Analysis of renal function in patients after scheduled orthopedic intervention on lower limb joints in real clinical practice

Background. Osteoarthritis (OA) with severe pain syndrome is the main reason for total arthroplasty of lower extremity joints. Majority of patients with OA are elderly people with comorbidities who take multiple medications, including nonsteroidal anti-inflammatory drugs (NSAIDs), that increases the risk of renal dysfunction.

Aim. To evaluate the frequency of renal dysfunction in patients undergoing scheduled arthroplasty of lower extremity joints in real clinical practice, the impact of NSAIDs and pain syndrome.

Materials and methods. The study included 1493 patients who underwent scheduled arthroplasty of the hip or knee joint. All patients provided information on concomitant diseases, previously prescribed therapy, pain severity on a ten-point scale and need for NSAIDs; serum creatinine level was assessed and glomerular filtration rate (GFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration formula with determination of the stage of chronic kidney disease (CKD). At 1, 3 and 6 months after surgery, patients were contacted and pain severity and need for NSAIDs were assessed.

Results. The study population included 636 men (42.6%) and 857 women (57.4%). Of these, 84.9% of patients were taking NSAIDs. The mean preoperative GFR was 73.2 ± 15.2 ml/min/1.73 m² (14.3% of patients had CKD stage 3a, 4.8% – CKD stage 3b, and 0.3% – CKD stage 4). The median pain score before surgery was 8 [7; 9] points, and after 3 months it was 1 [0; 3] point. During the study period, 54 patients were readmitted for scheduled arthroplasty on the second joint. In this sample, an increase in GFR (p < 0.001) and a decrease in the CKD stage (p < 0.001) were found, that correlated with less pain compared to the first surgery and a decrease in the need for NSAIDs (r = 0.684; p < 0.001).

Conclusion. Patients undergoing scheduled surgical treatment of OA are characterized by a high incidence of CKD and a significant burden of NSAIDs. In the postoperative period, a decrease in pain severity, use of NSAIDs and a statistically significant relationship between these factors with an increase in GFR and a decrease in the stage of CKD are found. This confirms the need to implement non-drug pain relief methods and patient education for OA.