Has the rate of in-hospital infections after total joint arthroplasty decreased?

Systemic Inflammatory Response Syndrome and Prosthetic Joint Infection

BACKGROUND

The development of systemic inflammatory response syndrome (SIRS) criteria leads to increased mortality. Little is known about development of SIRS in patients who have prosthetic joint infection (PJI). We aimed to determine the incidence, risk factors, clinical outcomes, and causative organisms in patients who develop SIRS with PJI.

METHODS

We retrospectively identified 655 patients (321 men, 334 women; 382 total hip, 273 total knee) who have hip or knee PJI at 1 institution between July 1, 2015 and December 31, 2020. We formed 2 groups: patients who have SIRS alert (PJI + SIRS) and patients who do not have SIRS alert (PJI). We analyzed clinical outcomes, comorbidities, and operating room culture results.

RESULTS

Of 655 patients, 63 developed SIRS with PJI (9.6%). Intensive care unit (ICU) admission rates (27.0 versus. 6.9%, P < .001) and length of stay (7.7 versus. 5.6 days, P = .003) were greater in PJI + SIRS. At 2 years, reoperation (36.5 versus. 22.3%, P = .01) and mortality rates (17.5 versus. 8.8%, P = .03) were greater in PJI + SIRS. Risk factors included deficiency anemia (P = .001), blood loss anemia (P = .013), uncomplicated diabetes (P = .006), diabetes with complication (P = .001), electrolyte disorder (P < .00001), neurological disorder (P = .0001), paralysis (P = .026), renal failure (P = .005), and peptic ulcer disease (P = .004). Staphylococcus aureus more commonly speciated on tissue cultures in PJI + SIRS (P = .002).

CONCLUSION

The incidence of SIRS is 10% among patients who have PJI. Development of PJI + SIRS is associated with increased lengths of stay, ICU admissions, and 2-year reoperation and mortality rates. Identifying certain comorbidities can stratify patients' risk of developing PJI + SIRS.

Impact of Biological Sex on Complications, Lengths of Stay, Readmission Rates, and Costs of Care Following Primary Total Knee Arthroplasty

The impact of gender on total knee arthroplasty (TKA) postoperative complications, readmission rates, and costs of care has not been often evaluated. Therefore, the purpose of this study was to investigate which sex had higher rates of: (1) medical complications; (2) implant complications; (3) lengths of stay (LOSs); (4) readmission rates; and (5) costs after TKA. A query was performed using an administrative claims database from January 1, 2005, to March 31, 2015. Patients who had TKAs were identified using International Classification of Diseases, Ninth Revision and Current Procedural Terminology codes. Males and females were filtered separately and matched according to age and various medical comorbidities leading to 1,590,626 patients equally distributed. Primary outcomes analyzed included 90-day medical complications, LOSs, 90-day readmission rates, in addition to day of surgery and total global 90-day episode of care costs. Pearson's chi-square analyses were used to compare medical complications and readmission rates. Welch's t-tests were used to test for significance in matching outcomes and costs. A p-value of less than 0.01 was considered statistically significant. Males had a smaller risk of complications than women (1.35 vs. 1.40%, p < 0.006) and higher rates of implant-related complications (2.28 vs. 1.99%, p < 0.0001). Mean LOSs were lower for males: 3.16 versus 3.34 days (p < 0.0001). The 90-day readmission rates were higher in men (9.67 vs. 8.12%, p < 0.0001). This study demonstrated that males undergoing primary TKA have lower medical complications and shorter LOSs then their female counterparts. However, males have higher implant-related complications, readmission rates, and costs of care.

Current Guidelines and Practice Recommendations to Prevent Hospital-Acquired Conditions After Major Orthopaedic Surgeries

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In 2016, a total of 48,771 hospital-acquired conditions (HACs) were reported in U.S. hospitals. These incidents resulted in an excess cost of >$2 billion, which translates to roughly $40,000 per patient with an HAC.

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Current guidelines for the prevention of venous thromboembolism and surgical site infection consist primarily of antithrombotic prophylaxis and antiseptic technique, respectively.

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The prevention of catheter-associated urinary tract infection (CA-UTI) and in-hospital falls and trauma is done best via education. In the case of CA-UTI, this consists of training staff about the indications for catheters and their timely removal when they are no longer necessary, and in the case of in-hospital falls and trauma, advising the patient and family about the patient's fall risk and communicating the fall risk to the health-care team.

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Blood incompatibility is best prevented by implementation of a pretransfusion testing protocol. Pressure ulcers can be prevented via patient positioning, especially during surgery, and via postoperative skin checks.

Preoperative risk factors for postoperative pneumonia following primary Total Hip and Knee Arthroplasty

BACKGROUND

The purpose of this study is to evaluate risk factors for pneumonia following THA and TKA.

METHODS

Patients were identified from the American College of Surgeons National Quality Improvement Database (NSQIP) who experienced postoperative pneumonia after undergoing primary THA and TKA.

RESULTS

Many characteristics including old age, anemia, diabetes, cardiac comorbidities, dialysis, and smoking were independent risk factors for postoperative pneumonia after THA or TKA.

CONCLUSION

This analysis offers new evidence on risk factors associated with the development of pneumonia after THA and TKA. These risk factors can help guide clinicians in preventing postoperative pneumonia after THA and TKA.

Annual Nationwide Infection Trends for Revision Total Knee Arthroplasty

Several recent intraoperative and wound management techniques have been developed and implemented in the United States over the past decade; however, it is unclear what the effects of these newer modalities have on reducing surgical site infection (SSI) rates. Therefore, the purpose of this study was to track the annual rate and trends of (1) overall, (2) deep, and (3) superficial SSIs following revision total knee arthroplasty (TKA). The National Surgical Quality Improvement Program database was queried for all revision TKA cases performed between 2011 and 2016, which yielded 9,887 cases. Cases with superficial and/or deep SSIs were analyzed separately and then combined to evaluate overall SSI rates. After an overall 6-year correlation and trends analysis, univariate analysis was performed to compare the most recent year, 2016, with the preceding 5 years. Correlation coefficients and chi-square tests were used to determine correlation and statistical significance. No significant correlations between combined, deep, and/or superficial SSI rates and year were noted (p > 0.05). The lowest overall SSI incidence was in 2012 (1.16%), while the greatest incidence was in 2014 (1.76%). The deep SSI incidence over the 6 years was 0.67% (66 out of 9,887 cases). Deep SSI rate decreased by 10% in 2016 compared with 2011 (0.50 vs. 0.56%, p  > 0.05). In this 6-year period, 94 cases out of 9,887 were complicated by a superficial SSI, an incidence of 0.95%. The lowest superficial SSI incidence occurred in 2015 (n = 17, 0.77%). Overall, the incidence of SSIs in revision TKA has remained fairly low with some annual variance, indicating room for improvement. These variations likely as revision surgeries can be more complex and have several associated confounding factors influencing outcomes, when compared with primary cases. Further research is needed to identify revision-specific strategies to reduce the risk of surgical site infections.

