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.

Total Hip Arthroplasty in a Patient With Fascioscapulohumeral Dystrophy.

Facioscapulohumeral dystrophy is an autosomal dominant disorder that results in progressive muscle weakness. Patients most commonly present with facial and periscapular muscle weakness, which progresses to involve their upper and lower extremities as well as truncal muscles. We present a patient with facioscapulohumeral dystrophy who underwent staged bilateral total hip arthroplasties but developed late prosthetic joint infection. This case also reports the management of periprosthetic joint infection after total hip arthroplasties through explant and placement of an articulating spacer as well as both neuraxial and general anesthetic management for this uncommon neuromuscular disorder.

Cannabis Use Does Not Increase Risk of Perioperative Complications Following Primary Total Hip Arthroplasty: A Cohort-Matched Comparison.

Introduction: Cannabis use among arthroplasty patients has dramatically increased throughout the United States. Despite this trend, knowledge remains particularly limited regarding the effects of cannabis use on perioperative outcomes in total hip arthroplasty (THA). Therefore, the goal of this research was to investigate how cannabis use affects risk of perioperative outcomes, cost and length of stay (LOS) after THA. Materials and Methods: The National Inpatient Sample was used to identify 331,825 patients who underwent primary THA between 2010 and 2014 using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9) procedure code 81.51. Patients with an ICD-9 diagnosis code correlating to history of thromboembolic events, cardiac events, or active substance use other than cannabis were eliminated. The ICD-9 diagnosis codes for cannabis use (304.3-304.32, 305.2-305.22) were used to identify 538 patients with active use. Cannabis users were matched 1:1 to nonusers on age, sex, tobacco use, and comorbidities. The chi-square test was used to determine risk of major and minor complications, whereas the Kruskal-Wallis H test was used to compare hospital charges and LOS. Results: A total of 534 (99.3%) patients with cannabis use were successfully matched with 534 patients without cannabis use. Risk of major complications among cannabis users (25, 4.68%) was similar to that of nonusers (20, 3.74%, p=0.446). Minor complications also occurred at similar rates between cannabis users (77, 14.4%) and nonusers (87, 16.3%, p=0.396). LOS for cannabis users (3.07±2.40) did not differ from nonusers (3.10±1.45, p=0.488). Mean hospital charges were higher for cannabis users ($17,847±10,024) compared with nonusers ($16,284±7025, p<0.001). Conclusion: Utilizing statistically matched cohorts within a nationally representative database demonstrated that cannabis use is not associated with increased risk of complications or prolonged LOS after primary THA. However, cannabis use is associated with higher hospital charges.

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.

Cost-Effectiveness of Preoperative Spinal Imaging Before Total Hip Arthroplasty.

BACKGROUND: The risk of instability, dislocation, and revision following total hip arthroplasty (THA) is increased in patients with abnormal spinopelvic mobility. Seated and standing lateral lumbar spine imaging can identify patients with stiff/hypermobile spine (SHS) to guide interventions such as changes in acetabular cup placement or use of a dual-mobility hip construct aimed at reducing dislocation risk. METHODS: A Markov decision model was created to compare routine preoperative spinal imaging (PSI) to no screening in patients with and without SHS. Screened patients with SHS were assumed to receive dual-mobility hardware while those without SHS and nonscreened patients were assumed to receive conventional THA. Cost-effectiveness was determined by estimating the incremental cost-effectiveness ratio. Effectiveness measured as quality-adjusted life years (QALYs), with $100,000 per additional QALY as the threshold for cost-effectiveness. Sensitivity analyses were performed to determine the robustness of the base-case result. RESULTS: The screening strategy with PSI had a lifetime cost of $12,515 and QALY gains of 16.91 compared with no-screening ($13,331 and 16.77). The PSI strategy reached cost-effectiveness at 5 years and was dominant (ie, less costly and more effective) at 11 years following THA. In sensitivity analyses, PSI remained the dominant strategy if prevalence of SHS was >1.9%, the cost of PSI was <$925, and the cost of dual-mobility hardware exceeded the cost of conventional hardware by <$2850. CONCLUSION: Screening patients for SHS prior to THA with PSI is both less costly and more effective and should be considered as part of standard presurgical workup.

