Surgical Site Infection After Arthroplasty: Comparative Effectiveness of Prophylactic Antibiotics: Do Surgical Care Improvement Project Guidelines Need to Be Updated?

Surgical prophylaxis in pediatric orthopedic patients with penicillin allergy: a multicentered retrospective prognostic study

Up to 20% of orthopedic surgeons still avoid the use of cephalosporins in patients with penicillin allergies despite its reported safety in the adult and general surgery pediatric population. The primary objective is to determine the incidence of adverse effects and allergic reactions when using cephalosporins in pediatric orthopedic patients labeled as penicillin-allergic as compared to those without previously reported penicillin allergy. A multicenter retrospective chart review was performed across three level 1 trauma centers from January 2013 to February 2020 to identify penicillin-allergic as well as non-penicillin-allergic pediatric patients treated for orthopedic injuries. Data were collected regarding patient demographics, antibiotic administered, timing of antibiotic administration, reported drug allergy, and described allergic reaction. Postoperative or intraoperative allergic reactions to antibiotics, surgical site infections, and complications were recorded. A total of 2289 surgeries performed by four fellowship-trained surgeons were evaluated. Eighty-five patients diagnosed with penicillin allergy were identified and underwent 95 surgeries and 95 patients without previously reported penicillin allergy underwent 95 surgeries. One patient, with a documented history of anaphylaxis to cefazolin, sustained an anaphylactic reaction intraoperatively to cefazolin. There were no other reported reactions, surgical site infections, or complications. There was no statistically significant difference in rate of allergic reaction in patients with previously reported penicillin allergy treated with cefazolin and those with no previous reported reaction ( P > 0.05). Prophylaxis with cephalosporins is not associated with increased risk for allergic reaction. Cephalosporins can be safely administered to pediatric patients with penicillin allergy undergoing orthopedic intervention. Level of evidence: Level II, Multicenter Retrospective Prognostic Study.

Additional doses of prophylactic antibiotics post-arthroplasty: Are there any benefits?

Guidelines for prophylactic antibiotic administration in total joint replacement vary considerably in terms of drug, dosage, route of administration and duration of cover. Despite the range of treatment options available, infection remains the most common reason for arthroplasty failure in the decades following a procedure, simultaneously increasing health care costs and lowering patient satisfaction considerably. This work aims to evaluate whether there are benefits to administering further doses of antibiotic post-arthroplasty, in addition to the recommendations of current protocols. We present a review of evidence surrounding infection rates in a variety of prophylactic regimens, and weigh this against further considerations such as cost to the patient and risks of nephrotoxicity. In summary, the available evidence does not suggest a benefit to administering additional doses post-arthroplasty in most cases. However, further doses may benefit those deemed at high risk of infection, or those in areas of high methicillin-resistant Staphylococcus aureus prevalence.

Is Penicillin Allergy a Clinical Problem? A Systematic Review of Total Joint Arthroplasty Procedures With Implications for Patient Safety and Antibiotic Stewardship

BACKGROUND

Patients undergoing total joint arthroplasty (TJA) who report penicillin allergy (PA) are frequently administered second-line antibiotics, although recent evidence suggests that this may be unnecessary and could increase infection risk. Many institutions have aimed to improve antibiotic deployment via allergy testing and screening; however, there is little standardization to this process. This review aimed to evaluate (1) antibiotic selection in patients who report PA and assess the impact of screening and testing interventions, (2) rates of allergic reactions in patients who report PA, and (3) the association between reported PA and screening or testing programs and odds of surgical site infection or periprosthetic joint infection.

METHODS

PubMed, EBSCOhost, and Google Scholar electronic databases were searched on February 4, 2023 to identify all studies published since January 1, 2000 that evaluated the impact of PA on patients undergoing TJA (PROSPERO study protocol registration: CRD42023394031). Articles were included if full-text manuscripts in English were available, and the study analyzed the impact of PA and related interventions on TJA patients. There were 11 studies evaluating 1,276,663 patients included. Interventions were compared via presentation of key findings regarding rates of clinically relevant or high-risk PA reported upon screenings or testings, cephalosporin utilizations, allergic reactions, and postoperative infections (surgical site infection and periprosthetic joint infection).

RESULTS

All 6 studies found that PA screening and testing markedly increase the use of first-line antibiotics. Testing showed low rates of true allergy (0.7 to 3%) and allergic reaction frequency for patients who have reported PA receiving cephalosporins was between 0% and 2%. Although there were mixed findings across studies, there was a trend toward second-line antibiotic prophylaxis being associated with a slightly higher rate of infection in PA patients.

CONCLUSIONS

Using PA screening and testing can promote antibiotic stewardship by safely increasing the use of first-line antibiotics in patients who have a reported PA.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

[Intraosseous vancomycin in total knee arthroplasty]

INTRODUCTION

intravenous antibiotic prophylaxis has significantly reduced the incidence of periprosthetic joint infection (PJI) in knee surgeries. However, for patients colonized with methicillin-resistant Staphylococcus aureus (MRSA) or those at risk of colonization, prophylaxis should include vancomycin. Intraosseous (IO) administration of vancomycin could enhance its effectiveness in total knee arthroplasty (TKA).

MATERIAL AND METHODS

a retrospective review was conducted, including 143 patients at risk of PJI scheduled for TKA who received IO vancomycin along with intravenous (IV) cefazolin, referred to as group I (GI), between May 2021 and December 2022. The occurrence of complications in the first three postoperative months was evaluated. Results were compared with 140 patients without risk factors who received standard IV prophylaxis, designated as group II (GII).

RESULTS

in GI, 500 mg of IO vancomycin was administered, injected into the proximal tibia, in addition to standard IV prophylaxis. In GII, patients received only IV cefazolin. The incidence of complications was 1.64% in GI and 1.4% in GII. The PJI rate at 90 postoperative days was 0.69% in GI and 0.71% in GII.

CONCLUSIONS

IO vancomycin administration, along with standard IV prophylaxis, provides a safe and effective alternative for patients at risk of MRSA colonization. This approach minimizes complications associated with IV vancomycin use and addresses logistical challenges of timely administration.

Addition of vancomycin to cefazolin is often unnecessary for preoperative antibiotic prophylaxis during total joint arthroplasties

PURPOSE

The gold standard to decrease total joint arthroplasty (TJA) periprosthetic joint infection (PJI) is preoperative antibiotic prophylaxis. Despite substantial prevention efforts, rates of PJIs are increasing. While cefazolin is the drug of choice for preoperative prophylaxis, adjunctive vancomycin therapy has been used in methicillin-resistant Staphylococcus aureus (MRSA) endemic areas. However, studies examining these combinations are lacking. Therefore, we sought to examine complications among vancomycin plus cefazolin and cefazolin-only recipients prior to primary TJA in a single institutional sample and specifically assessed: (1) microbiological aspects, including periprosthetic joint and surgical site infections, microbes cultured from the infection, and frequency of microbes cultured from nasal swab screening; (2) 30-day emergency department (ED) visits and re-admissions; as well as (3) associated risk factors for infection.

METHODS

A total of 2,907 patients (1,437 receiving both cefazolin and vancomycin and 1,470 given cefazolin only) who underwent primary TJA between 1 January 2014 and 31 May 2021 were identified. SSI and PJI as well as rates of cultured microbes rates were obtained through one year, those with prior nasal swab screening and 30-day re-admission were identified. Subsequently, multiple regression analyses were performed to investigate potential independent risk factors for PJIs.

RESULTS

There was no significant difference in the rates of SSI (P = 0.089) and PJI (P = 0.279) between the groups at one year after operation. Commonly identified organisms included Staphylococcus and Streptococcus species. The VC cohort did have a greater reduction of MRSA in the previously nasal swab-screened subset of patients. Multiple regression analyses demonstrated emergency as well as inpatient admissions as risk factors for PJI.

CONCLUSIONS

Adjunctive vancomycin therapy offers increased protection against MRSA in previously screened individuals. However, those negative for MRSA screening do not require vancomycin and have similar protection to infection compared to recipients of cefazolin only in a high-powered single institution analysis in an MRSA endemic area.

Association between preoperative hemoglobin with length of hospital stay among non-cardiac and non-obstetric surgery patients: a secondary analysis of a retrospective cohort study

BACKGROUND

Previous studies concerning the association between preoperative Hemoglobin (HB) level and the Length Of hospital Stay (LOS) in patients with non-cardiac surgery and non-obstetric surgery remain inconclusive. Herein, the objective of this study was to analyze whether and to what extent the preoperative HB level was connected with the LOS in non-cardiac and non-obstetric surgery patients.

METHODS

This retrospective cohort study was performed at a single institution, involving patients who underwent elective non-cardiac, non-obstetric surgery from April 2007 to September 2013. Clinical characteristics of patients such as demographics, comorbidities, preoperative HB level, LOS, mortality, procedure length, and pulmonary hypertension (PHTN) Severity Class data were collected. A univariate analysis was used to determine the association between clinical characteristics and LOS. Multivariate regression analysis was conducted to investigate the relationship between preoperative HB level and LOS.

