and I'm an assistant professor at the University of Georgia. Before I begin, I'd like to acknowledge my conflicts of interest for funding this study, and I'd specifically like to thank and acknowledge the UNC Department of Orthopedics. While radiographic findings in post-traumatic osteoarthritis-related symptoms do not always occur concurrently, 50% of patients will develop radiographic and symptomatic post-traumatic osteoarthritis within 20 years of ACL injury. So the question becomes, how do we identify individuals at risk so we can improve care, as well as reduce the societal burden of the disease? In a previous paper that we published, we identified that serum biomarker concentration changes from pre-op to six months following ACL reconstructed surgery, indicative of increased inflammation and cartilage breakdown, were associated with poor knee joint health of cartilage composition with lower proteoglycan density in the lateral tibial femoral cartilage compartment. However, it's unclear how these changes in serum biochemical biomarkers are associated with clinically relevant symptoms. Some serum biomarkers of interest that we used in this study were related, or indicative of inflammation, as indicated by MCP1, and cartilage degradation and breakdown, indicated by COMP, MMP3, and C2C-CP2 ratios. The reason why these biomarkers were chosen was because in previous literature, they've been identified to be greater compared to uninjured match controls, either preoperatively six months or 12 months post-surgery, and also potentially higher compared to pre-op time points at six and 12 months. As far as classifying clinically relevant post-traumatic osteoarthritis-related symptoms at 12 months, there has been proposed criteria using the COOS outcome, the COOS survey, in which a study following individuals with a meniscectomy 16 years after that surgery were identified as symptomatic based on these criteria, also if they had radiographic findings of osteoarthritis, and symptoms that were significant enough to seek medical care. When applied to this criteria into individuals after ACL reconstruction, 42% reported these clinically relevant knee symptoms at six months after their surgery, and the MOON cohort has identified that 39% of these individuals reported these clinically relevant knee symptoms at six months post-surgery. This analysis was part of a secondary analysis from a prospective longitudinal cohort study, which included individuals between the ages of 16 to 35 years old with a primary ACL injury. They planned to undergo ACL reconstruction with a bone patellar tendon bone graft, and reported no osteoarthritis preoperatively. They underwent a first blood draw within 15 days of injury, and a second blood draw within six months post-surgery. They also filled out the COOS survey at 12 months post-surgery. A K-means cluster analysis and one-way ANOVA were used to characterize serum biomarker profile changes from pre-op to six months based on the previously reported biomarkers I talked about in the last slide, and after the profiles were identified, we used ANOVAs and logistic regressions in order to compare self-reported knee function and clinically relevant post-traumatic related knee symptoms between profiles. We identified two profiles based on either increases or decreases in MCP1 and comp, and so profile two can be characterized by having increases in inflammation and cartilage breakdown from pre-op to six months post-surgery. As far as participant characteristic differences, there was a higher percentage of males in profile two compared to profile one, but there were no differences in age, meniscal injury, BMI, chondral injury, meniscectomy, or meniscal repair. There were also no differences in COOS scores based on any of the subscales, and there were no associations between serum profiles, no statistically significant associations between serum profiles and clinically relevant post-traumatic knee-related symptoms as identified by the odds ratio of 1.3 and confidence intervals that crossed one. So in conclusion, we didn't see these links between the serum biomarker concentration changes with clinically relevant post-traumatic osteoarthritis-related symptoms, and therefore, they may not be clinically, or they may not be useful for identifying individuals at risk for developing clinically relevant post-traumatic knee-related symptoms. However, based on our previous literature, these biomarker changes may still be useful in identifying individuals at risk for development of poor tibiofemoral cartilage concentration. Thank you.

post-traumatic osteoarthritis

ACL injury

serum biomarkers

inflammation

cartilage breakdown