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.

Process Mapping Total Knee Arthroplasty: A Comparison of Instrument Designs.

BACKGROUND: Total knee arthroplasty (TKA) is commonly performed with proprietary, manual instrumentation provided by the surgical implant manufacturer. Registry studies and meta-analysis, with few outliers, have consistently shown similar functional outcomes and implant survival after TKA regardless of implant manufacturer, implant design, or surgical technique. We hypothesized that process mapping could identify areas for improvement in TKA instrumentation. METHODS: Seventeen TKA implant systems from 10 companies representing over 90% of all TKAs performed in the United States were evaluated. Instrumentation required for femoral, tibial, and patellar preparation was compared. The number of steps including surgical technician assembly steps, instrument handoffs, and surgeon steps were tabulated based off application of a standardized surgical flow, adjusted for manufacturer-recommended steps during completion of a TKA operation. RESULTS: Cruciate-retaining (CR) knee instrumentation in studied systems required 158-225 discrete steps and posterior-stabilized (PS) knees required 181-230 steps. With the fewest steps for femoral, tibial, and patellar instrumentation, CR and PS knee systems could be improved to 145 and 163 steps, respectively. The Arthrex iBalance and the Biomet Vanguard Microplasty required fewest steps among CR systems; the OrthoDevelopment Balanced and the Corin Unity required fewest steps among PS systems. CONCLUSIONS: Process mapping identified potential areas for improved instrumentation in all studied systems, suggesting the possibility to reduce operative steps broadly across the TKA industry. Patient outcomes were not evaluated by system. Future implant system design changes may do well to reduce unnecessary steps and instrumentation.

Mortality Rates of Humerus Fractures in the Elderly: Does Surgical Treatment Matter?

INTRODUCTION: Multiple studies have shown the impact of hip fractures on geriatric mortality. Few evaluate mortality after proximal humerus (PH) or distal humerus (DH) fractures, and fewer determine differences in mortality based on management. We aim to evaluate a statewide cohort of elderly patients with PH or DH fractures to evaluate mortality, length of stay, discharge data, readmission, and differences based on management. METHODS: The New York Statewide Planning and Research Cooperative System database was used to identify patients 60 years and older admitted with a PH or DH fracture. Patient demographics, including age, gender, sex, race, weight, and insurance status, along with comorbid conditions using the Charlson Comorbidity Index, were determined. Seven-day, 30-day, and 1-year mortality was determined for operative and nonoperative cohorts. Logistic regression determined the competing risk of mortality when controlling for patient demographics, comorbid conditions, and treatment. RESULTS: Forty-two thousand five hundred eleven PH and 7654 DH fractures were evaluated. PH fractures had higher mortality than DH. Nonoperative treatment occurred in 76.2% of PH fractures and 53% of DH fractures. There were more comorbid conditions, longer length of stay, and higher mortality at 7 days, 30 days, and 1 year in patients treated nonoperatively. After controlling for patient demographics and comorbid conditions, there was no difference in mortality between PH and DH fractures, but operative treatment for either PH or DH was associated with lower mortality at all time points. DISCUSSION: Fewer PH than DH fractures were treated operatively. Operative treatment was associated with improved survival in patients hospitalized with PH or DH fracture even after controlling for patient demographic and comorbid factors. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Total Hip Arthroplasty for Femoral Neck Fractures: Improved Outcomes With Higher Hospital Volumes.