Preoperative Risk Factors for Postoperative Urinary Tract Infection After Primary Total Hip and Knee Arthroplasties

BACKGROUND

Establishing clear risk factors for complications such as urinary tract infection (UTI) after arthroplasty procedures helps guide clinical practice and provides more information to both surgeons and patients. This study aims to assess selected preoperative patient characteristics as risk factors for postoperative UTI after primary total hip and knee arthroplasties (THA and TKA).

METHODS

This was a retrospective analysis using current procedural terminology codes to investigate the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database for patients who underwent THA or TKA from 2010 to 2017. Patients were classified for UTI by NSQIP guidelines. Patient samples with all possible covariates were included for multivariate logistic regression analysis and assessed for independent associations.

RESULTS

In a cohort of 983 identified patients (983 of 119,096; 0.83%): ages 57+ years, preoperative red blood cell (RBC) transfusion, perioperative RBC transfusion, bleeding disorders, operative time 110+ minutes, preoperative steroid use, diabetes, pulmonary comorbidities, body mass index 30+ kg/m² were independent risk factors for postoperative UTI after THA. In a cohort of 1503 identified patients (1503 of 189,327; 0.8%): ages 60+ years, preoperative RBC transfusion, perioperative RBC transfusion, anemia, platelets less than 150k, preoperative steroid use, diabetes, and body mass index 30+ kg/m² were independent risk factors for postoperative UTI after TKA. Male sex was associated with a decreased risk of UTI in both THA and TKA.

CONCLUSION

This study provides novel evidence on risk factors associated with the development of UTI after THA or TKA. Clinicians should be aware of risk factors in the manifestation of postoperative UTI after primary THA or TKA procedures.

Does a pulmonary rehabilitation based ERAS program (PREP) affect pulmonary complication incidence, pulmonary function and quality of life after lung cancer surgery? Study protocol for a multicenter randomized controlled trial

BACKGROUND

Lung cancer surgery is associated with a high incidence of postoperative pulmonary complications (PPCs). Preliminary evidence suggests that ERAS processes can reduce overall incidence of PPCs as short- and long-term recovery improved by supporting units to adopt evidence-based care. However, the evidence is inconclusive due to insufficient high-level studies in this research field. No well-designed, adequately powered, randomized controlled trials (RCTs) have investigated the effects of pulmonary rehabilitation based ERAS program (PREP) on post-operative pulmonary complications, pulmonary function, and health related quality of life following lung cancer surgery.

METHODS

The PREP trial is a pragmatic, investigator-initiated, multi-center, randomized controlled, parallel group, clinical trial. Five hundred patients scheduled for minimally invasive pulmonary resection at six hospitals in China will be randomized with concealed allocation to receive either i) a pre-operative assessment and an information booklet or ii) a pre-operative assessment, an information booklet, plus an additional education, a 30-min pulmonary rehabilitation training session and the post-operative pulmonary rehabilitation program. The primary outcome is incidence of PPCs defined with the Melbourne Group Scale diagnostic scoring tool. Secondary outcomes include incidence of cardiopulmonary and other complications, pulmonary function, cardiopulmonary endurance, muscle strength, activity level, health-related quality of life (HRQoL), pre- and post-operative hospital length of stay (LOS), and total hospital LOS.

DISCUSSION

The PREP trial is designed to verify the hypothesis that pulmonary rehabilitation based ERAS program reduces incidence of PPCs and improves pulmonary function and HRQoL in patients following lung cancer surgery. This trial will furthermore contribute significantly to the limited knowledge about the pulmonary rehabilitation based ERAS program following lung cancer surgery, and may thereby form the basis of future recommendations in the surgical community.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR1900024646, 21 July 2019.

Indwelling Urinary Catheter for Total Joint Arthroplasty Using Epidural Anesthesia

BACKGROUND

The objective of this study was to evaluate if not placing an indwelling urinary catheter leads to a higher potential for adverse genitourinary (GU) issues after total joint arthroplasty (TJA) under epidural anesthesia.

METHODS

Three hundred thirty-five consecutive patients who underwent primary TJA using epidural anesthesia were retrospectively reviewed. The initial 103 patients received a preoperative urinary catheter, which was maintained until the morning of postoperative day 1. The subsequent 232 patients did not receive a preoperative urinary catheter. Demographics, medical complications, GU complications, and length of stay were compared between groups.

RESULTS

Compared between catheter and noncatheter groups, there were no differences in demographics including age, gender, or laterality of surgery. There was a difference in type of surgery (total knee arthroplasty vs total hip arthroplasty) (P = .008). There was no difference in American Society of Anesthesiologists score, but with a difference in body mass index (P = .01). There were no differences in GU complications among patients with benign prostatic hyperplasia or prostate cancer. However, among patients with a history of prostate disorders (benign prostatic hyperplasia or prostate cancer), urinary tract infection rate was higher in catheter group (P = .023). Postoperative GU complications were associated with increased median age in years and increased average length of stay in days.

CONCLUSION

Patients undergoing TJA under epidural anesthesia demonstrate no increased risk of postoperative urological complications without the placement of preoperative indwelling urinary catheter. The routine use of preoperative catheters can be reconsidered for this mode of anesthesia.

LEVEL OF EVIDENCE

Level II, retrospective comparative study.

A Simple Protocol to Stratify Pulmonary Risk Reduces Complications After Total Joint Arthroplasty

BACKGROUND

Pulmonary complications after total joint arthroplasty are a burden to patients and the healthcare system. The aim of this study is to demonstrate the effectiveness of a pulmonary screening questionnaire and intervention protocol developed at our institution to prevent pulmonary complications.

METHODS

Between 2010 and 2015, 7658 consecutive total joint arthroplasty patients at our institution were reviewed. Based on our pre-operative pulmonary risk assessment tool, 1625 patients were flagged as high pulmonary risk. Patients were determined to be high risk if they were a current or former heavy smoker with an abnormal spirometry, had a positive obstructive sleep apnea screening, required continuous positive airway pressure/bi-level positive airway pressure use, had a history of significant pulmonary disease, had an oxygen saturation <90%, or had body mass index >40. A standardized monitoring protocol and interventions including smoking cessation, treatment and optimization of primary pulmonary conditions, peri-operative inhaler use, spinal anesthesia, aspiration precautions, elevated head of bed >20° resting and >45° while eating, maintaining oxygen saturation ≥92%, early use of incentive spirometer, avoidance of narcotics and early respiratory therapy consult were initiated for all high risk patients.

