Surgical site infection in patients submitted to orthopedic surgery: the NNIS risk index and risk prediction

A predictive nomogram for surgical site infection in patients who received clean orthopedic surgery: a retrospective study

BACKGROUND

Surgical site infection (SSI) is a common and serious complication of elective clean orthopedic surgery that can lead to severe adverse outcomes. However, the prognostic efficacy of the current staging systems remains uncertain for patients undergoing elective aseptic orthopedic procedures. This study aimed to identify high-risk factors independently associated with SSI and develop a nomogram prediction model to accurately predict the occurrence of SSI.

METHODS

A total of 20,960 patients underwent elective clean orthopedic surgery in our hospital between January 2020 and December 2021, of whom 39 developed SSI; we selected all 39 patients with a postoperative diagnosis of SSI and 305 patients who did not develop postoperative SSI for the final analysis. The patients were randomly divided into training and validation cohorts in a 7:3 ratio. Univariate and multivariate logistic regression analyses were conducted in the training cohort to screen for independent risk factors of SSI, and a nomogram prediction model was developed. The predictive performance of the nomogram was compared with that of the National Nosocomial Infections Surveillance (NNIS) system. Decision curve analysis (DCA) was used to assess the clinical decision-making value of the nomogram.

RESULTS

The SSI incidence was 0.186%. Univariate and multivariate logistic regression analysis identified the American Society of Anesthesiology (ASA) class (odds ratio [OR] 1.564 [95% confidence interval (CI) 1.029-5.99, P = 0.046]), operative time (OR 1.003 [95% CI 1.006-1.019, P < 0.001]), and D-dimer level (OR 1.055 [95% CI 1.022-1.29, P = 0.046]) as risk factors for postoperative SSI. We constructed a nomogram prediction model based on these independent risk factors. In the training and validation cohorts, our predictive model had concordance indices (C-indices) of 0.777 (95% CI 0.672-0.882) and 0.732 (95% CI 0.603-0.861), respectively, both of which were superior to the C-indices of the NNIS system (0.668 and 0.543, respectively). Calibration curves and DCA confirmed that our nomogram model had good consistency and clinical predictive value, respectively.

CONCLUSIONS

Operative time, ASA class, and D-dimer levels are important clinical predictive indicators of postoperative SSI in patients undergoing elective clean orthopedic surgery. The nomogram predictive model based on the three clinical features demonstrated strong predictive performance, calibration capabilities, and clinical decision-making abilities for SSI.

Risk Factors and Dynamic Nomogram Development for Surgical Site Infection Following Open Wedge High Tibial Osteotomy for Varus Knee Osteoarthritis: A Retrospective Cohort Study

Background

As the worldwide population ages, the population receiving open wedge high tibial osteotomy (OWHTO) is growing, and surgical site infection (SSI) is a rare but fatal surgical complication. This study aimed to identify risk factors independently associated with SSI following OWHTO and develop a predictive nomogram.

Methods

Clinical data of patients who received OWHTO and followed up for more than 12 months in our hospital were retrospectively reviewed. Multivariable logistic regression was performed to determine independent risk factors for SSI and to construct predictive nomograms. The study further illustrated the predictive performance of the model by using the receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA).

Results

A total of 1294 eligible patients were included in the study. Multivariate analysis revealed tobacco consumption (OR=3.44, p=0.010), osteotomy size ≥12 mm (OR=3.3, p=0.015), the use of allogeneic bone or artificial bone graft substitutes (allogeneic bone vs none, OR=4.08, p=0.037; artificial bone vs none, OR=5.16, p=0.047), Kellgren-Lawrence (K-L) grade IV (OR=2.5, p=0.046), systemic immune-inflammation index (SII) >423.62 (OR=6.2, p<0.001), high-sensitivity C-reactive protein (HCRP) >2.6 mg/L (OR=2.42, p=0.044), and a higher level of fasting blood glucose (FBG) (OR=1.32, p=0.022) were the independent predictors of SSI. The cutoff score of the model was 148, with a sensitivity of 76.0% and specificity of 81.0%. The concordance index (C-index) and Brier score of the nomogram were 0.856 and 0.017, and the corrected values after 1000 bootstrapping validations were 0.820 and 0.018, respectively. Furthermore, the ROC curve, calibration curve, and DCA exhibited excellent predictive accuracy and clinical applicability of the model.