OBJECTIVES: To determine if hospital arthroplasty volume affects patient outcomes after undergoing total hip arthroplasty (THA) for displaced femoral neck fractures. METHODS: The Statewide Planning and Research Cooperative System database from the New York State Department of Health was used to group hospitals into quartiles based on overall THA volume from 2000 to 2010. The database was then queried to identify all patients undergoing THA specifically for femoral neck fracture during this time period. The data were analyzed to investigate outcomes between the 4 volume quartiles in 30-day and 1-year mortality, 1-year revision rate, and 90-day complication rate (readmission for dislocation, deep vein thrombosis, pulmonary embolism, prosthetic joint infection, or other complications related to arthroplasty in the treatment of femoral neck fractures with THA). RESULTS: Patients undergoing THA for femoral neck fracture at hospitals in the top volume quartile had significantly lower 30-day (0.9%) and 1-year (7.51%) mortality than all other volume quartiles. There were no significant differences on pairwise comparisons between the second, third, and fourth quartiles with regard to postoperative mortality. There was no significant difference in revision arthroplasty at 1 year between any of the volume quartiles. On Cox regression analysis, THA for fracture at the lowest volume (fourth) quartile [hazard ratio (HR), 1.91; P = 0.016, 95% confidence interval (CI), (1.13-3.25)], second lowest volume (third) quartile (HR, 2.01; P = 0.013, 95% CI, 1.16-3.5) and third lowest volume (second) quartile (HR, 2.13; P = 0.005, 95% CI, 1.26-3.62) were associated with increased risk for a 1-year postoperative mortality event. Hospital volume quartile was also a significant risk factor for increased 90-day complication (pulmonary embolism/deep vein thrombosis, acute dislocation, prosthetic joint infection) following THA for femoral neck fracture. Having surgery in the fourth quartile (HR, 2.71; P < 0.001, 95% CI, 1.7-4.31), third quartile (HR, 2.61; P < 0.001, 95% CI, 1.61-4.23), and second quartile (HR, 2.41; P < 0.001, 95% CI, 1.51-3.84), all were significant risk factors for increased 90-day complication risk. CONCLUSIONS: The results of this population-based study indicate that THA for femoral neck fractures at high-volume arthroplasty centers is associated with lower mortality and 90-day complication rates but does not influence 1-year revision rate. THA for femoral neck fractures at top arthroplasty volume quartile hospitals are performed on healthier patients more quickly. Patient health is a critical factor that influences mortality outcomes following THA for femoral neck fractures. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Length of hospital stay after hip fracture and risk of early mortality after discharge in New York state: retrospective cohort study.

STUDY QUESTION: Can the length of hospital stay for hip fracture affect a patient's risk of death 30 days after discharge? METHODS: In a retrospective cohort study, population based registry data from the New York Statewide Planning and Research Cooperative System (SPARCS) were used to investigate 188,208 patients admitted to hospital for hip fracture in New York state from 2000 to 2011. Patients were aged 50 years and older, and received surgical or non-surgical treatment. The main outcome measure was the mortality rate at 30 days after hospital discharge. STUDY ANSWER AND LIMITATIONS: Hospital stays of 11-14 days for hip fracture were associated with a 32% increased odds of death 30 days after discharge, compared with stays lasting one to five days (odds ratio 1.32 (95% confidence interval 1.19 to 1.47)). These odds increased to 103% for stays longer than 14 days (2.03 (1.84 to 2.24)). Other risk factors associated with early mortality included discharge to a hospice facility, older age, metastatic disease, and non-surgical management. The 30 day mortality rate after discharge was 4.5% for surgically treated patients and 10.7% for non-surgically treated patients. These findings might not be generalizable to populations in other US states or in other countries. The administrative claims data used could have been incomplete or include inaccurate coding of diagnoses and comorbid conditions. The database also did not include patient socioeconomic status, which could affect access to care to a greater extent in New York state than in European countries. Specific cause of death was not available because few autopsies are performed in this population. WHAT THIS STUDY ADDS: By contrast with recent findings in Sweden, decreased length of hospital stay for hip fracture was associated with reduced rates of early mortality in a US cohort in New York state. This could reflect critical system differences in the treatment of hip fractures between Europe and the USA.Funding, competing interests, data sharing University of Rochester grant from the Clinical Translational Science Institute for statistical analyses used in this work (National Institutes of Health (UL1 TR000042)) and the National Institutes of Health (K-08 AR060164-01A). No competing interests declared. Data may be obtained through SPARCS at https://www.health.ny.gov/statistics/sparcs/access/.