RESULTS AND DISCUSSION

In this study, 311 patients were included. We observed that compared with the LOS > 7 days group, the average HB level of patients in the LOS ≤ 7 days group was higher (12.04 ± 2.20 g/dl vs. 10.92 ± 2.22 g/dl, p < 0.001). In addition, there were fewer patients with moderate-to-severe anemia in LOS ≤ 7 days group than the LOS > 7 days group (32.74% vs 58.82%, p < 0.001). In addition, we found that patients with LOS ≤ 7 days were accompanied with lower mortality (0.44% vs. 7.06%, p < 0.001) and lower mean combined pulmonary artery systolic pressure (PASP) and right ventricular systolic pressure (RVSP) than that in patients with LOS > 7 days (42.56 ± 11.97 vs. 46.00 ± 12.37, p < 0.05). After controlling for relevant confounders, we discovered a nonlinear association between preoperative HB level and LOS as well as a threshold effect based on LOS. Specifically, when preoperative HB level was less than 11.9 g/dL, LOS decreased by 2 days for each 1 g/dL increase in HB level. However, LOS did not alter substantially with the rise of preoperative HB level when it was higher than 11.9 g/dL.

CONCLUSION

Our study showed a close non-linear association between preoperative HB level and LOS in patients with non-cardiac surgery and non-obstetric surgery. In particular, for patients with preoperative HB less than 11.9 g/dL, increasing the preoperative HB level can help shorten the LOS after operation.

Acetabular fractures in elderly patients are associated with high rates of complications during the initial admission

Background

Acetabular fractures among the elderly are common. Identification of risk factors predisposing elderly patients to in-hospital complications is critical to mitigating morbidity and mortality.

Methods

A retrospective cohort study was performed including 195 patients ≥60 years old who sustained acetabulum fractures treated at a single level 1 trauma center. Operative (n=110, 56.4%) or non-operative management was undertaken, and complications during the index hospitalization were defined.

Results

Seventy-three patients (37%) developed a complication during their hospitalization. Most common complications were acute respiratory failure: 13.3%, pneumonia: 10.3%, urinary tract infection: 10.3%, cardiac dysrhythmia: 9.7%, and acute kidney injury: 6.2%. On multivariable analysis, factors associated with in-hospital complications were increased age (adjusted OR (AOR): 1.06, 95% CI: 1.01 to 1.11, p=0.013), more comorbidities (AOR: 1.69, 95% CI: 1.07 to 2.65, p=0.024), operative management (AOR: 0.3, 95% CI: 0.12 to 0.76, p=0.011), and increased length of stay (AOR: 1.34, 95% CI: 1.2 to 1.51, p<0.001).

Conclusions

Acetabular fractures in the elderly are associated with high rates of in-hospital complications. Advanced age, more medical comorbidities and longer lengths of stay predicted higher risk of developing complications. Whereas operative management was associated with lower risk of developing complications during the initial admission, it is important to note the selection bias in which healthier patients with improved baseline functionality may be more likely to undergo operative management.

Level of evidence

Level III therapeutic.

Trial of Vancomycin and Cefazolin as Surgical Prophylaxis in Arthroplasty

BACKGROUND

The addition of vancomycin to beta-lactam prophylaxis in arthroplasty may reduce surgical-site infections; however, the efficacy and safety are unclear.

METHODS

In this multicenter, double-blind, superiority, placebo-controlled trial, we randomly assigned adult patients without known methicillin-resistant Staphylococcus aureus (MRSA) colonization who were undergoing arthroplasty to receive 1.5 g of vancomycin or normal saline placebo, in addition to cefazolin prophylaxis. The primary outcome was surgical-site infection within 90 days after surgery.

RESULTS

A total of 4239 patients underwent randomization. Among 4113 patients in the modified intention-to-treat population (2233 undergoing knee arthroplasty, 1850 undergoing hip arthroplasty, and 30 undergoing shoulder arthroplasty), surgical-site infections occurred in 91 of 2044 patients (4.5%) in the vancomycin group and in 72 of 2069 patients (3.5%) in the placebo group (relative risk, 1.28; 95% confidence interval [CI], 0.94 to 1.73; P = 0.11). Among patients undergoing knee arthroplasty, surgical-site infections occurred in 63 of 1109 patients (5.7%) in the vancomyin group and in 42 of 1124 patients (3.7%) in the placebo group (relative risk, 1.52; 95% CI, 1.04 to 2.23). Among patients undergoing hip arthroplasty, surgical-site infections occurred in 28 of 920 patients (3.0%) in the vancomyin group and in 29 of 930 patients (3.1%) in the placebo group (relative risk, 0.98; 95% CI, 0.59 to 1.63). Adverse events occurred in 35 of 2010 patients (1.7%) in the vancomycin group and in 35 of 2030 patients (1.7%) in the placebo group, including hypersensitivity reactions in 24 of 2010 patients (1.2%) and 11 of 2030 patients (0.5%), respectively (relative risk, 2.20; 95% CI, 1.08 to 4.49), and acute kidney injury in 42 of 2010 patients (2.1%) and 74 of 2030 patients (3.6%), respectively (relative risk, 0.57; 95% CI, 0.39 to 0.83).

CONCLUSIONS

The addition of vancomycin to cefazolin prophylaxis was not superior to placebo for the prevention of surgical-site infections in arthroplasty among patients without known MRSA colonization. (Funded by the Australian National Health and Medical Research Council; Australian New Zealand Clinical Trials Registry number, ACTRN12618000642280.).

Challenges and opportunities related to penicillin allergy in the Veterans Health Administration: a narrative review

The presence of a penicillin allergy label in a patient's medical chart is associated with negative clinical and economic outcomes. Given that less than 10% of reported reactions are truly immunoglobulin E-mediated, removal of unverified penicillin allergy labels is a public health priority and an area of ongoing implementation research. The Veterans Health Administration (VHA) is the largest integrated healthcare system in the United States, with almost 9 million veterans currently enrolled. However, studies analyzing the impact of the penicillin allergy label in this population are limited to single facilities and largely focus on short-term outcomes of allergy documentation correction, usage of β-lactams, and avoidance of antibiotic-related side effects. Broader, national VHA studies focusing on health outcomes and costs are lacking. As with non-VHA facilities, penicillin allergy evaluations are limited owing to the absence of formal allergy/immunology services at most VHA facilities. Pharmacy-driven screening and referral for clinic-based penicillin skin testing is a promising and frequently discussed modality in the literature, but its scalability within the VHA is not yet proven. Broader, evidence-based strategies that can be adapted to the available resources of individual VHA facilities, including those without on-site access to allergy providers, are needed.

Implementation of a Prevention Bundle to Decrease Rates of Staphylococcus aureus Surgical Site Infection at 11 Veterans Affairs Hospitals

Importance

While current evidence has demonstrated a surgical site infection (SSI) prevention bundle consisting of preoperative Staphylococcus aureus screening, nasal and skin decolonization, and use of appropriate perioperative antibiotic based on screening results can decrease rates of SSI caused by S aureus, it is well known that interventions may need to be modified to address facility-level factors.

Objective

To assess the association between implementation of an SSI prevention bundle allowing for facility discretion regarding specific component interventions and S aureus deep incisional or organ space SSI rates.

Design, Setting, and Participants

This quality improvement study was conducted among all patients who underwent coronary artery bypass grafting, cardiac valve replacement, or total joint arthroplasty (TJA) at 11 Veterans Administration hospitals. Implementation of the bundle was on a rolling basis with the earliest implementation occurring in April 2012 and the latest implementation occurring in July 2017. Data were collected from January 2007 to March 2018 and analyzed from October 2020 to June 2023.

Interventions

Nasal screening for S aureus; nasal decolonization of S aureus carriers; chlorhexidine bathing; and appropriate perioperative antibiotic prophylaxis according to S aureus carrier status. Facility discretion regarding how to implement the bundle components was allowed.

Main Outcomes and Measures

The primary outcome was deep incisional or organ space SSI caused by S aureus. Multivariable logistic regression with generalized estimating equation (GEE) and interrupted time-series (ITS) models were used to compare SSI rates between preintervention and postintervention periods.

Results

Among 6696 cardiac surgical procedures and 16 309 TJAs, 95 S aureus deep incisional or organ space SSIs were detected (25 after cardiac operations and 70 after TJAs). While the GEE model suggested a significant association between the intervention and decreased SSI rates after TJAs (adjusted odds ratio, 0.55; 95% CI, 0.31-0.98), there was not a significant association when an ITS model was used (adjusted incidence rate ratio, 0.88; 95% CI, 0.32-2.39). No significant associations after cardiac operations were found.

Conclusions and Relevance

Although this quality improvement study suggests an association between implementation of an SSI prevention bundle and decreased S aureus deep incisional or organ space SSI rates after TJAs, it was underpowered to see a significant difference when accounting for changes over time.

Effect of non-cephalosporin antibiotic prophylaxis on the risk of periprosthetic joint infection after total joint replacement surgery: a retrospective study with a 1-year follow-up

Background

Cephalosporins are recommended as first-line antibiotic prophylaxis in total joint replacement surgery. Studies have shown an increased risk for periprosthetic joint infection (PJI) when non-cephalosporin antibiotics have been used. This study examines the effect of non-cephalosporin antibiotic prophylaxis on the risk for PJI.

Methods

Patients with a primary hip or knee replacement performed from 2012 to 2020 were identified (27 220 joint replacements). The primary outcome was the occurrence of a PJI in a one-year follow-up. The association between perioperative antibiotic prophylaxis and the outcome was examined using logistic regression analysis.

