Efficacy and safety of platelet-rich plasma injections for the treatment of knee osteoarthritis: a systematic review and meta-analysis of randomized controlled trials.

Introduction: Knee osteoarthritis (KOA) is a prevalent degenerative joint disorder affecting a significant portion of the elderly population. Despite the availability of various non-surgical and pharmacological treatments, their effectiveness is often limited by temporary symptom relief and lack of disease-modifying properties. Platelet-rich plasma (PRP) has emerged as a promising biological therapy for KOA, with preclinical evidence suggesting its potential to promote cartilage repair and modulate inflammation. This systematic review and meta-analysis aims to comprehensively evaluate the efficacy and safety of PRP injections in the treatment of KOA.

Methods: A systematic literature search was conducted from January 1, 2021, to December 31, 2024, encompassing major medical databases, clinical trial registries, and grey literature sources. Randomized controlled trials (RCTs) comparing PRP with other treatments for KOA were included based on predefined eligibility criteria. Data extraction and analysis were performed using various statistical software packages and machine learning models. A neural network model was constructed to predict PRP treatment outcomes by integrating multidimensional clinical features. Study quality was assessed using the Cochrane Risk of Bias Tool, and publication bias was evaluated through funnel plot analysis and Egger's test.

Results: The meta-analysis included 28 RCTs with a total of 3246 KOA patients. PRP demonstrated comparable pain relief to hyaluronic acid (HA) but superior functional improvement, especially when combined with HA. Compared to corticosteroids, PRP showed no significant difference in efficacy as monotherapy but enhanced outcomes when used in combination. PRP also outperformed physical therapy and exercise therapy in both pain control and functional improvement. The optimal PRP concentration range was identified as 600-900 × 10⁹/L, with 3-5 injections at 7-14-day intervals yielding the best results. Early intervention, particularly in KL grade I-II patients, was associated with superior outcomes. The neural network model accurately predicted treatment responses based on patient characteristics and disease factors.

Discussion: The findings of this study have important implications for understanding the individualized regulatory mechanisms of PRP therapy. The nonlinear relationship between PRP concentration and treatment efficacy reflects the complex cytokine network dynamics and receptor saturation effects. The superiority of the 3-5 injection regimen may be attributed to its alignment with the time window of chondrocyte gene expression regulation, potentially mediated by epigenetic mechanisms. The synergistic effects of PRP with HA and the time-dependent treatment response patterns provide new insights for developing personalized, multi-target treatment strategies. The deep learning model demonstrated the potential of data-driven appjjroaches for optimizing PRP therapy and highlighted the need to address challenges in biological interpretability, data standardization, and clinical implementation.

Conclusions: This comprehensive evaluation of PRP therapy for KOA identified key parameters associated with optimal treatment outcomes, including PRP concentration, injection frequency, and early intervention. PRP demonstrated unique value and synergistic effects when combined with other treatments, and machine learning models provided new avenues for personalized treatment optimization. Future research should focus on addressing limitations in long-term follow-up data, standardizing evaluation criteria, and exploring the clinical application of artificial intelligence techniques to enhance the precision and effectiveness of PRP therapy for KOA.