RESULTS

Only 7 of 7658 (0.091%) patients suffered pulmonary complications after initiating our intervention protocol. These included 3 aspiration pneumonias, 1 asthma exacerbation, 1 chronic obstructive pulmonary disease exacerbation, 1 continuous positive airway pressure intolerance in a patient with obstructive sleep apnea, and 1 requirement of bi-level positive airway pressure. The pulmonary risk questionnaire accurately identified all patients who had pulmonary complications. The overall pulmonary complication rate at our institution decreased from 5.7% to 0.09% after implementing our screening questionnaire and intervention protocol (P < .0001).

CONCLUSION

Our results demonstrate a more than 63-fold reduction in pulmonary complications at our institution. Our screening questionnaire and intervention protocol is an effective way of identifying and preventing pulmonary complications.

The Evidence Behind Peroxide in Orthopedic Surgery

Peroxide is a strong oxidizing agent and disinfectant frequently used in orthopedic surgery. The authors conducted a systematic literature review of peroxide in orthopedic surgery, evaluating use, complications, efficacy, and appropriate concentrations. One hundred seventy-five reports were identified, with 24 being eligible for analysis. Orthopedic surgeons used peroxide for irrigation and bacterial reduction in various procedures. Complications included cytotoxicity, allergic reactions, suture damage, and inflammation. Use of the standard concentration of 3% peroxide and standard time in situ are without evidence. Laboratory studies suggest that diluted concentrations retain the benefit of bacterial decolonization without increasing the risk for complications. [Orthopedics. 2018; 41(6):e756-e764.].

What Is the Timing of General Health Adverse Events That Occur After Total Joint Arthroplasty?

BACKGROUND

Despite extensive research regarding risk factors for adverse events after total joint arthroplasty (TJA), there are few publications describing the timing at which such adverse events occur.

QUESTIONS/PURPOSES

(1) On which postoperative day do certain adverse events occur? (2) What adverse events occur earlier after TKA than after THA? (3) For each adverse event, what proportion occurred after hospital discharge?

METHODS

We screened the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) to identify all patients undergoing primary THA and primary TKA between 2005 and 2013, resulting in a study population of 124,657 patients evaluated as part of this retrospective database analysis. For each of eight different adverse events, the median postoperative day of diagnosis, interquartile range for day of diagnosis, and middle 80% for day of diagnosis were determined. Multivariate Cox proportional hazards modeling was used to test whether there is a difference of timing for each adverse event as stratified by TKA or THA. The proportion of adverse events occurring after versus before discharge was also calculated.

RESULTS

The median day of diagnosis (and interquartile range; middle 80%) for stroke was 2 (1-10; 1-19), myocardial infarction 3 (2-6; 1-15), pulmonary embolism 3 (2-7; 1-19), pneumonia 4 (2-9; 2-17), deep vein thrombosis 6 (3-14; 2-23), urinary tract infection 8 (3-16; 2-24), sepsis 10 (5-19; 2-24), and surgical site infection 17 (11-23; 6-28). For the later occurring adverse events (surgical site infection, sepsis), the rate of occurrence remained high at the end of the 30-day postoperative period. Timing was earlier in patients undergoing TKA for pulmonary embolism (day 3 [interquartile range 2-6] versus 5 [3-17], p < 0.001) and deep vein thrombosis (day 5 [2-11] versus 13 [6-22], p < 0.001). The proportion of events occurring after discharge for myocardial infarction was 97 of 283 (34%), stroke 42 of 118 (36%), pulmonary embolism 223 of 625 (36%), pneumonia 171 of 426 (40%), deep vein thrombosis 576 of 956 (60%), urinary tract infection 958 of 1406 (68%), sepsis 284 of 416 (68%), and surgical site infection 1147 of 1212 (95%).

CONCLUSIONS

As lengths of hospital stay after TJA continue to decrease, our findings suggest that caution is in order because several acute and immediately life-threatening findings, including myocardial infarction and pulmonary embolism, might occur after discharge. Furthermore, the timing of surgical site infection and sepsis suggests that even the 30-day followup afforded by the ACS-NSQIP may not be sufficient to study the latest occurring adverse events. Additionally, both pulmonary embolism and deep vein thrombosis tend to occur earlier after TKA than THA, and this should guide clinical surveillance efforts in patients undergoing those procedures. These findings also indicate that inpatient-only databases (such as the Nationwide Inpatient Sample) may fail to capture a very large proportion of postoperative adverse events, weakening the conclusions of many published studies using those databases.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Incidence, Risk Factors, and Clinical Implications of Pneumonia Following Total Hip and Knee Arthroplasty

BACKGROUND

The purpose of this study is to determine the incidence, risk factors, and clinical implications of pneumonia following total joint arthroplasty (TJA).

METHODS

The American College of Surgeons National Surgical Quality Improvement Program was used to conduct a retrospective cohort study of patients undergoing TJA. Independent risk factors for the development of pneumonia within 30 days of TJA were identified using multivariate regression. Mortality and readmission rates were compared between patients who did and did not develop pneumonia. Multivariate regression was used to adjust for all demographic, comorbidity, and procedural characteristics.

RESULTS

In total, 171,200 patients met inclusion criteria, of whom 66,493 (38.8%) underwent THA and 104,707 (61.2%) underwent TKA. Of the 171,200 patients, 590 developed pneumonia, yielding a rate of 0.34% (95% confidence interval = 0.32%-0.37%). Independent risk factors for pneumonia were chronic obstructive pulmonary disease, diabetes mellitus, greater age (most notably ≥80 years), dyspnea on exertion, dependent functional status, lower body mass index, hypertension, current smoker status, and male sex. The subset of patients who developed pneumonia following discharge had a higher readmission rate (82.1% vs 3.4%, adjusted relative risk [RR] = 16.6, P < .001) and a higher mortality rate (3.7% vs 0.1%, adjusted RR = 19.4, P < .001). Among 124 total mortalities, 22 (17.7%) occurred in patients who had developed pneumonia.

CONCLUSION

Pneumonia is a serious complication following TJA that occurs in approximately 1 in 300 patients. Approximately 4 in 5 patients who develop pneumonia are subsequently readmitted, and approximately 1 in 25 die. Given the serious implications of this complication, evidence-based pneumonia prevention programs including oral hygiene with chlorhexidine, sitting upright for meals, elevation of the head of the bed to at least 30°, aggressive incentive spirometry, and early ambulation should be considered for patients at greatest risk.

