Surgical Site Infections In Orthopedic Surgery Research Articles

Duration of surgical antibiotic prophylaxis and surgical site infection in orthopaedic surgery: A prospective cohort study.

The optimal duration for surgical antibiotic prophylaxis (SAP) for preventing surgical site infection (SSI) in orthopaedic surgeries remains poorly supported by high-level evidence. This study aimed to assess the association between SAP duration and the occurrence of SSI within one year postoperatively. This prospective cohort study was based on the database from Surgical Site Infection Surveillance and Improvement Project (SISIP) of a tertiary orthopaedic university hospital from October 2014 to December 2020. The main outcome was SSI, defined according to the CDC/NHSN criteria, determined by review of index hospitalization medical records, microbiology laboratory reports, and readmission records for SSI treatment within one-year after discharge. Adjusted Generalized additive models (GAMs) were performed to assess the relationships between SAP duration and SSI, determined the cut-off point of SAP duration, and estimate the relative contribution of each included variable, across the overall cohort and the three subgroups (open fracture, closed fracture, and non-traumatic group). Multivariable logistic regression models were used to estimate the association between prolonging SAP duration based on the cut-off point and SSI. There were 37,046 patients (55.1% male) included, with the overall SSI incidence of 2.35% (871/37,046). In adjusted GAMs, no statistically significant relationships were observed in overall cohort and open or closed group (P>0.05), but a nonlinear relationship was exhibited non-traumatic group (P=0.03); the cut-off point were 2.4 days for overall cohort and 3.6 days (open), 2.6 days (closed), 1.1 days (non-trauma) for three subgroups. In adjusted logistic regression, prolonging SAP duration did not demonstrate a statistically significant protective effect in overall cohort (aOR=0.868; 95% CI, 0.746-1.011) and three groups (open: aOR=0.867; 95% CI, 0.668-1.124; closed: aOR=0.925; 95% CI, 0.754-1.135; non-trauma: aOR=1.184; 95% CI, 0.832-1.683). The relative contribution ranks of SAP duration were 21st overall among 34 factors, 14th for open fractures, 28th for closed fractures, and 3rd for non-traumatic group among 33 factors. Prolonged postoperative SAP duration has no protective effect against SSI in orthopaedic surgery. Our findings support current guidelines against the practice of continuing SAP postoperatively.

Risk factors associated with surgical site infection in patients with musculoskeletal cancer

Background and objectives: surgical site infections (SSI) continue to be a major concern in orthopedic oncology and pose as great a challenge as cancer recurrence, despite the preventive potential of surgery. SSI can be avoided if evidence-based measures are taken. The objective was to assess the frequency of infections in oncological orthopedic surgeries and associated risk factors and inflammatory markers in a reference hospital in the state of Pernambuco. Methods: the frequency of SSI, the identification of isolated microorganisms, the risk factors and the profile of Th1 and Th2 inflammatory markers (IL-2, IL-4, IL-6, IL-10, TNF and IFN-Ƴ) in patients with musculoskeletal cancer were analyzed. Results: SSI were found in 9.1% of patients undergoing orthopedic surgery. Bivariate analysis revealed that a surgical team comprising more than five members (p=0.041) and the need for intraoperative transfusion (p=0.012) were correlated with a higher risk of SSI. The measurement of ultrasensitive C-reactive protein levels to assess the inflammatory response after SSI showed results that were superior to the reference values for each sample, ranging from >5 to >200mg/dl by the immunoturbidimetric method. Of the IL-2, INFγ and TNF (Th1) and IL-4, IL-6, IL-10 (Th2) levels, only interleukin 6 showed high levels, between 6.68 and 58.76 pg/mL. Conclusion: the study found that surgical team with five or more members and blood transfusion were factors associated with the development of SSI in orthopedic surgery in patients with musculoskeletal cancer. Among the inflammatory markers, interleukin 6 (IL-6) showed the highest correlation with the outcome.

