Robotic-assisted TKA is Not Associated With Decreased Odds of Early Revision: An Analysis of the American Joint Replacement Registry.

BACKGROUND: Robotic-assisted TKA continues to see wider clinical use, despite limited knowledge of its impact on patient satisfaction and implant survival. Most studies to date have presented small cohorts and came from single-surgeon or single-center experiences. Therefore, a population-level comparison of revision rates between robotic-assisted and conventional TKA in the registry setting may help arthroplasty surgeons better define whether robotic assistance provides a meaningful advantage compared with the conventional technique. QUESTIONS/PURPOSES: (1) After controlling for confounding variables, such as surgeon, location of surgery, and patient comorbidity profile, were robotic-assisted TKAs less likely than conventional TKAs to result in revision for any reason at 2 years? (2) After again controlling for confounding variables, were robotic-assisted TKAs less likely to result in any specific reasons for revision than the conventional technique at 2 years? METHODS: The American Joint Replacement Registry was used to identify patients 65 years or older who underwent TKA between January 2017 and March 2020 with a minimum of 2 years of follow-up. Patients were limited to age 65 yeas or older to link TKAs to Medicare claims data. Two retrospective cohorts were created: robotic-assisted TKA and conventional TKA. Patient demographic variables included in the analysis were age, gender, BMI, and race. Additional characteristics included the Charlson comorbidity index, anesthesia type, year of the index procedure, and length of stay. A total of 10% (14,216 of 142,550) of TKAs performed during this study period used robotics. Patients with robotic-assisted TKA and those with conventional TKA were similar regarding age (73 ± 6 years versus 73 ± 6 years; p = 0.31) and gender (62% [8736 of 14,126] versus 62% [79,399 of 128,334] women; p = 0.34). A multivariable, mixed-effects logistic regression model was created to analyze the odds of all-cause revision as a factor of robot use, and a logistic regression model was created to investigate specific revision diagnoses. RESULTS: After controlling for potentially confounding variables, such as surgeon, location of surgery, and Charlson comorbidity index, we found no difference between the robotic-assisted and conventional TKAs in terms of the odds of revision at 2 years (OR of robotic-assisted versus conventional TKA 1.0 [95% CI 0.8 to 1.3]; p = 0.92). The reasons for revision of robotic-assisted TKA did not differ from those of conventional TKA, except for an increased odds of instability (OR 1.6 [95% CI 1.0 to 2.4]; p = 0.04) and pain (OR 2.1 [95% CI 1.4 to 3.0]; p < 0.001) in the robotic-assisted cohort. CONCLUSION: In light of these findings, surgeons should not assume that robotic assistance in TKA will lead to improved early implant survival. Our findings do not support an improvement over conventional TKA with robotic assistance with regards to common causes of early revisions such malalignment, malposition, stiffness, pain, and instability, and in some cases, suggest there is a benefit to conventional TKA. Differences in the mid-term and long-term revision risk with conventional versus robotic-assisted TKA remain unknown. Appropriate informed consent around the use of robotic assistance should not imply decreased early revision risk. LEVEL OF EVIDENCE: Level III, therapeutic study.

Venous thromboembolism prophylaxis in shoulder surgery: a break-even cost-effectiveness study.

