Predictors and complications of blood transfusion in total hip and knee arthroplasty

Efficacy and Safety of Bone Wax Application at Different Time Points to Reduce Postoperative Blood Loss in Total Knee Arthroplasty: A Prospective Randomized Controlled Trial

OBJECTIVE

In addition to the surface hemorrhage of cancellous bone after large-area osteotomy, the intramedullary hemorrhage after the reamed knee joint is also a major cause of postoperative bleeding after total knee arthroplasty (TKA). This study evaluated the efficacy and safety of bone wax application at different time points of prone hemorrhage to reduce perioperative blood loss.

METHODS

From August 2023 to December 2023, 150 patients undergoing primary unilateral TKA were included in this prospective, randomized controlled trial, patients were randomly divided into three groups: group A, after autogenous osteotomy plug was used to fill the femoral medullary cavity, the residual space was sealed with bone wax and the exposed cancellous bone surface around the prosthesis was coated with bone wax after the prosthesis adhesion; group B, only the exposed cancellous bone surface around the prosthesis was coated with bone wax; and group C, no bone wax was used. The primary outcome was total perioperative blood loss. Secondary outcomes included occult blood loss, postoperative hemoglobin reduction, blood transfusion rate, lower limb diameter, and knee function, while length of hospital stay was recorded. Tertiary outcomes included the incidence of postoperative related adverse events.

RESULTS

The total blood loss in group A (551.5 ± 224.5 mL) and group B (656.3 ± 267.7 mL) was significantly lower than that in group C (755.3 ± 248.3 ml, p < 0.001), and the total blood loss in group A was also lower than that in group B (p < 0.05). There were also significant differences in the reduction of hemoglobin level and hidden blood loss among the three groups (p < 0.05). However, there was no significant improvement in postoperative lower limb swelling, knee joint activity and hospitalization time; there was no significant difference in the incidence of complications such as thromboembolism.

CONCLUSION

The use of bone wax in TKA can safely and effectively reduce perioperative blood loss and hemoglobin drop rate, and multiple use at time points during the operation when blood loss is prone to occur can produce more significant hemostatic effect.

Prediction of transfusion risk after total knee arthroplasty: use of a machine learning algorithm

INTRODUCTION

Total knee arthroplasty (TKA) carries a significant hemorrhagic risk, with a non-negligible rate of postoperative transfusions. The blood-sparing strategy has evolved to reduce blood loss after TKA by identifying the patient's risk factors preoperatively. In practice, a blood count is often performed postoperatively but rarely altering the patient's subsequent management. This study aimed to identify the preoperative variables associated with hemorrhagic risk, enabling the creation of a machine-learning model predictive of transfusion risk after total knee arthroplasty and the need for a complete blood count.

HYPOTHESIS

Based on preoperative data, a powerful machine learning predictive model can be constructed to estimate the risk of transfusion after total knee arthroplasty.

MATERIAL AND METHODS

This retrospective single-centre study included 774 total knee arthroplasties (TKA) operated between January 2020 and March 2023. Twenty-five preoperative variables were integrated into the machine learning model and filtered by a recursive feature elimination algorithm. The most predictive variables were selected and used to construct a gradient-boosting machine algorithm to define the overall postoperative transfusion risk model. Two groups were formed of patients transfused and not transfused after TKA. Odds ratios were determined, and the area under the curve evaluated the model's performance.

RESULTS

Of the 774 TKA surgery patients, 100 were transfused postoperatively (12.9%). The machine learning predictive model included five variables: age, body mass index, tranexamic acid administration, preoperative hemoglobin level, and platelet count. The overall performance was good with an area under the curve of 0.97 [95% CI 0.921-1], sensitivity of 94.4% [95% CI 91.2-97.6], and specificity of 85.4% [95% CI 80.6-90.2]. The tool developed to assess the risk of blood transfusion after TKA is available at https://arthrorisk.com.

CONCLUSION

The risk of postoperative transfusion after total knee arthroplasty can be predicted by a model that identifies patients at low, moderate, or high risk based on five preoperative variables. This machine learning tool is available on a web platform that is accessible to all, easy to use, and has a high prediction performance. The model aims to limit the need for routine check-ups, depending on the risk presented by the patient.

LEVEL OF EVIDENCE

II; diagnostic study.

Development and Validation of a Machine Learning Algorithm to Predict the Risk of Blood Transfusion after Total Hip Replacement in Patients with Femoral Neck Fractures: A Multicenter Retrospective Cohort Study

OBJECTIVE

Total hip arthroplasty (THA) remains the primary treatment option for femoral neck fractures in elderly patients. This study aims to explore the risk factors associated with allogeneic blood transfusion after surgery and to develop a dynamic prediction model to predict post-operative blood transfusion requirements. This will provide more accurate guidance for perioperative humoral management and rational allocation of medical resources.

METHODS

We retrospectively analyzed data from 829 patients who underwent total hip arthroplasty for femoral neck fractures at three third-class hospitals between January 2017 and August 2023. Patient data from one hospital were used for model development, whereas data from the other two hospitals were used for external validation. Logistic regression analysis was used to screen the characteristic subsets related to blood transfusion. Various machine learning algorithms, including logistic regression, SVA (support vector machine), K-NN (k-nearest neighbors), MLP (multilayer perceptron), naive Bayes, decision tree, random forest, and gradient boosting, were used to process the data and construct prediction models. A 10-fold cross-validation algorithm facilitated the comparison of the predictive performance of the models, resulting in the selection of the best-performing model for the development of an open-source computing program.

RESULTS

BMI (body mass index), surgical duration, IBL (intraoperative blood loss), anticoagulant history, utilization rate of tranexamic acid, Pre-Hb, and Pre-ALB were included in the model as well as independent risk factors. The average area under curve (AUC) values for each model were as follows: logistic regression (0.98); SVA (0.91); k-NN (0.87) MLP, (0.96); naive Bayes (0.97); decision tree (0.87); random forest (0.96); and gradient boosting (0.97). A web calculator based on the best model is available at: (https://nomo99.shinyapps.io/dynnomapp/).

CONCLUSION

Utilizing a computer algorithm, a prediction model with a high discrimination accuracy (AUC > 0.5) was developed. The logistic regression model demonstrated superior differentiation and reliability, thereby successfully passing external validation. The model's strong generalizability and applicability have significant implications for clinicians, aiding in the identification of patients at high risk for postoperative blood transfusion.

Blood transfusion in elective total hip arthroplasty: can patient-specific parameters predict transfusion?

Aims

Transfusion after primary total hip arthroplasty (THA) has become rare, and identification of causative factors allows preventive measures. The aim of this study was to determine patient-specific factors that increase the risk of needing a blood transfusion.

Methods

All patients who underwent elective THA were analyzed retrospectively in this single-centre study from 2020 to 2021. A total of 2,892 patients were included. Transfusion-related parameters were evaluated. A multiple logistic regression was performed to determine whether age, BMI, American Society of Anesthesiologists (ASA) grade, sex, or preoperative haemoglobin (Hb) could predict the need for transfusion within the examined patient population.

Results

The overall transfusion rate was 1.2%. Compared to the group of patients without blood transfusion, the transfused group was on average older (aged 73.8 years (SD 9.7) vs 68.6 years (SD 10.1); p = 0.020) and was mostly female (p = 0.003), but showed no significant differences in terms of BMI (28.3 kg/m2 (SD 5.9) vs 28.7 kg/m2 (SD 5.2); p = 0.720) or ASA grade (2.2 (SD 0.5) vs 2.1 (SD 0.4); p = 0.378). The regression model identified a cutoff Hb level of < 7.6 mmol/l (< 12.2 g/dl), aged > 73 years, and a BMI of 35.4 kg/m² or higher as the three most reliable predictors associated with postoperative transfusion in THA.

Conclusion

The possibility of transfusion is predictable based on preoperatively available parameters. The proposed thresholds for preoperative Hb level, age, and BMI can help identify patients and take preventive measures if necessary.

Identification of Data-Driven Preoperative Hemoglobin Strata That Predict the Likelihood of Blood Transfusion and the Risk of Major Complications and Prosthetic Joint Infection After Total Hip Arthroplasty

INTRODUCTION

Preoperative anemia is an independent risk factor of complications after primary total hip arthroplasty (THA). Currently used hemoglobin thresholds are not developed for risk stratification of arthroplasty patients and do not provide surgery-specific information on postoperative complication risk. Thus, we aimed to calculate THA-specific preoperative hemoglobin strata that observe the likelihood of 90-day blood transfusion and determine whether these strata are associated with increased risk of 90-day complications and 2-year prosthetic joint infection (PJI).

METHODS

A retrospective cohort analysis identified 56,101 patients who underwent primary THA from 2013 to 2022. Using the lowest hemoglobin value for each patient one month before THA, stratum-specific likelihood ratio (SSLR) analysis calculated sex-based hemoglobin strata associated with the likelihood of 90-day postoperative blood transfusion. Propensity score matching was performed. Incidence rates and risk of 90-day major complications and 2-year PJI were observed for each identified preoperative hemoglobin stratum.

RESULTS

SSLR analysis identified five male (strata, likelihood ratio [<10.4 g/dL, 12.5; 10.5 to 11.4 g/dL, 8.0; 11.5 to 12.4 g/dL, 2.4; 12.5 to 13.4 g/dL, 1.3; 13.5 to 13.9 g/dL, 0.5]) and five female (<8.9 g/dL, 10.7; 9.0 to 10.9 g/dL, 4.0; 11.0 to 11.4 g/dL, 2.0; 12.0 to 12.9 g/dL, 1.0; 13.0 to 13.4 g/dL, 0.6) preoperative hemoglobin strata associated with varying likelihoods of 90-day blood transfusion after THA. After matching in both male and female cohorts, as the calculated preoperative hemoglobin strata decreased, the relative risk of overall 90-day major complications and 2-year PJI increased incrementally (all P < 0.05).