Discussion

Cefuroxime was used as prophylaxis in 26,467 operations (97.2%), clindamycin in 654 (2.4%) and vancomycin in 72 (0.3%). The incidence of PJI was 0.86% (228/26,467) with cefuroxime and 0.80% (6/753) with other prophylactic antibiotics. There was no difference in the risk for PJI with different prophylactic antibiotics in the univariate (OR 1.06, 95% CI 0.47-2.39) or multivariable analysis (OR 1.02, 95% CI 0.45-2.30).

Conclusion

Non-cephalosporin antibiotic prophylaxis in primary total joint replacement surgery was not associated with an increased risk for PJI.

When intravenous vancomycin prophylaxis is needed in shoulder arthroplasty, incomplete administration is associated with increased infectious complications

BACKGROUND

Vancomycin is often used as antimicrobial prophylaxis for shoulder arthroplasty (SA) either when first generation cephalosporins are contraindicated or colonization with resistant bacteria is anticipated. In general, vancomycin necessitates longer infusion times to mitigate potential side effects. When infusion is started too close to the time of the incision, administration may not be complete during surgery. This study evaluated whether incomplete administration of intravenous vancomycin prior to SA affects the rate of infectious complications.

METHODS

Between 2000 and 2019, all primary SA types (hemiarthroplasty, anatomic total SA, reverse SA) performed at a single institution for elective and trauma indications using intravenous vancomycin as the primary antibiotic prophylaxis and a minimum follow-up of 2 yr were identified. The time between the initiation of vancomycin and skin incision was calculated. Complete administration was defined as at least 30 min of infusion prior to incision. Demographic characteristics and infectious complications including survival free of prosthetic joint infection (PJI) were generated. Multivariable analyses were conducted to evaluate the association between vancomycin timing and the development of PJI.

RESULTS

A total of 461 primary SAs were included. Infusion was incomplete (< 30 minutes preoperatively) for 163 [35.4%] SA and complete (> 30 minutes preoperatively) for 298 [64.6%] SAs. The incomplete group demonstrated higher rates of any infectious complication (8% vs. 2.3%; P = .005), PJI (5.5% vs. 1%; P = .004), and reoperation inclusive of revision due to infectious complications (4.9% vs. 1%; P = .009). Survivorship free of PJI was worse in SA with incomplete compared to those with complete vancomycin administration. Survival rates for incomplete and complete administration were 97.6% and 99.3% at 1 mo, 95.7% and 99.0% at 2 yr, 95.1% and 99.0% at 5 yr, and 93.9% and 99.0% at 20 yr, respectively (P = .006). Multivariable analyses confirmed that incomplete vancomycin administration was an independent risk factor for PJI compared with complete administration (hazard ratio, 4.22 [95% confidence interval, 1.12-15.90]; P = .033), even when other independent predictors of PJI (age, male sex, prior surgery, methicillin-resistant Staphylococcus aureus colonization, and follow-up) were considered.

CONCLUSIONS

When vancomycin is the primary prophylactic agent used at the time of primary SA, incomplete administration (infusion to incision time under 30 min) seems to adversely increase the rates of infectious complications and PJI. Prophylaxis protocols should ensure that complete vancomycin administration is achieved to minimize infection after SA.

Impact of Penicillin Allergy-Based Alternative Antibiotics on the Risk of Postoperative Central Nervous System Infection: A Retrospective Cohort Study

BACKGROUND

Central nervous system (CNS) infection is one of the most serious complications after neurosurgery. This study aimed to analyze the effect of penicillin allergy (PA) and alternative prophylactic antibiotics on risk of postoperative CNS infection in patients undergoing neurosurgery.

METHODS

Data of patients who underwent neurosurgical procedures from January 2015 to December 2021 were analyzed retrospectively. Patients with PA were compared with patients without PA in a 1:1 ratio. A multivariate logistic regression model was used to examine whether PA was a risk factor for postoperative CNS infection.

RESULTS

Overall, 15,049 eligible neurosurgical records were reviewed, from which 578 surgical records of 556 patients with PA were matched to 578 records of 570 patients without PA. Patients with PA showed significantly lower probability to receive prophylactic cephalosporins (55.9% vs. 98.8%, P < 0.01), but significantly higher probability to receive clindamycin (41.86% vs. 1.03%, P < 0.01), than patients without PA. Multivariate analysis revealed that patients with PA were more likely to experience postoperative CNS infection than patients without PA (odds ratio = 2.03; 95% confidence interval, 1.15-3.56; P = 0.014). The incidence of postoperative CNS infection returned to a level comparable to that in general population when patients with suspected PA received prophylactic cephalosporins.

CONCLUSIONS

PA is associated with higher risk of postoperative CNS infection in patients undergoing neurosurgery. This may be attributed to the use of alternative prophylactic antibiotics other than cephalosporins, especially clindamycin.

The association between penicillin allergy and surgical site infection after orthopedic surgeries: a retrospective cohort study

Background

Cephalosporins are used as first-line antimicrobial prophylaxis for orthopedics surgeries. However, alternative antibiotics are usually used in the presence of penicillin allergy (PA), which might increase the risk of surgical site infection (SSI). This study aimed to analyze the relationship between SSI after orthopedic surgeries and PA among surgical candidates and related alternative antibiotic use.

Methods

In this single-center retrospective cohort study, we compared inpatients with and without PA from January 2015 to December 2021. The primary outcome was SSI, and the secondary outcomes were SSI sites and perioperative antibiotic use. Moreover, pathogen characteristics of all SSIs were also compared between the two cohorts.

Results

Among the 20,022 inpatient records, 1704 (8.51%) were identified with PA, and a total of 111 (0.55%) SSI incidents were reported. Compared to patients without PA, patients with PA had higher postoperative SSI risk (1.06%, 18/1704 vs. 0.51%, 93/18318), shown both in multivariable regression analysis (odds ratio [OR] 2.11; 95% confidence interval [CI], 1.26-3.50; p= 0.004) and propensity score matching (OR 1.84; 95% CI, 1.05-3.23; p= 0.034). PA was related to elevated deep SSI risk (OR 2.79; 95% CI, 1.47-5.30; p= 0.002) and had no significant impact on superficial SSI (OR 1.39; 95% CI, 0.59-3.29; p= 0.449). The PA group used significantly more alternative antibiotics. Complete mediation effect of alternative antibiotics on SSI among these patients was found in mediation analysis. Pathogen analysis revealed gram-positive cocci as the most common pathogen for SSI in our study cohort, while patients with PA had higher infection rate from gram-positive rods and gram-negative rods than non-PA group.

Conclusion

Compared to patients without PA, patients with PA developed more SSI after orthopedic surgeries, especially deep SSI. The elevated infection rate could be secondary to the use of alternative prophylactic antibiotics.

Peri-Prosthetic Joint Infection in Patients Prescribed Suppressive Antibiotic Therapy Undergoing Primary Total Joint Arthroplasty: A 1:4 Case Control Matched Study

Background: Oral suppressive antibiotic therapy (SAT) has emerged as a potential means to increase rates of infection-free survival in many complex peri-prosthetic joint infection (PJI) cases after total joint arthroplasty (TJA). The purpose of the present study is to evaluate the risk of PJI of a new primary TJA in patients on oral SAT. Patients and Methods: A retrospective matched cohort study from five hospitals in a 20-year period within a large hospital network was performed. Inclusion criteria consisted of patients over age 18 undergoing primary TJA, with any order for oral long-term (>6 months duration) SAT, and minimum of one-year clinical follow-up. Patients were matched 1:4 on age, gender, body mass index (BMI), hip or knee surgery, diabetes mellitus, smoking status, and indication for primary TJA. Student t-test, Fisher exact, and χ² tests were utilized for group comparisons. Our study was powered to detect a 10.5% increase in PJI incidence compared with a 1% baseline rate of PJI. Results: We identified 45 TJA in 33 patients receiving SAT, which were matched to 180 control cases. There was no difference in the rate of development of PJI at any time point within follow-up between the SAT cohort and control group (2.22% vs. 1.11%; p = 0.561). Conclusions: We found a 2.22% rate of PJI in a cohort of patients receiving SAT identified over a 20-year period. As the clinical scenario of primary TJA while on SAT is rare but likely to become more prevalent, future large-scale studies can be performed to better clarify rates and risk of PJI in this population.

National surgical antibiotic prophylaxis guideline in Singapore

Introduction: Institutional surgical antibiotic prophylaxis (SAP) guidelines are in place at all public hospitals in Singapore, but variations exist and adherence to guidelines is not tracked consistently. A national point prevalence survey carried out in 2020 showed that about 60% of surgical prophylactic antibiotics were administered for more than 24 hours. This guideline aims to align best practices nationally and provides a framework for audit and surveillance. Method: This guideline was developed by the National Antimicrobial Stewardship Expert Panel’s National Surgical Antibiotic Prophylaxis Guideline Development Workgroup Panel, which comprises infectious diseases physicians, pharmacists, surgeons and anaesthesiologists. The Workgroup adopted the ADAPTE methodology framework with modifications for the development of the guideline. The recommended duration of antibiotic prophylaxis was graded according to the strength of consolidated evidence based on the scoring system of the Singapore Ministry of Health Clinical Practice Guidelines. Results: This National SAP Guideline provides evidence-based recommendations for the rational use of antibiotic prophylaxis. These include recommended agents, dose, timing and duration for patients undergoing common surgeries based on surgical disciplines. The Workgroup also provides antibiotic recommendations for special patient population groups (such as patients with β-lactam allergy and patients colonised with methicillin-resistant Staphylococcus aureus), as well as for monitoring and surveillance of SAP. Conclusion: This evidence-based National SAP Guideline for hospitals in Singapore aims to align practices and optimise the use of antibiotics for surgical prophylaxis for the prevention of surgical site infections while reducing adverse events from prolonged durations of SAP. Keywords: Antibiotic prophylaxis duration, antimicrobial resistance, antimicrobial stewardship, hospital-acquired infection, surgical site infections

Antimicrobial Stewardship in Total Joint Arthroplasty: Outcomes of a Collaborative Program Implementation

INTRODUCTION

Antimicrobial stewardship has been cited as a crucial component of orthopaedic surgical care; however, limited high-quality data exist to guide antibiotic use across the total joint arthroplasty continuum. Antimicrobial stewardship program (ASP) implementation and evaluation is needed in this space.

