p = 0.03, r = −0.96, p < 0.001 and r = −0.79, p < 0.001 respectively).ConclusionIntra-articular injection of PRP is an effective and safe method for treatment of knee OA. Maximal improvement is obtained in patients with young age and short disease duration.