BACKGROUND: Venous thromboembolism (VTE) is a serious complication following orthopedic shoulder surgery; however, research is limited involving the break-even cost-effectiveness of VTE prophylaxis. The purpose of this study was to determine whether the cost of aspirin and enoxaparin would break even for VTE prevention in patients following shoulder surgery. METHODS: A drug retail database was used to obtain the lowest price for a course of aspirin (81 mg) and enoxaparin (40 mg) to perform a break-even cost analysis. Our institutional purchasing records were then searched to estimate the cost of treating a symptomatic VTE. The TriNetX national database was queried to establish a rate of VTE after shoulder surgery. A break-even cost analysis was performed by determining the absolute risk reduction (ARR). This value was used to calculate the number of patients who are treated to prevent a single VTE while breaking even on cost. Sensitivity analyses were performed for drugs that did not break even at the database-derived VTE rates. RESULTS: Full medication courses of aspirin and enoxaparin were found to cost $1.18 and $125.37, respectively. The cost of treating a symptomatic VTE was determined to be $9407.00. Data from the TriNetX database showed rates of symptomatic VTE following shoulder arthroplasty, hemiarthroplasty, and arthroscopic rotator cuff repair of 1.60%, 1.50%, and 0.68%, respectively. Aspirin broke even on cost for all procedures if the initial rate decreased by an ARR of 0.01% (number needed to treat, 7972). Similarly, enoxaparin broke even for shoulder arthroplasty and hemiarthroplasty if the initial rate of VTE decreased by an ARR of 1.33% (number needed to treat, 75). Enoxaparin did not break even at the initial VTE rate for arthroscopic rotator cuff repair; however, sensitivity analysis found enoxaparin would break even if the drug could be obtained at a cost of ≤$60.00. Enoxaparin broke even if the cost of treating a symptomatic VTE was ≥$20,000.00. CONCLUSIONS: The cost of a 3-week course of twice-daily aspirin or once-daily enoxaparin breaks even for VTE prophylaxis following shoulder arthroplasty and hemiarthroplasty if these drugs reduce the VTE rate by a calculated ARR. Given the lower rate of VTE observed for patients undergoing arthroscopic rotator cuff repair, only the 3-week course of aspirin broke even under these conditions. Once-daily enoxaparin did not break even at current market rate. Further research is needed to help determine optimal VTE prophylaxis after shoulder surgery.

Vancomycin Powder Is Highly Cost-Effective in Total Ankle Arthroplasty.

Prosthetic joint infection (PJI) is a costly and potentially fatal complication in total ankle arthroplasty (TAA). Some surgeons apply topical vancomycin powder to minimize the risk of infection during TAA procedures. The purpose of our study was to determine the cost-effectiveness of using vancomycin powder to prevent PJI following TAA and to propose an economic model that can be applied by foot and ankle surgeons in their decision to incorporate vancomycin powder in practice. Using our institution's records of the cost of 1 g of topical vancomycin powder, we performed a break-even analysis and calculated the absolute risk reduction and number needed to treat for varying costs of vancomycin powder, PJI infection rates, and costs of TAA revision. Costing $3.06 per gram at our institution, vancomycin powder was determined to be cost-effective in TAA if the PJI rate of 3% decreased by an absolute risk reduction of 0.02% (Number Needed to Treat = 5304). Furthermore, our results indicate that vancomycin powder can be highly cost-effective across a wide range of costs, PJI infection rates, and varying costs of TAA revision. The use of vancomycin powder remained cost-effective even when (1) the price of vancomycin powder was as low as $2.50 to as high as $100.00, (2) infection rates ranged from .05 to 3%, and (3) the cost of the TAA revision procedure ranged from $1000 to $10 000.Levels of Evidence: IV.

Factors Associated With Amputation Following Ankle Fracture Surgery.

Patients with diabetes mellitus (DM) are at increased risk of complications following ankle fracture surgery. Previous research suggests that patients of low socioeconomic status are at increased risk of amputation following orthopedic complications. The purpose of this research was to determine if low socioeconomic status increases risk of below-knee amputation (BKA) following ankle fractures among patients with DM. The National Inpatient Sample (NIS) was queried from 2010 to 2014 to identify 125 diabetic patients who underwent ankle fracture surgical fixation followed by BKA. Two cohorts (BKA vs no BKA) and a multivariate logistic regression model were created to compare the effects of independent variables, including age, sex, race, primary payer, median household income by ZIP code, hospital location/teaching status, and comorbidities. The most predictive variables for BKA were concomitant peripheral vascular disease (odds ratio [OR] 5.35, 95% confidence interval [CI] 3.51-8.15), history of chronic diabetes-related medical complications (OR 3.29, CI 2.16-5.01), age in the youngest quartile (OR 2.54, CI 1.38-4.67), and male sex (OR 2.28, CI 1.54-3.36). Patient race and median household income were not significantly associated with BKA; however, risk of BKA was greater among patients with Medicaid (OR 2.23, CI 1.09-4.53) or Medicare (OR 1.85, CI 1.03-3.32) compared to privately insured patients. Diabetic inpatients with Medicaid insurance are at over twice the odds of BKA compared to privately insured patients following ankle fracture. Furthermore, peripheral vascular diseases, uncontrolled diabetes, younger age, and male sex each independently increase risk of BKA.

