Which is more important after total knee arthroplasty: Local inflammatory response or systemic inflammatory response?

We aimed to determine the relationship between functional recovery after knee arthroplasty and systemic and local inflammatory responses. A prospective, clinical study of thirty patients who had osteoarthritis was conducted. After the total knee arthroplasty (TKA), intraarticular IL-6 levels, serum IL-6 levels and serum CRP levels were measured. The primary outcome measures for functional recovery after TKA were the the Knee Society Score (KSS) and Western Ontario and McMaster Universities Index (WOMAC). All patients were examined preoperatively and at 4, 8 and 24 weeks postoperatively. The mean postoperative intraarticular IL-6 level was 218355.1 pg/ml, the mean postoperative serum CRP level was 109.9 mg/L and the mean postoperative serum IL-6 level was 219.0 pg/ml. Preoperative and 4-, 8- and 24-week postoperative KSS and WOMAC scores were evaluated. Significant correlations were found between intraarticular IL-6 concentrations and KSS and WOMAC scores at the first month according to the Pearson correlation test, but no correlations were found between serum IL-6 and CRP levels and KSS and WOMAC scores. The local inflammatory response is more important than the systemic response for early postoperative functional recovery. After TKA, control of local inflammation is much more important than control of systemic inflammation.