How Can Negative Pressure Wound Therapy Pay for Itself?-Reducing Complications Is Important.

Orthopaedic trauma demonstrates a relatively high rate of surgical site infections (SSI) as compared with other surgical specialties. SSIs provide significant clinical challenges and create significant health care costs. Incisional negative pressure wound therapy (iNPWT) has reduced the risk of SSI in orthopaedic surgery and other surgical specialties. The purpose of this study is to investigate potential cost savings with the use of iNPWT (3M Prevena Therapy, 3M, St. Paul, MN) in high-risk orthopaedic trauma patients with closed OTA/AO 41C and 43C fractures. This is a retrospective cohort study performed at a single, level-1 trauma center using data from a lower extremity fracture registry. Using the results from the registry and baseline infection rates derived from the literature, a health economic model was developed to evaluate the potential cost savings. A total of 79 patients included in the registry underwent open reduction and internal fixation of OTA/AO 41C and 43C fractures. A total of 10.1% developed a SSI. For those who received iNPWT, the rate of SSI was 7.4%. A health economic model suggests that the use of iNPWT may reduce the costs per patient by approximately $1381 to $4436 per patient. This health economic assessment and model suggests that judicious use of iNPWT may reduce health care costs in patients undergoing open reduction and internal fixation of OTA/AO 41C and 43C fractures. Economic Level IV.

Development and validation of a predictive nomogram for preoperative deep vein thrombosis (DVT) in isolated calcaneal fracture

The fact that most of the patients with preoperative DVTs after calcaneal fractures are asymptomatic brought challenges to the early intervention, and periodic imaging examinations aggravated the financial burden of the patients in preoperative detumescence period. This study aimed to use routine clinical data, obtained from the database of Surgical Site Infection in Orthopaedic Surgery (SSIOS), to construct and validate a nomogram for predicting preoperative DVT risk in patients with isolated calcaneal fracture. The nomogram was established base on 7 predictors independently related to preoperative DVT. The performance of the model was tested by concordance index (C-index), receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA), and the results were furtherly verified internally and externally. 952 patients were enrolled in this study, of which 711 were used as the training set. The AUC of the nomogram was 0.870 in the training set and 0.905 in the validation set. After internal verification, the modified C-index was 0.846. Calibration curve and decision curve analysis both performed well in the training set and validation set. In short, we constructed a nomogram for predicting preoperative DVT risk in patients with isolated calcaneal fracture and verified its accuracy and clinical practicability.

Effect of Prophylactic Antibiotics in Orthopaedic Surgery

Background: Orthopaedic surgeries require sensitive protocol for prevention of infection pre and post-surgery. Antibiotic-prophylaxis has been reported for reducing risk of infection in orthopaedic surgeries such as removal of implants. Aim: To assess the effect of prophylactic antibiotics in orthopaedic surgery. Study design: Retrospective study Place and duration of study: Dept. of Orthopaedics, Khyber Teaching Hospital, Peshawar from 1-1-2020 to 31-12- 2020. Methodology: One hundred and ten patients within 18-75 years were divided into two groups. Each group had 55 patients. Group 1 were given prophylactic antibiotics pre-operative as a single dose while group 2 were given only saline. All patients were admitted for removal of orthopaedic implants in foot, ankle or leg. Patients 30 days record was observed for any surgical-site infection. Results: The mean age of patient was 42.95±10.8 years. Group 1 and Group 2 had more males than females. There were 10.9% and 9.09% diabetic patients within group 1 and group 2. The 30 days assessment of post implant removal orthopaedic surgery showed a decrease of surgical-site infection in group 1. Surgical-site infection decreased by a rate of 5.4% among patients who were given cefazolin antibiotic. Conclusion: The effect of prophylactic antibiotic reduces chance of surgical-site infection in orthopaedic surgery. Keywords: Antibiotic-prophylaxis, Orthopaedic surgery, Implant-removal, Surgical-site infection

Theatre ventilation.

