The pre-operative levels of haemoglobin in the blood can be used to predict the risk of allogenic blood transfusion after total knee arthroplasty

Analysis of the incidence and risk factors of blood transfusion in total knee revision: a retrospective nationwide inpatient sample database study

OBJECTIVE

This study sought to determine the incidence and risk factors of blood transfusion among patients undergoing total knee revision (TKR) using a nationwide database.

METHODS

A retrospective data analysis was conducted based on the Nationwide Inpatient Sample (NIS), enrolling patients who underwent TKR from 2010 to 2019 with complete information. The patients were divided into two groups based on whether they received blood transfusion or not. The demographic characteristics (race, sex, and age), length of stay (LOS), total charge of hospitalization, hospital characteristics (admission type, insurance type, bed size, teaching status, location, and region of hospital), hospital mortality, comorbidities, and perioperative complications were analyzed. Finally, we conducted univariate and multivariate logistic regression to identify factors that were associated with TKR patients to require blood transfusion.

RESULTS

The NIS database included 115,072 patients who underwent TKR. Among them, 14,899 patients received blood transfusion, and the incidence of blood transfusion was 13.0%. There was a dramatic decrease in the incidence over the years from 2010 to 2019, dropping from 20.4 to 6.5%. TKR patients requiring transfusions had experienced longer LOS, incurred higher total medical expenses, utilized Medicare more frequently, and had increased in-hospital mortality rates (all P < 0.001). Independent predictors for blood transfusion included advanced age, female gender, iron-deficiency anemia, rheumatoid disease, chronic blood loss anemia, congestive heart failure, coagulopathy, uncomplicated diabetes, lymphoma, fluid and electrolyte disorders, metastatic carcinoma, other neurological diseases, paralysis, peripheral vascular disorders, pulmonary circulation disorders, renal failure, valvular disease, and weight loss. In addition, risk factors for transfusion in TKR surgery included sepsis, acute myocardial infarction, deep vein thrombosis, pulmonary embolism, gastrointestinal bleeding, heart failure, renal insufficiency, pneumonia, wound infection, lower limb nerve injury, hemorrhage/seroma/hematoma, wound rupture/non healing, urinary tract infection, acute renal failure, and postoperative delirium.

CONCLUSIONS

Our findings highlight the importance of recognizing the risk factors of blood transfusion in TKR to reduce the occurrence of adverse events.

Effect of recombinant human erythropoietin combined with iron sucrose on postoperative hemoglobin in patients undergoing artificial joint replacement

With the aging of the population, an increasing number of elderly patients are opting for artificial joint replacement, leading to the exploration of various rapid rehabilitation programs in the perioperative period. In this study, we aimed to investigate the effectiveness of combining recombinant human erythropoietin and iron sucrose in altering the range and trend of postoperative hemoglobin in patients undergoing arthroplasty. Specifically, we will examine whether this combination can effectively alter the rise and fall of postoperative haemoglobin, identify the inflection point of haemoglobin change or recovery after arthroplasty, and assess the effect of treatment on serum iron in postoperative blood. We conducted a retrospective study of 138 patients who underwent unilateral total joint arthroplasty by the same surgeon in the same hospital before July 2022. The results of this study may provide valuable insights for the development of effective rehabilitation programs for patients undergoing arthroplasty.

Efficacy of tranexamic acid supplemented with local infiltration analgesia in reducing blood loss in patients undergoing unicompartmental knee arthroplasty

This study aimed to investigate the efficacy of tranexamic acid supplemented with local infiltration analgesia in reducing blood loss in patients undergoing unicompartmental knee arthroplasty (UKA). This retrospective study was conducted on 176 individuals with a mean age of 64.27 (standard deviation [SD], 7.16) years undergoing unicompartmental cemented knee arthroplasty. The patients were divided into three groups according to patient blood management: I, patients without additional bleeding protocol (control group); II, patients intravenously administered tranexamic acid (TXA) (TXA group); and III, patients with exact TXA protocol combined with intraoperative local infiltration analgesia (LIA) (TXA + LIA group). Blood loss was measured as a substitute for blood loss by the maximal haemoglobin (Hb) drop compared with the preoperative Hb level. The mean Hb drops for the control, TXA, and TXA + LIA groups were 2.24 (16.0%), 2.14 (15.4%), and 1.81 (12.6%) g/dl, respectively. The mean hospitalisation days for patients in the control, TXA, and TXA + LIA groups were 5.91 (SD 1.24), 5.16 (SD 0.95), and 4.51 (SD 0.71) days, respectively. The combination of TXA with LIA reduces perioperative blood loss for patients after UKA.