Venous Thromboembolism Chemoprophylaxis in Knee Arthroscopy: A Break-Even Analysis of Cost.

BACKGROUND: Symptomatic venous thromboembolism (VTE) is a serious and costly complication after knee arthroscopy. There continues to be debate regarding the use of VTE prophylaxis after knee arthroscopy, and minimal research has explored its cost-effectiveness. HYPOTHESIS: Both aspirin and enoxaparin would be cost-effective in preventing symptomatic VTE. STUDY DESIGN: Economic and decision analysis; Level of evidence, 3. METHODS: The literature was searched and the TriNetX research database was queried to determine a range of initial rates of VTE. An open-access retail database was used to determine the mean retail price for aspirin (325 mg) and enoxaparin (30 mg and 40 mg). Our institutional records were used to determine the cost of treating VTE. A "break-even" analysis was then performed to determine the absolute risk reduction necessary to make these drugs cost-effective. This value was then used to calculate the number of patients who would need to be treated (NNT) to prevent a single VTE while still breaking even on cost. RESULTS: The cost of treating VTE was $9407 (US Dollars). Aspirin (325 mg), enoxaparin (30 mg), and enoxaparin (40 mg) were found to cost $1.86, $188.72, and $99.99, respectively. The low, TriNetX, and high rates of VTE were 0.34%, 0.86%, and 10.9%, respectively. Aspirin was cost-effective at all 3 rates if the initial rate decreased by 0.02% (NNT = 5058). Both formulations of enoxaparin were cost-effective at the high initial rate if they decreased by 2.01% (NNT = 50) and 1.06% (NNT = 94), respectively. However, at the low and TriNetX rates, the 2 doses of enoxaparin were not cost-effective because their final break-even rate exceeded the initial VTE rate. CONCLUSION: Aspirin and, in some cases, enoxaparin are cost-effective treatments for VTE prophylaxis after knee arthroscopy.

Cost-Effective Modeling of Thromboembolic Chemoprophylaxis for Total Ankle Arthroplasty.

BACKGROUND: Symptomatic venous thromboembolism (VTE) following total ankle arthroplasty (TAA) can cause substantial morbidity and mortality. To prevent this complication, surgeons often prescribe postoperative chemoprophylaxis. However, much controversy exists regarding the efficacy of chemoprophylaxis because of the limited studies exploring its use. Furthermore, even less is known about its cost-effectiveness. Therefore, this study sought to determine the cost-effectiveness of commonly prescribed chemoprophylactic agents using a break-even analysis economic model. METHODS: The literature was searched, and an online database was used to identify patients who developed a symptomatic VTE after undergoing TAA. Our institutional records were used to estimate the cost of treating a symptomatic VTE, and an online drug database was used to obtain the cost of commonly prescribed chemoprophylactic agents. A break-even analysis was then performed to determine the final break-even rate necessary to make a drug cost-effective. RESULTS: The low and high rates of symptomatic VTE were determined to be 0.46% and 9.8%. From 2011 to 2021, a total of 3455 patients underwent total ankle arthroplasty. Of these patients, 16 developed a postoperative symptomatic VTE (1.01%). Aspirin 81 mg was cost-effective if the initial symptomatic VTE rates decreased by an absolute risk reduction (ARR) of 0.0003% (NNT = 31 357). Aspirin 325 mg was also cost-effective if the initial rates decreased by an ARR 0.02% (NNT = 5807). Likewise, warfarin (5 mg) was cost-effective at all initial rates with an ARR of 0.02% (NNT = 4480). In contrast, enoxaparin (40 mg) and rivaroxaban (20 mg) were only cost-effective at higher initial symptomatic VTE rates with ARRs of 1.48% (NNT = 68) and 5.36% (NNT = 19). Additional analyses demonstrated that enoxaparin (40 mg) and rivaroxaban (20 mg) become cost-effective when costs of treating a symptomatic VTE are higher than our estimates. CONCLUSION: Chemoprophylaxis following TAA can be cost-effective. A tailored approach to VTE prophylaxis with cost-effectiveness in mind may be beneficial to the patient and health system.