One-year incidence of prosthetic joint infection in total hip arthroplasty: a cohort study with linkage of the Danish Hip Arthroplasty Register and Danish Microbiology Databases

OBJECTIVE

To examine the trend of Prosthetic Joint Infections (PJI) following primary total hip arthroplasty (THA) and the antimicrobial resistance of the bacteria causing these infections.

MATERIALS AND METHODS

We identified a population-based cohort of patients in the Danish Hip Arthroplasty Register (DHR) who had primary THA and received their surgery in Jutland or Funen between 2005 and 2014. We followed the patients until revision, emigration, death, or up to 1-year of follow-up. Data from the DHR were combined with those from microbiology databases, the National Register of Patients, and the Civil Registration System. We estimated the cumulative 1-year incidence of PJI for two 5-year periods; 2005-2009 and 2010-2014. The hazard ratio of PJI as a measure of relative risk after adjusting for multiple risk factors was calculated.

RESULTS

Of 48,867 primary THAs identified, 1120 underwent revision within 1 year. Of these, 271 were due to PJI. The incidence of PJI was 0.53% (95% confidence interval (CI): 0.44; 0.63) during 2005-2009 and 0.57% (95% CI: 0.49; 0.67) during 2010-2014. The adjusted relative risk was 1.05 (95% CI: 0.82; 1.34) for the 2010-2014 period vs the 2005-2009 period. The most common micro-organisms identified in the 271 PJI were Staphylococcus aureus (36%) and coagulase-negative staphylococci (CoNS) (33%); others commonly identified included Enterobacteriaceae, enterococci, and streptococci. Antimicrobial resistance to beta-lactams and gentamicin did not change during the study period.

CONCLUSION

The risk of PJI within 1-year after primary THA and the antimicrobial resistance of the most prevalent bacteria remained unchanged during the 2005-2014 study period.

Moderating effects of immunosuppressive medications and risk factors for post-operative joint infection following total joint arthroplasty in patients with rheumatoid arthritis or osteoarthritis

OBJECTIVE

Inconclusive findings about infection risks, importantly the use of immunosuppressive medications in patients who have undergone large-joint total joint arthroplasty, challenge efforts to provide evidence-based perioperative total joint arthroplasty recommendations to improve surgical outcomes. Thus, the aim of this study was to describe risk factors for developing a post-operative infection in patients undergoing TJA of a large joint (total hip arthroplasty, total knee arthroplasty, or total shoulder arthroplasty) by identifying clinical and demographic factors, including the use of high-risk medications (i.e., prednisone and immunosuppressive medications) and diagnoses [i.e., rheumatoid arthritis (RA), osteoarthritis (OA), gout, obesity, and diabetes mellitus] that are linked to infection status, controlling for length of follow-up.

METHODS

A retrospective, case-control study (N = 2212) using de-identified patient health claims information from a commercially insured, U.S. dataset representing 15 million patients annually (from January 1, 2007 to December 31, 2009) was conducted. Descriptive statistics, t-test, chi-square test, Fisher's exact test, and multivariate logistic regression were used.

RESULTS

Male gender (OR = 1.42, p < 0.001), diagnosis of RA (OR = 1.47, p = 0.031), diabetes mellitus (OR = 1.38, p = 0.001), obesity (OR = 1.66, p < 0.001) or gout (OR = 1.95, p = 0.001), and a prescription for prednisone (OR = 1.59, p < 0.001) predicted a post-operative infection following total joint arthroplasty. Persons with post-operative joint infections were significantly more likely to be prescribed allopurinol (p = 0.002) and colchicine (p = 0.006); no significant difference was found for the use of specific disease-modifying anti-rheumatic drugs and TNF-α inhibitors.

CONCLUSION

High-risk, post-operative joint infection groups were identified allowing for precautionary clinical measures to be taken.

Incidence, Risk Factors, and Sources of Sepsis Following Total Joint Arthroplasty

BACKGROUND

Sepsis is a rare but serious complication following total joint arthroplasty (TJA). Common sources include urinary tract infection (UTI), surgical site infection (SSI), and pneumonia. The purpose of this study is to characterize the incidence, risk factors, and sources of sepsis following TJA.

METHODS

Patients undergoing primary total hip arthroplasty or total knee arthroplasty during 2005-2013 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Independent associations were tested for using multivariate regression adjusting for baseline characteristics.

RESULTS

A total of 117,935 patients were identified (45,612 undergoing total hip arthroplasty and 72,323 undergoing total knee arthroplasty). Of these, 402 (0.34%) developed sepsis following surgery. Patients who developed sepsis had an elevated mortality rate (3.7% vs 0.1%, P < .001). Among the 402 patients who developed sepsis, 124 (31%) had concomitant UTI, 110 (27%) SSI, and 60 (15%) pneumonia. Twenty-one patients (5%) had multiple infectious sources and 129 patients (32%) had no identifiable source. Independent risk factors for sepsis included greater age, male sex, functional dependence, insulin-dependent diabetes, hypertension, chronic obstructive pulmonary disease, current smoker, and greater operative time.

CONCLUSION

These findings suggest that the rate of sepsis following TJA is about 1 in 300, and that sepsis is associated with a high risk of mortality. The most common sources of sepsis are UTI, SSI, and pneumonia, potentially accounting for at least two-thirds of cases. The information provided here can be used to guide the diagnostic workup of sepsis in patients following TJA.

Risk Factors for Postoperative Urinary Tract Infections in Patients Undergoing Total Joint Arthroplasty

Background. Urinary tract infections (UTIs) are the most common minor complication following total joint arthroplasty (TJA) with incidence as high as 3.26%. Bladder catheterization is routinely used during TJA and the Centers for Medicare and Medicaid Services (CMS) has recently identified hospital-acquired catheter associated UTI as a target for quality improvement. This investigation seeks to identify specific risk factors for UTI in TJA patients. Methods. We retrospectively studied patients undergoing TJA for osteoarthritis between 2006 and 2013 in the American College of Surgeon's National Surgical Improvement Program Database (ACS-NSQIP). A univariate analysis screen followed by multivariate logistic regression identified specific patient demographics, comorbidities, preoperative laboratory values, and operative characteristics independently associated with postoperative UTI. Results. 1,239 (1.1%) of 115,630 TJA patients we identified experienced a postoperative UTI. The following characteristics are independently associated with postoperative UTI: female sex (OR 2.1, 95% CI 1.6–2.7), chronic steroid use (OR 2.0, 95% CI 1.2–3.2), ages 60–69 (OR 1.5, 95% CI 1.0–2.1), 70–79 (OR 2.0, 95% CI 1.4–2.9), and ≥80 (OR 2.3, 95% CI 1.5–3.6), ASA Classes 3–5 (OR 1.5, 95% CI 1.2–1.9), preoperative creatinine >1.35 (OR 1.8, 95% CI 1.3–2.6), and operation time greater than 130 minutes (OR 1.8, 95% CI 1.3–2.4). Conclusions. In this large database query, postoperative UTI occurs in 1.1% of patients following TJA and several variables including female sex, age greater than 60, and chronic steroid use are independent risk factors for occurrence. Practitioners should be aware of populations at greater risk to support efforts to comply with CMS initiated quality improvement.