Conclusion

This study developed a dynamic nomogram based on seven predictors, which allowed surgeons to individualize risk stratification of patients and intervene promptly to reduce SSI rates.

Staples versus sutures for skin closure in hip arthroplasty: a meta-analysis and systematic review

Objective

The purpose of the present study was to estimate complications and other outcomes associated with staple and suture closure after hip arthroplasty through meta-analysis techniques and a systematic review.

Methods

We searched for articles in EMBASE, PubMed, Medline, Web of Science and the Cochrane Library. To determine the eligibility of the searched trials, Cochrane Collaboration's Review Manager software was used to perform the meta-analysis.

Results

Five randomized controlled trials and one retrospective cohort trial were included in our study. Our study indicated that for skin closure after hip arthroplasty, the risks of superficial infection and prolonged discharge were higher with staples than with sutures. There was no significant difference between the two groups in terms of allergic reaction, dehiscence, inflammation, abscess formation, the Hollander Wound Evaluation Scale or patient's satisfaction with skin closure methods. However, suturing required a longer operating time.

Conclusions

Closure with sutures is associated with lower risks of superficial infection and prolonged discharge than closure with staples following hip arthroplasty, but it may take more time.

Prevalence of surgical site infection after orthopaedic surgery with two types of drainage at three public hospitals in Iran

INTRODUCTION

Orthopaedic surgical site infections (SSIs) are among the most important and prevalent because implanted devices are used in such surgeries which increase the risk of infection. This study aimed to examine the incidence of infection in orthopaedic surgeries and related factors in a group of public hospitals in Iran.

METHODS

This analytical cross-sectional study was condcuted in 2018. Data were collected about the incidence of infection and related factors including use/non-use of drains and well as types of drain . The presence of SSIs were determined using a researcher-devised Wound Infection Checklist (WIC) and microbial cultures.

RESULTS

Of 110 included patients undergoing orthopaedic surgeries, 18.2% had an infection. The highest rate of infection was associated with lower extremity surgeries following tibia and fibula fractures. The incidence of infection among individuals under the age of 35 years was also higher. Emergency procedures demonstrated a higher incidence of infection. No significant relationship was observed between use of wound drains and development of SSIs.

CONCLUSION

Reducing the incidence of orthopaedic infection can be achieved by focusing more attention on open fractures occurring in the lower extremity. Use of surgical drains for the sole purpose of reducing the rate of infection is not effective. Accordingly, infection provention protocols should be implemented in orthopaedic surgery units to control and reduce rates of infection.

Can surgical site infections be controlled through microbiological surveillance? A three-year laboratory-based surveillance at an orthopaedic unit, retrospective observatory study

OBJECTIVE

The aims of the study were to analyse the surgical site infections (SSIs) in patients operated at an orthopaedic ward and to describe the drug-resistance of the aetiology of those infections. Also, analyse the possibility of SSI control through microbiological surveillance. Additionally, we have studied the information inferred by aggregating cumulative antibiograms for the SSIs of the studied orthopaedic unit.

DESIGN

Cross-sectional studies carried out in 2013-2015.

SETTING AND PATIENTS

Orthopaedic and Trauma Surgery Unit in Sosnowiec, Poland; 5995 patients, 5239 operations.

METHODS

Retrospective laboratory-based data collection study of surgical site infections.

RESULTS

SSI incidence rate was 6.6%, in the implantations-hip prosthesis 5.8% and knee prosthesis 5.4%, about 6 times higher compared with European HAI-Net. SSIs were usually caused by Gram-positive bacteria (56%). The prevalence of MDR microorganisms was 22.6%, and mainly concerned the Gram-negative bacilli: 97.6% of Acinetobacter baumannii and 50.0% of Klebsiella pneumoniae were multidrug-resistant. On the basis of what the Formula for Rational Empiric Antimicrobial Therapy analysis has shown, the use of amikacin, imipenem and ciprofloxacin has been recommended as the most efficient in the empirical therapy of SSIs.