Intraoperative Imaging in Total Hip Arthroplasty Is Cost-Effective Regardless of Surgical Approach.

BACKGROUND: Component positioning in total hip arthroplasty (THA) may be improved with utilization of intraoperative imaging. The purpose of this study is to determine if intraoperative imaging during THA is cost-effective. METHODS: A break-even analysis was used as a model for cost-effectiveness, which incorporates cost of imaging (including direct charges and the additional time required for imaging), rate of revision surgery, and cost of revision surgery, yielding a final revision rate that needs to be achieved with use of intraoperative imaging in order for its use to be cost-effective. Absolute risk reduction (ARR) is determined by the difference between the initial revision rate and final revision rate. RESULTS: At an anticipated institutional cost of $120 and requiring 4 additional minutes, intraoperative fluoroscopy would be cost-effective if the baseline rate of revision due to component mispositioning (0.62%) is reduced to 0.46%. Intraoperative flat plate radiographs ($127) are cost-effective at an ARR of 0.16%. Cost-effectiveness is achieved with lower ARR in the setting of lower imaging costs ($15, ARR 0.02%), and higher ARR with higher imaging costs ($225, ARR 0.29%). ARR for cost-effectiveness is independent of baseline revision rate, but varies with the cost of revision procedures. CONCLUSION: At current revision rates for component malpositioning, only 1 revision among 400 THAs needs to be prevented for the utilization of fluoroscopy (or 1 in 385 THAs with flat plate imaging), to achieve cost-effectiveness.

Intra-wound vancomycin and tobramycin powder for infection prophylaxis in orthopaedic trauma surgery: Economically justifiable?

OBJECTIVES: There is increasing interest regarding the risks and benefits of intrawound antibiotics applied directly to surgical wounds for the prevention of infection following orthopaedic trauma surgery. The purpose of this study was to investigate the economic justifiability of vancomycin and tobramycin powders for infection prophylaxis in orthopaedic trauma surgery. METHODS: The cost of vancomycin and tobramycin powders, infection rates and costs of treating surgical site infections were obtained from our institution's records and existing literature. A break-even analysis was then performed using vancomycin powder only, tobramycin powder only and combined vancomycin and tobramycin powders to determine the respective absolute risk reduction (ARR) in infection rate needed to make the prophylactic application of each therapy type break-even. RESULTS: At our institutional pricing of $20.64 and $75.80 for 1g vancomycin and 1.2g tobramycin, respectively, use of each individually would be economically justified if it reduced an average infection rate of 4.3% by an ARR of 0.02% and 0.07%, respectively. Used in combination for $90.66, the ARR was 0.09%. Varying cost of treating infection from $5,000-$200,000 while maintaining cost of antibiotic powder at $90.66 demonstrated a range in ARR from 1.93% to 0.05%, respectively. At the same cost of $90.66 but varying infection rate from 1% to 25% did not affect ARR, which was constant at 0.09%. CONCLUSIONS: Considering the cost of vancomycin and tobramycin powder at our institution, the application of these powders, whether independently or in combination, appear to be economically justifiable for infection prevention in orthopaedic trauma surgery.

Cost-effectiveness of Inpatient Tympanostomy Prophylaxis.