CONCLUSION

SSLR analysis established THA-specific sex-based preoperative hemoglobin strata that observe the likelihood of 90-day blood transfusion and predict the risk of 90-day medical complications and 2-year PJI. These strata are a first of their kind in THA research. While preoperatively optimizing patients, we recommend using these hemoglobin thresholds to help guide decisions on presurgery anemia optimization and to reduce the need for postoperative blood transfusion.

LEVEL OF EVIDENCE

Level III.

Surgical Site Infection Risk Factors in Hip Arthroplasty for Transcervical Femoral Neck Fractures

Background Hip fracture patients often experience surgical site infections (SSIs) as a major infectious complication after undergoing total hip arthroplasty (THA), which can lead to extended hospital stays, increased mortality, and higher healthcare costs. This study aimed to determine the incidence of SSI and identify the risk factors associated with it after THA. Objective This study aimed to explore the correlation between blood transfusion along with other factors and the occurrence of SSIs in postoperative patients who underwent THA for transcervical femoral neck fractures. Methods We conducted a retrospective analysis by reviewing the medical records of patients aged 60-80 years who underwent surgery for hip fractures at the Unidad Médica de Alta Especialidad Hospital de Traumatología y Ortopedia No. 21 in Monterrey, Mexico, between January 2020 and January 2021. We analyzed potential risk factors such as age, sex, transfusion necessity, preoperative hemoglobin levels, history of diabetes mellitus, arterial hypertension, and end-stage chronic disease. Data are presented as numbers and percentages, and statistical analyses were performed using IBM SPSS Statistics for Windows, Version 28.0 (Released 2021; IBM Corp., Armonk, New York, United States). Results The study included 87 patients, of whom 55 (63%) were women with an average age of 73 years. SSIs were identified in 12 (13.8%) patients. Among those with infections, nine (75%) had a history of blood transfusion (p=0.05). Diabetes, hypertension, and chronic kidney disease also increased the risk for infection. There was no association with gender, age, American Society of Anesthesiologists (ASA) risk, and preoperative hemoglobin. Conclusions We found a heightened risk of SSI in patients with a history of blood transfusions, emphasizing the need for careful consideration and monitoring during the perioperative period. Additionally, patients with comorbidities such as diabetes, hypertension, and chronic kidney disease were more susceptible to SSI, underscoring the importance of preoperative assessment and targeted preventive measures. Further research and collaboration are needed to refine strategies for mitigating SSI risk factors and optimizing healthcare resource utilization.

Risk factor analysis and establishment of a nomogram model to predict blood loss during total knee arthroplasty

PURPOSE

The risk factors for excessive blood loss and transfusion during total knee arthroplasty (TKA) remain unclear. The present study aimed to determine the risk factors for excessive blood loss and establish a predictive model for postoperative blood transfusion.

METHODS

This retrospective study included 329 patients received TKA, who were randomly assigned to a training set (n = 229) or a test set (n = 100). Univariate and multivariate linear regression analyses were used to determine risk factors for excessive blood loss. Univariate and multivariate logistic regression analyses were used to determine risk factors for blood transfusion. R software was used to establish the prediction model. The accuracy and stability of the models were evaluated using calibration curves, consistency indices, and receiver operating characteristic (ROC) curve analysis.

RESULTS

Risk factors for excessive blood loss included timing of using a tourniquet, the use of drainage, preoperative ESR, fibrinogen, HCT, ALB, and free fatty acid levels. Predictors in the nomogram included timing of using a tourniquet, the use of drainage, the use of TXA, preoperative ESR, HCT, and albumin levels. The area under the ROC curve was 0.855 (95% CI, 0.800 to 0.910) for the training set and 0.824 (95% CI, 0.740 to 0.909) for the test set. The consistency index values for the training and test sets were 0.855 and 0.824, respectively.

CONCLUSIONS

Risk factors for excessive blood loss during and after TKA were determined, and a satisfactory and reliable nomogram model was designed to predict the risk for postoperative blood transfusion.

Perioperative Blood Transfusion and Delirium after Total Knee or Hip Arthroplasty: Retrospective Analysis

We investigated the type of blood component transfusion associated with increased postoperative delirium. Adult patients who underwent total knee arthroplasty (TKA) or total hip arthroplasty (THA) between 2017 and 2022 were included. Delirium was evaluated and treated within two days after surgery. A total of 6737 patients (4112 TKA/2625 THA) were retrospectively studied; 2.48% of patients in the TKA (n = 102) and THA (n = 65) groups had postoperative delirium. The blood transfusion (BT) and non-BT groups had similar percentages of patients who experienced postoperative delirium (3.34 vs. 2.35%, p = 0.080). In the multivariable logistic regression model, BT was not associated with postoperative delirium-adjusted odds ratio (aOR): 1.03, confidence interval (CI): 0.62, 1.71; p = 0.917. Moreover, transfusion of packed red blood cells (p = 0.651), platelets (p = 0.998), and cryoprecipitate (p = 0.999) were not associated with delirium. However, transfusion of fresh frozen plasma was associated with a 5.96-fold higher incidence of delirium-aOR: 5.96, 95% CI: 2.72, 13.04; p < 0.001. In conclusion, perioperative BT was not associated with postoperative delirium in patients who underwent TKA or THA. However, FFP transfusion was associated with an increased incidence of postoperative delirium.

Development and Validation of Machine Learning-Based Predictive Model for Prolonged Hospital Stay after Decompression Surgery for Lumbar Spinal Canal Stenosis

Introduction

Precise prediction of hospital stay duration is essential for maximizing resource utilization during surgery. Existing lumbar spinal stenosis (LSS) surgery prediction models lack accuracy and generalizability. Machine learning can improve accuracy by considering preoperative factors. This study aimed to develop and validate a machine learning-based model for estimating hospital stay duration following decompression surgery for LSS.

Methods

Data from 848 patients who underwent decompression surgery for LSS at three hospitals were examined. Twelve prediction models, using 79 preoperative variables, were developed for postoperative hospital stay estimation. The top five models were chosen. Fourteen models predicted prolonged hospital stay (≥14 days), and the most accurate model was chosen. Models were validated using a randomly divided training sample (70%) and testing cohort (30%).

Results

The top five models showed moderate linear correlations (0.576-0.624) between predicted and measured values in the testing sample. The ensemble of these models had moderate prediction accuracy for final length of stay (linear correlation 0.626, absolute mean error 2.26 days, standard deviation 3.45 days). The c5.0 decision tree model was the top predictor for prolonged hospital stay, with accuracies of 89.63% (training) and 87.2% (testing). Key predictors for longer stay included JOABPEQ social life domain, facility, history of vertebral fracture, diagnosis, and Visual Analogue Scale (VAS) of low back pain.

Conclusions

A machine learning-based model was developed to predict postoperative hospital stay after LSS decompression surgery, using data from multiple hospital settings. Numerical prediction of length of stay was not very accurate, although favorable prediction of prolonged stay was accomplished using preoperative factors. The JOABPEQ social life domain score was the most important predictor.

Impact of intra- and extramedullary alignment on blood loss in total knee arthroplasty: a retrospective study

BACKGROUND

There is a scarcity of scientific data regarding the correlation between alignment techniques during total knee arthroplasty (TKA) and blood loss as well as transfusion rates. This study's hypothesis posited that intramedullary-aligned (IM) TKA exhibits higher blood loss and transfusion rates when contrasted with extramedullary-aligned (EM) TKA.

METHODS

We conducted a retrospective examination of 883 patients who underwent total knee arthroplasty (TKA) in 2021 at a solitary orthopedic center in Germany. These patients were divided into two groups based on their tibial alignment technique: extramedullary alignment and intramedullary tibial alignment.

RESULTS

In the intramedullary tibial alignment (IM) group, we observed a blood loss of 0.91 L, while in the extramedullary tibial alignment (EM) group, the blood loss was 0.89 L. These values did not demonstrate a significant difference (p = 0.69). Transfusion rates were 0.99% in the IM group and 0.21% in the EM group, and there was no significant distinction between them (Chi-squared test: p > 0.05).

CONCLUSION

We observed no statistically significant variance in blood loss between the IM and EM groups. Likewise, there was no substantial disparity in transfusion rates between these groups. It can be concluded that the selection of a knee arthroplasty system incorporating either intramedullary tibial alignment or extramedullary alignment does not significantly impact blood loss.

Closed Suction Drainage after Total Knee Arthroplasty with Concomitant Intravenous Tranexamic Acid Administration

Drain use in total knee arthroplasty (TKA) remains controversial. Use has been associated with increased complications, particularly postoperative transfusion, infection, increased cost, and longer hospital stays. However, studies examining drain use were performed before widespread adoption of tranexamic acid (TXA), which markedly reduces transfusion without increasing venous thromboembolism events. We aim to investigate incidence of postoperative transfusion and 90-day return to the operating room (ROR) for hemarthrosis in TKA with use of drains and concomitant intravenous (IV) TXA. Primary TKAs from a single institution were identified from August 2012 to December 2018. Inclusion criteria were primary TKA, age 18 years and over where use of TXA, drains, anticoagulant, and pre- and postsurgical hemoglobin (Hb) were documented during the patient's admission. Primary outcomes were 90-day ROR specifically for hemarthrosis and rate of postoperative transfusion. A total of 2,008 patients were included. Sixteen patients required ROR, three of which were due to hemarthrosis. Drain output was statistically higher in the ROR group (269.3 vs. 152.4 mL, p = 0.05). Five patients required transfusion within 14 days (0.25%). Patients requiring transfusion had significantly lower presurgical Hb (10.2 g/dL, p = 0.01) and 24-hour postoperative Hb (7.7 g/dL, p < 0.001). Drain output between the transfusion and no transfusion groups varied significantly (p = 0.03), with transfusion patients having higher postoperative day 1 drain output of 362.6 mL and total drain output of 376.6 mL. In this series, postoperative drain use with concomitant weight-based IV TXA is shown to be safe and efficacious. We observed exceedingly low risk of postoperative transfusion compared with prior reports of drain use alone as well as preserved low rate of hemarthrosis that has previously been positively linked to drain use.

