Long-term effectiveness of intra-articular injectables in patients with knee osteoarthritis: a systematic review and Bayesian network meta-analysis.

Background: Intra-articular injectables are proposed as a solution for pain relief and functional improvement in knee osteoarthritis (OA), however most studies involving intra-articular knee injectables are focused on short-term relief, leaving the recommendations regarding long-term management unclear. This network meta-analysis aimed to evaluate the mid- to long-term effectiveness of intra-articular knee injection of platelet-rich plasma (PRP), hyaluronic acid (HA), corticosteroids (CS), and their combinations for management of knee OA.

Methods: Relevant studies were searched through PubMed, EMBASE, Scopus, and Cochrane Register of Trials databases from inception to 20th October, 2024 for randomized controlled trials (RCTs) of knee OA patients who had taken intra-articular injectable treatment with a follow-up duration of at least one year. The study included 37 RCTs involving 5089 patients. The outcomes assessed were pain relief and functional improvement of knee joint. The random effects Bayesian model was carried out for network meta-analysis. The surface under the cumulative ranking (SUCRA) curve demonstrated the rank probability of each injectable therapy for different outcomes.

Results: Analysis revealed that, in terms of both knee pain relief and improvement of functional outcomes, the combined intra-articular injection of PRP and HA was ranked ahead of the isolated administration of PRP, followed by combination of HA with CS, HA alone, placebo, and CS at the end of one year.

Conclusions: These findings emphasize the sustained efficacy of PRP, particularly when combined with HA, in providing superior long-term pain relief and functional improvement in knee OA compared to other intra-articular injectables, highlighting its potential as a preferred treatment modality.