Revision Total Knee Arthroplasty in an Outpatient Setting: A Growing Alternative.

INTRODUCTION: Recent studies have focused on the safety and efficacy of performing primary total knee arthroplasty (TKA) in an outpatient setting. Despite being associated with greater costs, much less is known about the accompanying impact on revision TKA (rTKA). The purpose of this study was to describe the trends in costs and outcomes of patients undergoing inpatient and outpatient rTKA. METHODS: An observational cohort study was conducted using commercial claims databases. Patients who underwent one- and two-component rTKA in an inpatient setting, hospital-based outpatient department (HOPD), or ambulatory surgery center (ASC) from 2018 to 2020 were included. The primary outcome was the 30-day episode of care costs following rTKA. Secondary outcomes included surgical cost, 90-day readmission rate, and emergency department (ED) visit rate. Covariates for analyses included patient demographics, surgery type, and indication for revision. RESULTS: There were 6,515 patients who were identified, with 17.0% of rTKAs taking place in an outpatient setting. On adjusted analysis, patients in the highest quartile of 30-day postoperative costs were more likely to be those whose rTKA was performed in an inpatient setting. One-component revisions were more common in an outpatient setting (HOPD, 50.7%; ASC, 62.0%) compared to an inpatient setting (39.6%). The 90-day readmission rates were higher (P = 0.003) for rTKAs performed in inpatient (+9.2%) and HOPD (+8.6%) settings compared to those in an ASC. CONCLUSION: The ASC may be a suitable setting for simpler revisions performed for less severe indications and is associated with lower costs and 90-day readmission and ED visit rates.

Antibiotic Prophylaxis Prior to Dental Procedures After Total Hip and Knee Arthroplasty Does Not Decrease the Risk of Periprosthetic Joint Infection.

BACKGROUND: Periprosthetic joint infection (PJI) is a devastating complication after total hip and total knee arthroplasty (THA/TKA). While some guidelines no longer recommend routine use of prophylactic antibiotics for dental procedures, many surgeons continue to prescribe antibiotics for their THA/TKA patients. In a setting of increasing antibiotic resistance, it is important to reduce unnecessary antibiotic use. This study aims to evaluate antibiotics prior to dental procedures and the association between dental procedures and PJI. METHODS: We conducted a retrospective cohort study of patients who underwent THA/TKA between January 1, 2019 and December 31, 2020. The primary outcome was late-presenting PJI, occurring > 90 days after surgery. Patients were designated in the antibiotic group (2,000 mg of amoxicillin) or non-antibiotic group based on their surgeon's prophylaxis protocol. Dental-associated PJIs were considered if the patient had evidence of poor dentition or a recent dental procedure prior to the onset of PJI symptoms. RESULTS: There were 2,871 (26.4%) patients in the no antibiotics group and 8,023 (73.6%) patients in the antibiotics group. We found 27 (0.3%) late-presenting PJIs and 4 dental-associated PJIs. In the univariate and multivariable analyses, body mass index ≥-30 and revision surgery were the only variables that increased the odds of late-presenting PJI. All 4 dental-associated PJIs occurred in patients prescribed antibiotics. CONCLUSIONS: We found a low rate of late-presenting PJI. Routine antibiotics prior to dental procedures were not shown to affect the risk of late-presenting PJI. These findings suggest that routine antibiotic prophylaxis before dental procedures is not necessary after THA/TKA.

Staphylococcus epidermidis joint isolates: Whole-genome sequencing demonstrates evidence of hospital transmission and common antimicrobial resistance.