Disparities Associated With Total Joint Arthroplasty Transfusion Rates

BACKGROUND

Infections, readmissions, and mortalities after total joint arthroplasty (TJA) are serious complications, and transfusions have been associated with increased complication rates following TJA. Certain populations, including women, Black patients, patients who have public insurance and older adults have higher risks of transfusion. Recently, there has been a decline in transfusion rates and a greater emphasis on equity in medicine. This study examined whether disparities in transfusion rates still exist and what variables influence rates over time.

METHODS

We used a health care system database to identify 5,435 total knee arthroplasty (TKA) and 2,105 total hip arthroplasty (THA) patients from 2013 to 2021. Transfusion rates were 2.9 and 3.1% in the TKA and THA arthroplasty groups, respectively. White race represented 67.1 and 69.8% of the TKA and THA groups, respectively. Fisher exact and Wilcoxon rank sum tests were used to compare categorical and continuous variables. Multivariable logistic regressions were performed to predict transfusion rates within 5 days of surgery and adjust for potential confounders.

RESULTS

Transfusion rates declined over time. However, Black patients had a higher rate of transfusion than White patients despite similar hemoglobin levels, 5.1 versus 1.8% (P < .001) in the TKA group and 4.1 versus 2.7% (P = .103) in the THA group. Following adjustment, the biggest factor associated with a higher transfusion risk in the TKA group was being Black (adjusted odds ratio = 2.2, 95% confidence interval = 1.55 to 3.13).

CONCLUSIONS

Transfusion rates for TJA patients are declining; however, Black patients continued to receive transfusions at higher rates in patients receiving TKA.

Establishment and validation of a nomogram to predict postoperative anemia after total hip arthroplasty

BACKGROUND

Anemia is a common complication of total hip arthroplasty (THA). In this study, we evaluated the preoperative risk factors for postoperative anemia after THA and developed a nomogram model based on related preoperative and intraoperative factors.

METHODS

From January 2020 to May 2023, 927 THA patients at the same medical center were randomly assigned to either the training or validation cohort. The correlation between preoperative and intraoperative risk factors and postoperative anemia after THA was evaluated using univariate and multivariate logistic regression analysis. A nomogram was developed using these predictive variables. The effectiveness and validation for the clinical application of this nomogram were evaluated using the concordance index (C-index), receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA).

RESULTS

Through univariate and multivariate logistic regression analysis, 7 independent predictive factors were identified in the training cohort: Lower body mass index (BMI), extended operation time, greater intraoperative bleeding, lower preoperative hemoglobin level, abnormally high preoperative serum amyloid A (SAA) level, history of cerebrovascular disease, and history of osteoporosis. The C-index of the model was 0.871, while the AUC indices for the training and validation cohorts were 84.4% and 87.1%, respectively. In addition, the calibration curves of both cohorts showed excellent consistency between the observed and predicted probabilities. The DCA curves of the training and validation cohorts were high, indicating the high clinical applicability of the model.

CONCLUSIONS

Lower BMI, extended operation time, increased intraoperative bleeding, reduced preoperative hemoglobin level, elevated preoperative SAA level, history of cerebrovascular disease, and history of osteoporosis were seven independent preoperative risk factors associated with postoperative anemia after THA. The nomogram developed could aid in predicting postoperative anemia, facilitating advanced preparation, and enhancing blood management. Furthermore, the nomogram could assist clinicians in identifying patients most at risk for postoperative anemia.

Comparison of the effect of open-box versus closed-box prostheses on blood loss following total knee arthroplasty: a meta-analysis

Purpose

Postoperative blood loss is a common complication following total knee arthroplasty (TKA). The authors aimed to analyze the significance of open versus closed-box prostheses in reducing blood loss after TKA.

Methods

PubMed, Cochrane, Scopus, and Web of Science were searched. Observational studies and clinical trials comparing the effect of open-box versus closed-box prostheses on blood loss following TKA were included. The primary outcome was total blood loss following TKA. Secondary outcomes included average transfused units and total operation time. Continuous data were represented as mean difference (MD) and CI, while dichotomous data were presented as odds ratio (OR) and CI. RevMan software version 5.4 was used to conduct the analysis.

Results

Four studies with a total number of 687 patients were included. The pooled analysis showed a statistically significant association between closed-box and decreased total blood loss following TKA compared with open-box (MD=173.19, 95% CI=88.77-257.61, P value <0.0001). Similar findings were reported in unilateral TKA (MD=190.63, 95% CI=70.91-310.35, P value=0.002), and bilateral TKA (MD=160.79, 95% CI=61.70-359.86, P value=0.001). There was no significant difference between open and closed-box regarding average transfused units (MD=0.02, 95% CI=-0.07-0.11, P value=0.68), blood transfusion rate (OR=1.38, 95% CI=0.85-2.26, P value=0.20), length of stay (MD=0.06, 95% CI=-0.27 to 0.38, P value=0.74), and total operation time (MD=1.08, 95% CI=-4.62 to 6.79, P value=0.71).

Conclusion

Closed-box reduces the total blood loss following unilateral and bilateral TKA. More studies are warranted to explore the benefits of Closed-box in patients with high bleeding susceptibility.

The Efficacy and Safety of Tranexamic Acid in Total Hip and Knee Arthroplasty: A Literature Review

Historically, total hip arthroplasty (THA) and total knee arthroplasty (TKA) have been associated with significant perioperative blood loss and a relatively high rate of allogeneic blood transfusions. However, in recent years, tranexamic acid (TXA), a competitive inhibitor of tissue plasminogen activator, inhibiting fibrinolysis of existing thrombi, has substantially decreased the need for blood transfusion in THA and TKA. Various administration strategies have been studied, but there remains a lack of consensus on an optimal route and dosing regimen, with intravenous and topical regimens being widely used. A growing body of literature has demonstrated the safety and efficacy of TXA in primary and revision THA and TKA to reduce blood loss, allogeneic transfusions, and complications; it is associated with lowered lengths of stay, costs, and readmission rates.

Trends, complications, and readmission of allogeneic red blood cell transfusion in primary total hip arthroplasty in china: a national retrospective cohort study

INTRODUCTION

Decrease in allogenic red blood cell (RBC) transfusion rates following total hip arthroplasty (THA) has been reported in the United States, but whether other countries share the same trend remains unclear. Additionally, the relation of allogenic RBC transfusion to the risk of complications in THA remains controversial. Using the Chinese national inpatient database, the current study aimed to examine trends, complications, charges, and readmission patterns of allogeneic RBC transfusion in THA.

MATERIALS AND METHODS

Patients undergoing primary THA between 2013 and 2019 were included, and then stratified into the transfusion and the non-transfusion group based on the database transfusion records. A generalized estimating equation model was used to investigate trends in transfusion rates. After propensity-score matching, a logistic regression model was used to compare the complications, rates and causes of 30-day readmission between two groups.

RESULTS

A total of 10,270 patients with transfusion and 123,476 patients without transfusion were included. Transfusion rates decreased from 19.11% in 2013 to 9.94% in 2019 (P for trend < 0.001). After matching, no significant differences in the risk of of in-hospital death (odds ratio [OR], 4.00; 95% confidence interval [CI] 0.85-18.83), wound infection (OR 0.72; 95%CI 0.45-1.17), myocardial infarction (OR 1.17; 95%CI 0.62-2.19), deep vein thrombosis (OR 1.25; 95%CI 0.88-1.78), pulmonary embolism (OR 2.25; 95%CI 0.98-5.17), readmission rates (OR 1.07; 95%CI 0.88-1.30) and readmission causes were observed between two groups. However, the transfusion group had higher hospitalization charges than the non-transfusion group (72,239.89 vs 65,649.57 Chinese yuan [CNY], P < 0.001).

CONCLUSIONS

This study found that allogeneic RBC transfusion in THA was not associated with the increased risk of complications and any-cause readmission. However, the currently restrictive transfusion policy should be continued because excessive blood transfusion may increase the socioeconomic burden.

National Multi-Institutional Validation of a Surgical Transfusion Risk Prediction Model

BACKGROUND

Accurate estimation of surgical transfusion risk is important for many aspects of surgical planning, yet few methods for estimating are available for estimating such risk. There is a need for reliable validated methods for transfusion risk stratification to support effective perioperative planning and resource stewardship.

STUDY DESIGN

This study was conducted using the American College of Surgeons NSQIP datafile from 2019. S-PATH performance was evaluated at each contributing hospital, with and without hospital-specific model tuning. Linear regression was used to assess the relationship between hospital characteristics and area under the receiver operating characteristic (AUROC) curve.

RESULTS

A total of 1,000,927 surgical cases from 414 hospitals were evaluated. Aggregate AUROC was 0.910 (95% CI 0.904 to 0.916) without model tuning and 0.925 (95% CI 0.919 to 0.931) with model tuning. AUROC varied across individual hospitals (median 0.900, interquartile range 0.849 to 0.944), but no statistically significant relationships were found between hospital-level characteristics studied and model AUROC.

CONCLUSIONS

S-PATH demonstrated excellent discriminative performance, although there was variation across hospitals that was not well-explained by hospital-level characteristics. These results highlight the S-PATH's viability as a generalizable surgical transfusion risk prediction tool.

Risk factors for blood transfusion and postoperative anaemia following total knee arthroplasty

Aims

Blood transfusion and postoperative anaemia are complications of total knee arthroplasty (TKA) that are associated with substantial healthcare costs, morbidity, and mortality. There are few data from large datasets on the risk factors for these complications.

Methods

We retrospectively reviewed the records of TKA patients from a single tertiary care institution from February 2016 to December 2020. There were a total of 14,901 patients in this cohort with a mean age of 67.9 years (SD 9.2), and 5,575 patients (37.4%) were male. Outcomes included perioperative blood transfusion and postoperative anaemia, defined a priori as haemoglobin level < 10 g/dl measured on the first day postoperatively. In order to establish a preoperative haemoglobin cutoff, we investigated a preoperative haemoglobin level that would limit transfusion likelihood to ≤ 1% (13 g/dl) and postoperative anaemia likelihood to 4.1%. Risk factors were assessed through multivariable Poisson regression modelling with robust error variance.