Early Pulmonary Complications following Total Knee Arthroplasty under General Anesthesia: A Prospective Cohort Study Using CT Scan

Purpose. Postoperative pulmonary complications (PPCs) are common after major surgeries. However, the number of studies regarding PPCs following total knee arthroplasty (TKA) is limited. The aim of this study was to determine the incidence of early PPCs following TKA by computed tomography (CT) scan and to identify associated risk factors. Methods. Patients, who were diagnosed with osteoarthritis or rheumatoid arthritis and underwent primary TKA at our institution, were included in this prospective cohort study. Patients received a standard procedure of TKA under general anesthesia. Chest CT scan was performed during 5–7 days postoperatively. Univariate analysis and multivariate logistic regression analysis were employed to identify the risk factors. Results. The total incidence of early PPCs following TKA was 45.9%. Rates of pneumonia, pleural effusion, and atelectasis were 14.4%, 38.7%, and 12.6%, respectively. Lower body mass index and perioperative blood transfusion were independent risk factors for PPCs as a whole and associated with atelectasis. Postoperative acute episode of hypoxemia increased the risk of pneumonia. Blood transfusion alone was related to pleural effusion. Conclusions. The incidence of early PPCs following TKA was high. For patients with relevant risk factors, positive measures should be adopted to prevent PPCs.

Hyaluronic Acid Injections Are Associated with Delay of Total Knee Replacement Surgery in Patients with Knee Osteoarthritis: Evidence from a Large U.S. Health Claims Database

BACKGROUND

The growing prevalence of osteoarthritis (OA) and the medical costs associated with total knee replacement (TKR) surgery for end-stage OA motivate a search for agents that can delay OA progression. We test a hypothesis that hyaluronic acid (HA) injection is associated with delay of TKR in a dose-dependent manner.

METHODS AND FINDINGS

We retrospectively evaluated records in an administrative claims database of ~79 million patients, to identify all patients with knee OA who received TKR during a 6-year period. Only patients with continuous plan enrollment from diagnosis until TKR were included, so that complete medical records were available. OA diagnosis was the index event and we evaluated time-to-TKR as a function of the number of HA injections. The database included 182,022 patients with knee OA who had TKR; 50,349 (27.7%) of these patients were classified as HA Users, receiving ≥1 courses of HA prior to TKR, while 131,673 patients (72.3%) were HA Non-users prior to TKR, receiving no HA. Cox proportional hazards modelling shows that TKR risk decreases as a function of the number of HA injection courses, if patient age, gender, and disease comorbidity are used as background covariates. Multiple HA injections are therefore associated with delay of TKR (all, P < 0.0001). Half of HA Non-users had a TKR by 114 days post-diagnosis of knee OA, whereas half of HA Users had a TKR by 484 days post-diagnosis (χ2 = 19,769; p < 0.0001). Patients who received no HA had a mean time-to-TKR of 0.7 years; with one course of HA, the mean time to TKR was 1.4 years (χ2 = 13,725; p < 0.0001); patients who received ≥5 courses delayed TKR by 3.6 years (χ2 = 19,935; p < 0.0001).

CONCLUSIONS

HA injection in patients with knee OA is associated with a dose-dependent increase in time-to-TKR.

Burden of Surgical Site Infections Associated with Arthroplasty and the Contribution of Staphylococcus aureus

BACKGROUND

Patients undergoing arthroplasty are at considerable risk of experiencing post-operative complications, including surgical site infections (SSIs). In addition to potential economic consequences, SSIs can have a negative impact on patient outcomes and may potentially be life-threatening. Staphylococcus aureus has been consistently shown as the leading cause of SSIs associated with orthopedic surgery, with an important contribution from methicillin-resistant S. aureus (MRSA). This study evaluated the global burden of SSIs among patients undergoing orthopedic surgical procedures, and specifically those undergoing knee and hip arthroplasties.

METHODS

An extensive search of PubMed and recent conference proceedings was conducted. English articles published between 2003 and 2013 pertaining to SSI epidemiology, patient outcomes, and healthcare resource utilization and costs were reviewed.

RESULTS

Overall, 81 studies were included, mainly from North America and Europe. Median SSI and S. aureus SSI rates, calculated as percentage of all arthroplasty procedures, were 1.7% (range: 0.25%-4.4%; 15 studies) and 0.6% (range: 0.1%-23%), respectively. Median SSI rates were 1.3% (range: 0.05%-19%; 22 studies) after knee arthroplasty, and 2.1% (range: 0.05%-28%; 24 studies) after hip arthroplasty. S. aureus SSI rates ranged from 0.2%-2.4% and 0.18%-3.8% for patients undergoing knee and hip arthroplasty, respectively. The percentage of S. aureus SSIs because of MRSA varied widely within each patient category. SSI-related mortality data (14 studies) showed that in-hospital mortality rates were low (1.2%-2.5%), but increased with time after index arthroplasty procedure (up to 56% over 1 y). Studies assessing healthcare resource utilization (n = 21) revealed that developing post-orthopedic SSIs resulted in a two- to three-fold increase in length of hospital stay (LOS) compared with non-infected patients (median LOS: 18.9 d vs. 6 d for non-SSI patients). Patients with SSIs because of methicillin-resistant staphylococci incurred greater mean LOS compared with SSIs because of methicillin-sensitive organisms. Readmission rates reported in 11 studies indicate a greater likelihood in the presence of SSIs; comparison across studies was not feasible because of differences in data reporting. Consistent with increased healthcare resource utilization (LOS and readmission) associated with SSIs, cost studies (n = 23) revealed that the presence of SSIs was associated with up to three-fold cost increase compared with the absence of SSI across all orthopedic patient categories assessed.

CONCLUSIONS

SSIs are associated with increased morbidity, mortality rates, healthcare resource utilization, and costs. Despite the relatively low SSI incidence following orthopedic surgery and specifically arthroplasty, preventive methods, specifically those targeting S. aureus, would serve to minimize costs and improve patient outcomes.

