Comparison of clinical outcome, cartilage turnover, and inflammatory activity following either intra-articular or a combination of intra-articular with intra-osseous platelet-rich plasma injections in osteoarthritis knee: A randomized, clinical trial

•IA-PRP injections are common treatments for knee OA.•IA+IO-PRP injection provides better pain relief and functional improvement at 12-weeks.•IA-PRP and IA+IO-PRP injections reduce inflammatory markers (ESR and CRP) at 12-weeks.•IA-PRP and IA+IO-PRP PRP injections reduce u-CTX-II levels at 12-weeks.•IA+IO-PRP injection reduces u-NTX-I level at 12-weeks. The objective of the study was to determine the changes in clinical outcome (pain and knee activity) and assess bone/ cartilage biomarkers and inflammatory activity in persons with osteoarthritis (OA) knee following a single injection of intra-articular platelet-rich plasma (IA-PRP) and combination of intra-articular, intraosseous PRP (IA+IO-PRP). This prospective, randomized, single-blind clinical trial was conducted at a tertiary care teaching hospital in India. Ninety-six persons with OA knee with a Kellgren-Lawrence score of 3 were randomized into three groups- Group-I (IA-PRP), Group-II (IA+IO-PRP)], Group-III, [intra-articular normal saline (IA-NS)]. The primary outcome was a visual analog scale (VAS) for pain. The secondary outcomes were the Knee Injury and Osteoarthritis Outcome Score (KOOS), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), bone/ cartilage turnover biomarkers [C-telopeptide (CTX-II), N-telopeptide (NTX-I), cartilage oligomeric matrix protein (COMP), N-terminal propeptide of collagen type-IIA (PIIANP), and hyaluronic acid (HA)], ultrasonography (USG) findings of the knee joint. The outcome measures were assessed at baseline, 6, and 12 weeks of follow-up. Compared to IA-NS injection, IA-PRP and IA+IO-PRP injections significantly improved VAS-pain and KOOS scores at 6 and 12 weeks. Furthermore, both PRP groups showed a significant reduction in ESR, CRP, and CTX-II at 12 weeks following PRP injections. In addition, at 12 weeks, the IA+IO-PRP group showed a significant reduction (p=0.009) in NTX-I level. Persons in the IA+IO-PRP group reported significant reductions in the synovial-effusion and infra-patellar bursitis. Significant clinical improvements were noticed following IA-PRP and IA-IO-PRP injections compared to IA-NS injections. Both PRP groups reported a significant reduction in ESR, CRP, and CTX-II levels at 12 weeks. Persons in the IA+IO-PRP group reported significant changes in u-NTX-I level and knee-USG findings.