Results

In multivariable analyses, each gram of tranexamic acid reduced transfusion likelihood by 39% (adjusted risk ratio (ARR) 0.61 (95% confidence interval (CI) 0.47 to 0.78)). Risk factors associated with an increased risk of transfusion included operating time (ARR 2.07 (95% CI 1.54 to 2.77)) and drain use (ARR 1.73 (95% CI 1.34 to 2.24)).

Conclusion

In this study, we found that increased tranexamic acid dosing, decreased operating time, and decreased drain use may reduce transfusions following TKA. We also established a single preoperative haemoglobin cutoff of 13 g/dl that could help minimize transfusions and reduce postoperative complete blood counts.

Rural-urban differences in characteristics, postoperative outcomes, and costs for patients undergoing knee arthroplasty: a national retrospective propensity score matched cohort study

BACKGROUND

The rural-urban disparities in postoperative complications and costs among patients undergoing knee arthroplasty (KA) have not been thoroughly explored. This study aimed to determine whether such differences exist in this patient population.

MATERIAL AND METHODS

The study was conducted using data from the national Hospital Quality Monitoring System of China. Hospitalized patients undergoing KA from 2013 to 2019 were enrolled. Patient and hospital characteristics were compared between rural and urban patients, and differences in postoperative complications, readmissions, and hospitalization costs were analyzed using propensity score matching.

RESULTS

Of the 146 877 KA cases analyzed, 71.4% (104 920) were urban patients and 28.6% (41 957) were rural patients. Rural patients tended to be younger (64.4±7.7 years vs. 68.0±8.0 years; P <0.001) and had fewer comorbidities. In the matched cohort of 36 482 participants per group, rural patients were found to be more likely to experience deep vein thrombosis (OR: 1.31, 95% CI: 1.17-1.46; P <0.001) and require red blood cell (RBC) transfusion (OR: 1.38, 95% CI: 1.31-1.46; P <0.001). However, they had a lower incidence of readmission within 30 days (OR: 0.65, 95% CI: 0.59-0.72; P <0.001) and readmission within 90 days (OR: 0.61, 95% CI: 0.57-0.66; P <0.001) than their urban counterparts. In addition, rural patients incurred lower hospitalization costs than urban patients (57 396.2 Chinese Yuan vs. 60 844.3 Chinese Yuan; P <0.001).

CONCLUSION

Rural KA patients had different clinical characteristics compared with urban patients. While they had a higher likelihood of deep vein thrombosis and RBC transfusion following KA than urban patients, they had fewer readmissions and lower hospitalization costs. Targeted clinical management strategies are needed for rural patients.

Predictors of Blood Transfusion in Patients Undergoing Lumbar Spinal Fusion

OBJECTIVE

To determine risk factors for perioperative blood transfusion after lumbar fusion surgery.

METHODS

After institutional review board approval, a retrospective cohort study of adult patients who underwent lumbar fusion at a single, urban tertiary academic center was retrospectively retrieved. Our primary outcome, blood transfusion, was collected via chart query. A receiver operating characteristic curve was used to evaluate the regression model. A P-value < 0.05 was considered statistically significant.

RESULTS

Of the 3,842 patients, 282 (7.3%) required a blood transfusion. For patients undergoing posterolateral decompression and fusion, predictors of transfusion included age (P < 0.001) and more levels fused (P < 0.001). A higher preoperative hemoglobin level (P < 0.001) and revision surgery (P = 0.005) were protective of blood transfusion. For patients undergoing transforaminal lumbar interbody fusion, greater Elixhauser comorbidity index (P < 0.001), longer operative time (P = 0.040), and more levels fused (P = 0.030) were independent predictors of the need for blood transfusion. Patients with a higher body mass index (P = 0.012) and preoperative hemoglobin level (P < 0.001) had a reduced likelihood of receiving a transfusion. For circumferential fusion, greater age (P = 0.006) and longer operative times (P = 0.015) were independent predictors of blood transfusion, while a higher preoperative hemoglobin level (P < 0.001) and male sex (P = 0.002) were protective.

CONCLUSIONS

Our analysis identified older age, lower body mass index, greater Elixhauser comorbidity index, longer operative duration, more levels fused, and lower preoperative hemoglobin levels as independent predictors of requiring a blood transfusion following lumbar spinal fusion. Different surgical approaches were not found to be associated with transfusion.

Learning Curve for Short-Stem Total HIP Arthroplasty through an Anterolateral Approach

Background and Objectives: Short-stem total hip arthroplasty has become increasingly popular in recent years. While many studies have shown excellent clinical and radiological results, very little is known about the learning curve for short-stem total hip arthroplasty through an anterolateral approach. Therefore, the aim of this study was to determine the learning curve for short-stem total hip arthroplasty among five residents in training. Materials and Methods: We performed retrospective data analysis of the first 30 cases of five randomly selected residents (n = 150 cases) with no experience before the index surgery. All patients were comparable, and several surgical parameters and radiological outcomes were analyzed. Results: The only surgical parameter with a significant improvement was the surgical time (p = 0.025). The changes in other surgical parameters and radiological outcomes showed no significant changes; only trends can be derived. As a result, the correlation between surgical time, blood loss, length of stay, and incision/suture time can also be seen. Only two of the five residents showed significant improvements in all examined surgical parameters. Conclusions: There are individual differences among the first 30 cases of the five residents. Some improved their surgical skills faster than others. It could be assumed that they assimilated their surgical skills after more surgeries. A further study with more than 30 cases of the five surgeons could provide more information on that assumption.

Clinical outcomes and prediction nomogram model for postoperative hemoglobin < 80 g/L in patients following primary lumbar interbody fusion surgery

OBJECTIVE

To analyze the association between different postoperative hemoglobin (Hb) levels and postoperative outcomes in patients who have undergone primary lumbar interbody fusion, and to investigate the risk factors and establish a predictive nomogram mode for postoperative Hb < 80 g/L.

METHODS

We retrospectively analyzed 726 cases who underwent primary lumbar interbody fusion surgery between January 2018 and December 2021in our hospital. All patients were divided into three groups according to the postoperative Hb levels (< 70 g/L, 70-79 g/L, ≥ 80 g/L). The postoperative outcomes among the three groups were compared, and the risk factors for postoperative Hb < 80 g/L were identified by univariate and multivariable logistic regression analysis. Based on these independent predictors, a nomogram model was developed. Predictive discriminative and accuracy ability of the predicting model was assessed using the concordance index (C-index) and calibration plot. Clinical application was validated using decision curve analysis. Internal validation was performed using the bootstrapping validation.

RESULTS

Patients with postoperative Hb < 80 g/L had higher rates of postoperative blood transfusion, a greater length of stay, higher rates of wound complications, and higher hospitalization costs than those with postoperative Hb ≥ 80 g/L. Preoperative Hb, preoperative platelets, fusion segments, body mass index, operation time, and intraoperative blood loss independently were associated with postoperative Hb < 80 g/L. Intraoperative blood salvage was found to be a negative predictor for postoperative Hb < 80 g/L (OR, 0.21 [95% CI 0.09-0.50]). The area under the curve of the nomogram model was 0.950. After internal validations, the C-index of the model was 0.939. The DCA and calibration curve suggested that the nomogram model had a good consistency and clinical utility.

CONCLUSIONS

Postoperative Hb < 80 g/L in patients following primary lumbar interbody fusion surgery increased blood transfusions requirement and was independently associated with poor outcomes. A novel nomogram model was established and could conveniently predict the risk of postoperative Hb < 80 g/L in patients after this type of surgery.

The removal of total hip arthroplasty from the inpatient-only list has improved patient selection and expanded optimization efforts

INTRODUCTION

On January 1, 2020, the Centers for Medicare and Medicaid Services removed total hip arthroplasty (THA) from the Inpatient-Only (IPO) list. This study evaluated patient demographics and comorbidities, pre-operative optimization efforts, and 30-day outcomes of patients undergoing outpatient THA pre- and post- IPO-removal. The authors hypothesized that patients undergoing THA post-IPO removal would have improved optimization of modifiable risk factors and equivalent 30-day outcomes.

METHODS

There were 17,063 outpatient THA in a national database stratified by surgery performed pre- (2015 to 2019: 5,239 patients) and post-IPO (2020: 11,824 patients) removal. Demographics, comorbidities, and 30-day outcomes were compared with univariable and multivariable analyses. Pre-operative optimization thresholds were established for the following modifiable risk factors: albumin, creatinine, hematocrit, smoking history, and body mass index. The percentage of patients who fell outside the thresholds in each cohort were compared.

RESULTS

Patients undergoing outpatient THA post-IPO removal were significantly older; mean age 65 years (range, 18 to 92) vs 62 (range, 18 to 90) years (P<0.01), with a higher percentage of American Society of Anesthesiologists scores 3 and 4 (P<0.01). There was no difference in 30-day readmissions (P=0.57) or reoperations (P=1.00). A significantly lower percentage of patients fell outside the established threshold for albumin (P<0.01) post-IPO removal, and trended towards lower percentages for hematocrit and smoking status.

CONCLUSION

The removal of THA from the IPO list expanded patient selection for outpatient arthroplasty. Pre-operative optimization is critical to minimize post-operative complications, and the current study demonstrates that 30-day outcomes have not worsened post-IPO removal.

Predisposing factors for allogeneic blood transfusion in patients with ankylosing spondylitis undergoing primary unilateral total hip arthroplasty: a retrospective study

BACKGROUND

The transfusion rate is relatively high in patients with ankylosing spondylitis (AS) undergoing total hip arthroplasty (THA). However, relevant studies focusing on the predisposing factors for transfusion with a large sample size are lacking. This study aimed to investigate the incidence of and risk factors for allogeneic blood transfusion in patients with AS undergoing primary unilateral THA.

METHODS

This retrospective study included 331 patients with AS who underwent primary unilateral THA between 2011 and 2021. Relevant parameters were collected through a chart review. Multivariate logistic regression analysis was conducted to identify possible factors associated with perioperative allogeneic blood transfusion.

