Evaluation of the influence of inflammation markers and body mass index on the level of pain syndrome after joint replacement

Aims: To evaluate the relationship between the severity of pain in the early postoperative period after total joint replacement and the levels of laboratory markers of inflammation and body mass index. Methods: A prospective cohort study involved 21 patients (15 women, 6 men) with an average age of 65.3±7.65 years after total hip (n=18) or knee (n=3) replacement with an assessment of pain syndrome using a visual analogue scale in the early postoperative period and a study of its relationship with laboratory parameters (leukocytes, platelets, ESR) before and after the surgery. Results: Females, compared to males, had a higher BMI (30.98±4.82; 26.90±2.96; p=0.070), higher preoperative ESR levels (24.93±9.04; 15.33±3.20; p=0.021), and a significant increase in platelet count on the third postoperative day (289.00 [235.50; 345.00]; 190.00 [186.25; 218.50]; p=0.029). Patients with grade I obesity noted more severe pain in the early postoperative period compared to patients with normal weight (8.67±1.21; 6.00±1.00 p=0.0138), although the differences between the groups diminished within days. Correlation analysis revealed a moderate positive relationship between leukocyte level and VAS pain scores particularly on the third (r≈0.38, p=0.009 and fifth (r ≈0.45, p<0.05) postoperative days. Conclusion: The findings demonstrate that gender differences, BMI, and the severity of pain affect several clinical and laboratory parameters relevant to clinical practice. The systemic inflammatory response, as evidenced by changes in platelet counts and ESR, plays an important role in the pathogenesis of postoperative pain, with notable gender differences