Operative Mortality After Arthroplasty for Femoral Neck Fracture and Hospital Volume.

BACKGROUND: The purpose of the present study is to use a statewide, population-based data set to identify mortality rates at 30-day and 1-year postoperatively following total hip arthroplasty (THA) and hemiarthroplasty (HA) for displaced femoral neck fractures. The secondary aim of the study is to determine whether arthroplasty volume confers a protective effect on the mortality rate following femoral neck fracture treatment. METHODS: New York's Statewide Planning and Research Cooperative System was used to identify 45 749 patients older than 60 years of age with a discharge diagnosis of femoral neck fracture undergoing THA or HA from 2000 through 2010. Comorbidities were identified using the Charlson comorbidity index. Mortality risk was modeled using Cox proportional hazards models while controlling for demographic and comorbid characteristics. High-volume THA centers were defined as those in the top quartile of arthroplasty volume, while low-volume centers were defined as the bottom quartile. RESULTS: Patients undergoing THA for femoral neck fracture rather than HA were younger (79 vs 83 years, P < .001), more likely to have rheumatoid disease, and less likely to have heart disease, dementia, cancer, or diabetes (all P < .05). Thirty-day mortality after HA was higher (8.4% vs 5.7%; P < .001) as was 1-year mortality (25.9% vs 17.8%; P < .001). After controlling for age, gender, ethnicity, and comorbidities, risk of mortality following THA was 21% lower (hazard ratio [HR] 0.79; P = .003) at 30 days and 22% lower (HR 0.78; P < .001) at 1 year than HA. Patients undergoing THA at high-volume arthroplasty centers had improved 1-year mortality when compared to those undergoing THA at low-volume hospitals (HR 0.55; P = .008). CONCLUSIONS: Based on this large, population-based study, there is no basis to assume THA carries a greater mortality risk after hip fracture than does standard HA, even when accounting for institutional volume of hip arthroplasty.

Longitudinal HR-pQCT and image registration detects endocortical bone loss in kidney transplantation patients.

Patients with chronic kidney disease (CKD) who undergo kidney transplantation experience bone loss and increased risk of fracture. However, the mechanisms of this bone loss are unclear. Our objective was to use image registration to define the cortex to assess changes in cortical porosity (Ct.Po) in patients undergoing first-time kidney transplantation. We obtained serial measurements of parathyroid hormone (PTH) and bone turnover markers and used high-resolution peripheral quantitative computed tomography (HR-pQCT) to scan the distal radius and tibia in 31 patients (21 men, 10 women; aged 51.9 ± 13.4 years) at transplant and after 1 year. Baseline and 1-year images were aligned using a fully automated, intensity-based image registration framework. We compared three methods to define the cortical region of interest (ROI) and quantify the changes: 1) cortical bone was independently defined in baseline and follow-up scans; 2) cortical bone was defined as the common cortical ROI; and 3) the cortical ROI at baseline was carried forward to 1-year follow-up (baseline-indexed). By the independently defined ROI, Ct.Po increased 11.7% at the radius and 9.1% at the tibia, whereas by the common ROI, Ct.Po increased 14.6% at the radius and 9.1% at the tibia. By the baseline-indexed ROI, which provides insight into changes at the endocortical region, Ct.Po increased 63.4% at the radius and 17.6% at the tibia. We found significant relationships between changes in Ct.Po and bone formation and resorption markers at the radius. The strongest associations were found between markers and Ct.Po using the baseline-index method. We conclude that Ct.Po increases throughout the cortex after kidney transplant, and this increase is particularly marked at the endocortical surface. These methods may prove useful for all HR-pQCT longitudinal studies, particularly when changes are expected at the endocortical region.

Kidney transplantation with early corticosteroid withdrawal: paradoxical effects at the central and peripheral skeleton.

