Platelet-rich plasma preserves cartilage thickness and delays total knee arthroplasty in osteoarthritis with an inflammatory phenotype: a 5-year follow-up retrospective study

Abstract Background This study aims to explore whether platelet-rich plasma (PRP) can delay the progression of disease, reduce the incidence of Total knee arthroplasty (TKA) and improve clinical symptoms in patients with typical inflammatory phenotype knee osteoarthritis (KOA) Methods This was a retrospective cohort study with 5-year follow-up. According to clinical manifestations, magnetic resonance imaging (MRI) Osteoarthritis Knee Score (MOAKS), and serum inflammation markers C-reactive protein (CRP), we selected patients with typical inflammatory phenotype of KOA. Patients were divided into groups based on whether they had received PRP, hyaluronic acid (HA), or other conservative treatment (OCT). The Kellgren-Lawrence (K-L) grade and Minimum joint space width (MJSW) in knee X-rays were used to evaluate the progression of KOA. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, Knee Society scores (KSS), minimal clinically important difference (MCID) and Osteoarthritis Research Society International Set Responder Criteria Osteoarthritis Clinical Trials Revisited (OMERACT-OARSI) tool were used to evaluate the improvement of KOA symptoms. The incidence and timing of TKA was statistically analyzed. Results A total of 646 patients were finally included, including 211 received PRP, 209 received HA and 226 received OCT. PRP showed better results in K-L grade and MJSW compared with HA and OCT (The results at 12m, 24m, 36m, 48m, 60m, respectively, were as follows; K-L grade, PRP vs. HA, P = 0.957, P = 0.534, P = 0.230, P < 0.001, P < 0.001; PRP vs. OCT, P = 0.240, P = 0.012, P = 0.004, P < 0.001, P < 0.001; MJSW, PRP vs. HA, P = 0.249, P = 0.013, P < 0.001, P < 0.001, P < 0.001; PRP vs. OCT, P = 0.155, P = 0.001, P < 0.001, P < 0.001, P < 0.001). Compared with HA and OCT, PRP group exhibited significant lower TKA incidence (PRP vs. HA, P = 0.001; PRP vs. OCT, P = 0.001; HA vs OCT, P = 0.732) and delayed time to TKA (log-rank, PRP vs HA,P < 0.001, PRP vs OCT, P < 0.001, HA vs OCT, P = 0.467). The WOMAC, KSS and KSS-F in PRP group were significantly better than those in HA group and OCT group at each time point after treatment (P < 0.05). Conclusions Intra articular injection of PRP can delay progression of KOA, reduce or postpone occurrence of TKA and improve clinical symptoms in strictly screened patients with typical inflammatory phenotype KOA. Level of Evidence: III, retrospective cohort.