Owing to the COVID-19 pandemic, there has been significant disruption to all surgical specialties. In the UK, units have cancelled elective surgery and a decrease in aerosol generating procedures (AGPs) was favoured. Centres around the world advocate the use of negative pressure environments for AGPs in reducing the spread of infectious airborne particles. We present an overview of operating theatre ventilation systems and the respective evidence with relation to surgical site infection (SSI) and airborne pathogen transmission in light of COVID-19. A literature search was conducted using the PubMed, Cochrane Library and MEDLINE databases. Search terms included "COVID-19", "theatre ventilation", "laminar", "turbulent" and "negative pressure". Evidence for laminar flow ventilation in reducing the rate of SSI in orthopaedic surgery is widely documented. There is little evidence to support its use in general surgery. Following previous viral outbreaks, some centres have introduced negative pressure ventilation in an attempt to decrease exposure of airborne pathogens to staff and surrounding areas. This has again been suggested during the COVID-19 pandemic. A limited number of studies show some positive results for the use of negative pressure ventilation systems and reduction in spread of pathogens; however, cost, accessibility and duration of conversion remain an unexplored issue. Overall, there is insufficient evidence to advocate large scale conversion at this time. Nevertheless, it may be useful for each centre to have its own negative pressure room available for AGPs and high risk patients.

Prevention of surgical site infections in orthopaedic surgery: a synthesis of current recommendations.

Despite adopted precautions, surgical site infection (SSI) rate in orthopaedic surgery and its consequences still remain a major problem. Worldwide, infection prevention and control in perioperative settings are considered of primary importance for every healthcare system. The management of perioperative infections carries a heavy psychological and financial burden, since patients who experience SSI have increased hospital length of stay, morbidity and mortality rates, and higher hospital costs. As the treatment of such infections is particularly difficult in the presence of an implanted biomaterial, the prevention of SSI in orthopaedic surgery represents a challenging key issue, requiring the integration of a range of measures before, during and after surgery. In fact, over the years several aspects of SSI prevention have been studied in order to identify the best SSI prevention strategies and set out appropriate clinical practices. This article will review and summarize the recent international guidelines released on this subject together with other published relevant evidence.

Screening for nasal carriage of Staphylococcus aureus among patients scheduled to undergo orthopedic surgery: Incidence of surgical site infection by nasal carriage.

Staphylococcus aureus (S.aureus), including MRSA, is considered to be the leading cause of surgical site infection (SSI) after orthopedic surgery. We screened for nasal carriers of S.aureus among patients who were scheduled to undergo orthopedic surgery at our hospital to reveal the effect of nasal S.aureus carriage on SSI. Our study design clearly has the intent of finding S.aureus nasal carriage and eradicating MRSA when found, and this strategy is to verify whether it's effective for preventing orthopedic surgical infections. Subjects were 4148 patients who underwent preoperative screening for nasal carrier and subsequently underwent orthopedic surgery during a 7-year period between April 2007 and March 2014. The incidence of SSI among patients who were operated in our department was investigated, and the rates were compared between patients with and without nasal carriage to reveal the effect of preoperative nasal carriage on SSI. In total, 1036 patients were nasal carriers of S.aureus (carriage rate, 25.0%), whereas 140 patients carried MRSA (carriage rate, 3.4%). SSI developed in 24 patients [incidence, 0.58% (24/4148)] consisting of 12 non-carriers [0.39% (12/3112)] and 12 carriers [1.16% (12/1036)] with a significant difference in the incidence between the groups. Among 24 cases of SSI, more than half (13 cases) were caused by bacterial species other than S.aureus or those that could not be detected by the tests used. Only 7 patients out of 24 SSI patients, S.aureus was the bacterium detected in preoperative nasal cultures and the causal bacterium for SSI (concordance rate of 29.2%). It was difficult to reduce the incidence rate of SSI in eradication group to the same level as nasal culture negative group. However, nasal carriage of S.aureus or MRSA may be a risk factor for SSI in orthopedic surgery.