METHODS

We pursued a prospective, sequential cohort study of an interprofessional ASP for total joint arthroplasty (TJA) formed in late 2017 at the study institution. Twelve total evidence-based recommendations for protocol change were issued, with 11 accepted and implemented across three project phases spanning March 2018 to December 2019. The primary study outcome was the rate of optimal preoperative intravenous antibiotic selection as assessed for Baseline versus Postintervention time periods. Secondary outcomes included individual antibiotic utilization rates. Descriptive statistics were pursued for institutional surgical site infection (SSI) and postoperative acute kidney injury (AKI) rates across the affected time frame. A cost-benefit analysis of the ASP was estimated from the institutional perspective.

RESULTS

The rate of optimal preoperative antibiotic selection increased from 64.9% in the Baseline Period (February 2018, n = 57) to 95.4% in the Postimplementation period (June 2018 to December 2019, n = 1,220) (P < 0.001). The rates of second-line preoperative antibiotics and total perioperative antibiotic exposures decreased. Total SSI and AKI rates in primary elective TJA seemed to decrease from calendar year 2018 to 2019 (deep SSI 1.00% to 0.22%, superficial SSI 0.66% to 0.00%, and AKI 1.97% to 1.03%). The institution realized an estimated $197,050 cost savings per 1000 TJA procedures.

DISCUSSION

A comprehensive ASP for TJA was associated with an increased use of optimal preoperative antibiotic selection, decreased total antibiotic exposures, and cost savings, without apparent detriment to SSI or AKI rates.

Dual Antibiotic Prophylaxis in Primary Total Knee Arthroplasty-No Benefit for Extremely Obese Patients

We performed this study to assess the effectiveness of multimodal total knee arthroplasty prosthetic joint infection (TKA-PJI) prophylaxis including "on-time" dual-antibiotic prophylaxis, and the influence of body mass index (BMI) on prophylaxis effectiveness. After obtaining Institutional Review Board approval, we assessed 1,802 primary TKAs (1,496 patients) who received cefazolin alone or cefazolin combined with vancomycin for TKA-PJI prophylaxis. A detailed chart review was performed to determine patient demographic features (age, gender, BMI, American Society of Anesthesiologists Score), antibiotic selection, vancomycin administration timing, and 1-year PJI rates. Statistical assessment was accomplished using a two-sided Student's t-test or Fisher's exact test. Patients who received dual-antibiotic prophylaxis with "on time" vancomycin infusion (Group CVt) had significantly lower infection rates than other TKA patients (0.8 vs. 2.7%, p < 0.01). "On Time" vancomycin administration was associated with a lower TKA-PJI rate for patients with a BMI < 45 kg/m² (0.5 vs. 2.6%, p < 0.01) with no infections in 120 TKA patients with a BMI between 40 and 44.9 kg/m² (p < 0.01). No difference was noted for patients with a BMI ≥ 45 kg/m² (3.3 vs. 2.6%, p = 0.71). There were no infections in 150 TKA patients with a normal BMI (18-25 kg/m²) in any PJI-prophylaxis treatment group. Adoption of a dual-antibiotic prophylaxis approach can successfully reduce TKA-PJI rates among overweight and moderately obese patients. The approach does not appear to influence outcomes for low risk patients with a normal BMI (18-25 kg/m²) or for higher risk patients with a BMI > 45 kg/m².

Preoperative Prophylactic Antibiotics in Total Hip and Knee Arthroplasty: What, When, and How

Although there are numerous nonpatient-related factors that may help reduce infection risk, the proper use of prophylactic antibiotics is most responsible for reducing infection. The role of prophylactic antibiotics is to reduce early periprosthetic joint replacement, which is accomplished by having adequate antibiotic tissue levels at the time of skin incision. The goal of this section of the symposium is to review current antibiotic recommendations, how to manage patients with a self-reported penicillin allergy, review the use of dual antibiotics, discuss the use of antibiotics in the outpatient total joint setting, as well as very briefly discuss the administration of intraosseous antibiotics in knee arthroplasty.

Antibiotic Prophylaxis with Cefazolin Is Associated with Lower Shoulder Periprosthetic Joint Infection Rates Than Non-Cefazolin Alternatives

BACKGROUND

Although prophylactic antibiotics are considered the standard of care, data with regard to the comparative efficacy of specific antibiotics in the prevention of periprosthetic joint infection (PJI) have remained limited. This study evaluated whether perioperative antibiotic choice affects rates of PJI development in shoulder arthroplasty.

METHODS

From 2000 to 2019, all primary shoulder arthroplasty types (hemiarthroplasty, anatomic total shoulder arthroplasty, reverse shoulder arthroplasty) performed for elective and trauma indications with perioperative antibiotic data and a minimum follow-up of 2 years were identified from a single institution. Demographic characteristics, PJI risk factors, and PJI-free survivorship data were retrieved. Multivariable analyses were conducted to determine the association between the antibiotic administered and the development of PJI.

RESULTS

Of 7,713 shoulder arthroplasties, cefazolin was administered in 6,879 procedures (89.2%) and non-cefazolin antibiotics consisting of vancomycin (465 procedures [6.0%]), clindamycin (345 procedures [4.5%]), and alternative regimens (24 procedures [0.31%]) were administered in 834 procedures (10.8%). PJIs occurred in 101 shoulder arthroplasties (1.3%), with Cutibacterium acnes as the most common pathogen (44 procedures [43.6%]). PJI-free survivorship was greater in shoulder arthroplasties in which cefazolin was administered compared with those in which non-cefazolin antibiotics were administered, with 0.91% greater survival free of PJI at 1 month, 1.4% at 1 year, and 2.7% at 15 years (p < 0.001). Cefazolin administration, compared with non-cefazolin administration, was associated with a 69% reduction in all-cause PJI risk and a 78% reduction in C. acnes PJI risk (p < 0.001). A higher risk of PJI for both groups was observed with vancomycin; the hazard ratio [HR] was 2.32 (95% confidence interval [CI], 1.22 to 4.40; p = 0.010) for all-cause PJI and 2.94 (95% CI, 1.12 to 7.49; p = 0.028) for C. acnes PJI. A higher risk of PJI was also observed for both groups for clindamycin; the HR was 5.07 (95% CI, 2.83 to 9.05; p < 0.001) for all-cause PJI and 8.01 (95% CI, 3.63 to 17.42; p < 0.001) for C. acnes PJI.

CONCLUSIONS

In primary shoulder arthroplasty, cefazolin administration was associated with a significantly lower rate of PJI compared with non-cefazolin alternatives, including both vancomycin and clindamycin. These risk discrepancies were observed across all infectious pathogens and may be considered even greater when C. acnes was the infecting bacterium.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Use of prophylactic antibiotics on surgical site infections in arthroplasty patients (Scoping Review)

Background

Increased demand for arthroplasty also increases the number of complications of arthroplasty, especially surgical site infection (SSI). One of the effective strategies in preventing surgical site infection is the use of appropriate prophylactic antibiotics.

Objective

To identify and analyse information from clinical studies regarding factors affecting the effectiveness of prophylactic antibiotics in arthroplasty patients.

Methods

A scoping review was conducted through the PubMed, Scopus, and Google Scholar databases within a publication range from January 2004 to August 2020. Study data are extracted and analysed by a minimum of two reviewers.

Results

The search results found 2.419 articles, with 39 articles were included for further analysis. Cefazolin monotherapy was the most frequently studied antibiotic (15 articles) followed by vancomycin monotherapy (8 articles). Most widely used antibiotics in arthroplasty were cefazolin mono-therapy (997.599 procedures with SSI incidence range: 0,20–16,05%) followed by vancomycin mono-therapy (125.170 procedures with SSI incidence range: 0.27–3,88%) The correct antibiotic dose has a lower percentage of the SSI than the wrong antibiotic dose. Meanwhile, administration of antibiotics within single dose or <24 h had a lower SSI percentage than administration of antibiotics >24 h. Administration antibiotics before incision also have a lower SSI percentage than after incision. There were no studies that discussed re-dosing of antibiotics in this scoping review.

Conclusions

There is still a need for further research related to the duration and specific timing of first dose of prophylactic antibiotics, especially regarding single dose or multiple dose antibiotics to obtain maximum effectiveness of antibiotic prophylaxis

Cefazolin remains the linchpin for preventing acute periprosthetic joint infection following primary total knee arthroplasty

Aims

Despite recent literature questioning their use, vancomycin and clindamycin often substitute cefazolin as the preoperative antibiotic prophylaxis in primary total knee arthroplasty (TKA), especially in the setting of documented allergy to penicillin. Topical povidone-iodine lavage and vancomycin powder (VIP) are adjuncts that may further broaden antimicrobial coverage, and have shown some promise in recent investigations. The purpose of this study, therefore, is to compare the risk of acute periprosthetic joint infection (PJI) in primary TKA patients who received cefazolin and VIP to those who received a non-cephalosporin alternative and VIP.

