Preoperative relationship of nasal staphylococcal carriage with postoperative infections in patients with KNEE and hip prostheses

Objectives: In this study, preoperative nasal staphylococcus carriage screening in patients with knee or hip prosthesis implantation at Istanbul University Istanbul Faculty of Medicine Orthopedics Clinic.The aim of this study was to evaluate and compare the rates of development of early prosthesis infection in patients with and without carriage following the first three months of operation. Material and Methods: The study was planned as prospective cohort and 151 patients over 18 years of age were included in the study between 02.01.2019 and 31.08.2019 at Istanbul University, Istanbul Medical Faculty, Orthopedics Clinic. A total of 151 patients above age 18 were included in the study. The data of all patients included in the study were recorded in previously prepared forms. The antibiogram of the bacteria was made by Mueller-Hinton agar by disk diffusion method and evaluated according to EUCAST limit values. MRSA and MSSA strains determined. Patients underwent monthly examinations for 3 months in the postoperative period; In this study, parameters such as pain, temperature increase, redness and swelling of the operated joint were evaluated and hemogram was monitored by erythrocyte sedimentation rate and CRP. At the end of the three month, patients who developed infection according to the criteria specified in the 2013 IDSA Manual of Infectious Diseases Diagnosis and Management of Prosthetic Joint Infections were identified. In the statistical analysis of study data, IBM SPSS Statistics for Windows. Version 21.0 (Statistical Package for the Social Sciences, IBM Corp., Armonk, NY, USA) program; In the analysis of continuous variables, if the distribution is normal, Student's t-test and Mann-Whitney U test if the distribution is not normal; 2 test or Fisher's exact test in the analysis of categorical variables; Logistic regression analysis will be used in order to determine independent parameters. Findings: Demographic data of 151 patients were analyzed. When gender distribution was examined, 34 (22.5%) patients were male and 117 (77.5%) were female. When the most common comorbidities were determined, hypertension was observed in 71 (47%) patients, diabetes in 40 (26.5%) patients, hypothyroidism in 18 (11.9%) patients, coronary artery disease in 11 patients (7.3%), rheumatoid arthritis in 7 patients (4.6%). diagnosis was determined. 16 patients were immunosuppressed for various reasons. Of 151 patients who underwent knee or hip replacement, 76 (50.4%) patients underwent hip replacement and 75 (49.6%) underwent knee replacement. There was no growth in the swab culture of 12 (7.9%) patients who had preoperative nasal swabs. Methicillin-resistant coagulase-negative staphylococci (MRCNS) was isolated in 57 (37.7%) patients. Methicillin-sensitive coagulase negative staphylococci (MSCNS) growth was detected in 64 (42.4%) patients. Methicillin sensitive Staphylococcus aureus (MSSA) was isolated in 15 (10%) patients. Methicillin-resistant Staphylococcus aureus (MRSA) was isolated in 3 (2%) patients. Prosthetic infection developed in 5 (3.3%) patients in the postoperative three months. None of these patients had susceptible or resistant Staphylococcus aureus growth in preoperative nasal swab culture. Of 5 patients who developed prosthesis infection, 4 (80%) had no immunosuppression. Of the 5 infected patients, 4 (80%) were female. Hip prosthesis implantation was performed in 4 patients and knee prosthesis implantation was performed in one patient. One patient had Klebsiella pneumoniae, one patient had Pseudomonas aeruginosa and Klebsiella pneumoniae, one patient had Proteus mirabilis, one had Corynebacterium spp, and one had C/G group streptococci. Intraoperative tissue cultures of 1 patient did not grow. Univariate analysis of postoperative prosthesis infection in immunosuppressed patients did not reveal a significant increase in risk between immunosuppression and prosthesis infection (p=0.528). In the univariate analysis performed to evaluate the relationship between smoking and methicillin-resistant staphylococcus carriage, the risk of preoperative nasal methicillin-resistant stafilococcus carriage was higher in smokers (p=0.030). In the univariate analysis of preoperative nasal coagulase-negative staphylococcal carriage and postoperative prosthesis infection, univariate analysis showed a significant increase in risk of prosthetic infection in nasal coagulase-negative staphylococcal carriage (p = 0.025). When 5 patients with prosthetic infection were evaluated according to the dates they were operated, 3 patients were operated in spring and 2 patients were operated in winter. According to this data, in our study, it can be said that the development of prosthesis infection in spring operations is more. Conclusion: Prosthetic infections are an important cause of morbidity all over the world. In addition to the cost of treatment, it also causes serious material damage due to the loss of labor. In our study, the relationship between staphylococcal carriage and development of early prosthetic infection was investigated; there was no statistically significant relationship between S.aureus carriage and infection development. In order to determine the statistically significant relationship, the sample size should include more patients. However, it is very important to find a statistically significant increase in the risk of infection in patients with coagulase-negative staphylococcus carriers. Although there were 5 patients with early prosthesis infection, delayed prosthesis infections especially with low-grade infection agents such as coagulase-negative staphylococci could not be detected in our study due to the short follow-up period of 3 months. By repeating our study with a longer follow-up, the relationship between coagulase-negative staphylococcal carriage and infection development will be more accurately demonstrated. Our study is a prospective study on this subject and with its results, it also has significant results in terms of preventing surgical site infections due to coagulase-negative staphylococci, which is increasingly seen. In our study, it was once again shown that Gram-negative rods can be effective in early prosthetic infections. Therefore, especially in early empirical treatment of prosthetic infections, Gram-negative rods should be included. Key words: nasal carriage of Staphylococcus spp., prosthetic joint infections, osteomyelitis