CONCLUSIONS

The infection control was a significant problem at the studied orthopaedic unit, as evidenced by the SSI incidence rate significantly higher than expected. We suggest implementing the infection control and prevention based on evidence-based medicine, and a unit-based surveillance. A cumulative unit-based antibiogram reflects the drug-susceptibility pattern for the strains from the infections acquired at the unit.

Complication rate of different wound closures after primary hip arthroplasty - A survey of 373 patients

BACKGROUND

Wound closure is highly associated with wound complications and the best wound closure method was controversial in total hip arthroplasty.

METHODS

We performed a retrospective study of primary hip arthroplasty and compared three types of closure method.

RESULTS

155 cases were closed using continuous subcuticular sutures then with staples, 111 using staples, 141 using interrupted sutures. 28 cases of wound complications occurred. Wound complication rates in subcuticular suture group, staple group and interrupted suture group were 1.9%, 11.7% and 8.5%, respectively (p < 0.01).

CONCLUSION

Wound complication rate was significantly lower when wound was closed with continuous subcuticular suturue.

Incidence and risk factors for surgical site infection in general surgeries

Objective:

to estimate the incidence of surgical site infection in general surgeries at a large Brazilian hospital while identifying risk factors and prevalent microorganisms.

Method:

non-concurrent cohort study with 16,882 information of patients undergoing general surgery from 2008 to 2011. Data were analyzed by descriptive, bivariate and multivariate analysis.

Results:

the incidence of surgical site infection was 3.4%. The risk factors associated with surgical site infection were: length of preoperative hospital stay more than 24 hours; duration of surgery in hours; wound class clean-contaminated, contaminated and dirty/infected; and ASA index classified into ASA II, III and IV/V. Staphyloccocus aureus and Escherichia coli were identified.

Conclusion:

the incidence was lower than that found in the national studies on general surgeries. These risk factors corroborate those presented by the National Nosocomial Infection Surveillance System Risk Index, by the addition of the length of preoperative hospital stay. The identification of the actual incidence of surgical site infection in general surgeries and associated risk factors may support the actions of the health team in order to minimize the complications caused by surgical site infection.

ANALYSIS OF SURGICAL SITE INFECTIONS IN PEDIATRIC PATIENTS AFTER ORTHOPEDIC SURGERY: A CASE-CONTROL STUDY

Objectives:

To describe the rate of surgical site infections in children undergoing orthopedic surgery in centers of excellence and analyze the patients’ profiles.

Methods:

Medical records of pediatric patients undergoing orthopedic surgery in the Jamil Haddad National Institute of Traumatology and Orthopedics from January 2012 to December 2013 were analyzed and monitored for one year. Patients diagnosed with surgical site infection were matched with patients without infection by age, date of admission, field of orthopedic surgery and type of surgical procedure. Patient, surgical and follow-up variables were examined. Descriptive, bivariate and correspondence analyses were performed to evaluate the patients’ profiles.

Results:

347 surgeries and 10 surgical site infections (2.88%) were identified. There was association of infections with age - odds ratio (OR) 11.5 (confidence interval - 95%CI 1.41-94.9) -, implant - OR 7.3 (95%CI 1.46-36.3) -, preoperative period - OR 9.8 (95%CI 1.83-53.0), and length of hospitalization - OR 20.6 (95%CI 3.7-114.2). The correspondence analysis correlated the infection and preoperative period, weight, weight Z-score, age, implant, type of surgical procedure, and length of hospitalization. Average time to diagnosis of infection occurred 26.5±111.46 days after surgery.

Conclusions:

The rate of surgical site infection was 2.88%, while higher in children over 24 months of age who underwent surgical implant procedures and had longer preoperative periods and lengths of hospitalization. This study identified variables for the epidemiological surveillance of these events in children. Available databases and appropriate analysis methods are essential to monitor and improve the quality of care offered to the pediatric population.

Survey of infection in orthopedic postoperative and their causative agents: a prospective study

OBJECTIVE

to evaluate the cases of wound infections in orthopedic postoperative period.