Methods

This was a retrospective cohort study of 11,550 primary TKAs performed at an orthopaedic hospital between 2013 and 2019. The primary outcome was PJI occurring within 90 days of surgery. Patients were stratified into two groups (cefazolin vs non-cephalosporin) based on their preoperative antibiotic. All patients also received the VIP protocol at wound closure. Bivariate and multiple logistic regression analyses were performed to control for potential confounders and identify the odds ratio of PJI.

Results

In all, 10,484 knees (90.8%) received cefazolin, while 1,066 knees (9.2%) received a non-cephalosporin agent (either vancomycin or clindamycin) as preoperative prophylaxis. The rate of PJI in the cefazolin group (0.5%; 48/10,484) was significantly lower than the rate of PJI in the non-cephalosporin group (1.0%; 11/1,066) (p = 0.012). After controlling for confounding variables, the odds ratio (OR) of developing a PJI was increased in the non-cephalosporin cohort compared to the cefazolin cohort (OR 2.389; 1.2 to 4.6); p = 0.01).

Conclusion

Despite the use of topical irrigant solutions and addition of local antimicrobial agents, the use of a non-cephalosporin perioperative antibiotic continues to be associated with a greater risk of TKA PJI compared to cefazolin. Strategies that increase the proportion of patients receiving cefazolin rather than non-cephalosporin alternatives must be emphasized.

Cite this article: Bone Jt Open 2022;3(1):35–41.

Surgical Antibiotic Prophylaxis in an Era of Antibiotic Resistance: Common Resistant Bacteria and Wider Considerations for Practice

The increasing incidence of antimicrobial resistance (AMR) presents a global crisis to healthcare, with longstanding antimicrobial agents becoming less effective at treating and preventing infection. In the surgical setting, antibiotic prophylaxis has long been established as routine standard of care to prevent surgical site infection (SSI), which remains one of the most common hospital-acquired infections. The growing incidence of AMR increases the risk of SSI complicated with resistant bacteria, resulting in poorer surgical outcomes (prolonged hospitalisation, extended durations of antibiotic therapy, higher rates of surgical revision and mortality). Despite these increasing challenges, more data are required on approaches at the institutional and patient level to optimise surgical antibiotic prophylaxis in the era of antibiotic resistance (AR). This review provides an overview of the common resistant bacteria encountered in the surgical setting and covers wider considerations for practice to optimise surgical antibiotic prophylaxis in the perioperative setting.

A Simple Algorithmic Approach Allows the Safe Use of Cephalosporin in "Penicillin-Allergic" Patients without the Need for Allergy Testing

BACKGROUND

Patients who report a penicillin allergy are often given second-line antibiotic prophylaxis during total joint arthroplasty (TJA), with only a minority of patients undergoing additional consultations and allergy testing. In an effort to increase the use of cephalosporin prophylaxis in TJA, the present study aimed to assess the effectiveness of a simple, protocol-driven penicillin allergy screening program without the need for additional work-up.

METHODS

Following implementation of a questionnaire-based screening protocol in May 2019, all patients scheduled for primary TJA were risk-stratified into low or high-risk categories. The low-risk cohort received cefazolin, and the high-risk cohort received non-cefazolin antibiotics. Patients were monitored prospectively, and data on antibiotic usage and adverse outcomes were documented. The protocol group (n = 2,078) was propensity score matched 1:1 with a control group that included patients who underwent TJA in the same institution prior to implementation of the protocol. The primary end point was the efficacy of the protocol in reducing unnecessary use of non-cephalosporin antibiotics for prophylaxis. Secondary outcomes included the rate of surgical site infections and allergic reactions to the administered antibiotic.

RESULTS

A total of 357 patients (17.2%) reported a penicillin allergy in the protocol group compared with 310 patients (14.9%) with a recorded allergy in the control group (p = 0.052). The number of patients who received non-cephalosporin antibiotics was significantly lower in the protocol group (5.7% compared with 15.2% in the control group; p < 0.001), whereas there was no difference in the rate of total allergic reactions (0.8% compared with 0.7%, respectively; p = 0.857). Of the 239 low-risk patients (66.9%) in the protocol group, only 3 (1.3%) experienced a mild cutaneous reaction following cefazolin administration. There were no differences in the rates of superficial wound, deep periprosthetic, or Clostridioides difficile infections between the protocol and control groups.

CONCLUSIONS

A simple screening protocol allowed two-thirds of patients with a self-reported allergy to receive cefazolin without the need for additional consultations or testing. We believe this protocol can be safely implemented to increase the rate of cefazolin usage without a corresponding increase in the number of allergic reactions.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Clinical and Administrative Databases Used in Lower Extremity Arthroplasty Research

BACKGROUND

The use of national databases in lower extremity arthroplasty research has grown rapidly in recent years. We aimed to better characterize available databases by: (1) quantifying the number of these studies in the highest impact arthroplasty journals; (2) comparing respective sample sizes; and (3) contrasting their measured variables/outcomes.

METHODS

An extensive literature search was conducted to identify all database studies in the top 12 highest impact factor journals that published arthroplasty research between January 1, 2018 and December 31, 2019. A total of 5070 publications were identified. These studies were sorted by both database utilized and journal published. Tables were constructed to compare/contrast databases by metrics and measured outcome parameters including coding, patient sample size, preoperative comorbidities, postoperative complications, and limitations/barriers to their use.

RESULTS

Four hundred twenty-six database studies (8.4%, range 0.4%-29.7% per journal) were identified, of which 139 were from non-English-speaking arthroplasty databases. Among English-speaking arthroplasty databases, the 5 most common sources were National Surgical Quality Improvement Project (n = 72), Medicare (n = 62, 39 from Medicare Claims and 23 from PearlDiver), Nationwide Inpatient Sample (n = 35), PearlDiver non-Medicare private insurance (n = 18), and Statewide Planning and Research Cooperative System (n = 18). Metrics, outcome parameters, and features of commonly used registries were reviewed.

CONCLUSION

Database studies constitute an important part of arthroplasty-specific orthopedic research. Their use will continue to grow in the future, and it would be beneficial for clinicians/researchers to be aware of and familiarize themselves with their features to understand which are most appropriate for their work.

Evolution in the Acute Management of Open Fracture Treatment? Part 1

INTRODUCTION

Despite decades of advancement in wound debridement, prophylactic antibiotic therapy, fracture stabilization, and soft tissue reconstruction, infection remains a serious complication after open fracture. Inconclusive historical data and new challenges with resistant organisms and antimicrobial stewardship having created a difficult environment within which to develop sound, evidence-based treatment protocols that can be applied universally. The first part of this 2-part series will synthesize the historical perspective along with the current concepts surrounding bacteriology and antibiotic use/stewardship. Part 2 will analyze and summarize the current literature regarding the management of open fracture and prevention of subsequent infection.Numerous authors from Hippocrates to Larrey noted that superior results were obtained with an early aggressive debridement of necrotic tissue after wounding.1-7 Historically, the usual outcome after open fracture was infection, sepsis, amputation, and death before the introduction of antibiotics.8-11 As recently as the first half of the 20th century, surgeons argued that if an appropriate debridement was performed, antibiotics were not necessary and advocated against their routine use over concern for resistant organisms.The current period of open fracture treatment (starting in the 1970s) heralded a more scientific era with critical evaluation of antibiotics, surgical debridement, and the development of standardized evidence-based protocols. This era began with 3 classic articles by Patzakis and Gustilo that, to this day, remain central to the discussion of infection prevention after open fractures.12-14.

LEVEL OF EVIDENCE

Therapeutic Level V. See Instructions for Authors for a Complete description of levels of evidence.

Preoperative β-lactam antibiotic prophylaxis is superior to bacteriostatic alternatives in immediate expander-based breast reconstruction

BACKGROUND

Staged implant-based breast reconstruction is the most common reconstructive modality following mastectomy. Postoperative implant infections can have a significant impact on adjuvant oncologic care and reconstructive outcome. Here, we investigate the impact of β-lactam antibiotics (i.e., bactericidal) compared to alternative antibiotic agents on postoperative outcomes for implant-based breast reconstruction.

METHODS

A retrospective analysis of patients who underwent immediate sub-pectoral tissue expander placement with an inferior acellular dermal matrix (ADM) sling at a single institution between May 2008 and July 2018 was performed. Patient demographics, comorbidities, and complication rates were retrieved. The impact of antibiotic regimen on postoperative outcomes, including infection rate and reconstructive failure, was investigated.

RESULTS

A total of 320 patients with a mean age and BMI of 48.2 years and 25.0 kg/m² , respectively, who underwent 542 immediate breast reconstructions were included in the study. The use of a β-lactam antibiotic was protective against postoperative infection (odds ratio [OR] = 0.467, p = .046), infection requiring operative management (OR = 0.313, p = .022), and reconstructive failure (OR = 0.365, p = .028). Extended, that is, post-discharge, prophylaxis was not associated with any clinical benefit.

CONCLUSION

The use of β-lactam antibiotics for pre-/peri-operative prophylaxis is superior to alternative antibiotics with a bacteriostatic mechanism of action regarding rates of postoperative infection and reconstructive failure following immediate tissue expander-based breast reconstruction. Extended, that is, post-discharge, prophylaxis does not appear to be indicated, regardless of the antibiotic chosen.