OBJECTIVE: Tympanostomy is the most common pediatric ambulatory surgery. Post-tympanostomy otorrhea is a prevalent complication leading to high costs to patients for treatment. The cost-effectiveness of intraoperative prophylaxis for both patient and institution has not been examined. STUDY DESIGN: An analytical observational study of data collected from the literature and purchasing records. METHODS: A break-even analysis was performed to determine the required absolute risk reduction (ARR) and final infection rate in post-tympanostomy otorrhea to make intraoperative prophylaxis using ofloxacin and ciprofloxacin dexamethasone otic version cost effective with the following outpatient treatments: ofloxacin, ciprofloxacin-dexamethasone ophthalmic version, and ciprofloxacin-dexamethasone otic version. Absolute risk reduction is a statistic used to express the difference in risk between a treatment and control. The conservative initial infection rate used was 10%. RESULTS: Ofloxacin intraoperative prophylaxis was not cost effective when prescribing ofloxacin outpatient treatment with an ARR of 0.20. Ofloxacin intraoperative prophylaxis was cost-effective with an ARR of 0.08 for ciprofloxacin-dexamethasone ophthalmic version outpatient treatment. Ofloxacin intraoperative prophylaxis was cost-effective for ciprofloxacin-dexamethasone otic version outpatient treatment with an ARR of 0.01.Ciprofloxacin-dexamethasone intraoperative prophylaxis was not cost-effective when prescribing ofloxacin outpatient treatment with an ARR of 1.52. Ciprofloxacin-dexamethasone intraoperative prophylaxis was not cost-effective when prescribing ciprofloxacin-dexamethasone ophthalmic version outpatient treatment with an ARR of 0.60. Ciprofloxacin-dexamethasone intraoperative prophylaxis was cost effective when prescribing ciprofloxacin-dexamethasone otic version outpatient treatment with an ARR of 0.09. CONCLUSION: Intraoperative prophylaxis can be cost effective for preventing post-tympanostomy otorrhea. Physicians can use this economic model to determine the cost-effectiveness of these interventions for their patients and institutions.

In-Hospital Complications following Arthrotomy versus Arthroscopy for Septic Knee Arthritis: A Cohort-Matched Comparison.

There is a paucity of literature comparing the relative merits of open arthrotomy versus arthroscopy for the surgical treatment of septic knee arthritis. The primary goal of this study is to compare the risk of perioperative complications between these two surgical techniques. To this end, 560 patients treated for septic arthritis of the native knee with arthroscopy were statistically matched 1:1 with 560 patients treated with open arthrotomy. The outcome measures included major complications, minor complications, mortality, inpatient hospital charges, and length of stay (LOS). Major complications were defined as myocardial infarction, cardiac arrest, stroke, deep vein thrombosis, pulmonary embolism, pneumonia, postoperative shock, unplanned ventilation, deep surgical site infection, wound dehiscence, infected postoperative seroma, hospital acquired urinary tract infection, and retained surgical item. Minor complications included phlebitis and thrombophlebitis, postprocedural emphysema, minor surgical site infection, peripheral nerve complication, and intraoperative hemorrhage. Mortality data were extracted from the database using the Uniform Bill patient disposition. Complications were analyzed using univariate and multivariate logistic regression models, whereas mean costs and LOS were compared using the Kruskal-Wallis H-test. Major complications occurred in 3.8% of the patients in the arthroscopy cohort and 5.4% of the patients in the arthrotomy cohort (p = 0.20). Too few patients in our sample died to report based on National (Nationwide) Impatient Sample (NIS) minimum reporting standards. Rates of minor complications were similar for the arthroscopy and arthrotomy cohorts (12.5 vs. 13.9%; p = 0.48). Multivariate analysis did not reveal any greater risk of minor or major complication between the two procedures. Inpatient hospital cost was similar for arthroscopy ( = $15,917; standard deviation [SD] = 14,424) and arthrotomy ( = $16,020; SD = 18,665; p = 0.42). LOS was also similar for both arthrotomy (6.78 days, SD = 6.75) and arthroscopy (6.24 days, SD = 5.95; p = 0.23). Patients undergoing arthroscopic treatment of septic arthritis of the knee showed no difference in relative risk of perioperative complications, LOS, or hospital cost compared with patients who underwent open arthrotomy.

The Cost-Effectiveness of Vancomycin Powder in Lumbar Laminectomy.