RESULTS

A total of 113 (34.1%) patients received perioperative allogeneic blood transfusions. Factors related to receiving an allogeneic blood transfusion included prolonged operative duration (odds ratio [OR] per 10 min = 1.139, P = 0.047), increased estimated intraoperative blood loss (OR per 100 mL = 1.348, P < 0.001), and increased postoperative drainage volume (OR per 100 mL = 1.235, P = 0.024). A higher body mass index (BMI) (OR = 0.914, P = 0.012), perioperative tranexamic acid (TXA) use (OR = 0.166, P < 0.001), and a higher preoperative hemoglobin level (OR per 1 g/dL = 0.744, P = 0.004) decreased the risk of transfusion.

CONCLUSIONS

In patients with AS undergoing THA, prolonged operative duration, increased estimated intraoperative blood loss, and increased postoperative drainage volume were found to be risk factors for transfusion, whereas a higher BMI, perioperative TXA use, and a higher preoperative hemoglobin level were protective factors. These results may aid in developing a better perioperative management strategy, ultimately reducing the need for transfusion.

Prediction of red blood cell transfusion after orthopedic surgery using an interpretable machine learning framework

Objective

Postoperative red blood cell (RBC) transfusion is widely used during the perioperative period but is often associated with a high risk of infection and complications. However, prediction models for RBC transfusion in patients with orthopedic surgery have not yet been developed. We aimed to identify predictors and constructed prediction models for RBC transfusion after orthopedic surgery using interpretable machine learning algorithms.

Methods

This retrospective cohort study reviewed a total of 59,605 patients undergoing orthopedic surgery from June 2013 to January 2019 across 7 tertiary hospitals in China. Patients were randomly split into training (80%) and test subsets (20%). The feature selection method of recursive feature elimination (RFE) was used to identify an optimal feature subset from thirty preoperative variables, and six machine learning algorithms were applied to develop prediction models. The Shapley Additive exPlanations (SHAP) value was employed to evaluate the contribution of each predictor towards the prediction of postoperative RBC transfusion. For simplicity of the clinical utility, a risk score system was further established using the top risk factors identified by machine learning models.

Results

Of the 59,605 patients with orthopedic surgery, 19,921 (33.40%) underwent postoperative RBC transfusion. The CatBoost model exhibited an AUC of 0.831 (95% CI: 0.824-0.836) on the test subset, which significantly outperformed five other prediction models. The risk of RBC transfusion was associated with old age (>60 years) and low RBC count (<4.0 × 10¹²/L) with clear threshold effects. Extremes of BMI, low albumin, prolonged activated partial thromboplastin time, repair and plastic operations on joint structures were additional top predictors for RBC transfusion. The risk score system derived from six risk factors performed well with an AUC of 0.801 (95% CI: 0.794-0.807) on the test subset.

Conclusion

By applying an interpretable machine learning framework in a large-scale multicenter retrospective cohort, we identified novel modifiable risk factors and developed prediction models with good performance for postoperative RBC transfusion in patients undergoing orthopedic surgery. Our findings may allow more precise identification of high-risk patients for optimal control of risk factors and achieve personalized RBC transfusion for orthopedic patients.

The effectiveness of a multifaceted, group-facilitated audit and feedback intervention to increase tranexamic acid use during total joint arthroplasty

PURPOSE

Intraoperative tranexamic acid (TXA) is used to reduce blood loss and the need for transfusions following total hip arthroplasty (THA) and total knee arthroplasty (TKA). Despite evidence in literature and local practice protocols supporting TXA as a part of standard of care for joint arthroplasty, TXA administration is underutilized. We aimed to use group-facilitated audit and feedback as the foundation of a knowledge translation strategy to increase TXA use for THA and TKA procedures.

METHODS

Anesthesiologists consented to receive two data reports summarizing their individual rates of TXA use and postoperative blood transfusions compared with site peers. Variables collected included patient demographics, TXA usage, and the frequency and volume of red blood cell transfusions administered in the 72-hr postoperative period. The facilitated feedback session discussed report findings and focused on factors contributing to local practice patterns and opportunities for change.

RESULTS

Tranexamic acid use increased for THA procedures at the intervention site from 66.6 to 74.4% (absolute change, 7.9%; 95% confidence interval [CI], 2.4 to 13.3). Likewise, TXA use for TKA procedures increased from 62.4 to 82.3% (absolute change, 19.9%; 95% CI 15.0 to 25.0).

CONCLUSIONS

Physicians and their teams were able to review their practice data on TXA utilization, reflect on differences compared with evidence-based guidelines, discuss findings with peers, and identify opportunities for improvement. The intervention increased the use of TXA for both TKA and THA and shifted the dosage to better align with evidence-based practice guidelines.

Evaluation of Blood Loss in Conventional vs MAKOplasty Total Knee Arthroplasty

Background

Methods

Results

Conclusions

Personalized Surgical Transfusion Risk Prediction Using Machine Learning to Guide Preoperative Type and Screen Orders

BACKGROUND

Accurate estimation of surgical transfusion risk is essential for efficient allocation of blood bank resources and for other aspects of anesthetic planning. This study hypothesized that a machine learning model incorporating both surgery- and patient-specific variables would outperform the traditional approach that uses only procedure-specific information, allowing for more efficient allocation of preoperative type and screen orders.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program Participant Use File was used to train four machine learning models to predict the likelihood of red cell transfusion using surgery-specific and patient-specific variables. A baseline model using only procedure-specific information was created for comparison. The models were trained on surgical encounters that occurred at 722 hospitals in 2016 through 2018. The models were internally validated on surgical cases that occurred at 719 hospitals in 2019. Generalizability of the best-performing model was assessed by external validation on surgical cases occurring at a single institution in 2020.

RESULTS

Transfusion prevalence was 2.4% (73,313 of 3,049,617), 2.2% (23,205 of 1,076,441), and 6.7% (1,104 of 16,053) across the training, internal validation, and external validation cohorts, respectively. The gradient boosting machine outperformed the baseline model and was the best- performing model. At a fixed 96% sensitivity, this model had a positive predictive value of 0.06 and 0.21 and recommended type and screens for 36% and 30% of the patients in internal and external validation, respectively. By comparison, the baseline model at the same sensitivity had a positive predictive value of 0.04 and 0.144 and recommended type and screens for 57% and 45% of the patients in internal and external validation, respectively. The most important predictor variables were overall procedure-specific transfusion rate and preoperative hematocrit.

CONCLUSIONS

A personalized transfusion risk prediction model was created using both surgery- and patient-specific variables to guide preoperative type and screen orders and showed better performance compared to the traditional procedure-centric approach.

EDITOR’S PERSPECTIVE

Assessment of perioperative total blood loss during total ankle arthroplasty

BACKGROUND

Although many authors have discussed total blood loss after arthroplasty of the knee, hip, and shoulder, reports on perioperative blood loss after total ankle arthroplasty (TAA) are rare. The purpose of this study was to assess total blood loss after TAA and to identify correlated factors.

METHODS

A total of 103 cases (99 patients) of TAA for end-stage ankle osteoarthritis were enrolled in this study. Perioperative total blood loss was divided into intraoperative and postoperative blood loss. The patient-related variables evaluated for total blood loss were age, sex, body mass index, American Society of Anesthesiologists Classification score, comorbidities, history of previous ankle surgery, preoperative use of anticoagulants, platelet count and prothrombin time/international normalized ratio. Operation-related variables including type of anesthesia, operation time, TAA implant, and procedures performed in addition to TAA (if any) were evaluated to analyze correlations with total blood loss. In addition, the rate of transfusions after surgery was identified, and risk factors for transfusion were statistically analyzed.

RESULTS

The total blood loss was mean 795.5±351.1mL, which included 462.2±248.5mL of intraoperative blood loss and 333.2±228.6mL of postoperative blood loss. Sex, TAA implant, and additional bony procedures performed along with TAA were significantly correlated with total blood loss (p=0.039, 0.024, 0.024, respectively) but the other variables were not significant (p>0.05). Transfusions were administered for 4 cases (3.8%) but no risk factors for transfusion could be identified.

CONCLUSION

The total blood loss after TAA was 795.5mL and the rate of transfusions was 3.8%. This study demonstrated that male sex, use of TAA implants with a larger cutting surface, and bony procedures performed in addition to TAA were associated with an increase in total blood loss after TAA. The findings of this study will help surgeons to better predict blood loss and make optimal surgical plans accordingly.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Who Is Still Receiving Blood Transfusions After Primary and Revision Total Joint Arthroplasty?

BACKGROUND

Incidence of blood transfusions after primary and revision total hip and knee arthroplasty (primary total hip arthroplasty [pTHA], revision THA [rTHA], primary total knee arthroplasty [pTKA], and revision TKA [rTKA]) has been decreasing for a multitude of reasons. The purpose of this study was to assess whether transfusion rates have continued to decline and evaluate patient factors associated with transfusions.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program was queried to identify patients undergoing pTHA, pTKA, rTHA, and rTKA between 2011 and 2019. Patients undergoing bilateral procedures and arthroplasty for fracture, infection, or tumor were excluded. Trends in blood transfusions were assessed. Patient factor association with blood transfusions was evaluated using 2018 and 2019 data.

RESULTS

Transfusion rates decreased from 21.4% in 2011 to 2.5% in 2019 for pTHA (P < .0001). For pTKA, transfusion rates declined from 17.6% to 0.7% (P < .0001). In rTHA, the transfusion rate decreased from 33.5% to 12.0% from 2011 to 2019 (P < .0001). Transfusion rates declined from 19.4% to 2.6% for rTKA during the study period (P < .0001). Transfusions were more frequent in patients who were older, female, with more comorbidities, with lower hematocrit, receiving nonspinal anesthesia, and with longer operative time. Lower preoperative hematocrit, history of bleeding disorders, and preoperative transfusion were associated with greater odds for postoperative transfusion after multivariate analysis.

