14 Management of Complications of Thumb CMC Surgery: Trapeziectomy, Arthrodesis, and Total Joint Arthroplasty

AbstractOne of the most challenging complications of total knee arthroplasty (TKA) is periprosthetic joint infection (PJI). There is growing evidence of a good anti-infective effect of intrawound vancomycin powder in total joint arthroplasty. At the same time, various different locally applied substances have become popular in total joint arthroplasty. The objective of this study was therefore to investigate a possible inhibition of the bactericidal effect of vancomycin by tranexamic acid, adrenalin, lidocaine, or dexamethasone. The bactericidal effect of vancomycin was quantified using the established method of the agar diffusion test. The plates were incubated with Staphylococcus aureus or Staphylococcus epidermidis and four wells were stamped out. The wells were filled with vancomycin alone, the tested substance alone or a mixture of the two. The fourth well remained empty as a control. The plates were incubated overnight at 37 °C and the zone of inhibition in each field was measured on the next day. All tests were run three times for each pathogen and mean values and standard deviations of the measurements were calculated. Differences between the substances were tested using the t-test at a level of significance of 0.05. The bacterial growth was homogeneous on all plates. The baseline value for the zone of inhibition of vancomycin was on average 6.2 ± 0.4 mm for Staphylococcus aureus and 12 ± 0.3 mm for Staphylococcus epidermidis. In all other substances, no inhibition was detected around the well. The combination of vancomycin and each other substance did not show any different result compared to vancomycin alone. The bactericidal effect of vancomycin on staphylococci is not altered by tranexamic acid, adrenalin, dexamethasone, or lidocaine in vitro.

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Differences in Hospital Costs among Octogenarians and Nonagenarians Following Primary Total Joint Arthroplasty

Geriatrics ◽

10.3390/geriatrics6010026 ◽

2021 ◽

Vol 6 (1) ◽

pp. 26

Author(s):

Christopher Fang ◽

Andrew Hagar ◽

Matthew Gordon ◽

Carl T. Talmo ◽

David A. Mattingly ◽

...

Keyword(s):

Length Of Stay ◽

Total Joint Arthroplasty ◽

Hospital Costs ◽

Cost Effective ◽

Joint Arthroplasty ◽

Nursing Facilities ◽

Activity Based Costing ◽

Skilled Nursing ◽

Value Based Care ◽

Hospital Expenses

The proportion of patients over the age of 90 years continues to grow, and the anticipated demand for total joint arthroplasty (TJA) in this population is expected to rise concomitantly. As the country shifts to alternative reimbursement models, data regarding hospital expenses is needed for accurate risk-adjusted stratification. The aim of this study was to compare total in-hospital costs following primary TJA in octogenarians and nonagenarians, and to determine the primary drivers of cost. This was a retrospective analysis from a single institution in the U.S. We used time-drive activity-based costing (TDABC) to capture granular total hospital costs for each patient. 889 TJA’s were included in the study, with 841 octogenarians and 48 nonagenarians. Nonagenarians were more likely to undergo total hip arthroplasty (THA) (70.8% vs. 42.4%; p < 0.0001), had higher ASA classification (2.6 vs. 2.4; p = 0.049), and were more often privately insured (35.4% vs. 27.8%; p = 0.0001) as compared to octogenarians. Nonagenarians were more often discharged to skilled nursing facilities (56.2% vs. 37.5%; p = 0.0011), experienced longer operating room (OR) time (142 vs. 133; p = 0.0201) and length of stay (3.7 vs. 3.1; p = 0.0003), and had higher implant and total in-hospital costs (p < 0.0001 and 0.0001). Multivariate linear regression showed implant cost (0.700; p < 0.0001), length of stay (0.546; p < 0.0001), and OR time (0.288; p < 0.0001) to be the strongest associations with overall costs. Primary TJA for nonagenarians was more expensive than octogenarians. Targeting implant costs, length of stay, and OR time can reduce costs for nonagenarians in order to provide cost-effective value-based care.

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Testing the proportional hazards assumption in cox regression and dealing with possible non-proportionality in total joint arthroplasty research: methodological perspectives and review

BMC Musculoskeletal Disorders ◽

10.1186/s12891-021-04379-2 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Ilari Kuitunen ◽

Ville T. Ponkilainen ◽

Mikko M. Uimonen ◽

Antti Eskelinen ◽

Aleksi Reito

Keyword(s):

Survival Analysis ◽

Regression Model ◽

Total Joint Arthroplasty ◽

Full Text ◽

Proportional Hazards ◽

Cox Regression ◽

Joint Arthroplasty ◽

Central Research ◽

Cox Regression Model ◽

Pubmed Database

Abstract Background Survival analysis and effect of covariates on survival time is a central research interest. Cox proportional hazards regression remains as a gold standard in the survival analysis. The Cox model relies on the assumption of proportional hazards (PH) across different covariates. PH assumptions should be assessed and handled if violated. Our aim was to investigate the reporting of the Cox regression model details and testing of the PH assumption in survival analysis in total joint arthroplasty (TJA) studies. Methods We conducted a review in the PubMed database on 28th August 2019. A total of 1154 studies were identified. The abstracts of these studies were screened for words “cox and “hazard*” and if either was found the abstract was read. The abstract had to fulfill the following criteria to be included in the full-text phase: topic was knee or hip TJA surgery; survival analysis was used, and hazard ratio reported. If all the presented criteria were met, the full-text version of the article was then read. The full-text was included if Cox method was used to analyze TJA survival. After accessing the full-texts 318 articles were included in final analysis. Results The PH assumption was mentioned in 114 of the included studies (36%). KM analysis was used in 281 (88%) studies and the KM curves were presented graphically in 243 of these (87%). In 110 (45%) studies, the KM survival curves crossed in at least one of the presented figures. The most common way to test the PH assumption was to inspect the log-minus-log plots (n = 59). The time-axis division method was the most used corrected model (n = 30) in cox analysis. Of the 318 included studies only 63 (20%) met the following criteria: PH assumption mentioned, PH assumption tested, testing method of the PH assumption named, the result of the testing mentioned, and the Cox regression model corrected, if required. Conclusions Reporting and testing of the PH assumption and dealing with non-proportionality in hip and knee TJA studies was limited. More awareness and education regarding the assumptions behind the used statistical models among researchers, reviewers and editors are needed to improve the quality of TJA research. This could be achieved by better collaboration with methodologists and statisticians and introducing more specific reporting guidelines for TJA studies. Neglecting obvious non-proportionality undermines the overall research efforts since causes of non-proportionality, such as possible underlying pathomechanisms, are not considered and discussed.

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