Long-term Effect of Injection Treatment for Osteoarthritis in the Knee by Orthokin Autologous Conditioned Serum

BACKGROUND: Orthokin is an intra-articular autologous conditioned serum (ACS). Its use might have a beneficial biological effect on pain and function of osteoarthritis in the knee. However, earlier studies lack any consensus on its clinical application and disease modifying effect. OBJECTIVE: The aim of this study was to investigate the long-term effect of Orthokin injection treatment on prevention of surgical treatment for end-stage knee osteoarthritis. STUDY DESIGN: Prospective cohort study. METHODS: Patients of the previously published Orthokin cohort were contacted to determine whether any intra-articular surgical intervention or osteotomy of the study knee had taken place during the past decade. A log-rank test was performed to evaluate the differences in the survival distribution for the 2 types of intervention: Orthokin versus placebo. RESULTS: The survival distributions for the 2 interventions were not statistically significantly different, χ(2)(1) = 2.069, P = 0.150. After 7.5 ± 3.9 years, 46.3% of the placebo and 40.3% of the Orthokin group had been treated surgically. CONCLUSION: The use of Orthokin in knee osteoarthritis patients did not result in a delay regarding surgical treatment. CLINICAL RELEVANCE: The intra-articular use of Orthokin does not seem to prevent or delay surgical intervention at 10 years after treatment for end-stage knee osteoarthritis.