STUDY DESIGN: Break-even cost analysis. OBJECTIVE: The goal of this study is to examine the cost-effectiveness of vancomycin powder for preventing infection following lumbar laminectomy. METHODS: The product cost of vancomycin powder was obtained from our institution's purchasing records. Infection rates and revision costs for lumbar laminectomy and lumbar laminectomy with fusion were obtained from the literature. A break-even analysis was then performed to determine the absolute risk reduction (ARR) in infection rate to make prophylactic application of vancomycin powder cost-effective. Analysis of lumbar laminectomy with fusion was performed for comparison. RESULTS: Costing $3.06 per gram at our institution, vancomycin powder was determined to be cost-effective in lumbar laminectomy if the infection rate of 4.2% decreased by an ARR of 0.015%. Laminectomy with fusion was also determined to be cost-effective at the same cost of vancomycin powder if the infection rate of 8.5% decreased by an ARR of 0.0034%. The current highest cost reported in the literature, $44.00 per gram of vancomycin powder, remained cost-effective with ARRs of 0.21% and 0.048% for laminectomy and laminectomy with fusion, respectively. Varying the baseline infection rate did not influence the ARR for either procedure when the analysis was performed using the product cost of vancomycin at our institution. CONCLUSIONS: This break-even analysis demonstrates that prophylactic vancomycin powder can be highly cost-effective for lumbar laminectomy. At our institution, vancomycin powder is economically justified if it prevents at least one infection out of 6700 lumbar laminectomy surgeries.

The Cost of Robot-assisted Total Hip Arthroplasty: Comparing Safety and Hospital Charges to Conventional Total Hip Arthroplasty.

INTRODUCTION: Utilization of robotic assistance is increasing for total hip arthroplasty (THA). However, few studies have directly examined the efficacy of this technique at reducing complications. This research aims to compare the rates of perioperative complications of robotic-assisted THA (RA-THA) with conventional THA (C-THA). METHODS: This study screened more than 35 million hospital discharges between 2010 to 2014 using the National Inpatient Sample. The International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes were used to identify 292,836 patients who underwent C-THA (ICD 81.51) and 946 patients who underwent RA-THA (ICD 81.51 and ICD 17.41, 17.49). Perioperative complications were identified using ICD-9-CM diagnosis codes. Patient mortality was determined using the Uniform Bill patient disposition. The RA-THA cohort was statistically matched 1:1 to C-THA about patient age, sex, race, comorbidities, hospital type, and calendar year. Mean cost and length of stay (LOS) for each cohort were calculated and compared using the Kruskal-Wallis H test. Logistic regression was used to compare the risks of major and minor complications between the cohorts. RESULTS: We matched 758 (80.13%) RA-THA patients with 758 patients who underwent C-THA. No patient in our sample died. When compared with the conventional group, multivariate analysis revealed that the risk of major complications was similar in RA-THA patients (odds ratio = 0.698, 95% confidence interval = 0.282 to 1.727). In addition, although the rate of minor complications was higher in the RA-THA cohort (21.6% versus 12.5%, P = 0.004), no difference was observed on multivariate analysis (odds ratio = 1.248, 95% confidence interval = 0.852 to 1.829). The average inpatient hospital cost of a RA-THA was $20,046 (SD = 6,165) compared with $18,258 (SD = 6,147) for C-THA (P < 0.001). The average LOS was for RA-THA was 2.69 days (SD = 1.25) compared with 2.82 days for C-THA (SD = 1.18, P < 0.001). DISCUSSION: In a statistically matched cohort, the risk of perioperative complication in patients who underwent RA-THA versus C-THA patients were similar. However, RA-THA was costlier despite shorter LOS. LEVEL OF EVIDENCE: Level III, retrospective cohort analysis.

Socioeconomic Status Is Associated With the Risk of Girdlestone Resection Arthroplasty After Periprosthetic Infection of the Hip.