Effect of Body Weight on Cefazolin and Vancomycin Trabecular Bone Concentrations in Patients Undergoing Total Joint Arthroplasty

BACKGROUND

Effective use of prophylactic antibiotics decreases the incidence of surgical site infections (SSIs) after total joint arthroplasty (TJA). The purpose of this prospective study was to determine the viability of weight-based dosing protocols for cefazolin and vancomycin to determine if appropriate minimum inhibitory concentrations (MIC) are met.

METHODS

Trabecular bone was harvested from discarded bone samples from 34 patients undergoing total knee arthroplasty (TKA) and total hip arthroplasty (THA). The cefazolin and vancomycin concentrations were determined in the trabecular bone using high-performance liquid chromatography.

RESULTS

No difference was noted in bone concentration with respect to patient weight for cefazolin. Regarding vancomycin, a substantial difference was noted in trabecular bone concentrations with respect to patient weight with lower body mass index (BMI) achieving greater concentrations. Using the current weight-based protocol of antibiotic prophylaxis, 84% and 87% of patients receiving vancomycin and cefazolin, respectively, achieved bone concentrations above the MIC.

CONCLUSIONS

Our assessment of trabecular concentration of cefazolin during TJA did not show any differences with respect to patient weight. However, vancomycin concentrations did show a difference with respect to BMI but this may be the result of the specific weight-based dosing protocol of vancomycin. Whereas the majority of cases were able to achieve adequate antibiotic concentrations in bone, further studies may be required to determine if increasing the pre-operative dosage of antibiotics is mandated given the findings of this pilot study.

Who leaves the hospital against medical advice in the orthopaedic setting?

BACKGROUND

Patients who leave the hospital against medical advice are at risk for readmission and for a variety of complications and are likely to consume more healthcare resources. However, little is known about which factors, if any, may be associated with self-discharge (discharge against medical advice) among orthopaedic inpatients.

QUESTIONS/PURPOSES

We studied the frequency and factors associated with self-discharge in patients hospitalized for orthopaedic trauma and musculoskeletal infection.

METHODS

Using discharge records from the Nationwide Inpatient Sample (2002-2011), we identified approximately 7,067,432 patient hospitalizations for orthopaedic trauma and 5,488,686 for musculoskeletal infection. We calculated the proportions of admissions that ended in self-discharge for both trauma and infection patients; then, we examined patient demographics, diagnoses, and hospital factors. Multivariable logistic regression models were constructed to determine independent predictors of self-discharge.

RESULTS

Approximately one in 333 (0.3%) patients hospitalized for an isolated fracture and one in 47 (2.1%) patients with musculoskeletal infection left against medical advice. Patient characteristics associated with self-discharge included age < 75 years (trauma: odds ratio [OR] 2.7, 95% confidence interval [CI] 2.5-2.8, p < 0.001; infection: OR 3.9, 95% CI 3.8-4.1, p < 0.001), male sex (trauma: OR 1.7, 95% CI 1.7-1.8, p < 0.001; infection: OR 1.4, 95% CI 1.3-1.4, p < 0.001), black race/ethnicity (trauma: OR 1.5, 95% CI 1.4-1.6, p < 0.001; infection: OR 1.1, 95% CI 1.1-1.1, p < 0.001), low household income (trauma: OR 1.5, 95% CI 1.4-1.5, p < 0.001; infection: OR 1.4, 95% CI 1.4-1.4, p < 0.001), nonprivate insurance (Medicare [trauma: OR 1.7, 95% CI 1.6-1.8, p < 0.001; infection: OR 2.5, 95% CI 2.4-2.5, p < 0.001] and Medicaid [trauma: OR 2.6, 95% CI 2.5-2.7, p < 0.001; infection: OR 3.2, 95% CI 3.2-3.3, p < 0.001]), and no insurance coverage (trauma: OR 3.0, 95% CI 2.9-3.1, p < 0.001; infection: OR 3.5, 95% CI 3.4-3.5, p < 0.001), less medical comorbidity (trauma: OR 0.94 per one-unit increase in the number of comorbidities, 95% CI 0.93-0.95, p < 0.001; infection: OR 0.88, 95% CI 0.87-0.88, p < 0.001), alcohol (trauma: OR, 2.3, 95% 2.2-2.4, p < 0.001; infection: OR 1.5, 95% CI 1.5-1.5, p < 0.001), opioid (trauma: OR 2.9, 95% CI 2.7-3.1, p < 0.001; infection: OR 4.4, 95% CI 4.3-4.4, p < 0.001) and nonopioid drug abuse (trauma: OR, 2.0, 95% CI 1.9-2.1, p < 0.001; infection: OR 2.8, 95% CI 2.8-2.9, p < 0.001), psychosis (trauma: OR 1.3, 95%CI 1.2-1.3, p < 0.001; infection: OR 1.3, 95% CI 1.3, 1.4, p < 0.001), and AIDS/HIV infection (trauma: OR 1.5, 95% CI 1.2-1.8, p < 0.001; infection: OR 1.3, 95% CI 1.3-1.4, p < 0.001). Patients with upper extremity fractures (OR 1.9, 95% CI 1.8-1.9, p < 0.001) or fractures of the neck and trunk (OR 2.1, 95% CI 2.0-2.2, p < 0.001) were more likely to leave against medical advice than patients with lower extremity fractures. Among infection hospitalizations, patients with cellulitis had the highest odds of self-discharge compared with carbuncle/furuncle (OR 1.3, 95% CI 1.2-1.5, p < 0.001). Self-discharges were more likely to occur at hospitals of larger size (trauma: OR 1.2, 95% CI 1.1-1.2, p < 0.001; infection: nonsignificant), located in urban settings (trauma: OR 1.3, 95% CI 1.2-1.4, p < 0.001; infection: OR 1.6, 95% CI 1.5-1.6, p < 0.001), and in the Northeast (trauma: OR 1.7, 95% CI 1.6-1.8, p < 0.001; infection: OR 1.6, 95% CI 1.6-1.6, p < 0.001) than at small, rural hospitals in the South.

CONCLUSIONS

Our data can be used to promptly identify orthopaedic inpatients at higher risk of self-discharge on admission and target interventions to optimize treatment adherence. Strategies to enhance physician communication skills among patients with low health literacy, improve cultural sensitivity, and proactively address substance abuse issues early during hospital admission may aid in preventing discharge dilemmas and merit additional study.

LEVEL OF EVIDENCE

Level III, prognostic study. See the Instructions for Authors for complete description of levels of evidence.