Identification of the haemoglobin level associated with a lower risk of complications after total hip and knee arthroplasty

BACKGROUND

Preoperative anaemia is associated with poor outcomes in surgical patients, but the preoperative haemoglobin cut-off that determines lower morbidity in total knee arthroplasty (TKA) and total hip arthroplasty (THA) is not well established.

METHODS

Planned secondary analysis of data collected during a multicentre cohort study of patients undergoing THA and TKA in 131 Spanish hospitals during a single 2-month recruitment period. Anaemia was defined as haemoglobin <12 g dl-1 for females and < 13 g dl-1 for males. The primary outcome was the number of patients with 30-day in-hospital postoperative complications according to European Perioperative Clinical Outcome definitions and specific surgical TKA and THA complications. Secondary outcomes included the number of patients with 30-day moderate-to-severe complications, red blood cell transfusion, mortality, and length of hospital stay. Binary logistic regression models were constructed to assess association between preoperative Hb concentrations and postoperative complications, and variables significantly associated with the outcome were included in the multivariate model. The study sample was divided into 11 groups based on preoperative Hb values in an effort to identify the threshold at which increased postoperative complications occurred.

RESULTS

A total of 6099 patients were included in the analysis (3818 THA and 2281 TKA), of whom 8.8% were anaemic. Patients with preoperative anaemia were more likely to suffer overall complications (111/539, 20.6% vs. 563/5560, 10.1%, p < .001) and moderate-to-severe complications (67/539, 12.4% vs. 284/5560, 5.1%, p < .001). Multivariable analysis showed preoperative haemoglobin ≥14 g dl-1 was associated with fewer postoperative complications.

CONCLUSION

Preoperative haemoglobin ≥14 g dl-1 is associated with a lower risk of postoperative complications in patients undergoing primary TKA and THA.

Comparison of Blood Loss with the Use of Intravenous and Intraarticular Tranexamic Acid Versus Isolated Intraarticular in Primary Knee Arthroplasty

Objective  The objective of this work is to compare blood loss during primary knee arthroplasty with the use of intravenous and intraarticular (IV + IA) tranexamic acid versus intraarticular (IA) tranexamic acid alone. Methods  This is a randomized, double-blind clinical trial. Patients with indication for primary total knee arthroplasty were recruited in a specialized clinic, where they were operated by the same surgeon, always using the same surgical technique. Thirty patients were allocated in the IV + IA tranexamic acid group and 30 patients in the IA tranexamic acid group, according to randomization. Blood loss was compared through hemoglobin, hematocrit, drain volume, and blood loss estimation (Gross and Nadler calculus). Results  After collection, data from 40 patients were analyzed, 22 in the IA group and 18 in the IV + IA group. There were 20 losses due to collection error. Between groups IA and IV + IA, there were no significant differences in 24 hours between hemoglobin levels (10.56 vs. 10.65 g/dL; F _1.39 = 0.63, p  = 0.429), erythrocyte (3.63 vs. 3.73 million/mm ³ ; F _1.39 = 0.90, p  = 0.346); hematocrit (32.14 vs. 32.60%; F _1.39 = 1.39, p  = 0.240); drainage volume (197.0 vs. 173.6 mL; F _1.39  = 3.38 p  = 0.069); and estimated blood loss (1,002.5 vs. 980.1; F _1.39 = 0.09, p  = 0.770). The same occurred in comparisons conducted after 48 hours postoperatively. Time was a significant factor for the change of all outcome variables. However, the treatment did not modify the effect of time on these outcomes. No individual presented any thromboembolic event during the work period. Conclusions  The use of IV + IA tranexamic acid showed no advantage in reducing blood loss when compared to the use of IA tranexamic acid alone in primary knee arthroplasties. This technique proved to be safe, since no thromboembolic event occurred during the development of the work.

The association between perioperative blood transfusions and venous thromboembolism risk following surgical management of hip fractures

Introduction

Despite high rates of transfusion reported among hip fracture patients in the perioperative period, the relationship between perioperative transfusions and VTE has not been thoroughly explored. Therefore, we used a national database to evaluate how perioperative transfusions among patients undergoing surgical management of hip fractures impacted 1) deep vein thrombosis (DVT) and 2) pulmonary embolism (PE) risk.