CONCLUSION

Transfusions after both primary and revision total joint arthroplasty have continued to decrease. Studies of arthroplasty complications should account for decreasing transfusions when assessing overall complication rates. Future studies should consider interventions to further reduce transfusions in revision arthroplasty.

Risk Factors for Blood Transfusions in Primary Anatomic and Reverse Total Shoulder Arthroplasty for Osteoarthritis

BACKGROUND

The purpose of this study was to determine risk factors for blood transfusion in primary anatomic and reverse total shoulder arthroplasty (TSA) performed for osteoarthritis.

METHODS

Patients who underwent anatomic or reverse TSA for a diagnosis of primary osteoarthritis were identified in a national surgical database from 2005 to 2018 by utilizing both CPT and ICD-9/ICD-10 codes. Univariate analysis was performed on the two transfused versus non-transfused cohorts to compare for differences in comorbidities and demographics. Independent risk factors for perioperative blood transfusions were identified via multivariate regression models.

RESULTS

305 transfused and 18,124 nontransfused patients were identified. Female sex (p<0.001), age >85 years (p=0.001), insulin-dependent diabetes mellitus (p=0.001), dialysis dependence (p=0.001), acute renal failure (p=0.012), hematologic disorders (p=0.010), disseminated cancer (p<0.001), ASA ≥ 3 (p<0.001), and functional dependence (p=0.001) were shown to be independent risk factors for blood transfusions on multivariate logistic regression analysis.

CONCLUSION

Several independent risk factors for blood transfusion following anatomic/reverse TSA for osteoarthritis were identified. Awareness of these risk factors can help surgeons and perioperative care teams to both identify and optimize high-risk patients to decrease both transfusion requirements and its associated complications in this patient population. Level of Evidence: III.

Transfusion Trends of Knee Arthroplasty in Korea: A Nationwide Study Using the Korean National Health Insurance Service Sample Data

Knee arthroplasties are strongly associated with blood transfusion to compensate for perioperative bleeding. The purpose of this study was to evaluate trends of transfusion associated with knee arthroplasties using nationwide data of the National Health Insurance Service-National Sample Cohort (NHIS-NSC). Using data from the nationwide claims database of the Health Insurance Review Assessment Service managed by the NHIS, 50,553 knee arthroplasties under three categories (total knee replacement arthroplasty, uni-knee replacement arthroplasty, and revision arthroplasty) from 2012 to 2018 were identified. Overall transfusion rate, transfusion count, proportion of each type of transfusion, and cost associated with each type of operation were investigated. Overall transfusion rate was 83.4% (5897/7066) in 2012, 82.7% (5793/7001) in 2013, 79.6% (5557/6978) in 2014, 75.9% (5742/7557) in 2015, 73.1% (6095/8337) in 2016, 68.2% (4187/6139) in 2017, and 64.6% (4271/6613) in 2018. The proportion of each type of transfusion was 1.8% for fresh frozen plasma, 0.5% for platelets, and 97.7% for red blood cells. The average cost of transfusion was $109.1 ($123 in 2012, $124 in 2013, $123.3 in 2014, $110.6 in 2015, $100 in 2016, $92.9 in 2017, and $90.1 in 2018). In this nationally representative study of trends in transfusion associated with knee arthroplasty, we observed significantly high rates of blood transfusion among patients undergoing knee arthroplasties. Although the overall rate of transfusion had declined, the allogeneic transfusion rate was still high from 2012 to 2018 in Korea. Thus, surgeons need to develop various patient blood management plans and minimize the use of allogeneic transfusion when performing knee arthroplasties.

The Effects of Press-Fit Technique Combined with Tranexamic Acid on Duration of Surgery and Intraoperative Blood Loss in Primary Total Hip Arthroplasty

Background: Prolonged operative time and blood loss may affect the success rate in total hip arthroplasty (THA). The aim of the current study was to evaluate the effects of the press-fit (PF) technique without screws combined with tranexamic acid (TXA) on operative time and intraoperative blood loss in THA.

Methods: We retrospectively evaluated 114 hips treated with THA between March 2017 and January 2021 in this study. The patients were divided into three groups, including PF-TXA group, only PF group, and screw group. PF-TXA group received intravenous (IV) 1 g TXA 15 minutes before surgical incision, followed by a peri-articular 1 g/50 ml TXA. Only the PF group and screw group did not receive TXA. The primary outcome measures were operative time and intraoperative blood loss. Secondary outcomes included postoperative blood loss, hemoglobin and hematocrit levels, allogeneic blood transfusions, length of hospital stay, the Harris Hip Score (HHS), and thromboembolic complications.

Results: Operative time was lower in the PF-TXA group than that in the only PF and the screw group (p=0.0001). Intraoperative blood loss was significantly different in the PF-TXA group compared with the only PF and the screw group (423 ml, 516 ml, and 534 ml; respectively). The patients who received the PF technique combined with TXA had significantly less hospital stay length than the only PF group and the screw group (p=0.021).

Conclusion: The findings obtained in this study suggest that although only the PF technique can provide a shorter operative time compared to using screws, less blood loss may not be obtained using this technique in THA. PF technique combined with TXA significantly decreased operation time and intraoperative blood loss as well as the length of hospital stay following primary THA.

Utilization of machine learning methods for predicting surgical outcomes after total knee arthroplasty

Background

Predictive models could help clinicians identify risk factors that cause adverse events after total knee arthroplasty (TKA), allowing for appropriate preoperative preventive interventions and allocation of resources.

Methods

The National Inpatient Sample datasets from 2010–2014 were used to build Logistic Regression (LR), Gradient Boosting Method (GBM), Random Forest (RF), and Artificial Neural Network (ANN) predictive models for three clinically relevant outcomes after TKA—disposition at discharge, any post-surgical complications, and blood transfusion. Model performance was evaluated using the Brier scores as calibration measures, and area under the ROC curve (AUC) and F1 scores as discrimination measures.

Results

GBM-based predictive models were observed to have better calibration and discrimination than the other models; thus, indicating comparatively better overall performance. The Brier scores for GBM models predicting the outcomes under investigation ranged from 0.09–0.14, AUCs ranged from 79–87%, and F1-scores ranged from 41–73%. Variable importance analysis for GBM models revealed that admission month, patient location, and patient’s income level were significant predictors for all the outcomes. Additionally, any post-surgical complications and blood transfusions were significantly predicted by deficiency anemias, and discharge disposition by length of stay and age groups. Notably, any post-surgical complications were also significantly predicted by the patient undergoing blood transfusion.

Conclusions

The predictive abilities of the ML models were successfully demonstrated using data from the National Inpatient Sample (NIS), indicating a wide range of clinical applications for obtaining accurate prognoses of complications following orthopedic surgical procedures.

Low muscle mass is an independent risk factor for postoperative blood transfusion in total knee arthroplasty: a retrospective, propensity score-matched cohort study

Background

Sarcopenia, an age-related loss of skeletal muscle mass and function, is correlated with adverse outcomes after some surgeries. This study examined the characteristics of sarcopenic patients undergoing primary total knee arthroplasty (TKA), and identified low muscle mass as an independent risk factor for postoperative TKA complications.

Methods

A retrospective cohort study examined 452 patients who underwent TKA. The skeletal muscle index (SMI) was obtained via bioelectrical impedance analysis (BIA), along with demographics, the Charlson Comorbidity Index, and medication, laboratory and operative data for 2018–2021. Patients were categorized into normal (n = 417) and sarcopenic (n = 35) groups using the SMI cut-off suggested by the Asian Working Group for Sarcopenia 2019 (males, < 7.0 kg/m²; females, < 5.7 kg/m²). Three postoperative complications were analysed: blood transfusion, delirium, and acute kidney injury (AKI). Baseline characteristics were propensity score-matched to address potential bias and confounding factors.

Results

The proportion of sarcopenic patients in primary TKA was 7.7% (35/452). The sarcopenic group had a lower preoperative haemoglobin (12.18 ± 1.20 vs. 13.04 ± 1.73 g/dL, p = 0.004) and total protein (6.73 ± 0.42 vs. 7.06 ± 0.44 mg/dL, p = 0.001). Propensity scoring matching and logistic regression showed that more patients in the sarcopenic group received postoperative blood transfusions (OR = 6.60, 95% CI: 1.57–45.5, p = 0.021); there was no significant difference in AKI or delirium. Univariate receiver operating characteristic curve analysis of the propensity-matched group, to determine the predictive value of SMI for postoperative transfusion, gave an AUC of 0.797 (0.633–0.96) and SMI cut-off of 5.6 kg/m².

Conclusions

Low muscle mass determined by BIA was an independent risk factor for postoperative transfusion in TKA. Multifrequency BIA can serve as a screening tool for sarcopenia that may influence the orthopaedic decision-making process or treatment planning in patients with sarcopenia undergoing primary TKA.

Level of evidence

III, retrospective cohort study.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-02903-0.

Are Morbidly Obese Patients Equally Benefitting From Care Improvements in Total Hip Arthroplasty?

BACKGROUND

Morbidly obese patients have increased rates of complications following primary total hip arthroplasty (THA) and it is not clear whether improvements in THA care pathways are equally benefitting these patients. The purpose of this study is to assess if reductions in complications have similarly improved for both morbidly obese and non-morbidly obese patients after THA.

METHODS

Patients undergoing primary THA between 2011 and 2019 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Patients were stratified by body mass index (BMI) <40 and ≥40 kg/m². Thirty-day rates of infectious complications, readmissions, reoperation, and any complication were assessed. Trends in complications were compared utilizing odds ratios and multivariate analyses.

RESULTS

In total, 234,334 patients underwent THA and 16,979 (7.8%) had BMI ≥40 kg/m². Patients with BMI ≥40 kg/m² were at significantly higher odds for readmission, reoperation, and infectious complications. Odds for any complication were lower for morbidly obese patients in 2011, not different from 2012 to 2014, and higher from 2015 to 2019 compared to lower BMI patients. Odds for any non-transfusion complication were higher for morbidly obese patients and there was no improvement for either group over the study period. There were improvements in rates of readmission and reoperation for patients with BMI <40 kg/m² and readmission for BMI >40 kg/m².