The use of early corticosteroid withdrawal (ECSW) protocols after kidney transplantation has become common, but the effects on fracture risk and bone quality are unclear. We enrolled 47 first-time adult transplant recipients managed with ECSW into a 1-year study to evaluate changes in bone mass, microarchitecture, biomechanical competence, and remodeling with dual energy x-ray absorptiometry (DXA), high-resolution peripheral quantitative computed tomography (HRpQCT), parathyroid hormone (PTH) levels, and bone turnover markers obtained at baseline and 3, 6, and 12 months post-transplantation. Compared with baseline, 12-month areal bone mineral density by DXA did not change significantly at the spine and hip, but it declined significantly at the 1/3 and ultradistal radii (2.2% and 2.9%, respectively; both P<0.001). HRpQCT of the distal radius revealed declines in cortical area, density, and thickness (3.9%, 2.1%, and 3.1%, respectively; all P<0.001), trabecular density (4.4%; P<0.001), and stiffness and failure load (3.1% and 3.5%, respectively; both P<0.05). Findings were similar at the tibia. Increasing severity of hyperparathyroidism was associated with increased cortical losses. However, loss of trabecular bone and bone strength were most severe at the lowest and highest PTH levels. In summary, ECSW was associated with preservation of bone mineral density at the central skeleton; however, it was also associated with progressive declines in cortical and trabecular bone density at the peripheral skeleton. Cortical decreases related directly to PTH levels, whereas the relationship between PTH and trabecular bone decreases was bimodal. Studies are needed to determine whether pharmacologic agents that suppress PTH will prevent cortical and trabecular losses and post-transplant fractures.

Pancreas-kidney transplantation is associated with reduced fracture risk compared with kidney-alone transplantation in men with type 1 diabetes.

Both type 1 diabetes mellitus and end-stage renal disease are associated with increased fracture risk, likely because of metabolic abnormalities that reduce bone strength. Simultaneous pancreas-kidney transplantation is a treatment of choice for patients with both disorders, yet the effects of simultaneous pancreas-kidney and kidney transplantation alone on post-transplantation fracture risk are unknown. From the United States Renal Data System, we identified 11,145 adults with type 1 diabetes undergoing transplantation, of whom 4933 had a simultaneous pancreas-kidney transplant and 6212 had a kidney-alone transplant between 2000 and 2006. Post-transplantation fractures resulting in hospitalization were identified from discharge codes. Time to first fracture was modeled and propensity score adjustment was used to balance covariates between groups. Fractures occurred in significantly fewer (4.7%) of pancreas-kidney compared with kidney-alone transplant (5.9%) cohorts. After gender stratification and adjustment for fracture covariates, pancreas-kidney transplantation was associated with a significant 31% reduction in fracture risk in men (hazard risk 0.69). Older age, white race, prior dialysis, and pre-transplantation fracture were also associated with increased fracture risk. Prospective studies are needed to determine the gender-specific mechanisms by which pancreas-kidney transplantation reduces fracture risk in men.

How can we utilize livers from advanced aged donors for liver transplantation for hepatitis C?

Advanced age donors have inferior outcomes of liver transplantation for Hepatitis C (HCV). Aged donors grafts may be transplanted into young or low model for end stage liver disease (MELD) patients in order to offset the effect of donor age. However, it is not well understood how to utilize liver grafts from advanced aged donors for HCV patients. Using the UNOS database, we retrospectively studied 7508 HCV patients who underwent primary liver transplantation. Risk factors for graft failure and graft survival using advanced aged grafts (donor age ≥ 60 years) were analyzed by Cox hazards models, donor risk index (DRI) and organ patient index (OPI). Recipient's age did not affect on graft survival regardless of donor age. Advanced aged grafts had significant inferior survival compared to younger aged grafts regardless of MELD score (P < 0.0001). Risk factors of HCV patients receiving advanced aged grafts included donation after cardiac death (DCD, HR: 1.69) and recent hospitalization (HR: 1.43). Advanced aged grafts showed significant difference in graft survival of HCV patients with stratification of DRI and OPI. In conclusion, there was no offsetting effect by use of advanced aged grafts into younger or low MELD patients. Advanced aged grafts, especially DCD, should be judiciously used for HCV patients with low MELD score.