Methods

The Targeted Hip Fracture Database of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) was queried for patients undergoing surgical management of hip fractures from 2016 to 2019. A multivariate logistic regression was conducted using various patient-specific variables to identify risk factors for DVT and PE. A nearest-neighbor propensity score matched (PSM) comparison between patients receiving and not receiving perioperative blood transfusions (1:1) was additionally conducted.

Results

Prior to our PSM, preoperative transfusions were not associated with DVT incidence (OR: 1.48, 95% CI: 0.80-2.50; p = 0.2). However, intra-operative/post-operative transfusions (OR: 1.26, 95% CI: 1.02-1.56; p = 0.00.30) as well as the receipt of both transfusion types (OR: 1.81, 95% CI: 1.10-2.81; p = 0.012) were associated with an increased risk of DVT. The latter of these findings remained significant following PSM (OR: 1.73, 95% CI: 1.04-2.73; p = 0.025). No relationship was demonstrated between PE risk and perioperative transfusion receipt.

Conclusion

Our findings emphasize the importance of perioperative blood management strategies among patients undergoing surgical repair of hip fracture. Specifically, orthopaedic surgeons should aim to optimize hip fracture patients prior to surgical intervention as well as intra-operatively to reduce transfusion incidence.

Predict Postoperative Anemia of Patients: Nomogram Construction and Validation

Introduction

The loss of blood is a significant problem in Total Knee Arthroplasty (TKA). Anemia often occurs after such surgeries, leading to serious consequences, such as higher postoperative infection rates and longer hospital stays. Tools for predicting possible anemia can provide additional guidance in realizing better blood management of patients.

Methods

2,165 patients who underwent TKA from 2015 to 2019 in the same medical center were divided into training and validation cohorts. Both univariate and multivariate logistic regression analyses were performed to identify independent preoperative risk factors for anemia. Based on these predictors, a nomogram was established using the area under the curve (AUC), calibration curve (AUC), and the area under the curve (AUC). The model was then applied to the validation cohort, and decision curve analyses (DCA) were also plotted.

Results

Through analysis of both univariate and multivariate logistic regression, five independent predictors were found in the training cohort: female, relatively low BMI, low levels of preoperative hemoglobin, abnormally high levels of ESR, and simultaneously two sides of TKA in the same surgery. The AUCs of the nomogram were 74.6% (95% CI, 71.35%–77.89%) and 68.8% (95% CI, 63.37%–74.14%) of training and the validation cohorts separately. Furthermore, the calibration curves of both cohorts illustrated the consistency of the nomogram with the actual condition of anemia of patients after TKA. The DCA curve was higher for both treat-none and treat-all, further indicating the relatively high practicality of the model.

Conclusion

Female, lower BMI, lower levels of preoperative Hb, simultaneous bilateral TKA, and high levels of preoperative ESR were figured out as five independent risk factors for postoperative anemia (&lt;9.0 g/dL) in patients undergoing TKA. Based on the findings, a practical nomogram was constructed to predict risk of postoperative anemia. The evidence level should be level 4 according to guideline.

Utility of pre-operative haemoglobin concentration to guide peri-operative blood tests for hip and knee arthroplasty: A decision curve analysis

Objective

Assess the prognostic value of pre‐operative haemoglobin concentration (Hb) for identifying patients who develop severe post‐operative anaemia or require blood transfusion following primary total hip or knee, or unicompartmental knee arthroplasty (THA, TKA, UKA).

Background

Pre‐operative group and save (G&S), and post‐operative Hb measurement may be unnecessary for many patients undergoing hip and knee arthroplasty provided individuals at greatest risk of severe post‐operative anaemia can be identified.

Methods and Materials

Patients undergoing THA, TKA, or UKA between 2011 and 2018 were included. Outcomes were post‐operative Hb below 70 and 80 g/L, and peri‐operative blood transfusion. Logistic regression assessed the association between pre‐operative Hb and each outcome. Decision curve analysis compared strategies for selecting patients for G&S and post‐operative Hb measurement.