1025Impact of Nasal Decontamination with Nasal Iodine as part of a Preoperative Surgical Site Infection (SSI) Prevention Bundle in Orthopedic Implant Surgeries

Nasal iodine as a bundled approach can be a rapid and effective method for prevention of all Surgical Site Infections (SSIs) and also S. aureus SSIs in orthopedic implant surgeries by decontamination of the nares. The individual effect of nasal iodine in reduction of SSI in orthopedic surgeries will need to be determined in future studies, but this offers an alternative to screening and decolonization with mupirocin. Conclusion  Staphylococcus aureus is the leading cause of surgical site infections. 80 percent of S. aureus infections are caused by the patients own nasal flora. Nasal iodine (3MTM Skin and Nasal Antiseptic ) is effective for 1 to 12 hours post application and can be used for decolonization (reduces organism burden by 99.5% in the nares) Nasal iodine application is quick and generally done as a single application just prior to surgery. Background This study was conducted at Detroit Receiving hospital starting March, 2013.  This approach was used as part of a bundle which included perioperative CHG bathing and addition of vancomycin prophylaxis.  Infection rates for knee and hip surgeries were collected by infection control personnel during routine surveillance for surgical site infections. Infection rates were compared 1 year before and 1 year after intervention. Methods Results Background: Nasal carriage of Staphylococcus aureus (SA) has been shown to be an independent risk factor for SA surgical site infections (SSI), with a SSI rate 2-9 times higher in carriers. Decolonization with nasal mupirocin is often recommended for carriers or high risk individuals, however this process requires preoperative screening and patient compliance with application days prior to surgery. Nasal decontamination with nasal iodine just prior to surgery offers a rapid method of decreasing the nasal burden of SA in high risk joint implant surgeries. Methods: Nasal decontamination with nasal iodine (3MTM Skin and Nasal Antiseptic) of all patients undergoing hip and knee prosthetic joint replacement was implemented pre-operatively since March 2013 at Detroit Receiving Hospital. This intervention was coupled with reinforcement of perioperative CHG bathing and the addition of vancomycin to routine Blactam prophylaxis. Hip arthroplasty (HPRO) and knee arthroplasty (KPRO) infection rates were reviewed for 1 year before and after intervention. Results: There was a 43.25% reduction in HPRO and KPRO infections during this time period. A decrease in the average rate from 2.59 to 1.45 infections per 100 procedures (OR-0.56, p=0.24) was seen. SA infection were reduced from an average rate of 1.29 to 0.63 infections per 100 procedures (OR – 0.48, p=0.30). This resulted in a reduction of 5 infections and an approximate net cost saving of $142,409. Conclusions: Nasal decontamination with iodine offers an alternative to nasal decolonization with mupirocin in the prevention of orthopedic implant infections and was effective as part of a perioperative SSI prevention bundle.  A decrease in the average rate from 2.59 to 1.45 infections per 100 procedures (OR-0.56, p=0.24) was seen. {Rate of HPRO decreased from 2.1 to 1.86 infections per 100 procedures (OR-0.87, p=0.84) and rate of KPRO decreased from 3.07 to 1.12 infections per 100 procedures (OR0.36, p=0.14)}  SA infection were reduced from an average rate of 1.29 to 0.63 infections per 100 procedures (OR – 0.48, p=0.30).  This resulted in a reduction of 5 infections and an approximate net cost saving of $142,409. Surgical site Combined Hip and Knee prosthesis infections / # procedures by OR month x 100

Smoking is a risk factor of organ/space surgical site infection in orthopaedic surgery with implant materials

In recent guidelines, smoking is reported as a factor increasing the risk of surgical site infection (SSI). The accurate analysis of the literature shows that this recommendation relies on low level of evidence in orthopaedic surgery with material implantation (arthroplasty components or implants for internal fixation). This study aimed to assess the attributable risk of smoking on organ/space SSI in orthopaedic surgery with implants. Risk factors of organ/space SSI were studied in a prospective cohort including 3,908 patients from June 2003 to December 2006. Smoking was found as a significant risk factor for organ/space SSI. We also observed a significant difference between smokers and non-smokers for surgical wound complications (hematoma, discharge or wound dehiscence) during the period between surgical procedure and discharge from hospital. This is the first large prospective report of a significant association between smoking and organ/space SSI in orthopaedic surgery with implants.