CONCLUSION

Odds for readmission and reoperation for non-morbidly obese patients and readmission for morbidly obese patients improved from 2011 to 2019. Reductions in transfusions are largely responsible for improvements in overall complication rates. Although morbidly obese patients remain at higher risk for complications, there does not appear to be a growing disparity in outcomes between morbidly obese and non-morbidly obese patients.

Predictors and Outcomes of Postoperative Hemoglobin of <8 g/dL in Total Joint Arthroplasty

BACKGROUND

Restrictive transfusion practices have decreased transfusions in total joint arthroplasty (TJA). A hemoglobin threshold of <8 g/dL is commonly used. Predictors of this degree of postoperative anemia in TJA and its association with postoperative outcomes, independent of transfusions, remain unclear. We identified predictors of postoperative hemoglobin of <8 g/dL and outcomes with and without transfusion in TJA.

METHODS

Primary elective TJA cases performed with a multimodal blood management protocol from 2017 to 2018 were reviewed, identifying 1,583 cases. Preoperative and postoperative variables were compared between patients with postoperative hemoglobin of <8 and ≥8 g/dL. Logistic regression and receiver operating characteristic curves were used to assess predictors of postoperative hemoglobin of <8 g/dL.

RESULTS

Positive predictors of postoperative hemoglobin of <8 g/dL were preoperative hemoglobin level (odds ratio [OR] per 1.0-g/dL decrease, 3.0 [95% confidence interval (CI), 2.4 to 3.7]), total hip arthroplasty (OR compared with total knee arthroplasty, 2.1 [95% CI, 1.3 to 3.4]), and operative time (OR per 30-minute increase, 2.0 [95% CI, 1.6 to 2.6]). Negative predictors of postoperative hemoglobin of <8 g/dL were tranexamic acid use (OR, 0.42 [95% CI, 0.20 to 0.85]) and body mass index (OR per 1 kg/m2 above normal, 0.90 [95% CI, 0.86 to 0.94]). Preoperative hemoglobin levels of <12.4 g/dL in women and <13.4 g/dL in men best predicted postoperative hemoglobin of <8 g/dL. Overall, 5.2% of patients with postoperative hemoglobin of 7 to 8 g/dL and 95% of patients with postoperative hemoglobin of <7 g/dL received transfusions. Patients with postoperative hemoglobin of <8 g/dL had longer hospital stays (p < 0.001) and greater rates of emergency department visits or readmissions (p = 0.001) and acute kidney injury (p < 0.001). Among patients with postoperative hemoglobin of <8 g/dL, patients who received transfusions had a lower postoperative hemoglobin nadir (p < 0.001) and a longer hospital stay (p = 0.035) than patients who did not receive transfusions.

CONCLUSIONS

Postoperative hemoglobin of <8 g/dL after TJA was associated with worse outcomes, even for patients who do not receive transfusions. Optimizing preoperative hemoglobin levels may mitigate postoperative anemia and adverse outcomes.

LEVEL OF EVIDENCE

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

Hidden blood loss in direct anterior total hip arthroplasty: a prospective, double blind, randomized controlled trial on topical versus intravenous tranexamic acid

BACKGROUND

Despite a plethora of literature reporting on the use of tranexamic acid (TXA) in total hip arthroplasty (THA), little is available on its effect on post-operative hidden blood loss and even less on its use in the direct anterior approach (DAA), which is gaining popularity.

MATERIALS AND METHODS

This study was designed as a prospective, double blind, single centre, randomized controlled trial. Sixty patients were allocated to intravenous administration of 1.5 g of TXA just before wound closure while 60 patients were allocated to topical application of 3.0 g of TXA via a subfascial drain at the end of the procedure. Post-operative blood loss was (1) calculated via a well-established formula based on pre- and post-operative Hb levels, patients characteristics and intra-operative blood loss and (2) measured via the amount that collected in the subfascial drain over time.

RESULTS

No statistical significant difference in post-operative blood loss was found, neither when the formula was used (0.55 L [topical] vs 0.67 L [IV]; p = .140) nor when looking at the drain output (0.25 L [topical] vs 0.29 L [IV]; p = .108). No significant difference in secondary outcome measures, such as transfusion of units of packed red blood cells, length of hospital stay or the occurrence of venous thromboembolisms, could be found either.

CONCLUSIONS

This study provides detailed insights into the intra- and post-operative blood loss in DAA THA and shows that topical and IV TXA have similar effects on hidden blood loss. Clinical Trial Number: NCT01940692.

LEVEL OF EVIDENCE I

Level I-Randomized Controlled Trial.

Predictive Factors for Blood Transfusion after Total Knee Arthroplasty

Objectives  The present paper aims to (1) verify the incidence and volume of blood transfusion among patients undergoing unilateral cemented total knee arthroplasty (TKA) in a single Brazilian reference center; (2) identify pre and perioperative variables to determine subjects with higher risk (i.e., predictive factors) for blood transfusion within 48 hours following surgery; (3) estimate the risk of blood transfusion during the first 48 hours after the procedure.

Methods  The initial sample consisted of all patients undergoing TKA from August 2010 to August 2013. After applying the exclusion criteria, 234 patients aged 30 to 83 years old and diagnosed with primary or secondary osteoarthritis due to rheumatoid arthritis remained in the study.

Results  Preoperative hemoglobin levels ≤ 12.3 g/dL and ischemia time ≥ 87 minutes were independent predictors for post-TKA blood transfusion, with a relative risk of 2.48 and 1.78, respectively. Approximately half of the TKA patients (51.3%) presenting these two variables required a blood transfusion.

Conclusion  The incidence of post-TKA blood transfusion was 33.7%. On average, each transfused patient received 480 mL of packed red blood cells. Preoperative hemoglobin levels ≤ 12.3 g/dL ( p  < 0.001) and ischemia time ≥ 87 minutes ( p  < 0.047) were independent predictors for blood transfusion in TKA using a pneumatic cuff, with a relative risk of 2.48 and 1.78, respectively. Age, gender, diagnosis, or body mass index were not considered independent predictors for the need for blood transfusion up to 48 hours after the procedure.

Are surgeons still performing primary total knee arthroplasty in the morbidly obese?

AIMS

The purpose of this study was to assess total knee arthroplasty (TKA) volume and rates of early complications in morbidly obese patients over the last decade, where the introduction of quality models influencing perioperative care pathways occurred.

METHODS

Patients undergoing TKA between 2011 to 2018 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Patients were stratified by BMI < 40 kg/m² and ≥ 40 kg/m² and evaluated by the number of cases per year. The 30-day rates of any complication, wound complications, readmissions, and reoperation were assessed. Trends in these endpoints over the study period were compared between groups using odds ratios (ORs) and multivariate analyses.

RESULTS

In total, 314,695 patients underwent TKA and 46,362 (15%) had BMI ≥ 40 kg/m². The prevalence of morbid obesity among TKA patients did not change greatly, ranging between 14% and 16%. Reoperation rate decreased from 1.16% to 0.96% (odds ratio (OR) 0.81 (95% confidence interval (CI) 0.66 to 0.99)) for patients with BMI < 40 kg/m², as did rates of readmission (4.46% to 2.87%; OR 0.61 (0.55 to 0.69)). Patients with BMI ≥ 40 kg/m² also had fewer readmissions over the study period (4.87% to 3.34%; OR 0.64 (0.49 to 0.83)); however, the rate of reoperation did not change (1.37% to 1.41%; OR 0.99 (0.62 to 1.56)). Significant improvements were not observed for infective complications over time for either group; patients with BMI ≥ 40 kg/m² had increased risk of both deep infection and wound complications compared to non-morbidly obese patients. Rate of any complication decreased for all patients.

CONCLUSION

The proportion of TKAs in morbidly obese patients has not significantly changed over the past decade. Although readmission rates improved for all patients, reductions in reoperation in non-morbidly obese patients were not experienced by the morbidly obese, resulting in a widening of the complication gap between these cohorts. Care improvements have not lowered the differential risk of infective complications in the morbidly obese. Cite this article: Bone Joint J 2021;103-B(6 Supple A):38-44.

Perioperative red blood cell infusion and deep vein thrombosis in patients with femoral and pelvic fractures: a propensity score matching

BACKGROUND

The relationship between perioperative red blood cell (RBC) infusion and deep vein thrombosis (DVT) has not been determined.

OBJECTIVES

To analyze the time-event relationship between perioperative RBC infusion and DVT in patients with femoral and pelvic fractures after adjusting for confounding factors and to provide reference for optimizing DVT risk factors.

METHODS

The clinical data of 569 patients with femoral and pelvic fractures who received surgical treatment from May 2018 to December 2019 were retrospectively analyzed. Propensity score matching (PSM) was performed on 20 covariates of DVT. With the formation or progression of DVT after RBC infusion as the end point, the time-event relationship between perioperative RBC infusion and DVT in patients was analyzed by binary logistic regression.

RESULTS

After 1:1 PSM of 569 patients included in this study, 126 patients were in the transfusion group and the non-transfusion group, respectively. Before PSM (P = 0.023, OR = 1.496 [95% CI, 1.058-2.115]), perioperative RBC infusion was associated with DVT formation for femoral and pelvic fractures. This conclusion was still obtained after PSM (P = 0.038, OR = 1.728, 95% CI = (1.031, 2.896)). The risk of DVT in patients with RBC infusion of 2-4U and > 4U is 1.833 and 2.667 times that of ≤ 2U, respectively. After excluding patients who received preoperative RBC infusion and had DVT formation or progression prior to RBC infusion, perioperative RBC infusion was still associated with the formation of DVT in femoral and pelvic fractures (P = 0.037, OR = 2.231 [95% CI, 1.049-4.745]).

CONCLUSION

Perioperative RBC infusion is one of the causes of DVT in patients with femoral and pelvic fractures, and the risk of DVT is positively correlated with the amount of RBC infusion.