Results

10 015 THA, TKA and UKA procedures were performed in 8582 patients. The incidence of blood transfusion (4.5%) decreased during the study. Using procedure specific Hb thresholds to select patients for pre‐operative G&S and post‐operative Hb testing had a greater net benefit than selecting all patients, no patients, or patients with pre‐operative anaemia.

Conclusions

Pre‐operative G&S and post‐operative Hb measurement may not be indicated for UKA or TKA when adopting restrictive transfusion thresholds, provided clinicians accept a 0.1% risk of patients developing severe undiagnosed post‐operative anaemia (Hb < 70 g/L). The decision to perform these blood tests for THA patients should be based on local institutional data and selection of acceptable risk thresholds.

Effect of severity and cause of preoperative anemia on the transfusion rate after total knee arthroplasty

This study aimed to (1) evaluate the preoperative Hb cut-off value for transfusion after unilateral and bilateral staged (1 week apart) TKAs, respectively, and (2) determine whether cause of preoperative anemia can affect transfusion rate after TKA. A total of 951 patients who underwent TKA (unilateral: 605, bilateral staged: 346) from 2016 to 2019 were reviewed retrospectively. Patient demographics, comorbidities, preoperative Hb level, surgery types, and cause of anemia were evaluated as possible risk factors. The cut-off values for preoperative Hb level to reduce transfusion after TKA were evaluated in each surgery type. Preoperative Hb level, surgery type, and cardiac disease were identified as the risk factors for transfusion after TKA, and preoperative Hb levels of 11.8 (AUC 0.88) and 12.8 (AUC 0.76) were the cut-off values for transfusion after unilateral and staged bilateral TKAs, respectively. Although transfusion rate was higher in anemia with iron deficiency (ID) group than anemia without ID group, preoperative Hb level was also lower in anemia with ID group than anemia without ID group. Single use of preoperative Hb level with different cut-offs depending on the surgery types can be useful indicator for preoperative optimization regardless of cause of anemia.

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.

Incidence and risk factors for blood transfusion in simultaneous bilateral total hip arthroplasty

OBJECTIVES

This study aims to investigate the incidence and risk factors for blood transfusion in patients undergoing simultaneous bilateral total hip arthroplasty (SimBTHA).

PATIENTS AND METHODS

Between January 2011 and June 2021, a total of 341 patients (289 males, 52 females; median age: 53 years; range, 43 to 66 years) who underwent SimBTHA were retrospectively analyzed. The patients were divided into two groups as those who did and did not require allogeneic blood transfusion. Univariate and multivariate logistic regression models were used to identify independent risk factors for transfusion.

RESULTS

The incidence of transfusion in SimBTHA was 12.9%. We found that a higher preoperative hemoglobin level (odds ratio [OR]: 0.91; 95% confidence interval [CI]: 0.86-0.96), tranexamic acid (TXA) use (OR: 0.25; 95% CI: 0.09-0.58), and intraoperative autologous blood transfusion from a closed suction drainage system (OR: 0.30; 95% CI: 0.09-0.80) were protective against the need for transfusion in patients after SimBTHA. In addition, drainage use (OR: 3.52; 95% CI: 1.49-8.32) and intraoperative blood loss (OR: 1.17; 95% CI: 1.04-1.33) were the independent risk factors for blood transfusion.

CONCLUSION

The risk factors for transfusion after SimBTHA should be evaluated to establish specific, personalized transfusion risk assessments for each individual patient. For SimBTHA, the main risk factors include intraoperative bleeding and the use of drainage tube, while higher preoperative hemoglobin levels, TXA use, and autologous blood transfusion from a closed suction drainage system may reduce transfusion risk.

Effect of an Elevated Preoperative International Normalized Ratio on Transfusion and Complications in Primary Total Hip Arthroplasty with the Enhanced Recovery after Surgery Protocol

Objective

To verify whether an elevated preoperative international normalized ratio (INR) increases transfusion and complications independently in primary total hip arthroplasty (THA) with the management of an enhanced recovery after surgery (EARS) protocol.

Methods

We retrospectively reviewed the database of adults who underwent primary THA between 2014 and 2018 by the same surgeon. A total of 552 patients were assigned into three groups by preoperative INR class: INR ≤ 0.9, 0.9 < INR < 1.0, and INR ≥ 1.0. We regarded transfusion within 90 days during the same hospitalization as the primary outcome. We also included perioperative blood loss, maximum Hb drop, postoperative anaemia requiring medicine, and length of hospital stay (LOS) during the same hospitalization in the study. Complications and reoperation at 90 days and mortality at 90 days and 12 months were also included in the study. Univariable analyses were utilized to compare baselines and outcomes among the three groups. Multivariate logistic regressions were used to adjust for differences at baseline among the groups.