METHODS

postoperative patients who developed infection during the period from November 2012 to November 2013 were studied. Secretions were collected during surgery using sterile swabs, and sent for microbiological analysis.

RESULTS

during the period analyzed, 38 surgical procedures progressed to infection. The type of surgery presenting the largest number of infections was osteosynthesis, in 36 (94.7%) patients. Among the materials used, 18 (36%) surgeries that used external fixator were infected, and 17 (34%) using plate. The species of bacteria that caused the largest number of infections were Staphylococcus aureus, infecting 16 (43.9%) patients, followed by Acinetobacter baumannii, which infected four (10.5%) patients. Regarding the resistance profile of Gram-positive strains to antibiotics, 100% of Staphylococcus aureus strains were susceptible to vancomycin and 31.3%, to ceftriaxone. As for the Gram-negative bacteria, 100% of Acinetobacter baumannii strains were resistant to ceftriaxone, gentamicin and imipenem.

CONCLUSION

infection control in the postoperative period is necessary, using antibiotics correctly and consciously, avoiding resistance of bacterial agents.

Risk factors for surgical site infection in a teaching hospital: a prospective study of 1,138 patients

BACKGROUND

The purpose of this study was to identify risk factors for surgical site infection (SSI) in a teaching hospital.

METHODS

A prospective study was initiated to investigate risk factors for SSI at a university-affiliated tertiary care center from July 2013 to December 2014. The chi-square test for categorical variables was used to determine the significance of association, whereas the multivariate logistic regression model was used to examine independent risk factors for SSI.

RESULTS

A total of 1,138 patients met the inclusion criteria, in whom 36 cases of infection occurred during the hospitalization period and two cases occurred after discharge. Univariate analysis showed that SSI was associated with the type of operation, wound classification, volume of blood loss, blood transfusion, American Society of Anesthesiology score before surgery, risk index, duration of surgery, diabetes, cancer, gastrointestinal catheter, urinary catheter, postoperative drainage, and preprocedural white blood cell count. Multivariate analysis identified six independent parameters correlating with the occurrence of SSI: diabetes (odds ratio [OR] 6.400; 95% confidence interval [CI] 2.582-15.866; P=0.000); cancer (OR 2.427; 95% CI 1.028-5.732; P=0.043); preprocedural white blood cell count more than 10×10(9)/L (OR 6.988; CI 3.165-15.425; P=0.000); wound classification (clean contaminated [OR: 7.893; CI: 2.244-27.762; P=0.001]; contaminated [OR: 7.031; CI: 1.652-29.922; P=0.008]; dirty [OR: 48.778; CI: 5.418-439.164; P=0.001]); operative duration more than 120 minutes (OR 4.289; CI 1.773-10.378; P=0.001); and postoperative drainage (OR 3.957; CI 1.422-11.008; P=0.008).

CONCLUSION

Our data suggest that all these risk factors could be regarded as potential indicators of SSI and that relevant preventive measures should be taken to reduce SSI and improve patient outcomes.

Surgical site infections in women and their association with clinical conditions

INTRODUCTION

Surgical site infections (SSIs) can affect body tissues, cavities, or organs manipulated in surgery and constitute 14% to 16% of all infections. This study aimed to determine the incidence of SSIs in women following their discharge from a gynecology outpatient clinic, to survey different types of SSIs among women, and to verify the association of SSIs with comorbidities and clinical conditions.

METHODS

Data were collected via analytical observation with a cross-sectional design, and the study was conducted in 1,026 women who underwent gynecological surgery in a teaching hospital in the municipality of Teresina, in the northeast Brazilian State of Piauí, from June 2011 to March 2013.

RESULTS

The incidence of SSIs after discharge was 5.8% among the women in the outpatient clinic. The most prevalent surgery among the patients was hysterectomy, while the most prevalent type of SSI was superficial incisional. Comorbidities in women with SSIs included cancer, diabetes mellitus, and hypertension.

CONCLUSIONS

Surveillance of SSIs during the post-discharge period is critical for infection prevention and control. It is worth reflecting on the planning of surgical procedures for patients who have risk factors for the development of SSIs.