Low blood transfusion rate after implementation of tranexamic acid for fast- track hip- and knee arthroplasty. An observational study of 5205 patients

The purpose of this study was to retrospectively evaluate the efficacy of a tranexamic acid (TXA) perioperative protocol for primary hip- and knee arthroplasty, in terms of allogenic blood transfusion rates. A retrospective cohort study was conducted and included all primary hip and knee arthroplasty procedures in the period of 2014-2019. Patients who underwent surgery due to trauma or revision were excluded. A total amount of 5205 patients were eligible for inclusion. Two equal and weight depending doses of TXA were given, preoperative as an oral dose and intravenously at wound closure. The primary outcome was blood transfusion rate. Further analysis on patient characteristics (e.g. age, gender), blood loss, perioperative haemoglobin (Hb) levels and complication/readmission rate was performed. A total of 49 (0.9%) patients received perioperative allogenic blood transfusions. Mean age, distribution of gender, body-mass index, American Society of Anaesthesiologists score, duration of surgery, type of arthroplasty, estimated blood loss, perioperative Hb levels and length of stay were statistically significant different between transfused and not-transfused patients. The incidence of thromboembolic adverse events (e.g. deep vein thrombosis/lung embolism) was 0.5%. Low blood transfusion rate was found after implementation of a standardized perioperative TXA protocol for primary hip and knee arthroplasty.

Relationship of epidural patient-controlled analgesia with postoperative bleeding after unilateral total knee arthroplasty: a propensity score-matching analysis

Although epidural patient-controlled analgesia (PCA) to control postoperative pain after total knee arthroplasty (TKA), the relationship of epidural PCA with postoperative bleeding remains controversial. Therefore, we aimed to evaluate the effect of epidural and intravenous PCA on postoperative bleeding in patients undergoing unilateral TKA. Total of 2467 patients who underwent TKA were divided to intravenous PCA (n = 2339) or epidural PCA (n = 128) group. After 1:1 propensity score-matching, 212 patients were analyzed to assess the associations between the perioperative blood loss and epidural PCA between the groups. Mean postoperative blood loss was significantly greater in epidural PCA than in intravenous PCA (900.9 ± 369.1 mL vs. 737.8 ± 410.1 mL; P = 0.007). The incidence of red blood cell (RBC) administration (> 3 units) was significantly higher in epidural PCA than in intravenous PCA (30.2% vs. 16.0%; OR 2.5; 95% CI 1.201–5.205; P = 0.014). Epidural PCA may be strongly related to postoperative bleeding and the incidence of RBC transfusion of more than 3 units after unilateral TKA, as compared to intravenous PCA. Therefore, the use of epidural PCA may be carefully considered for postoperative pain management in TKA.

Do Low Hemoglobin Levels Affect the Healing Process of Periprosthetic Joint Infection?

Background

Revision knee arthroplasty (RKA) is associated with low hemoglobin (Hb) levels after surgery, which results mostly from perioperative blood loss. Periprosthetic joint infection (PJI) is one of the common reasons for RKA. This study aimed to determine whether low Hb levels affect the healing process of PJI.

Methodology

This retrospective study included 69 patients who underwent two-stage revision for PJI between 2013 and 2016. Patients were divided into two groups according to the latest Hb levels (Hb < 10 and Hb > 10 g/dL) during hospitalization for the first-stage revision surgery. Laboratory parameters of infection were measured during the cement spacer retention period: C-reactive protein (CRP), sedimentation rate (SEDIM), and white blood cell (WBC) count. Treatment was evaluated in two periods: cement spacer retention period (between the first surgery and second surgery) and the first normal CRP period (between the first surgery with the first normal CRP level during the cement spacer retention period). Infection parameters in the two time periods and reoperation with cement spacer were compared between the groups.

Results

The mean patient age was 67.3 ± 7.94 (50-87) years, and the female-to-male ratio was 4:1. No difference was found in the postoperative first control CRP, SEDIM, and WBC between the groups (p = 0.953, p = 0.3341, and p = 0.444, respectively). CRP-SEDIM control curves were observed in parallel, and no significant difference was found. The cement spacer retention period was 60.3 ± 24.8 (17-123) days, and the first normal CRP period was 87.3 ± 28.4 (14-161) days; no statistical difference was found between the groups (p = 0.727, p = 0.754).

Conclusions

In RKA, as low Hb level was not a negative factor of infection, blood transfusion should be avoided as it has many complications.

Knee Prosthesis in the Computer Era

Over the past two decades, computer assistance has revolutionalized surgery and has enabled enormous advancements in knee prosthesis surgery. Total knee arthroplasty (TKA) is a hot topic of orthopaedic research. Reflecting population dynamics, its use continues to increase, especially in high demand populations. Therefore, efforts to achieve the best fit and precise alignment in TKA continue. Computer assistance is valuable for knee prosthesis surgeons in this regard. This manuscript investigated the use of computer assistance in knee prosthesis surgery. The effects of computer use on important facets of knee prosthesis surgery, such as precision, clinical aspects, and costs, were examined. Moreover, an overall review of the recent literature on the navigation and personalized cutting guides was conducted.

Estimation of blood volume and blood loss in primary total hip and knee replacement: An analysis of formulae for perioperative calculations and their ability to predict length of stay and blood transfusion requirements

Introduction

Blood loss continues to be a common surgical risk in total hip (THR) and knee replacements (TKR). Accurate prediction of blood loss permits appropriate counselling of risks to patients, target optimisation and forecasting future transfusion requirements. We compared blood volume formulae of Moore and Nadler, and blood loss formulae of Liu, Mercuriali, Bourke, Ward, Gross, Lisander and Meunier, to assess associations between calculated values with length of stay and transfusion requirements and determine which are useful in contemporary practice.

Methods

We retrospectively studied patients undergoing primary THR and TKR. We collected data on patient demographics, surgical interventions, pre- and postoperative haemoglobin and haematocrit values, length of stay and blood transfusion requirements. Spearman correlation tests and least squares multiple linear regression were performed.

Results

149 THRs and 90 TKRs in 239 patients were analysed over four months. There was a very strong correlation between blood volume formulae. There were multiple very strong and strong associations between blood loss formulae. Bourke correlated significantly to length of stay, and Liu, Mercuriali, Lisander and Meunier correlated for incidence of transfusion.

Conclusion

Accurate estimation of perioperative blood loss is increasingly important as demand for joint replacement surgery increases in an ageing population. If the primary interest is the association of blood loss and length of stay, Bourke's formula should be preferred. If the primary interest is calculating risk of transfusion, the formulae of Liu or Meunier should be preferred. The formulae of Mercuriali and Lisander are becoming redundant in contemporary practice.

Tranexamic acid use to decrease blood loss in primary shoulder and elbow replacement: A systematic review and meta-analysis

PURPOSE

Tranexamic acid (TXA) is an inexpensive antifibrinolytic agent that significantly reduces peri-operative blood loss and transfusion requirements after total hip and knee replacement. This meta-analysis demonstrates the effects of TXA on blood loss in total shoulder replacement (TSR) and total elbow replacement (TER).

METHODS

We systematically searched MEDLINE, EMBASE and CENTRAL from inception to September 03, 2020 for randomised controlled trial (RCTs) and observational studies. Our primary outcome was blood loss. Secondary outcomes included the need for blood transfusion, and post-operative venous thromboembolic (VTE) complications. Mean differences (MD) and relative risks with 95% confidence intervals (CIs) were reported.

RESULTS

Four RCTs and five retrospective cohort studies (RCS) met eligibility criteria for TSRs, but none for TERs. RCT data determined that TXA administration significantly decreased estimated total blood loss (MD -358mL), post-operative blood loss (MD -113mL), change in haemoglobin (Hb) (MD -0.71 g/dL) and total Hb loss (MD -35.3g) when compared to placebo. RCS data demonstrated significant association between TXA administration and decreased in post-operative blood loss, change in Hb, change in Hct and length of stay. There was no significant difference in transfusion requirements or VTE complications.

CONCLUSION

TXA administration in safe and effective in patients undergoing primary TSR: it significantly decreases blood loss compared with placebo and is associated with shorter length of stay compared with no treatment. No significant increase in VTE complications was found. TXA administration should be routinely considered for patients undergoing TSR. Further research is needed to demonstrate the treatment effect in patients undergoing TER.

Routine Basic Metabolic Panels Are Not Needed in All Patients After Primary Total Joint Arthroplasty: An Opportunity for Cost Reduction

BACKGROUND

As the incidence of total joint arthroplasty (TJA) increases, identifying methods for cost reduction is essential. Basic metabolic panels (BMPs) are obtained routinely after TJA. We aimed at assessing the prevalence of intervention secondary to abnormal BMPs after primary TJA and at identifying predictors of the need for postoperative BMPs.

METHODS

We reviewed 802 cases (758 patients) of primary lower-extremity TJA performed from January 1 through December 31, 2018, at our tertiary care medical center. Patient characteristics, preoperative and postoperative BMPs, comorbidities, current medications, and in-hospital interventions were recorded. Age-adjusted Charlson Comorbidity Index (AA-CCI) values were calculated. Institutional costs of 1 BMP and of all BMPs not prompting intervention were calculated. We used multiple regression to identify independent predictors of in-hospital interventions secondary to abnormal postoperative BMPs.

RESULTS

Our institutional BMP cost was $36. A total of 1032 postoperative BMPs were ordered; 958 (93%) prompted no intervention. This equated to $34,488 of avoidable BMP costs. We identified 27 cases (3.4%) requiring intervention secondary to abnormal BMPs. Independent predictors of intervention were preoperative renal dysfunction (ie, abnormal creatinine or glomerular filtration rate <60 mL/min) (odds ratio [OR], 7.8; 95% confidence interval [CI], 2.8-22), number of current nephrotoxic medications (OR, 1.9; 95% CI, 1.3-2.9), and AA-CCI value (OR, 1.2; 95% CI, 1.0-1.5).

CONCLUSION

Routine postoperative BMPs are unwarranted for most patients undergoing primary TJA. Testing may be reserved for those with renal dysfunction, those taking multiple nephrotoxic medications, or those with a high AA-CCI value.