Association of perioperative blood transfusion and adverse events after operative treatment of proximal humerus fractures

BACKGROUND

The purpose of this study was to assess the relationship between perioperative blood transfusion for proximal humerus fracture and inpatient mortality, adverse events, prolonged hospital stay, and nonroutine disposition.

METHODS

Among the >55,000 patients with an operatively treated proximal humerus fracture identified in the Nationwide Inpatient Sample between 2008 and 2011, 17% received a perioperative blood transfusion. Multivariable logistic regression analyses addressed the association of blood transfusion with inpatient mortality, adverse events, hospital stay, and nonroutine discharge, accounting for comorbidities and other known confounders.

RESULTS

Perioperative blood transfusion for fracture of the proximal humerus was not associated with inhospital death, but it was independently associated with inpatient adverse events (odds ratio (OR) 4.4, 95% confidence interval (CI) 4.2-4.6), prolonged hospital stay (OR 2.8, 95% CI 2.7-2.9), and increased nonroutine discharge (OR 1.8, 95% CI 1.7-1.9).

CONCLUSIONS

Inpatients with fracture of the proximal humerus who receive transfusion are not more likely to die in hospital, but they do stay longer, experience more adverse events, and are less likely to be discharged home. Additional study is merited to determine if the judicious use of blood transfusion in the perioperative period can decrease inpatient morbidity and health-care resource utilisation.

LEVEL OF EVIDENCE

Level II, Retrospective Design, Prognosis Study.

Minorities are less likely to receive autologous blood transfusion for major elective orthopaedic surgery

BACKGROUND

Surgeons commonly arrange for patients to perform autologous blood donation before elective orthopaedic surgery. Understanding sociodemographic patterns of use of autologous blood transfusion can help improve quality of care and cost containment.

QUESTIONS/PURPOSES

We sought to determine whether there were (1) racial disparities, (2) insurance-based disparities, or (3) income-based disparities in autologous blood use. Additionally, we evaluated the combined effect of (4) race and insurance and (5) race and income on autologous blood use, and we compared ratios of autologous with allogeneic blood use.

METHODS

Of the more than 3,500,000 patients undergoing major elective orthopaedic surgery identified in the Nationwide Inpatient Sample between 2008 and 2011, 2.4% received autologous blood transfusion and 12% received allogeneic blood transfusion. Multivariable logistic regression was performed to determine the influence of race, insurance status, and income on autologous blood use.

RESULTS

Compared with white patients, Hispanic patients had lower odds of autologous blood use for elective hip (odds ratio [OR], 0.75; 95% CI, 0.69-0.82) and knee arthroplasties (OR, 0.71; 95% CI, 0.67-0.75). Black patients had lower odds of receiving autologous blood transfusion for hip arthroplasty (OR, 0.78; 95% CI, 0.74-0.83). Compared with the privately insured, uninsured and publicly insured patients were less likely to receive autologous blood for total joint arthroplasty and spinal fusion. Patients with low and medium income were less likely to have autologous blood transfusion for total joint arthroplasty and spinal fusion compared with high-level income earners. Even at comparable income and insurance levels with whites, Hispanic and black patients tended to be less likely to receive autologous blood transfusion. Ratios of autologous to allogeneic blood use were lower among minority patients.

CONCLUSIONS

Historically disadvantaged populations receive fewer autologous blood transfusions for elective orthopaedic surgery. Whether the differential use is attributable to patient preference or unequal access to this practice should be investigated further.

LEVEL OF EVIDENCE

Level II, prognostic study. See the Instructions for Authors for a complete description of levels of evidence.

Racial and insurance disparities in the utilization of supportive care after inpatient admission for proximal humerus fracture

BACKGROUND

Post-discharge supportive services such as home health assistance and rehabilitation or skilled nursing facilities are often utilized after inpatient care for fracture of the proximal humerus. It is unclear whether sociodemographic disparities exist in the utilization of post-hospital supportive care. The present study aimed to evaluate the individual and combined effects of race and insurance status on the utilization of supportive services after hospital admission for fracture of the proximal humerus.

METHODS

Among the more than 40,000 patients with a proximal humerus fracture identified in the Nationwide Inpatient Sample (2008 to 2011), 85% were white, 7.7% were Hispanic and 7.0% were black. More black patients (19%) and Hispanic patients (15%) were uninsured compared to white patients (8.7%). Multivariable logistic regression was performed to determine the effect of race/ethnicity and insurance status on the utilization of post-hospital supportive care.

RESULTS

Sixty-nine percent of patients were discharged home, 13% went to home health care and 15% went to rehabilitation or skilled nursing facilities. Compared to white patients, Hispanic patients [odds ratio (OR) = 0.71; 95% confidence interval (CI) = 0.64 to 0.79] and black patients (OR = 0.79; 95% CI = 0.71 to 0.88) exhibited lower odds for the utilization of specialized post-hospital supportive services. Uninsured patients were significantly less likely to use post-discharge supportive services (OR = 0.38; 95% CI = 0.33 to 0.42) compared to privately insured patients. Even when insured at levels comparable to whites, Hispanic and black patients tended to experience decreased rates of discharge to post-acute supportive care.

CONCLUSIONS

The utilization of post-hospital supportive services varies by race, ethnicity and insurance status after an inpatient admission for proximal humerus fracture.

Focused risk analysis: regression model based on 5,314 total hip and knee arthroplasty patients from a single institution

We aimed to identify significant demographic, preoperative comorbidity and surgical predictors for major complications for use in the development of a risk prediction tool for a well-defined population as Total Joint Arthroplasty (TJA) patients. Data on 5314 consecutive patients who underwent primary total hip or knee arthroplasty from October 1, 2008 through September 30, 2011 at a single institution were used in a multivariate regression analysis. The overall incidence of a primary endpoint (reoperation during same admission, extended length of stay, and 30-day readmission) was 3.8%. Significant predictors include certain preexisting genitourinary, circulatory and respiratory conditions; ASA>2; advanced age and prolonged operating time. Mental health conditions demonstrate a strong predictive effect for subsequent serious complication(s) in TJA patients and should be included in a risk-adjustment tool.

Risk factors for surgical site infection following total joint arthroplasty

BACKGROUND

Currently, most hospitals in the United States are obliged to report infections that occur following total joint arthroplasty to the Centers for Disease Control and Prevention through the National Healthcare Safety Network surveillance. The objective of this study was to identify the risk factors of surgical site infections that were reported to the Centers for Disease Control and Prevention from a single institution.

