Summary
Autologous protein solution does not improve symptoms of knee osteoarthritis, and may in fact, worsen symptoms.
Abstract
Background
Knee osteoarthritis is characterised by a chronic inflammatory process involving multiple cytokine pathways, leading to articular cartilage degeneration. Intra-articular therapies using pharmaceutical or autologous anti-inflammatory factors offer potential non-surgical treatment options. Autologous protein solution (APS) is one such product that uses the patient’s blood to produce a concentrate of cells and anti-inflammatory cytokines.
Purpose
This study evaluated the effect of APS intra-articular injection on patient-reported outcome measures compared to saline in moderate knee osteoarthritis.
Methods
A parallel, double-blinded, placebo-controlled randomised clinical trial was conducted, where patients with unilateral moderate knee osteoarthritis (Kellgren-Lawrence grade 2 or 3) received either APS or saline (placebo) injection to their symptomatic knee. The primary outcome was the difference in WOMAC (Western Ontario and McMaster Universities Arthritis Index) total score at 12 months post-intervention. Secondary outcomes included WOMAC component scores, KOOS (Knee Osteoarthritis Outcome Score), and VAS (Visual Analogue Scale) scores at all follow-up time points (3, 6, and 12 months).
Results
Forty patients were analysed (21 APS; 19 saline) in the study. No significant difference was found between APS and saline groups for WOMAC total score at 12 months (mean difference: -10.4, CI95 -24.4 to 3.6, P = 0.141). Furthermore, there were no significant differences in WOMAC and KOOS scores across all time points. However, VAS scores favoured the saline group for both rest and worst pain scales at 12 months post-injection (mean difference [worst] 12 months: 21.5, CI95 6.2 – 36.8, P = 0.008; mean difference [rest] 12 months: 17.8, CI95 2.2 – 33.4, P = 0.026).
Conclusion
Despite promising preclinical evidence and positive outcomes in smaller studies, our findings show no significant differences between APS and saline groups in KOOS and WOMAC scores over time. Notably, APS injection resulted in significantly worse pain symptoms at 12 months compared to saline injection.