INTRODUCTION: Girdlestone resection arthroplasty (GRA) is a radical but sometimes necessary treatment of periprosthetic joint infection (PJI) of the hip. The purpose of this of this study was to identify the independent risk factors for GRA after PJI of the hip. METHODS: This is a retrospective, cross-sectional analysis of the National (Nationwide) Inpatient Sample from 2010 to 2014. The International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) was used to identify 27,404 patients with PJI of the hip, including 889 patients who underwent GRA (ICD-9-CM 80.05). A multivariate model was created to examine the association between GRA and patient characteristics such as age, sex, race, primary payer, median household income, and location and teaching status of the hospital where the procedure was performed. Furthermore, the model controlled for patient comorbidities, including diabetes, anemias, hypertension, congestive heart failure, chronic pulmonary disease, peripheral vascular disease, and drug abuse. RESULTS: The strongest independent risk factor for GRA was Medicare insurance (odds ratio [OR], 1.859, 95% confidence interval [CI], 1.500 to 2.304). Medicaid insurance was also associated with GRA (OR, 1.662, CI, 1.243 to 2.223). Compared with the wealthiest quartile for household income, patients in the poorest quartile (OR, 1.299, CI, 1.046 to 1.614) and second poorest quartile (OR, 1.269, CI, 1.027 to 1.567) were significantly more likely to have a GRA. Furthermore, patients older than 80 years old were at a higher risk of GRA than all other age groups (P < 0.05). No statistical differences were seen regarding patient race or sex. CONCLUSIONS: This study demonstrates that poorer patients, patients with government health insurance plans, and elderly patients are each at independently heightened risk of undergoing a GRA for the treatment of PJI of the hip. LEVEL OF EVIDENCE: III, retrospective cohort study.

Cost-effectiveness of Preoperative Staphylococcus aureus Screening and Decolonization in Cochlear Implantation.

OBJECTIVE: Infection following cochlear implantation is medically and economically devastating. The cost-effectiveness (CE) of colonization screening and decolonization for infection prophylaxis in cochlear implantation has not been examined. STUDY DESIGN: An analytic observational study of data collected from purchasing records and the literature. METHODS: Costs of Staphylococcus aureus colonization screening and decolonization were acquired from purchasing records and the literature. Infection rates after cochlear implantation and average total costs for evaluation and treatment were obtained from a review of the literature. A break-even analysis was performed to determine the required absolute risk reduction (ARR) in infection rate to make colonization screening or decolonization CE. RESULTS: Nasal screening ($144.07) is CE if the initial infection rate (1.7%) had an ARR of 0.60%. Decolonization with 2% intranasal mupirocin ointment ($5.09) was CE (ARR, 0.02%). A combined decolonization technique (2% intranasal mupirocin ointment, chlorhexidine wipes, chlorhexidine shower, and prophylactic vancomycin: $37.57) was CE (ARR, 0.16%). Varying infection rate as high as 15% demonstrated that CE did not change by maintaining an ARR of 0.16%. CE of the most expensive decolonization protocol was enhanced as the cost of infection treatment increased, with an ARR of 0.03% at $125,000. CONCLUSIONS: Prophylactic S aureus decolonization techniques can be CE for preventing infection following cochlear implantation. Decolonization with mupirocin is economically justified if it prevents at least 1 infection out of 5000 implants. S aureus colonization screening needed high reductions in infection rate to be CE.

Socioeconomic Status Is Associated with Risk of Above-knee Amputation After Periprosthetic Joint Infection of the Knee.