METHODS

For this study, 6111 primary and revision total joint arthroplasties performed from April 2010 to June 2012 were identified. Surgical site infection cases captured by infection surveillance staff on the basis of the Centers for Disease Control and Prevention definition were identified. Surgical site infection cases with index surgery performed at another institution were excluded. All cases were followed up for one year for development of surgical site infection. The model for predictors of surgical site infection was created by logistic regression and was validated by bootstrap resampling.

RESULTS

Of all performed total joint arthroplasties, surgical site infection developed in eighty cases (1.31% [95% confidence interval, 1.02% to 1.59%]). The highest rate of surgical site infection was observed in revision total knee arthroplasty (4.57% [95% confidence interval, 2.31% to 6.83%]) followed by revision total hip arthroplasty (1.94% [95% confidence interval, 0.75% to 3.13%]). Among the variables examined, the predictive factors of surgical site infection were higher Charlson Comorbidity Index (odds ratio for a Charlson Comorbidity Index of ≥ 2, 2.29 [95% confidence interval, 1.32 to 3.94] and odds ratio for a Charlson Comorbidity Index of 1, 2.09 [95% confidence interval, 1.06 to 4.10]), male sex (odds ratio, 1.79 [95% confidence interval, 1.11 to 2.89]), and revision total knee arthroplasty (odds ratio, 3.13 [95% confidence interval, 1.17 to 8.34]), and a higher level of preoperative hemoglobin (odds ratio, 0.85 per point [95% confidence interval, 0.73 to 0.98 per point]) was protective against surgical site infection. The C-statistic of the model was 0.709 without correction and 0.678 after bootstrap correction, indicating that the model has fair predictive power.

CONCLUSIONS

Low preoperative hemoglobin level is one of the risk factors for surgical site infection and preoperative correction of hemoglobin may reduce the likelihood of postoperative surgical site infection.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Does the timing of surgery for proximal humeral fracture affect inpatient outcomes?

BACKGROUND

Delayed surgical treatment of hip fractures is associated with adverse medical outcomes, but it is unclear whether the same is true for proximal humeral fractures. The purpose of this study was to evaluate the relationship between surgical delay for proximal humeral fracture and inpatient adverse events, in-hospital death, prolonged postoperative stay, and nonroutine discharge.

METHODS

Of the more than 70,000 patients with an operatively treated proximal humeral fracture identified in the Nationwide Inpatient Sample between 2008 and 2011, 87% underwent surgery within 2 days of admission and 13% underwent surgery 3 days or more after admission. Multivariable logistic regression analyses were performed to evaluate the effect of surgical delay on inpatient outcomes and to identify risk factors associated with late surgery.

RESULTS

Surgery 3 days or more after admission for fracture of the proximal humerus had no influence on in-hospital death but was independently associated with inpatient adverse events (odds ratio [OR], 2.1; 95% confidence interval [CI], 2.0-2.2), prolonged postoperative stay (OR, 1.7; 95% CI, 1.7-1.9), and increased nonroutine discharge (OR, 2.7; 95% CI, 2.6-2.9). Risk factors for surgery 3 days or more after admission included advanced age, male sex, Elixhauser comorbidity score, polytrauma, Hispanic race or black race, no insurance coverage, low household income, and weekend admission.

CONCLUSIONS

Even when comorbidities and complexity are controlled for, delaying surgery for proximal humeral fracture is likely to increase inpatient morbidity, postoperative length of stay, and nonroutine discharge. It appears that avoiding nonmedical delays is advantageous.

A nationwide analysis of risk factors for in-hospital myocardial infarction after total joint arthroplasty

PURPOSE

Despite acute myocardial infarction (AMI) being a feared medical complication and currently a major cause of death after total hip and knee arthroplasty (THA/TKA), little is known about its peri-operative associated factors.

METHODS

Data for this retrospective cohort study were extracted from the Nationwide Inpatient Sample for 2008-2011. Multivariate logistic regression modeling was performed to determine peri-operative factors associated with the development of inpatient AMI following THA/TKA.

RESULTS

An estimated 3,096,791 procedures were identified. Perioperative AMI rates were 0.25 % for THA and 0.18 % for TKA. Patients with AMI had significantly greater comorbidity burden, higher peri-operative mortality rates, longer length of hospital stay and increased complication rates. Independent risk factors for the development of AMI comprised advance age, male gender [odds ratio (OR) 1.4, 95 % confidence interval (CI) 1.4-1.5], THA surgery (OR 1.3, 95 % CI 1.3-1.4), low household income (OR 1.3, 95 % CI 1.2-1.4), history of cardiac disease (coronary artery disease: OR 4.9, 95 % CI 4.6-5.2; congestive heart failure: OR 2.6, 95 % CI 2.4-2.8; valvular disease: OR 1.2, 95 % CI 1.1-1.3), diabetes (OR 1.1, 95 % CI 1.1-1.2), pulmonary circulation disorders (OR 1.4, 95 % CI 1.2-1.6), cerebrovascular disease (OR 2.3, 95 % CI 2.0-2.6), peripheral vascular disorders (OR 1.5, 95 % CI 1.4-1.7), coagulopathy (OR 1.4, 95 % CI 1.2-1.5), AIDS/HIV infection (OR 7.9, 95 % CI 4.5-13.9), deficiency anaemia (OR 1.4, 95 % CI 1.3-1.5), fluid and electrolyte disorders (OR 1.9, 95 % CI 1.8-2.0) and the occurrence of concomitant postoperative complications.

CONCLUSION

Our findings can be used to better identify patients at high risk of AMI and to develop strategies aimed at diminishing its incidence, which could in turn translate to improved hospital efficiency and quality of care.

Antibacterial surface treatment for orthopaedic implants

It is expected that the projected increased usage of implantable devices in medicine will result in a natural rise in the number of infections related to these cases. Some patients are unable to autonomously prevent formation of biofilm on implant surfaces. Suppression of the local peri-implant immune response is an important contributory factor. Substantial avascular scar tissue encountered during revision joint replacement surgery places these cases at an especially high risk of periprosthetic joint infection. A critical pathogenic event in the process of biofilm formation is bacterial adhesion. Prevention of biomaterial-associated infections should be concurrently focused on at least two targets: inhibition of biofilm formation and minimizing local immune response suppression. Current knowledge of antimicrobial surface treatments suitable for prevention of prosthetic joint infection is reviewed. Several surface treatment modalities have been proposed. Minimizing bacterial adhesion, biofilm formation inhibition, and bactericidal approaches are discussed. The ultimate anti-infective surface should be “smart” and responsive to even the lowest bacterial load. While research in this field is promising, there appears to be a great discrepancy between proposed and clinically implemented strategies, and there is urgent need for translational science focusing on this topic.