OBJECTIVE: We investigated genetic, epidemiologic, and environmental factors contributing to positive Staphylococcus epidermidis joint cultures. DESIGN: Retrospective cohort study with whole-genome sequencing (WGS). PATIENTS: We identified S. epidermidis isolates from hip or knee cultures in patients with 1 or more prior corresponding intra-articular procedure at our hospital. METHODS: WGS and single-nucleotide polymorphism-based clonality analyses were performed, including species identification, in silico multilocus sequence typing (MLST), phylogenomic analysis, and genotypic assessment of the prevalence of specific antibiotic resistance and virulence genes. Epidemiologic review was performed to compare cluster and noncluster cases. RESULTS: In total, 60 phenotypically distinct S. epidermidis isolates were identified. After removal of duplicates and impure samples, 48 isolates were used for the phylogenomic analysis, and 45 (93.7%) isolates were included in the clonality analysis. Notably, 5 S. epidermidis strains (10.4%) showed phenotypic susceptibility to oxacillin yet harbored mecA, and 3 (6.2%) strains showed phenotypic resistance despite not having mecA. Smr was found in all isolates, and mupA positivity was not observed. We also identified 6 clonal clusters from the clonality analysis, which accounted for 14 (31.1%) of the 45 S. epidermidis isolates. Our epidemiologic investigation revealed ties to common aspirations or operative procedures, although no specific common source was identified. CONCLUSIONS: Most S. epidermidis isolates from clinical joint samples are diverse in origin, but we identified an important subset of 31.1% that belonged to subclinical healthcare-associated clusters. Clusters appeared to resolve spontaneously over time, suggesting the benefit of routine hospital infection control and disinfection practices.

Venous Thromboembolism in Total Hip and Total Knee Arthroplasty.

Importance: The optimal pharmacologic thromboprophylaxis agent after total hip and total knee arthroplasty is uncertain and consensus is lacking. Quantifying the risk of postoperative venous thromboembolism (VTE) and bleeding and evaluating comparative effectiveness and safety of the thromboprophylaxis strategies can inform care. Objective: To quantify risk factors for postoperative VTE and bleeding and compare patient outcomes among pharmacological thromboprophylaxis agents used after total hip and knee arthroplasty. Design, Setting, and Participants: This retrospective cohort study used data from a large health care claims database. Participants included patients in the United States with hip or knee arthroplasty and continuous insurance enrollment 3 months prior to and following their surgical procedure. Patients were excluded if they received anticoagulation before surgery, received no postsurgical pharmacological thromboprophylaxis, or had multiple postsurgery thromboprophylactic agents. In a propensity-matched analysis, patients receiving a direct oral anticoagulant (DOAC) were matched with those receiving aspirin. Exposures: Aspirin, apixaban, rivaroxaban, enoxaparin, or warfarin. Main Outcomes and Measures: The primary outcome was 30-day cumulative incidence of postdischarge VTE. Other outcomes included postdischarge bleeding. Results: Among 29 264 patients included in the final cohort, 17 040 (58.2%) were female, 27 897 (95.2%) had inpatient admissions with median (IQR) length of stay of 2 (1-2) days, 10 948 (37.4%) underwent total hip arthroplasty, 18 316 (62.6%) underwent total knee arthroplasty; and median (IQR) age was 59 (55-63) years. At 30 days, cumulative incidence of VTE was 1.19% (95% CI, 1.06%-1.32%) and cumulative incidence of bleeding was 3.43% (95% CI, 3.22%-3.64%). In the multivariate analysis, leading risk factors associated with increased VTE risk included prior VTE history (odds ratio [OR], 5.94 [95% CI, 4.29-8.24]), a hereditary hypercoagulable state (OR, 2.64 [95% CI, 1.32-5.28]), knee arthroplasty (OR, 1.65 [95% CI, 1.29-2.10]), and male sex (OR, 1.34 [95% CI, 1.08-1.67]). In a propensity-matched cohort of 7844 DOAC-aspirin pairs, there was no significant difference in the risk of VTE in the first 30 days after the surgical procedure (OR, 1.14 [95% CI, 0.82-1.59]), but postoperative bleeding was more frequent in patients receiving DOACs (OR, 1.36 [95% CI, 1.13-1.62]). Conclusions and Relevance: In this cohort study of patients who underwent total hip or total knee arthroplasty, underlying patient risk factors, but not choice of aspirin or DOAC, were associated with postsurgical VTE. Postoperative bleeding rates were lower in patients prescribed aspirin. These results suggest that thromboprophylaxis strategies should be patient-centric and tailored to individual risk of thrombosis and bleeding.

