Serial Platelet-Rich Plasma Intra-articular Injections in Kellgren and Lawrence Grade IV Knee Joint Osteoarthritis: A Prospective Blinded Placebo-Controlled Interventional Study

Abstract

Purpose: The purpose of this study was to evaluate whether serial intra-articular (IA) Platelet-Rich Plasma (PRP) injections improve pain and function in patients of Kellgren-Lawrence (K-L) Grade IV primary knee osteoarthritis (KOA), not willing for arthroplasty or having relative contraindications to surgery.

Methods: 90 patients (84 available at final follow-up) of Grade IV KOA were given 3 PRP or Normal Saline injections at 1-month interval. Pain and functional assessment was done with Visual analog scale (VAS) and Western Ontario and McMaster universities osteoarthritis index (WOMAC) respectively, at baseline and then at three and six months of follow-up. Both groups were homogenous with similar baseline characteristics.

Results: Both groups showed statistically significant improvements in the outcome scores but only PRP showed minimal clinically important difference (25% in WOMAC and > 2 cm difference of mean in VAS at follow-up). For inter-group comparison, PRP showed better results as there was statistically significant difference in WOMAC at 3 months (Difference = - 9.220, 95% CI = - 13.1945 to - 5.2455, P < 0.0001) and at 6 months (Difference = - 10.360, 95% CI = - 14.5358 to - 6.1842, P < 0.0001). Similar results were seen for VAS also (Difference = - 0.580, 95% CI = - 1.1412 to - 0.0188, P = 0.04 at 3 months, Difference = - 0.870, 95% CI - 1.3993 to - 0.3407, P = 0.001 at 6 months). Outcome scores significantly correlated with age and sex but not with body mass index (BMI).

Conclusion: Serial Intra-articular Injections of autologous PRP mildly improve short-term subjective pain and knee function scores in patients of Grade IV KOA without any major complications.

Keywords: Kellgren–Lawrence (K–L) grading; Knee osteoarthritis; Platelet-rich plasma (PRP); VAS; WOMAC.