Timing of Preoperative Surgical Antibiotic Prophylaxis After Primary One-Level to Three-Level Lumbar Fusion

OBJECTIVE

The purpose of this study was to examine the relationship between timing of preoperative surgical antibiotic prophylaxis and postoperative surgical site infections (SSIs) among patients with 1-level to 3-level lumbar fusion.

METHODS

Patients having undergone a primary 1-level to 3-level lumbar fusion at a single institution were allocated into 5 groups based on the time from preoperative antibiotic administration to incision (group A, 0-15 minutes; group B, 16-30 minutes; group C, 31-45 minutes; group D, 46-60 minutes; and group E, 61+ minutes). Timing of antibiotic administration as a continuous variable was also analyzed. All patients received irrigation with 3 L of normal saline containing bacitracin as well as local administration of vancomycin powder. SSIs were identified by the definition set forth by the 2017 Centers for Disease Control and Prevention guidelines.

RESULTS

Among 1131 patients, 27 (2.4%) were found to have an SSI. Compared with patients with antibiotic administration within 0-15 minutes before incision, patients with administration 61+ minutes before incision (group 4) had significantly higher odds of developing an SSI (P < 0.001). Patients had a 1.05-fold higher likelihood of infection for each additional minute delay of administration before incision (P < 0.001). Receiver operating characteristic analysis reported an area under the curve of 0.733 and 0.776 for time as a continuous and categorical variable, respectively. Age (P = 0.02), body mass index (P = 0.03), diabetes mellitus diagnosis (P = 0.04), and type of antibiotic (P = 0.004) were significant predictors of SSI.

CONCLUSIONS

Our results show that preoperative antibiotic administration beyond 1 hour in patients who have undergone lumbar fusion is associated with higher rates of SSI.

Evaluation of Antibiotic Allergies in Surgical Patients

Antibiotic administration in the perioperative period is the foundation of preventing surgical site infections. β-Lactam antibiotics, notably the first-generation cephalosporin cefazolin, are the drugs of choice for this indication. However, reported antibiotic allergies often result in the use of suboptimal alternative agents that can lead to an increased risk of infection and adverse effects. A comprehensive allergy history and risk stratification should be completed preoperatively to determine whether or not a patient can be rechallenged with a β-lactam antibiotic and what testing may be necessary prior to administration. Nursing staff can play a critical role in understanding the implications and management of reported antibiotic allergies in surgical patients in order to optimize patient care.

The impact of patient-reported penicillin or cephalosporin allergy on surgical site infections

OBJECTIVE

To determine the impact of a documented penicillin or cephalosporin allergy on the development of surgical site infections (SSIs).

BACKGROUND

Appropriate preoperative antibiotic prophylaxis reduces SSI risk, but documented antibiotic allergies influence the choice of prophylactic agents. Few studies have examined the relationship between a reported antibiotic allergy and risk of SSI and to what extent this relationship is modified by the antibiotic class given for prophylaxis.

METHODS

We conducted a retrospective cohort study of adult patients undergoing coronary artery bypass, craniotomy, spinal fusion, laminectomy, hip arthroplasty and knee arthroplasty at 3 hospitals from July 1, 2013, to December 31, 2017. We built a multivariable logistic regression model to calculate the adjusted odds ratio (aOR) of developing an SSI among patients with and without patient-reported penicillin or cephalosporin allergies. We also examined effect measure modification (EMM) to determine whether surgical prophylaxis affected the association between reported allergy and SSI.

RESULTS

We analyzed 39,972 procedures; 1,689 (4.2%) with a documented patient penicillin or cephalosporin allergy, and 374 (0.9%) resulted in an SSI. Patients with a reported penicillin or cephalosporin allergy were more likely to develop an SSI compared to patients who did not report an allergy to penicillin or cephalosporins (adjusted odds ratio, 3.26; 95% confidence interval, 2.71-3.93). Surgical prophylaxis did not have significant EMM on this association.

CONCLUSIONS

Patients who reported a penicillin or cephalosporin allergy had higher odds of developing an SSI than nonallergic patients. However, the increase in odds is not completely mediated by the type of surgical prophylaxis. Instead, a reported allergy may be a surrogate marker for a more complicated patient population.

Virtual Reality and Augmented Reality-Translating Surgical Training into Surgical Technique

PURPOSE OF REVIEW

As immersive learning outside of the operating room is increasingly recognized as a valuable method of surgical training, virtual reality (VR) and augmented reality (AR) are increasingly utilized in orthopedic surgical training. This article reviews the evolving nature of these training tools and provides examples of their use and efficacy. The practical and ethical implications of incorporating this technology and its impact on both orthopedic surgeons and their patients are also discussed.

RECENT FINDINGS

Head-mounted displays (HMDs) represent a possible adjunct to surgical accuracy and education. While the hardware is advanced, there is still much work to be done in developing software that allows for seamless, reliable, useful integration into clinical practice and training. Surgical training is changing: AR and VR will become mainstays of future training efforts. More evidence is needed to determine which training technology translates to improved clinical performance. Volatility within the HMD industry will likely delay advances in surgical training.

The impact of antibiotic allergy labels on antibiotic exposure, clinical outcomes, and healthcare costs: A systematic review

OBJECTIVE

A growing body of evidence suggests that antibiotic allergy labels as documented in medical records are a risk factor for poor clinical outcomes. In this systematic review, we aimed to determine how antibiotic allergy labels influence 3 domains: antibiotic use and exposure, clinical outcomes, and healthcare-related costs.

DESIGN

We performed a systematic review to identify studies reporting outcomes in patients with antibiotic allergy labels compared to nonallergic counterparts. The search included PubMed, EMBASE, Cochrane CENTRAL, EBSCO, Cochrane Database of Abstracts of Reviews of Effects and Web of Science. Two reviewers independently screened studies for inclusion and abstracted data. Studies were graded using the Newcastle-Ottawa quality assessment scale. Study outcomes included antibiotic use, clinical outcomes, and economic outcomes.

RESULTS

In total, 41 studies met our criteria for inclusion. These studies varied in medical specialty, patient population, healthcare delivery system, and design, but most were conducted among adults age >18 years (85%) in the inpatient setting (82.5%). Among 34 studies examining antibiotic exposure, 32 (94%) found that patients with antibiotic allergy labels received more broad-spectrum antibiotics. Moreover, 31 studies examined clinical outcomes such as length of hospitalization, ICU admission, hospital readmission, multidrug-resistant or opportunistic infection, or mortality, and 27 (87%) found that allergy-labeled patients had at least 1 negative outcome. Of 9 studies examining healthcare costs, 7 (78%) found that allergy-labeled patients incurred significantly higher drug or hospital-related costs.

CONCLUSIONS

Antibiotic allergy labels have negative effects on antibiotic use, clinical outcomes, and economic outcomes in a variety of clinical settings and populations.

Risk Factors for Surgical Site Infection in Orthopaedic Oncology

INTRODUCTION

Surgical site infections (SSIs) are common complications after surgeries involving musculoskeletal tumors, but we know little about SSI risk factors unique to orthopaedic oncology. A greater understanding of these factors will help risk-stratify patients and guide surgical decision-making.

METHODS

A retrospective review at a single-institution identified 757 procedures done on 624 over 6 years. The patients had a preoperative diagnosis of a malignant or potentially malignant neoplasm of the bone or soft tissues. Patient-specific and procedure-specific variables and diagnosis of SSI were recorded for each case. Data were analyzed through univariate analysis and multiple logistic regression.

RESULTS

On univariate analysis, significant patient-specific risk factors for SSI included malignancy (P < 0.001), smoking history (P = 0.041), and American Society of Anesthesiologists Score (P = 0.002). Significant procedure-specific risk factors for SSI on univariate analysis included surgery time (P < 0.001), estimated blood loss (P < 0.001), blood transfusion volume (P < 0.001), neoadjuvant chemotherapy (P < 0.001), neoadjuvant radiation therapy (P < 0.001), inpatient surgery (P < 0.001), and number of previous surgeries within the study period (P < 0.001). The two factors that independently predicted risk of SSI when controlling for all other variables in a multiple logistic regression were whether the surgery was done on an inpatient basis (P = 0.005) and the number of previous surgeries done on the same site (P = 0.001).

CONCLUSIONS

We found a number of risk factors that correlate markedly with SSI after orthopaedic oncology surgery. The surgeon can use these risk factors to aid in surgical decision-making.

Characteristics of Antibiotic Prophylaxis and Risk of Surgical Site Infections in Primary Total Hip and Knee Arthroplasty

BACKGROUND

Despite numerous antibiotic prophylaxis options for total hip arthroplasty (THA) and total knee arthroplasty (TKA), an assessment of practice patterns and comparative effectiveness is lacking. We aimed to characterize antibiotic utilization patterns and associations with infection risk and hypothesized differences in infection risk based on regimen.

