Commonality Between the Proteome Signatures of Clinical Response to Surgically Sustained and Acute Traumatic Cartilage Injuries in Two Human Knee Cohorts

Purpose: Autologous Chondrocyte Implantation (ACI) is a two-stage surgical procedure aimed at repairing chondral/osteochondral defects. The first arthroscopic surgery requires a harvest of articular cartilage from a low weight-bearing region of the knee, after which chondrocytes are extracted and culture expanded, before implantation into a symptomatic defect 3-4 weeks later. The harvest procedure can be seen as a controlled surgical acute ‘injury’ to the cartilage, which we have shown initiates a marked inflammatory response measurable in synovial fluid (SF), particularly in patients who do not demonstrate clinical improvement. Separately, we have shown that acute traumatic knee injuries are also associated with a rapid inflammatory response measurable in SF which is associated with longitudinal outcomes. This study compares the SF responses to ACI cartilage harvest injury and acute traumatic knee injury, to i) determine the proteome signatures associated with each type of injury and ii) compare the proteomes of these two groups in terms of their longitudinal clinical response.