Impact of comorbidities on hospitalization costs following hip fracture.

BACKGROUND: Hip fractures are common in the elderly, and patients with hip fractures frequently have comorbid illnesses. Little is known about the relationship between comorbid illness and hospital costs or length of stay following the treatment of hip fracture in the United States. We hypothesized that specific individual comorbid illnesses and multiple comorbid illnesses would be directly related to the hospitalization costs and the length of stay for older patients following hip fracture. METHODS: With use of discharge data from the 2007 Nationwide Inpatient Sample, 32,440 patients who were fifty-five years or older with an isolated, closed hip fracture were identified. Using generalized linear models, we estimated the impact of comorbidities on hospitalization costs and length of stay, controlling for patient, hospital, and procedure characteristics. RESULTS: Hypertension, deficiency anemias, and fluid and electrolyte disorders were the most common comorbidities. The patients had a mean of three comorbidities. Only 4.9% of patients presented without comorbidities. The average estimated cost in our reference patient was $13,805. The comorbidity with the largest increased hospitalization cost was weight loss or malnutrition, followed by pulmonary circulation disorders. Most other comorbidities significantly increased the cost of hospitalization. Compared with internal fixation of the hip fracture, hip arthroplasty increased hospitalization costs significantly. CONCLUSIONS: Comorbidities significantly affect the cost of hospitalization and length of stay following hip fracture in older Americans, even while controlling for other variables.

Determinants of medicare all-cause costs among elderly patients with renal cell carcinoma.

BACKGROUND: Renal cell carcinoma (RCC) is the third most common genitourinary cancer and the most common primary renal neoplasm. Estimates of the economic burden of RCC in the United States range from approximately $400 million (in year 2000 dollars) to $4.4 billion (in year 2005 dollars). Actual costs associated with RCC, particularly for elderly Medicare patients who account for 46% of U.S. patients hospitalized for RCC, are poorly understood. OBJECTIVE: To estimate all-cause health care costs associated with RCC using the combined Surveillance Epidemiology and End Results (SEER)-Medicare database. METHODS: The sample was limited to non-HMO patients aged 65 years or older who were diagnosed with a first primary RCC (SEER site recode 59, kidney and renal pelvis) between 1995 and 2002. Our final sample included 4,938 patients with RCC and 9,876 non-HMO noncancer comparison group cases without chronic renal disease drawn from the SEER 5% Medicare sample and matched by a propensity score calculated from age, gender, race/ethnicity, and comorbidities. Costs were defined as payments made by Medicare for all-cause medical treatments including inpatient stays, emergency room visits, outpatient procedures, office visits, home health visits, durable medical equipment, and hospice care, but excluding out-patient prescription drugs. Using the method of Bang and Tsiatis (2000), we estimated cumulative costs at 1 and 5 years by estimating average costs for each patient in each month up to 60 months following diagnosis. Total costs were weighted sums of monthly costs, where weights were the inverse probability that the patient was not censored, and inverse probabilities were estimated by Kaplan-Meier estimates of time to censoring. Using the method of Lin (2000), we performed multivariate analyses of costs by fitting each of the 60 monthly costs to linear models that controlled for demographic characteristics and comorbidities. Marginal effects of covariates on 1- and 5-year costs were obtained by summing the coefficients for months 1 through 12 and months 1 through 60, respectively. Confidence intervals were obtained by bootstrapping. RESULTS: Patients with RCC and matched comparison group cases had similar demographic characteristics, comorbidities, and chronic conditions. At the start of the fifth year post-diagnosis, there were 1,208 Medicare RCC cases of the original 4,938 (20.8%). Mean costs per patient per month (PPPM) in the first year were $3,673 for patients with RCC and $793 for comparison group patients. PPPM costs were higher for RCC patients with more advanced stage (i.e., regional or distant) disease. Average cumulative total costs for RCC patients were $33,605 per patient in the first year following diagnosis and $59,397 per patient in the first 5 years following diagnosis. Several patient-specific factors were associated with 1- and 5-year costs in multivariate analyses, including age, race/ethnicity, and comorbidities. Among RCC patients, treatment with surgery and radiation was associated with higher costs per patient than treatment with surgery alone at 1 year ($24,556, 95% CI = $16,673-$32,940) and 5 years ($30,540, 95% CI = $17,853-$43,648). RCC patients who received chemotherapy as part of their treatment regimen also had significantly higher costs per patient than those who received surgery alone at 1 year ($15,144, 95% CI = $ 9,979-$20,344) and 5 years ($13,440, 95% CI = $1,257-$27,572). CONCLUSIONS: Newly diagnosed RCC is associated with a significant economic burden, which is largely determined by several patient characteristics, disease stage, and treatment choice.