BACKGROUND: Above-knee amputation (AKA) is a severe but rare complication of TKA. Recent evidence suggests there are sex and racial disparities with regard to AKA after TKA. However, whether lower socioeconomic status is associated with an increased risk of AKA after TKA has not been conclusively established. QUESTIONS/PURPOSES: (1) Is low socioeconomic status or use of public health insurance plans associated with an increased risk of AKA after periprosthetic joint infection (PJI) of the knee? (2) Is race or sex associated with an increased risk of AKA after PJI of the knee? METHODS: This cross-sectional study screened the National Inpatient Sample (NIS) between 2010 and 2014 using the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) procedure and diagnosis codes to identify 912 AKAs (ICD 84.17) among 32,907 PJIs of the knee. The NIS is a large national database of inpatient hospitalizations frequently used by researchers to study outcomes and trends in orthopaedic procedures. The NIS was selected over other databases with more complete followup data such as the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) due to its unique ability to examine income levels and insurance type. Cases were identified by taking all patients with an ICD diagnosis code related to PJI of the knee and limiting that cohort to patients with an ICD procedure code specific to TKA. A total of 912 AKAs after PJI were identified (912 of 32,907, [3%] of all PJIs of the knee) with males comprising 52% of the AKA sample (p = 0.196). Multivariate logistic regression was used to compare risk of AKA after PJI of the knee after controlling for patient demographics, hospital characteristics, and comorbidities. RESULTS: Compared with the wealthiest income quartile by ZIP code, patients in the lowest income quartile by ZIP code were more likely to sustain an AKA (OR = 1.58; 95% confidence interval [CI] 1.25-1.98; p < 0.001). Compared with patients with private insurance, patients with Medicare (OR = 1.94; 95% CI, 1.55-2.43; p < 0.001) and Medicaid (OR = 1.86; 95% CI, 1.37-2.53; p < 0.001) were at higher risk of AKA. There were no differences with regard to risk of AKA for white patients (670 of 24,004 [3%]; OR = 0.99; 95% CI, 0.77-1.26; p = 0.936) and black patients (95 of 3178 [3%], OR = 0.95; 95% CI, 0.69-1.30; p = 0.751) when compared with others (reference, 83 of 3159 [3%]). When compared with female patients, male patients did not have a greater risk of undergoing AKA (OR = 1.02; 95% CI, 0.88-1.29; p = 0.818). CONCLUSIONS: This study did not observe any racial or sex disparities with regard to risk of AKA after PJI. However, there was a greater risk of AKA after PJI for poorer patients and patients participating in Medicare or Medicaid insurance plans. Surgeons should be cognizant when treating PJI in patients from lower income backgrounds as these patients may be at greater risk for AKA. Future research should explore the role of physician attitudes or preconceptions about predicted patient followup in treating PJI, as well as the effect of concurrent peripheral vascular disease on the risk of AKA after PJI. LEVEL OF EVIDENCE: Level III, therapeutic study.

The Cost Effectiveness of Dilute Betadine Lavage for Infection Prophylaxis in Total Joint Arthroplasty.

BACKGROUND: This article presents a break-even analysis for intraoperative Betadine lavage for the prevention of infection in total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS: Protocol costs, baseline infection rates after arthroplasty, and average revision costs were obtained from institutional records and the literature. The break-even analysis determined the absolute risk reduction (ARR) in infection rate required for cost effectiveness. RESULTS: At our institutional price of $2.54, dilute (0.35%) Betadine lavage would be cost effective if initial infection rates of both TKA (1.10%) and THA (1.63%) have an ARR of 0.01%. At a hypothetical lowest cost of $0.50, the ARR is so low as to be immediately cost effective. At a hypothetical high price of $40.00, Betadine is cost effective with ARRs of 0.16% (TKA) and 0.13% (THA). CONCLUSION: Intraoperative Betadine lavage, at typical institutional prices, can be highly cost effective in reducing infection after joint arthroplasty.

The Cost-Effectiveness of Preoperative Staphylococcus aureus Screening and Decolonization in Total Joint Arthroplasty.

BACKGROUND: This article presents a break-even analysis for preoperative Staphylococcus aureus colonization screening and decolonization protocols in total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS: Protocol costs, baseline infection rates after arthroplasty, and average revision costs were obtained from institutional records and the literature. The break-even analysis determined the absolute risk reduction (ARR) in infection rate required for cost-effectiveness. RESULTS: S aureus nasal screening ($144.07) was cost effective when initial infection rates of TKA (1.10%) and THA (1.63%) had an ARR of 0.56% and 0.45%, respectively. The most inexpensive decolonization treatment ($5.09) was cost effective with an ARR of 0.02% for both TKA and THA. The most expensive decolonization option ($37.67) was cost effective with ARRs of 0.15% (TKA) and 0.12% (THA). CONCLUSION: Preoperative S aureus decolonization can be highly cost effective, whereas colonization screening requires excessively high reductions in infection rate.