METHODS

A retrospective cohort study was performed using data from 436,724 THA and 862,918 TKA (Premier Healthcare Database; 2006-2016). Main exposures were antibiotic type and duration: day of surgery only (day 0) or through postoperative day 1 (day 1). The primary outcome was surgical site infection (SSI) <30 days postoperation. Mixed-effect models measured associations between prophylaxis regimen and SSI as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

SSI prevalence was 0.21% (n = 914) for THA and 0.22% (n = 1914) for TKA. Among THA procedures, the most commonly used antibiotics were cefazolin (74.1%), vancomycin (8.4%), "other" antibiotic combinations (7.1%), vancomycin + cefazolin (5.1%), and clindamycin (3.3%). Here, 51.8% received prophylaxis on day 0 only, whereas 48.2% received prophylaxis through day 1. Similar patterns existed for TKA. Relative to cefazolin, higher SSI odds were seen with vancomycin (OR = 1.36; CI 1.09-1.71) in THA and with vancomycin (OR = 1.29; CI = 1.10-1.52), vancomycin + cefazolin (OR = 1.35; CI = 1.12-1.64), clindamycin (OR = 1.38; CI = 1.11-1.71), and "other" antibiotic combinations (OR = 1.28; CI = 1.07-1.53) in TKA. Prophylaxis duration did not alter SSI odds. Results were corroborated in sensitivity analyses.

CONCLUSION

Antibiotic prophylaxis regimens other than cefazolin were associated with increased SSI risk among THA/TKA patients. These findings emphasize a modifiable intervention to mitigate infection risk.

Methicillin-Resistant Staphylococcus Aureus Carrier Rate in Orthopaedic Trauma Patients: A Prospective Cohort Study

OBJECTIVES

To identify the methicillin-resistant Staphylococcus aureus (MRSA) carrier rate among surgical patients on an orthopaedic trauma service and to determine whether screening is an effective tool for reducing postoperative MRSA infection in this population.

DESIGN

Prospective.

SETTING

Level 1 trauma center.

PATIENTS/PARTICIPANTS

Two hundred forty-eight patients with operatively managed orthopaedic trauma conditions during the study period. Two hundred three patients (82%) had acute orthopaedic trauma injuries. Forty-five patients (18%) underwent surgery for a nonacute orthopaedic trauma condition, including 36 elective procedures and 9 procedures to address infection.

INTERVENTION

MRSA screening protocol, preoperative antibiotics per protocol.

MAIN OUTCOME MEASUREMENTS

MRSA carrier rate, overall infection rate, MRSA infection rate.

RESULTS

Our screening captured 71% (175/248) of operatively treated orthopaedic trauma patients during the study period. The overall MRSA carrier rate was 3.4% (6/175). When separated by group, the acute orthopaedic trauma cohort had an MRSA carrier rate of 1.4% (2/143), and neither MRSA-positive patient developed a surgical site infection. Only one MRSA infection occurred in the acute orthopaedic trauma cohort. The nonacute group had a significantly higher MRSA carrier rate of 12.5% (4/32, P = 0.01), and the elective group had the highest MRSA carrier rate of 15.4% (4/26, P < 0.01). The odds ratio of MRSA colonization was 10.1 in the nonacute group (95% confidence interval, 1.87-75.2) and 12.8 for true elective group (95% confidence interval, 2.36-96.5) when compared with the acute orthopaedic trauma cohort.

CONCLUSIONS

There was a low MRSA colonization rate (1.4%) among patients presenting to our institution for acute fracture care. Patients undergoing elective surgery for fracture-related conditions such as nonunion, malunion, revision surgery, or implant removal have a significantly higher MRSA carrier rate (15.4%) and therefore may benefit from MRSA screening. Our results do not support routine vancomycin administration for orthopaedic trauma patients whose MRSA status is not known at the time of surgery.

LEVEL OF EVIDENCE

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

The Impact of Patient-Reported Penicillin Allergy on Risk for Surgical Site Infection in Total Joint Arthroplasty

BACKGROUND

Penicillin (PCN) allergy is reported in 10% to 20% of the population; studies show that only 1% to 3% of patients have a true allergy. Most patients reporting a PCN allergy receive second-line antibiotic prophylaxis preoperatively, which raises concerns about antimicrobial efficacy. Studies also suggest that second-line antibiotics may increase the rate of surgical site infection (SSI). In this study we aim to analyze the effect of PCN allergy on antibiotic type prescribed and SSI in our total joint arthroplasty population.

METHODS

A retrospective review of 4,903 primary total hip and total knee arthroplasty performed from January 2015 to June 2017 in a single institution. A detailed chart review was performed to identify reported reactions and antibiotic prescribed.

RESULTS

Seven hundred ninety-six patients (16.2%) reported a PCN allergy; the reactions were classified into three tiers. Six hundred fifteen patients (12.5%) reported an IgE-mediated allergy, hypersensitivity, or a possible allergy; 89 (1.8%) reported an adverse effect; and 92 (1.9%) had an unknown reaction. Patients reporting a PCN allergy were less likely to receive cefazolin (94.9 versus 6.9%; P < 0.001) and more likely to receive clindamycin (1.1 versus 80.7%; P < 0.001) or vancomycin (4.0 versus 12.4%; P < 0.001). There was no difference in infection rate by reported PCN allergy (0.6 versus 0.4%; P = 0.473) or antibiotic prescribed (0.5 versus 0.6%; P = 0.4817).

CONCLUSION

No patient with a PCN allergy and given cefazolin experienced a reaction; based on reported reactions, most patients with a PCN allergy can safely receive first-line antibiotic therapy. In this population, PCN allergy and second-line antibiotic therapy did not influence the rate of SSI.

Multicentre randomised double-blind placebo controlled trial of combination vancomycin and cefazolin surgical antibiotic prophylaxis: the Australian surgical antibiotic prophylaxis (ASAP) trial

INTRODUCTION

Resistant Gram-positive organisms, such as methicillin-resistant staphylococci, account for a significant proportion of infections following joint replacement surgery. Current surgical antimicrobial prophylaxis guidelines recommend the use of first-generation or second-generation cephalosporin antibiotics, such as cefazolin. Cefazolin, however, does not prevent infections due to these resistant organisms; therefore, new prevention strategies need to be examined. One proposed strategy is to combine a glycopeptide antibiotic with cefazolin for prophylaxis. The clinical benefit and cost-effectiveness of this combination therapy compared with usual therapy, however, have not been established.

METHODS AND ANALYSIS

This randomised, double-blind, parallel, superiority, placebo-controlled, phase 4 trial will compare the incidence of all surgical site infections (SSIs) including superficial, deep and organ/space (prosthetic joint) infections, safety and cost-effectiveness of surgical prophylaxis with cefazolin plus vancomycin to that with cefazolin plus placebo. The study will be performed in patients undergoing joint replacement surgery. In the microbiological sub-studies, we will examine the incidence of SSIs in participants with preoperative staphylococci colonisation (Sub-Study 1) and incidence of VRE acquisition (Sub-Study 2). The trial will recruit 4450 participants over a 4-year period across 13 orthopaedic centres in Australia. The primary outcome is the incidence of SSI at 90 days post index surgery. Secondary outcomes include the incidence of SSI according to joint and microorganism and other healthcare associated infections. Safety endpoints include the incidence of acute kidney injury, hypersensitivity reactions and all-cause mortality. The primary and secondary analysis will be a modified intention-to-treat analysis consisting of all randomised participants who undergo eligible surgery. We will also perform a per-protocol analysis.

ETHICS AND DISSEMINATION

The study protocol was reviewed and approved by The Alfred Hospital Human Research Ethics Committee (HREC/18/Alfred/102) on 9 July 2018. Study findings will be disseminated in the printed media, and learnt forums.

TRIAL REGISTRATION NUMBER

ACTRN12618000642280.

The Impact of a Reported Penicillin Allergy on Surgical Site Infection Risk

Background

A reported penicillin allergy may compromise receipt of recommended antibiotic prophylaxis intended to prevent surgical site infections (SSIs). Most patients with a reported penicillin allergy are not allergic. We determined the impact of a reported penicillin allergy on the development of SSIs.

Methods

In this retrospective cohort study of Massachusetts General Hospital hip arthroplasty, knee arthroplasty, hysterectomy, colon surgery, and coronary artery bypass grafting patients from 2010 to 2014, we compared patients with and without a reported penicillin allergy. The primary outcome was an SSI, as defined by the Centers for Disease Control and Prevention's National Healthcare Safety Network. The secondary outcome was perioperative antibiotic use.

Results

Of 8385 patients who underwent 9004 procedures, 922 (11%) reported a penicillin allergy, and 241 (2.7%) had an SSI. In multivariable logistic regression, patients reporting a penicillin allergy had increased odds (adjusted odds ratio, 1.51; 95% confidence interval, 1.02-2.22) of SSI. Penicillin allergy reporters were administered less cefazolin (12% vs 92%; P < .001) and more clindamycin (49% vs 3%; P < .001), vancomycin (35% vs 3%; P < .001), and gentamicin (24% vs 3%; P < .001) compared with those without a reported penicillin allergy. The increased SSI risk was entirely mediated by the patients' receipt of an alternative perioperative antibiotic; between 112 and 124 patients with reported penicillin allergy would need allergy evaluation to prevent 1 SSI.

Conclusions

Patients with a reported penicillin allergy had a 50% increased odds of SSI, attributable to the receipt of second-line perioperative antibiotics. Clarification of penicillin allergies as part of routine preoperative care may decrease SSI risk.

Have We Actually Reduced Our 30-Day Short-Term Surgical Site Infection Rates in Primary Total Hip Arthroplasty in the United States?

BACKGROUND

The purpose of this study is to track the 30-day postoperative annual rates and trends of (1) overall, (2) deep, and (3) superficial surgical site infections (SSIs) following total hip arthroplasty (THA) using a large nationwide database.