Relationship of Hyperglycemia and Surgical-Site Infection in Orthopaedic Surgery

The impact of perioperative hyperglycemia in orthopaedic surgery is not well defined. We hypothesized that hyperglycemia is an independent risk factor for thirty-day surgical-site infection in orthopaedic trauma patients without a history of diabetes at hospital admission. Patients eighteen years of age or older with isolated orthopaedic injuries requiring acute operative intervention were studied. Patients with diabetes, injuries to other body systems, a history of corticosteroid use, or admission to the intensive care unit were excluded. Blood glucose values were obtained, and hyperglycemia was defined in two ways. First, patients with two or more blood glucose levels of ≥200 mg/dL were identified. Second, the hyperglycemic index, a validated measure of overall glucose control during hospitalization, was calculated for each patient. A hyperglycemic index of ≥1.76 (equivalent to ≥140 mg/dL) was considered to indicate hyperglycemia. The primary outcome was thirty-day surgical-site infection. Multivariable logistic regression models evaluating the effect of the markers of hyperglycemia, after controlling for open fractures, were constructed. Seven hundred and ninety patients were identified. There were 268 open fractures (33.9%). Twenty-one thirty-day surgical-site infections (2.7%) were recorded. Age, race, comorbidities, injury severity, and blood transfusion were not associated with the primary outcome. Of the 790 patients, 294 (37.2%) had more than one glucose value of ≥200 mg/dL. This factor was associated with thirty-day surgical-site infection, with thirteen (4.4%) of the 294 patients with that indication of hyperglycemia having a surgical-site infection versus eight (1.6%) of the 496 patients without more than one glucose value of ≥200 mg/dL (p = 0.02). One hundred and thirty-four (17.0%) of the 790 patients had a hyperglycemic index of ≥1.76, and this was also associated was thirty-day surgical-site infection (ten [7.5%] of 134 versus eleven [1.7%] of 656; p < 0.001). Multivariable logistic regression models demonstrated that two or more blood glucose levels of ≥200 mg/dL was a risk factor for thirty-day surgical-site infection (odds ratio [OR]: 2.7, 95% confidence interval [CI]: 1.1 to 6.7) after adjustment for open fractures (OR: 3.2, 95% CI: 1.3 to 7.8). A second model demonstrated that a hyperglycemic index of ≥1.76 was an independent risk factor for surgical-site infection (OR: 4.9, 95% CI: 2.0 to 11.8) after controlling for open fractures (OR: 3.3, 95% CI: 1.4 to 8.3). Hyperglycemia was an independent risk factor for thirty-day surgical-site infection in orthopaedic trauma patients without a history of diabetes.

Surgical site infections: incidence and trends at a community teaching hospital

Background There has been increased national attention on methicillin-resistant Staphylococcus aureus (MRSA) and surgical site infections (SSIs) highlighted by the media, the public, and federal agencies. It was therefore considered important to analyze the trends and incidence of inpatient detected SSIs and associated resistant organisms at our own institution. Methods The analysis reflects the cultures and sensitivities of SSI on the surgical services at Monmouth Medical Center, a 527-bed community teaching hospital, from January 2003 through December 2007. The SSIs included in the study were those detected in hospitalized patients. Results There were 312 surgical patients who developed SSIs. Contrary to observed national trends, our study demonstrated a statistically significant decrease in the incidence of MRSA among all the surgical services. We also noted a statistically significant decrease trend of SSIs in orthopedic surgery. The 312 patients' cultures yielded 399 bacterial strains. The most common strains varied with the service. Overall, the most common isolate identified was Staphylococcus species, numbering 143% or 35.8% of all isolates. MRSA was identified in 46 SSIs and 8 SSIs were positive for vancomycin-resistant enterococci (VRE). Conclusions Only a hospital-specific SSI analysis can help focus improvement with clinical impact. The scrutiny of SSI analysis has highlighted SSI problems in the pediatric and orthopedic surgery services that have been addressed.