Arthroscopic Procedures Are Performed in 5% of Patients With Knee Osteoarthritis 1 Year Preceding Total Knee Arthroplasty and Are Associated With Increased Stiffness and Increased Costs.

Purpose: To describe the different types of arthroscopic procedures that patients undergo in the year prior to total knee arthroplasty (TKA), reveal the cost associated with these procedures, and understand the relationship between preoperative arthroscopy and clinical outcomes after TKA. Methods: An observational cohort study was conducted using the IBM Watson Health MarketScan databases. Patients with knee osteoarthritis who underwent unilateral isolated primary TKA between January 1, 2018, and September 30, 2019, were included. Knee arthroscopic procedures performed in the 1-year period before a primary TKA was identified. The primary outcomes of interest were cost of these procedures and the risk of 90-day postoperative complications. Results: In total, 2,904 patients, representing 5.2% of the analyzed cohort, underwent arthroscopic procedures in the year prior to TKA. The most common procedure and diagnosis were meniscectomy and meniscal tear, respectively, with procedures performed an average of 7.2 ± 3.0 months before TKA. Average per patient costs were $9,716 ± $5,500 in the highest payment quartile vs $1,789 ± 636 in the lowest payment quartile. Patients with a history of arthroscopy were more likely to develop postoperative stiffness (P = .001), while no difference was found in the risk of 90-day periprosthetic joint infection (PJI). Conclusions: Of the patients, 5.2% underwent knee arthroscopy in the year prior to TKA. While no association was seen with PJI risk, the costs associated with these procedures are high and may increase the overall cost of management of knee osteoarthritis. Level of Evidence: Level III, retrospective comparative study.

The trend and future projection of technology-assisted total knee arthroplasty in the United States.

BACKGROUND: As technology-assisted surgery has boosted in the last decades, we aimed to investigate the factors affecting adoption and to predict the future utilization of technology among patients who underwent total knee arthroplasty (TKA). METHODS: Patients underwent TKA in 2017-2019 in the MarketScan Database were included. Percentage of technology-assisted surgery was calculated. Multivariable logistic regression models were performed to analyse the factors and make the prediction. RESULTS: Of 112,161 TKA procedures, 7.2% were technology-assisted. The proportion of technology-assisted TKA is expected to reach 50% by 2032. The West showed the highest proportion of technology-assisted TKA (12.3%), while the South had the lowest (5.7%). Over time, the Midwest showed the greatest increase in technology adoption (OR = 1.26 compared to the Northeast, 95% CI [1.15, 1.38]). CONCLUSIONS: Technology adoption rate of TKA will continue to increase for the next 20 years in the United States with a slight geographical variation.

A Safe Number of Perioperative Opioids to Reduce the Risk of New Persistent Usage Among Opioid-Naïve Patients Following Total Joint Arthroplasty.

BACKGROUND: Higher initial opioid dosing increases the risk of prolonged opioid use following total joint arthroplasty (TJA), and the safe amounts to prescribe are unknown. We examined the relationship between perioperative opioid exposure and new persistent usage among opioid-naïve patients after total knee and hip arthroplasty. METHODS: In this retrospective cohort study, 22,310 opioid-naïve patients undergoing primary TJA between 2018 and 2019 were identified within a commercial claims database. Perioperative opioid exposure was defined as total dose of opioid prescription in morphine milligram equivalents (MME) between 1 month prior to and 2 weeks after TJA. New persistent usage was defined as at least one opioid prescription between 90 and 180 days postoperatively. Multivariate regression analyses were performed to examine the relationship between the perioperative dosage group and the development of new persistent usage. RESULTS: For the total patient cohort, 8.1% developed new persistent usage. Compared to patients who received <300 MME, patients who received 600-900 MME perioperatively had a 77% increased risk of developing new persistent usage (odds ratio 1.77, 95% CI, 1.44-2.17), and patients who received ≥1,200 MME perioperatively had a 285% increased risk (odds ratio 3.85, 95% CI, 3.13-4.74). CONCLUSION: We found a dose-dependent association between perioperative MME and the risk of developing new persistent usage among opioid-naïve patients following TJA. We recommend prescribing <600 MME (equivalent to 80 pills of 5 mg oxycodone) during the perioperative period to reduce the risk of new persistent usage. LEVEL OF EVIDENCE: Level III.

