Decreased IL-6 Levels more than 9,46 pg/ml and TNF-α Levels more than 14,43 pg/ml as Predictors of Functional Outcome of Oxford Knee Score 6 Weeks Post Total Knee Arthroplasty in Kellgren-Lawrence Grade IV Osteoarthritis Patients


Introduction: Knee osteoarthritis (OA) occurs when there is a disruption of the dynamic balance between degradation and tissue synthesis. Operative management with Total Knee Artrhoplasty (TKA) is considered a late-stage therapeutic option. One of the reasons for the TKA is to reduce pain and improve knee movement function. However, the research has not extensively covered the impact of these proinflammatory cytokines and mechanical variables that emerge after the surgery and it is still unclear how they relate to post-TKA outcomes. This study aims to further prove the relationship between the magnitude of the decrease in inflammatory markers IL-6 and TNF-α with the functional output of post-TKA as measured by the Oxford Knee Score.


Methods: This investigation is a retrospective cohort. With a total of 28 patients of grade IV Knee OA based on Kellgren-Lawrence Classification who were candidates for TKA surgery between January 2022 until April 2022. Blood samples were obtained the day before surgery and six weeks thereafter. The Oxford Knee Score (OKS) was used to evaluate the patient’s functional status after surgery. Subjects were divided into two groups depending on whether or not they had reduced IL-6 and TNF-α levels to below the cut-off point by 6 weeks postoperatively, as calculated using ROC analysis. Chi-square tests were used to demonstrate the test's validity, and Pearson correlation test is also performed.


Results: Average difference in TNF-α levels was 20.19 (CI = 8.58564-31.81007), which is statistically significant at the 0.002 level (p 0.05), according to the findings of a paired t-test. When comparing IL-6 levels using a paired t-test, a mean difference of 10.52 (IC = 3.32833-17.70738) was found, which is statistically significant at the 0.002 level (p 0.05). TNF-α levels were considered to have been reduced at a cut off value of 14.43 pg/mL with an AUC of 0.837. As for IL-6, the threshold for a reduced level was 9.46 pg/mL with an AUC of 0.837. OKS was also associated with a 6.0-fold lower relative risk between lowered TNF-α and IL-6 levels.


Conclusion: There is a positive link between OKS and the reduction in IL-6 and TNF-α serum levels that occurs 6 weeks after surgery. Decreased level of serum IL-6 more than 9,56 pg/mL and TNF- α more than 14,43 pg/mL can be used as a predictor of good OKS after 6 weeks post TKA.
