Correlation of blood sedimentation rate, blood white cell count, and C-reactive protein with tissue polymerase chain reaction in patients with knee and hip prosthesis with suspected infection

Correlation of blood sedimentation rate, C reactive protein and blood white cell count with PCR in patients with knee and hip prosthesis with suspected infection. OBJECTIVE: With the increase in average age, osteoarthritis has become one of the common joint diseases. Thanks to joint arthroplasties with high success rates, the pain caused by osteoarthritis has been reduced and increased in mobilization. Periprosthetic infections are one of the most difficult complications of joint arthroplasties today. Correct diagnosis should be made for an effective treatment in periprosthetic joint infections. Today, blood sedimentation rate, C-reactive protein and blood white cell count are used for periprosthetic joint infections. However, these values may also increase due to non-infectious reasons, especially inflammation. In our study, a cut-off value was investigated for blood sedimentation rate, C-reactive protein, and blood white cell count to assist in the diagnosis of periprosthetic infections. MATERIAL AND METHOD: Our study was approved by Gazi University Clinical Research Ethics Committee with the date of 29.03.2021 and the decision number 331. PCR used in our study is the general name of the reactions applied for the enzymatic reproduction of a specific region between two known DNA segments. Samples obtained from tissues were separated under sterile conditions. DNA and RNA were determined from the obtained tissue. Taq polymerase enzyme was used for separation and the microorganism was identified by obtaining sufficient length chains from a limited number of DNA segments thanks to replication. Between July 2018 and December 2020, 26 patients with suspected periprosthetic infection were evaluated. Blood sedimentation rate, CRP and blood leukocyte count, erythrocyte distribution width and Neutrophil / Lymphocyte ratio in blood count were studied from patients with physical examination and clinical findings and suspected infection. Patients who were suspected of using drugs to suppress the immune system affecting blood sedimentation rate, CRP and blood leukocyte count, urinary tract infection, oral and dental infection, and respiratory tract infection were not included in the study. Twenty-six patients who met the specified criteria were included in the study. Of the patients, 21 were total knee arthroplasty and 5 were total hip arthroplasty cases. 19 women and 7 men were included in the study. The mean age of the patients was 72.19 (56-85), 16 patients had prosthesis loosening, preoperative examination and laboratory examination (blood sedimentation, complete blood count and C-reactive protein) of the patients were consistent with periprosthetic joint infection. The first operation of all patients with prosthesis loosening was performed in an external center, and all of them had a history of preoperative antibiotic use. Antibiotics were discontinued 10 days preoperatively in order not to affect the culture result. All implants were removed in the first session in all 16 patients. Antibiotic spacer was applied to the patients. Appropriate samples were taken from tissues thought to be infected for culture and PCR analysis. The samples were delivered within 30 minutes to the appropriate laboratory for culture and PCR study. Culture results were obtained within an average of 3 days (2-4 days) and PCR within 24 hours. Although there was no growth in culture in 5 of 16 patients, pathogenic microorganism was detected by PCR. In 1 patient, both culture growth was detected and it was detected by PCR. According to the detected microorganism, appropriate postoperative antibiotherapy was started. According to preoperative clinical examination and blood sedimentation rate, CRP and blood leukocyte results, 10 patients who were not suspected of periprostatic joint infection but who had prosthesis loosening were revised in the first session. Samples were taken from tissues suspicious of infection and sent to the laboratory for culture and PCR analysis within 30 minutes. No pathogenic microorganism was detected in any of the aforementioned 10 patient groups by culture and PCR. RESULTS: Twenty-six patients with 21 total knee arthroplasty and 5 total hip arthroplasty were included in our study. Of these patients, 19 were women and 7 were men. No statistically significant correlation was found between PCR status and gender, case, and culture result status. (p> 0.05). There is no statistically significant difference between the PCR groups in terms of age (years), WBC, RDW and N / L (p> 0.05). A statistically significant difference was found between the PCR groups in terms of CRP and Sediment (p <0.05). The CRP and Sedimentation values of the PCR positive ones are significantly higher than the negative ones. There is no statistically significant relationship between RDW and N / L in PCR positive patients (p> 0.05). As a result of the ROC analysis made to determine the cut-off; CRP and Sedimentation values were found to be significant predictors in differentiating according to PCR positive status. In the distinction made according to PCR positive; The CRP cut-off value was found to be 24.5 with 100.0% sensitivity and 90.0% specificity (p <0.05). Likewise, the sedimentation cut-off value was found to be 64.5 with 80.0% sensitivity and 85.7% specificity (p <0.05). CONCLUSION: There is no correlation between PCR positivity and blood white cell count, RDW and N / L. The CRP and blood sedimentation rate is high in patients with a positive PCR result, and the cut-off value of CRP was found to be 24.5 with 100.0% sensitivity and 90.0% specificity for patients with suspected periprosthetic joint infection according to the PCR result (p <0.05 ). Likewise, the sedimentation cut-off value was found to be 64.5 with 80.0% sensitivity and 85.7% specificity (p <0.05). Keywords: Periprosthetic infection, Blood sedimentation rate, C-reactive protein, Blood white cell count, Erythrocyte distribution width, Neutrophil / Lymphocyte ratio