Costs of Nonoperative Procedures for Knee Osteoarthritis in the Year Prior to Primary Total Knee Arthroplasty.

BACKGROUND: The convergence of national priorities to reduce health-care costs and deliver high-value care warrants the need to examine health-care utilization. The objective of this study was to describe the costs associated with nonoperative procedures in the 1-year period leading up to primary total knee arthroplasty (TKA). METHODS: An observational cohort study was conducted using the IBM Watson Health MarketScan databases. Patients with late-stage knee osteoarthritis (OA) who underwent unilateral, isolated primary TKA from January 1, 2018, to December 31, 2019, were included. The main outcome was the cost of knee OA-related payments for identified nonoperative procedures in the 1-year period before surgery. Nonoperative procedures examined were (1) physical therapy (PT); (2) bracing; (3) intra-articular injections: professional fee, hyaluronic acid (IA-HA), and corticosteroids (IA-CS); (4) medication: nonsteroidal anti-inflammatory drugs (NSAIDs), opioids, and acetaminophen; and (5) knee-specific imaging. RESULTS: The study population included 24,492 TKA patients with a mean age of 60.4 ± 8.0 years. The average total cost of nonoperative procedures per patient was $1,355 ± $2,087. The most common nonoperative treatment prescribed was IA-CS (54.3%). The nonoperative procedure with the highest cost per patient was IA-HA ($1,019 ± $913 per patient). The total cost of nonoperative procedures was higher among female compared with male patients ($1,440 ± $2,159 versus $1,254 ± $1,992 per patient; p < 0.01). The highest costs were found for patients in the Northeast ($1,740 ± $2,437 per patient). A total of 14,346 (58.6%) and 7,831 (32.0%) of the patients had >1 and ≥3 nonoperative treatments, respectively. CONCLUSIONS: There is substantial variation in the type and the cost of nonoperative treatment for patients with late-stage OA. Future studies should investigate the effectiveness of nonoperative treatments at different stages of the disease. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Drivers of Unequal Healthcare Costs in the Nonoperative Treatment of Late-Stage Knee Osteoarthritis Prior to Primary Total Knee Arthroplasty.

BACKGROUND: In the United States, patients with late-stage knee osteoarthritis (OA) often undergo several nonoperative treatments and related procedures prior to total knee arthroplasty. The costs of these treatments and procedures are substantial, and the variation in healthcare costs among different groups of patients may exist. The purpose of this study is to examine these costs and determine the drivers of costs in patients with the highest healthcare expenditure. METHODS: An observational cohort study was conducted using the IBM Watson Health MarketScan databases from January 1, 2017 to December 31, 2019. The primary outcome was the cost of payments for nonoperative procedures which included (i) physical therapy (PT), (ii) bracing, (iii) intra-articular injections: professional fee, hyaluronic acid (IA-HA), and corticosteroids (IA-CS), (iv) medication: nonsteroidal anti-inflammatory drugs (NSAIDs), opioids, and acetaminophen, and (v) knee-specific imaging. RESULTS: Among the 24,492 patients included in the study, the total payments per patient for nonoperative care were $3,735 ± 3,049 in the highest payment quartile (Q4) and $137 ± 70 in the lowest payment quartile (Q1). Per-patient-per-month costs generally increased across quartiles for procedures. Comparing Q4 to Q1, the largest changes in prevalence were found in IA-HA (348×), bracing (10×), and PT (7×). Patients who were prescribed IA-HA and PT had a 28.3-times and 4.8-times greater likelihood, respectively, to be a higher-paying patient. CONCLUSION: Unequal healthcare costs in the nonoperative treatment of late-stage knee OA are driven by differences in prevalent management strategies. Overall healthcare expenditure may be reduced if only guideline-concordant treatments are used.

Elimination of Routine Urinalysis before Elective Orthopaedic Surgery Reduces Antibiotic Utilization without Impacting Catheter-associated Urinary Tract Infection or Surgical Site Infection Rates.