Surgical site infection in orthopaedic oncology

BACKGROUND

This study addressed risk factors for surgical site infection in patients who had undergone orthopaedic oncology surgical procedures.

METHODS

We retrospectively reviewed data on 1521 orthopaedic oncologic surgical procedures in 1304 patients. We assessed patient demographics, updated Charlson comorbidity index, surgery-specific data, and treatment-related data and attempted to identify predictors of surgical site infection with bivariate and multivariable analysis.

RESULTS

Eight factors independently predicted surgical site infection: body mass index (odds ratio [OR]:, 1.03, 95% confidence interval [CI]: 1.00 to 1.07), age (OR: 1.18, 95% CI: 1.05 to 1.33), total number of preceding procedures (OR: 1.19, 95% CI: 1.07 to 1.34), preexisting implants (OR: 1.94, 95% CI: 1.17 to 3.21), infection at another site on the date of the surgery (OR: 4.13, 95% CI: 1.57 to 10.85), malignant disease (OR: 1.46, 95% CI: 0.94 to 2.26), hip region affected (OR: 1.96, 95% CI: 1.35 to 2.84), and duration of the procedure (OR: 1.16, 95% CI: 1.07 to 1.25).

CONCLUSIONS

These factors can inform patients and surgeons of the probability of surgical site infection after orthopaedic oncologic surgery. While most risk factors are unmodifiable or related to the complexity of the case, infection at another site on the date of the surgery is one factor amenable to intervention.

Body mass index and risk of surgical site infection following spine surgery: a meta-analysis

PURPOSE

Inconsistent results have been reported in the literature on the association between obesity, expressed as increased body mass index (BMI), and risk for surgical site infection (SSI) following spine surgery. The objective of this study was to review and quantify the association between increased BMI and risk of spinal SSI in adults.

METHODS

We performed a comprehensive search for relevant studies using PubMed, Embase, and references of published manuscripts. Study-specific risk measures were transformed into slope estimates and combined using the random effects meta-analysis model to establish the risk of SSI associated with every 5-unit increase in BMI.

RESULTS

Thirty-four articles underwent full-text review. Variations were noted among these studies in relation to SSI diagnosis criteria and BMI cut-off levels used to define obesity. Data from 12 retrospective studies were included in the analyses. Results showed that BMI was significantly positively associated with the risk of spinal SSI. Unadjusted risk estimates demonstrated that a 5-unit increase in BMI was associated with 13 % increased risk of SSI [Crude odds ratio (OR): 1.13; 95 % CI: 1.07-1.19, p < 0.0001]. Pooling of risk estimates adjusted for diabetes and other confounders resulted in a 21 % increase in risk of spinal SSI for every 5-unit increase in BMI (adjusted OR: 1.21; 95 % CI 1.13-1.29, p < 0.0001).

CONCLUSION

Higher BMI is associated with the increased risk of SSI following spine surgery. Prospective studies are needed to confirm this association and to determine whether other measures of fat distribution are better predictors of risk of SSI.

A survey of recently published papers on orthopedics in the Brazilian scientific press

This paper is a review of articles published in Brazilian scientific periodicals in recent years. Its main purpose is to bring to the attention of the readership of Acta Ortopedica Brasileira original contributions to the field published in non-specialized journals. We hope that this will serve as a general scientific update for readers. The review includes works published in six ISI indexed non-orthopedic journals, following a literature search conducted in fourteen such journals.

Risk of surgical site infection in patients undergoing orthopedic surgery

This study aimed to identify risk factors associated with surgical site infections in orthopedic surgical patients at a public hospital in Minas Gerais, Brazil, between 2005 and 2007. A historical cohort of 3,543 patients submitted to orthopedic surgical procedures. A descriptive analysis was conducted and surgical site infection incidence rates were estimated. To verify the association between infection and risk factors, the Chi-square Test was used. The strength of association of the event with the independent variables was estimated using Relative Risk, with a 95% confidence interval and p<0.05. The incidence of surgical site infection was 1.8%. Potential surgical wound contamination, clinical conditions, time and type of surgical procedure were statistically associated with infection. Identifying the association between surgical site infection and these risk factors is important and contributes to nurses’ clinical practice.