Unexpectedly increased rate of surgical site infections following implant surgery for hip fractures: Problem solution with the bundle approach

Introduction Surgical site infections (SSIs) are the most common nosocomial infections after surgery. However, clinical guidance on how to handle any suspicious clusters of SSI in orthopaedic surgery is missing. We report on problem analysis and solution finding following the observation of an increased rate of SSI in trauma implant surgery. Setting Trauma unit of a university hospital. Methods Over a 2-year observation period, all patients ( n = 370) following surgical stabilisation of proximal femur fractures in a trauma unit of a university hospital were consecutively followed using a standardised case report form. First, a retrospective cohort of 217 patients was collected for whom an increased SSI rate was detected. Based on risk analysis, new standard perioperative procedures were developed and implemented. The impact was evaluated in a prospective cohort of 153 comparable patients. Uni- and multivariable analysis of factors associated with the risk for SSI was undertaken. Results The intervention bundle resulted in a significant reduction of an initially increased SSI incidence of 6.9 (down) to 2.0% ( p = 0.029). Multivariable analysis revealed four risk factors significantly associated with a higher risk of SSI caused by different bacteria: duration of surgery ( p = 0.002), hemiarthroplasty ( p = 0.002), haematoma ( p = 0.004) and the presence of two operating room staff members ( p < 0.001 and 0.035). Conclusions A standardised prospective SSI protocol and detection system offering the simultaneous use of data should guarantee every institution immediate alarm registration to avoid comparable problem situations. Detailed interdisciplinary analysis followed by the implementation of coherent interventions, based on a best-evidence structured bundle approach, may adequately resolve similar critical incidence episodes.

Incidence of surgical-site infections in orthopaedic surgery: a northern Italian experience

SUMMARYA prospective cohort study with a 1-year telephone follow-up was performed to estimate the incidence of surgical-site infections (SSIs) in hip and knee prostheses. Twenty-five public hospitals equipped with orthopaedic units in two Italian regions were involved. An 8-month surveillance period was set to obtain significant data at a regional level and data were collected by the infection control nurses of each centre. One-year follow-up was completed in 75% of cases. SSIs were recorded in 45 cases (incidence rate 1·9/100 person-years, 95% CI 1·4-2·5). Thirty-six percent of SSIs were diagnosed during hospitalization and 95·3% within 90 days post-operation. This incidence is similar to that reported by European and USA surveillance systems. The proposed investigative method proved to be reliable and feasible. A prolonged surveillance for at least 3 months post-operation yields a good estimate of SSI in joint replacements.

Is nasal carriage of Staphylococcus aureus the main acquisition pathway for surgical-site infection in orthopaedic surgery?

The endogenous or exogenous origin of Staphylococcus aureus, responsible for orthopaedic surgical-site infections (SSI), remains debated. We conducted a multicentre prospective cohort study to analyse the respective part of exogenous contamination and endogenous self-inoculation by S. aureus during elective orthopaedic surgery. The nose of each consecutive patient was sampled before surgery. Strains of S. aureus isolated from the nose and the wound, in the case of SSI, were compared by antibiotypes or pulsed-field gel electrophoresis (PFGE). A total of 3,908 consecutive patients undergoing orthopaedic surgery were included. Seventy-seven patients developed an SSI (2%), including 22 related to S. aureus (0.6%). S. aureus was isolated from the nose of 790 patients (20.2%) at the time of surgery. In the multivariate analysis, S. aureus nasal carriage was found to be a risk factor for S. aureus SSI in orthopaedic surgery. However, only nine subjects exhibiting S. aureus SSI had been found to be carriers before surgery: when compared, three pairs of strains were considered to be different and six similar. In most cases of S. aureus SSI, either an endogenous origin could not be demonstrated or pre-operative nasal colonisation retrieved a strain that was different from the one recovered from the surgical site.

