PURPOSE: To systematically review the available clinical data regarding the use of autologous IL-1 receptor antagonist blood products (AILBPs) and their validity as an alternative intra-articular (IA) therapy for symptomatic knee osteoarthritis (OA).
METHODS: The PubMed, MEDLINE, Embase, and Cochrane Library databases were searched from inception to June 2018. All randomized controlled trials (RCTs) and noncomparative studies that evaluated the clinical efficacy of AILBPs (i.e., autologous protein solution and autologous conditioned serum) for knee OA were included. The primary outcome measure was the Western Ontario and McMaster Universities Osteoarthritis Index. The secondary outcomes measured were the Knee Injury and Osteoarthritis Outcome Score, visual analog scale score, Short Form 36 (SF-36) score, radiographic scores, and adverse events, which were qualitatively analyzed.
RESULTS: We included 8 studies, comprising 3 RCTs (Level II) and 5 noncomparative studies (Level IV), with a total of 592 patients (mean age, 56.4 years; 49.7% male patients). The RCTs represented high methodologic quality, whereas the noncomparative studies represented moderate to good quality. With AILBPs, 2 of 4 studies (50%) showed improvements in the Knee Injury and Osteoarthritis Outcome Score symptom and sport subscales, 5 of 7 studies (71%) achieved improvements in the Western Ontario and McMaster Universities Osteoarthritis Index score, and 4 of 5 studies (80%) attained improvements in the visual analog scale pain score from baseline to final follow-up. Most adverse events associated with AILBPs were mild to moderate in severity and were primarily localized to the injection site.
CONCLUSIONS: Limited evidence substantiates that AILBPs are a safe and tolerable IA injection therapy that may improve pain parameters and functionality for mild to moderate knee OA patients and may be an effective adjunct for those unresponsive to traditional IA therapies.
LEVEL OF EVIDENCE: Level IV, systematic review of Level II through IV studies.