METHODS

The National Surgical Quality Improvement Program database was queried for all THA cases performed between 2012 and 2016. After an overall 5-year correlation and trends analysis, univariate analysis was performed to compare the most recent year, 2016, with the preceding 4 years. Correlation coefficients and chi-squared tests were used to determine correlation and statistical significance.

RESULTS

The lowest incidence of SSIs was in the most recent year, 2016 (0.81%), while the greatest incidence was in the earliest year, 2012 (1.12%), marking a 31% decrease (P < .01). The lowest rate was in the most recent year, 2016 (0.23%), marking a 26% decrease from 2012. The lowest superficial SSI incidence occurred in the most recent year, 2016 (0.58%), while greatest incidence was in 2012 (0.83%), marking a 31% decrease over time (P < .05). There was an inverse correlation among overall, deep, and superficial SSI rates with operative year.

CONCLUSION

The findings from this study suggest a decreasing trend in SSIs within 30 days following THA. Furthermore, deep SSIs, which can pose substantial threats to implant survivorship, have also decreased throughout the years. These results highlight that potentially through improved medical and surgical techniques, we are winning the fight against short-term infections, but that more can still be done.

Proceedings from the 2018 International Consensus Meeting on Orthopedic Infections: prevention of periprosthetic shoulder infection

The Second International Consensus Meeting on Orthopedic Infections was held in Philadelphia, Pennsylvania, in July 2018. Over 800 international experts from all 9 subspecialties of orthopedic surgery and allied fields of infectious disease, microbiology, and epidemiology were assembled to form a consensus workgroup. The following proceedings on the prevention of periprosthetic shoulder infection come from 16 questions evaluated by delegates from the shoulder section.

Management of a surgical patient with a label of penicillin allergy: narrative review and consensus recommendations

Unsubstantiated penicillin-allergy labels are common in surgical patients, and can lead to significant harm through avoidance of best first-line prophylaxis of surgical site infections and increased infection with resistant bacterial strains. Up to 98% of penicillin-allergy labels are incorrect when tested. Because of the scarcity of trained allergists in all healthcare systems, only a minority of surgical patients have the opportunity to undergo testing and de-labelling before surgery. Testing pathways can be modified and shortened in selected patients. A variety of healthcare professionals can, with appropriate training and in collaboration with allergists, provide testing for selected patients. We review how patients might be assessed, the appropriate testing strategies that can be used, and the minimum standards of safe testing.

Protective effect of intraoperative re-dose of prophylactic antibiotics on surgical site infection in diabetic patients: a retrospective cohort study

Background

Surgical site infection (SSI) has a high incidence in diabetic surgical patients. Preoperative antibiotic prophylaxis followed by an intraoperative re-dose was a common strategy in diabetic prolonged procedures. However, there were lacking studies on the relative benefits of this strategy on SSI. Our study aimed to clarify the effect of intraoperative re-dose of prophylactic antibiotics on SSI in diabetic patients.

Methods

A total of 1,840 diabetic patients with prolonged surgeries were included and Cefazolin was the only type of antibiotic prophylaxis. We assessed the relationship between intraoperative re-dose of cefazolin and 30-day incidence of SSI using a retrospective cohort study method.

Results

There were 361 diabetic cases with preoperative antibiotics only and 1,479 cases with pre- plus intraoperative antibiotics, in which 60 subjects suffered from SSI. Pre- plus intraoperative prophylaxis group had a lower rate of SSI in the overall and subgroup analyses when compared with preoperative only group. Operation location, combined with hypertension, poor blood glucose control, high WBC count and ASA score >2 were significantly associated with an increased risk of SSI for diabetic surgical patients (all P<0.05). Intraoperative re-dose of prophylactic antibiotics was statistically related to a lower incidence rate of SSI than preoperative prophylaxis alone (crude RR =0.47; 95% CI, 0.27-0.82; P<0.01), while the association remained significant even after adjusting the potential confounders (adjusted RR =0.51; 95% CI, 0.29-0.90; P=0.02).

Conclusions

For diabetic patients, intraoperative re-dose of prophylactic antibiotics may be an independent protective factor for the prevention of SSI. A specific perioperative antibiotics injection strategy should be encouraged for diabetic patients with prolonged surgeries to minimize the possibility of SSI.

A 6-year trends analysis of infections after revision total hip arthroplasty

Background

Substantial efforts have been made to reduce the risk of infection after total hip arthroplasty (THA), including pre-operative patient optimization, skin preparation with alcohol-based solutions, perioperative antibiotics, and minimizing wound drainage with novel sutures and dressings. While these approaches have been effective in primary THA, their effects on revision THA to improve surgical site infection (SSI) rates are less clear. Therefore, the purpose of this study was to identify the annual rates and trends of: (I) overall; (II) deep; and (III) superficial SSIs following revision THA using the most recent results (2011 to 2016) from a large, nationwide database.

Methods

The National Surgical Quality Improvement Program (NSQIP) database was queried for all revision THA cases (CPT code 27134) between 2011 and 2016, yielding 8,562 cases. A steady increase in the total number of revision THA cases was observed from 2011 to 2016 (750 vs. 1,951, 260%). Cases with reported superficial and/or deep SSI were analyzed separately and then combined to evaluate overall SSI rates. The infection incidence for each year was calculated. After an overall 6-year correlation and trends analysis, univariate analysis was performed to compare the most recent year, 2016, with each of the preceding 5 years. Additionally, percent differences between 2016 and each previous year were calculated to evaluate rate changes. Pearson correlation coefficients and chi-squared tests were used to determine correlation and statistical significance which was maintained at a P value less than 0.05.

Results

There were 217 cases out of 8,562 (2.53% of all cases) complicated by any SSI. Overall, there was an inverse correlation between combined SSI rate and year, however, this was not statistically significant (P>0.05). The lowest incidence was in 2016 (n=41, 2.10%), while the highest incidence was in 2014 (n=45, 2.86%). The combined SSI rate in 2016 decreased by 22% when compared to 2015 (2.10% vs. 2.69%, P>0.05). A larger, 27% decrease in rate was found between 2016 and 2014 (2.10% vs. 2.86%, P>0.05). For deep SSI, there was an inverse correlation between rate and year of surgery, however, this was not statistically significant (P>0.05). The deep SSI incidence over the 5 years was 1.38% (118 out of 8,562 cases). There was a 35% decrease in deep SSI rate from 2016 to 2015 (0.92% vs. 1.43%, P>0.05). A larger, 53% decrease, was seen between 2016 and 2014 (0.92% vs. 1.04%, P<0.01). For superficial SSI, there was an inverse correlation between rate and year, however, this was not statistically significant (P>0.05). In this 6-year period, 99 cases out of 8,562 were complicated by a superficial SSI; an incidence of 1.16%. The lowest incidence occurred in 2014 (n=14, 0.89%), while 2012 had the highest incidence (n=17, 1.61%). The rate in 2016 decreased by 6% when compared to 2015 (1.18% vs. 1.07%, P>0.05). A larger, 27% decrease in rate was observed between 2016 and 2012 (1.18% vs. 1.61%, P>0.05).

Conclusions

Revision total hip arthroplasties exhibited a trend towards decreasing overall SSI nationwide between 2011 and 2016. Deep SSI rates had marked improvements, specifically between 2014 and 2016. This trend indicates some benefit from pre- and post-operative infection preventative strategies, but importantly, indicates continued room for improvement. Due to the potentially devastating complications associated with infection in revision THAs, further research is required to identify revision-specific strategies to lower the rates of SSIs.

Postoperative Blood Glucose Levels Predict Infection After Total Joint Arthroplasty

BACKGROUND

Perioperative hyperglycemia has many etiologies, including medication, impaired glucose tolerance, uncontrolled diabetes mellitus, or stress, the latter of which is common in patients postoperatively. Our study investigated the influence of postoperative blood glucose levels on periprosthetic joint infection after elective total joint arthroplasty to determine a threshold for glycemic control for which surgeons should strive during a patient's hospital stay.

METHODS

A single-institution retrospective review was conducted on 24,857 primary total joint arthroplasties performed from 2001 to 2015. Of these, 13,196 had a minimum follow-up of 1 year (mean, 5.9 years). Postoperative day 1 morning blood glucose levels were utilized and were correlated with periprosthetic joint infection, as defined by the International Consensus Group on Periprosthetic Joint Infection. Multivariable analysis was used to determine the influence of several important covariates on infection. An alpha level of 0.05 was used to determine significance.

RESULTS

The rate of periprosthetic joint infection increased linearly from blood glucose levels of ≥115 mg/dL. Multivariable analysis revealed that blood glucose levels were significantly associated with periprosthetic joint infection (p = 0.028). The optimal blood glucose threshold to reduce the likelihood of periprosthetic joint infection was 137 mg/dL. The periprosthetic joint infection rate in the entire cohort was 1.59% (1.46% in patients without diabetes compared with 2.39% in patients with diabetes; p = 0.001). There was no significant association between blood glucose level and periprosthetic joint infection in patients with diabetes (p = 0.276), although there was a linear trend.

CONCLUSIONS

The relationship between postoperative blood glucose levels and periprosthetic joint infection increased linearly, with an optimal cutoff of 137 mg/dL. Immediate and strict postoperative glycemic control may be critical in reducing postoperative complications, as even mild hyperglycemia was significantly associated with periprosthetic joint infection.

LEVEL OF EVIDENCE

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