Electronic measures of surgical site infection: implications for estimating risks and costs.

OBJECTIVE: Electronic measures of surgical site infections (SSIs) are being used more frequently in place of labor-intensive measures. This study compares performance characteristics of 2 electronic measures of SSIs with a clinical measure and studies the implications of using electronic measures to estimate risk factors and costs of SSIs among surgery patients. METHODS: Data included 1,066 general and vascular surgery patients at a single academic center between 2007 and 2008. Clinical data were from the National Surgical Quality Improvement Program (NSQIP) database, which includes a nurse-derived measure of SSI. We compared the NSQIP SSI measure with 2 electronic measures of SSI: MedMined Nosocomial Infection Marker (NIM) and International Classification of Diseases, Ninth Revision (ICD-9) coding for SSIs. We compared infection rates for each measure, estimated sensitivity and specificity of electronic measures, compared effects of SSI measures on risk factors for mortality using logistic regression, and compared estimated costs of SSIs for measures using linear regression. RESULTS: SSIs were observed in 8.8% of patients according to the NSQIP definition, 2.6% of patients according to the NIM definition, and 5.8% according to the ICD-9 definition. Logistic regression for each SSI measure revealed large differences in estimated risk factors. NIM and ICD-9 measures overestimated the cost of SSIs by 134% and 33%, respectively. CONCLUSIONS: Caution should be taken when relying on electronic measures for SSI surveillance and when estimating risk and costs attributable to SSIs. Electronic measures are convenient, but in this data set they did not correlate well with a clinical measure of infection.

Risk of fractures after renal transplantation in the United States.

BACKGROUND: Although it is known that the incidence of fracture events is increased in renal transplantation recipients, the timing and the factors associated with risk of fractures are less well understood. The objective of this study was to estimate the time to fracture in renal transplantation recipients and to determine whether risk was associated with patient and transplantation characteristics. METHODS: Using the U. S. Renal Data System, we retrospectively studied 68,814 patients, who underwent renal transplantation between 1988 and 1998. Fractures were identified from International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes in billing data. Time to first fracture was modeled during the first 5 years posttransplant using the Kaplan-Meier method and Cox proportional hazards models. RESULTS: Of the patients who underwent transplantation, 22.5% developed a fracture within 5 years. Woman (hazard ratio [HR] 1.36, P<0.0001), patients older than 45 years of age (HR 1.14, P<0.0001) especially older than 65 years (HR 1.69, P<0.0001), and whites (HR 1.28, P<0.0001) were at increased risk of a fracture. Additionally, receipt of a deceased donor kidney (HR 1.30, P<0.0001), increased human leukocyte antigen mismatches (HR 1.09, P<0.014), diabetes (HR 1.88, P<0.0001), pretransplant dialysis (HR 1.08, P<0.0001), and an aggressive induction immunosuppression regimen (HR 1.14, P<0.0001) all significantly increased risk of fracture events during the first 5 years. CONCLUSIONS: In addition to patient demographic features, donor factors, including suboptimal organ quality and the need for more intense immunosuppression, were associated with an increased risk of fractures during the first 5 years after a renal transplant.