MRSA - 'bug-bear' of a surgical practice: reducing the incidence of MRSA surgical site infections.

Adverse publicity (the 'superbug') has demonstrated that the problem of MRSA (methicillin-resistant Staphylococcus aureus) is prevalent in many of the country's most prestigious hospitals. The results of the mandatory UK Department of Health (DH) surveillance for early surgical site infections in orthopaedic surgery (SSIS) have been published recently for the period April 2004 to March 2005 when 41,242 operations were studied (<http://www.dh.gov.uk/PublicationsAndStatistics/Publications/PublicationsStatistic> 28 October 2005). Infection rates were generally and gratifyingly low but 48% of surgical site infections were caused by Staph. aureus and of those 68% were MRSA. The following article will discuss the aetiology and prevention of MRSA surgical site infection.

Surgical site surveillance and standardized infection ratios in an orthopedic specialty hospital

BACKGROUND: Surgical site infection (SSI) surveillance data is an essential part of infection control programs. Benchmarking data against the National Nosocomial Infections Surveillance System (NNIS) system has been used since 1999 to evaluate SSI in an orthopedic specialty hospital. The presentation of this data is intended to demonstrate trends and risk factors associated within this patient population. METHODS: NNIS criteria were used to classify SSI in orthopedic surgery as superficial, deep, and organ/space. The infection rates were benchmarked with the NNIS report by stratifying total hips, total knees, spinal fusions, and laminectomies by risk factors 0, 1, 2 and 3 (ASA score, duration of operation, and degree of wound contamination). The expected versus actual number of infections, the infection rate, the standardized infection ratio, and probability value were calculated. RESULTS: From fiscal year (FY) 1999 through FY2004, there were 26,202 orthopedic cases with 229 SSIs (0.9%). In FY2004, data were stratified by type of surgery and showed the following infection rates: total hips, 0.3; total knees, 1.0; laminectomies, 0.9; and spinal fusions, 2.0. The standardized infection ratio (the number of infections divided by the expected number of infections) for each group was 0.2, 0.7, 0.8 and 0.9, respectively. Stratification by risk factors (SIR) for each category demonstrated an increased rate in spinal fusions in patients with greater 2 and 3 risk factors (9.3, as compared to the NNIS threshold of 6.3). An investigation revealed additional risk factors in this group: obesity, diabetes, and allograft implantation. Control measures were implemented and infection rates were reduced. CONCLUSION: SSI surveillance in an orthopedic specialty hospital analyzed over a 6-year period has demonstrated rates below NNIS benchmarking using SIR and probability values. The analysis of data in this manner is useful to detect specific problems and focus investigative activities.

A comparison of two methods for identifying surgical site infections following orthopaedic surgery

Many infection control practitioners (ICPs) dedicate a significant amount of time and resources to surveillance of surgical site infections (SSIs). Alternative surveillance methods need to be explored to reflect the changes to the healthcare system and the increasing economic constraints placed on infection control units. This study was undertaken to compare two methods of identifying SSIs in orthopaedic surgery. Surveillance data collected routinely by ICPs was compared with data obtained from the International Classification of Disease, 9th Revision, Clinical Modification (ICD-9-CM) coding in the medical record. Concordant results between the two methods were obtained. The use of ICD-9-CM coding, as stored in hospital patient administration system databases, has the ability to enhance routine surgical site surveillance programmes. These systems can be used as the basis for screening large data sets for SSIs and identifying where SSIs resulted in patient re-admission. A reduction in the duplication of data and time spent by the ICP on the collection of information for surveillance purposes can be achieved.