PURPOSE: Routine preoperative urinalysis has been the standard of care for the orthopedic population for decades, regardless of symptoms. Studies have demonstrated antibiotic overuse and low concordance between bacteria cultured from the surgical wound and the urine. Testing and treatment of asymptomatic urinary tract colonization before total joint arthroplasty (TJA) is unnecessary and increases patient risk. We investigated reducing antibiotic use by (1) modifying testing algorithms to target patients at risk, (2) modifying reflex to culture criteria, and (3) providing treatment guidelines. MATERIALS AND METHODS: A pre-post study was conducted to determine identify the impact of eliminating universal urinalysis prior to TJA on surgical site infection (SSI) and catheter-associated urinary tract infection (CAUTI) rates and number of antibiotic prescriptions. Patients who underwent primary hip or knee TJA or spinal fusions from February 2016 to March 2018 were included. Patient data was collected for pre- and post-practice change period (February 2016-October 2016 and August 2017-March 2018). Patient demographics, urinalysis results, cultures, and prescriptions were analyzed retrospectively from every tenth chart in the pre-period and prospectively on all patients in the post-period. RESULTS: A total of 4,663 patients were studied. There was a 96% decrease in urinalyses performed (P<0.0001), and a 93% reduction rate in antibiotic utilization (P<0.001). No significant difference in SSI and CAUTI rates was observed (P>0.05). CONCLUSION: The elimination of routine urinalysis before orthopedic surgery resulted in a reduction in antibiotic utilization with no significant change in the SSI or CAUTI rates. Cost savings resulted from reduced antibiotic usage.

Addressing decontaminated respirators: Some methods appear to damage mask integrity and protective function.

Decontamination of N95 respirators is being used by clinicians in the face of a global shortage of these devices. Some treatments for decontamination, such as some vaporized hydrogen peroxide methods or ultraviolet methods, had no impact on respiratory performance, while other treatments resulted in substantial damage to masks.

Risk factors for Staphylococcus aureus colonization in a presurgical orthopedic population.

BACKGROUND: Preoperative colonization with Staphylococcus aureus (SA) increases risk of surgical site infection. Screening for SA followed by skin and nasal decolonization can help to reduce the risk of postoperative infections. Risk factors for colonization are, however, not completely understood. METHODS: A case-control study using questionnaires and patient demographics specifically designed to observe SA colonization risk factors in a presurgical orthopedic population. A total of 115 subjects with a positive preoperative screen for SA nasal colonization prior to orthopedic surgery completed a questionnaire to assess for SA risk factors: these subjects served as our cases. An additional 476 controls completed similar questionnaires. Data collected included demographic, health, and lifestyle information. Multivariable logistic regression was used to generate odds ratios (OR) for risk of SA colonization. RESULTS: Several risk factors were identified. Male sex (OR 2.3; 95% confidence interval [CI], [1.4-3.8]) and diabetes (OR 3.8 [1.8-7.8]) significantly increased the risk of SA colonization. Older age, visiting public places (OR 0.2 [0.1-0.3]), recent antibiotic use (OR 0.2 [0.1-0.6]), and the presence of facial hair (OR 0.3 [0.1-0.6]) significantly lowered the risk of SA colonization. CONCLUSIONS: By identifying patients who may be at greater risk of SA colonization, we can better streamline our presurgical techniques to help reduce risk of surgical site infections and improve patient outcomes.

Disinfection of Blood Pressure Cuffs and Electrocardiographic Telemetry Leads With 0.5% Hydrogen Peroxide Wipes.

