LAUSR

Osteoarthritis (OA) is the commonest reason for orthopaedic referral in the UK, with the burden of knee OA affecting 10-25% of patients over 60 and 6% of those over 30. Intra-articular (IA) corticosteroid (CS) injections are the mainstay of treatment for symptomatic management in knee OA, particularly in the UK. IA platelet-rich-plasma (PRP) injections are a promising alternative, but no systematic reviews to date have compared them to the current standard of care, IA CS injections. We aim to investigate the effect of IA PRP injections versus IA corticosteroid injections for the symptomatic management of knee OA. All published trials comparing IA PRP and CS injections for knee OA were included. MEDLINE, EMBASE, Scopus and Web of Science were searched through June 2020. Risk of bias was assessed using the Cochrane Risk of Bias tool and overall was deemed low. A random effects model was used to calculate standardized mean difference with 95% confidence interval in WOMAC, VAS and KOOS scores (or subscores), comparing IA PRP to CS injections across studies at different time points of follow-up. Where studies used different outcome measures, these were combined using the standardised mean difference (SMD). 8 studies and 648 patients were included. 443 (68%) were female, mean age 59 years, with a mean BMI of 28.4. OA was diagnosed radiologically using the Kellgren-Lawrence scale. Compared with CS injections, PRP was significantly better in reducing OA symptoms (pain, stiffness, functionality) at 3-, 6- and 9-months post-intervention (P < 0.01). The greatest effect was observed at 6 and 9 months (-0.78 (-1.34 to -0.23) SD and -1.63 (-2.14 to -1.12) SD respectively). At 6 months, this equates to an additional reduction of 9.51 in WOMAC or 0.97 on the VAS pain scales. On WOMAC pain and stiffness subscales, there were significant additional reductions in the PRP group for pain and stiffness (-2.66 (-4.73 to -0.60), P < 0.01 and 1.95 (-2.30 to -1.59), P < 0.01 respectively), but not functionality at 6 months. At 6 months PRP allowed greater return to sporting activities than CS injections, as measured by the KOOS subscale for sporting activity, of magnitude 9.7 (-0.45 to 19.85) (P = 0.06). Triple injections of PRP, generally separated by a week, were superior to single injections over 12 months of follow-up (P < 0.001). Considerable heterogeneity in the preparation of PRP was observed. IA-PRP injections produce superior outcomes when compared with CS injections for symptomatic management of knee OA, including improved pain management, less joint stiffness and better participation in exercise/sporting activity at 12 months follow-up. Giving three IA-PRP, with injections separated by a week, appears more effective than one IA-PRP injection. IA corticosteroid injections should no longer be routinely used for symptomatic management of knee OA. Disclosure M.E.D. McLarnon: None. N. Heron: None.