BACKGROUND: Disinfection of frequently touched surfaces in the hospital is critical for providing safe care. Because of their complex intricate surfaces, blood pressure cuffs and electrocardiographic telemetry leads may be harder than other equipment to disinfect. OBJECTIVE: To determine the effectiveness of 0.5% hydrogen peroxide wipes in cleaning and disinfecting inpatient hospital surfaces, including hook and loop (Velcro) fasteners of blood pressure cuffs and electrocardiographic telemetry leads. METHODS: A prospective study of an inpatient telemetry unit was designed to measure the persistence of a UV indicator and the presence of bacterial colonization on electrocardiographic telemetry leads and blood pressure cuffs. Call buttons and patient trays were used as control surfaces, because they are often touched but are easy to disinfect via standard practices. RESULTS: A total of 392 samples were collected between July 11 and August 3, 2016, and cultured for microorganisms. Among the cultures, 247 (63%) had at least 1 colony-forming unit. After adjustments in a multivariable analysis, odds of a contaminated surface (≥ 10 colony-forming units) after final cleaning with 0.5% hydrogen peroxide wipes were 3.70 times greater for patient trays than for blood pressure cuffs (P = .03) and 3.80 times greater for telemetry leads than for blood pressure cuffs (P = .04). The UV indicator persisted longer on blood pressure cuffs and telemetry leads than on patient trays or call buttons (P < .001). CONCLUSION: Wipes with 0.5% hydrogen peroxide adequately disinfect blood pressure cuffs but not telemetry leads.

Door openings in the operating room are associated with increased environmental contamination.

Door openings in the operating room (OR) have been hypothesized to increase OR environmental contamination. This study measured average colony-forming units (CFU) in the OR as a function of door openings and other potentially important variables. Bacterial settle plates were placed inside and outside of laminar airflow (LAF) by both exit doors, on the instrument table, and on the back instrument table (if applicable) for 48 orthopedic and general surgery procedures. CFU data were paired to Staphylococcus aureus colonization status, door openings, surgery duration, time of day, OR location, number of staff, use of warming devices, temperature, and humidity. The number of door openings in the OR and surgery duration were significantly associated with increased CFU in the OR overall and outside of LAF. However, under LAF conditions, only the number of OR personnel was significantly associated with increased CFU.

Invasiveness Index as a Predictor of Surgical Site Infection after Spinal Fusion, Revision Fusion, or Laminectomy.

OBJECTIVE To evaluate invasiveness index as a potential predictor of spine surgical site infection (SSI) after spinal fusion, revision fusion, or laminectomy. DESIGN Retrospective cohort study. SETTING Single, large, academic medical center. PATIENTS Adults undergoing spinal fusion, revision fusion, or laminectomy. METHODS Data were obtained from electronic hospital databases; cases of SSI were extracted from the infection control database using National Healthcare Safety Network (NHSN) definitions. For each case, an invasiveness index, determined by surgical approach, procedure, and number of spine levels treated, was calculated using current procedural terminology (CPT) billing codes. Statistical analyses were performed using univariate and multivariate logistic regression models. RESULTS In total, 3,143 patients met inclusion criteria, and 43 of these developed SSI. Multivariate regression showed that advanced age (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.005-1.05, for each year of life) and invasiveness index (medium invasiveness index OR, 5.36; 95% CI, 1.92-14.96; high invasiveness index OR, 14.1; 95% CI, 4.38-45.43) were significant predictors of infection. In subgroup analyses of spinal fusion patients, morbid obesity (OR, 2.542; 95% CI, 1.08-5.99), trauma (OR, 2.41; 95% CI, 1.05-5.55), and invasiveness index (medium invasiveness index OR, 5.39; 95% CI, 1.56-18.61; high invasiveness index OR, 13.44; 95% CI, 3.28-55.01) were significant predictors of SSI. Models containing invasiveness index were compared to NHSN models and demonstrated similar performance. CONCLUSIONS Invasiveness index is a predictor of SSI after spinal fusion and performs similarly to NHSN models. Invasiveness index shows promise as a potential risk stratification tool that is easily calculated and is available preoperatively. Infect Control Hosp Epidemiol 2016:1-7.

Intrinsic and acquired resistance mechanisms in enterococcus.

Enterococci have the potential for resistance to virtually all clinically useful antibiotics. Their emergence as important nosocomial pathogens has coincided with increased expression of antimicrobial resistance by members of the genus. The mechanisms underlying antibiotic resistance in enterococci may be intrinsic to the species or acquired through mutation of intrinsic genes or horizontal exchange of genetic material encoding resistance determinants. This paper reviews the antibiotic resistance mechanisms in Enterococcus faecium and Enterococcus faecalis and discusses treatment options.