Results

All patients had an INR < 1.5 preoperatively and were managed with the ERAS protocol. Among them, 93 (16.8%) patients had INR ≤ 0.9, 268 (48.6%) patients had 0.9 < INR < 1.0, and 191 (34.6%) patients had INR ≥ 1.0. In the univariable analyses, as the INR increased, the transfusion rates increased from 1.08% for INR ≤ 0.9, to 1.12% for 0.9 < INR < 1.0 and to 5.76% for INR ≥ 1.0 (P < 0.05). The overall complication rate increased from 10.8% for INR ≤ 0.9, to 16.4% for 0.9 < INR < 1.0, and to 22.5% for INR ≥ 1.0 (P < 0.05). The length of stay (LOS) in the INR ≥ 1.0 group was 5.7 ± 2.2 days, which was significantly longer than that in the INR ≤ 0.9 group (4.7 ± 1.6 days, P = 0.000) and 0.9 < INR < 1.0 group (5.1 ± 2.0 days, P = 0.007). No statistical significance was detected among the groups regarding blood loss, maximum Hb drop, or the incidence of postoperative anaemia that required medicine. There was no significant difference in reoperation or mortality among the groups. When controlling for demographic and comorbidity characteristics, there was no statistically significant difference in the odds of transfusion during the same hospitalization or overall complications at 90 days among the groups (P > 0.05).

Conclusions

Elevated preoperative INR cannot increase transfusion or complication rates independently in primary THA with the management of the ERAS protocol. With the improvement in the ERAS protocol and the use of tranexamic acid (TXA), an INR < 1.5 is still a conventional safe threshold for THA surgery.

Modifiable Individual Risks of Perioperative Blood Transfusions and Acute Postoperative Complications in Total Hip and Knee Arthroplasty

BACKGROUND

The primary aim of this study was to identify modifiable patient-related predictors of blood transfusions and perioperative complications in total hip and knee arthroplasty. Individual predictor-adjusted risks can be used to define preoperative treatment thresholds.

METHODS

We performed this retrospective monocentric study in orthopaedic patients who underwent primary total knee or hip arthroplasty. Multivariate logistic regression models were used to assess the predictive value of patient-related characteristics. Predictor-adjusted individual risks of blood transfusions and the occurrence of any perioperative adverse event were calculated for potentially modifiable risk factors.

RESULTS

3754 patients were included in this study. The overall blood transfusion and complication rates were 4.8% and 6.4%, respectively. Haemoglobin concentration (Hb, p < 0.001), low body mass index (BMI, p < 0.001) and estimated glomerular filtration rate (eGFR, p = 0.004) were the strongest potentially modifiable predictors of a blood transfusion. EGFR (p = 0.001) was the strongest potentially modifiable predictor of a complication. Predictor-adjusted risks of blood transfusions and acute postoperative complications were calculated for Hb and eGFR. Hb = 12.5 g/dL, BMI = 17.6 kg/m², and eGFR = 54 min/mL were associated, respectively, with a 10% risk of a blood transfusion, eGFR = 59 mL/min was associated with a 10% risk of a complication.

CONCLUSION

The individual risks for blood transfusions and acute postoperative complications are strongly increased in patients with a low preoperative Hb, low BMI or low eGFR. We recommend aiming at a preoperative Hb ≥ 13g/dL, an eGFR ≥ 60 mL/min and to avoid a low BMI. Future studies must show if a preoperative increase of eGFR and BMI is feasible and truly beneficial.

Routine Preoperative Group Crossmatching and Postoperative Check Hemoglobin Is not Necessary in Patients Undergoing Total Knee Arthroplasty

This study aims to find out if routine preoperative group crossmatch and postoperative check hemoglobin for total knee arthroplasty (TKA) patients is necessary. A retrospective analysis was performed on patients who underwent unilateral TKAs for osteoarthritis from January 1, 2004 to December 31, 2014. The main outcome measures were postoperative hemoglobin levels and transfusion requirements. Patients' demographics, comorbidities, laboratory results, and surgical details were analyzed. A total of 955 TKAs were included in this study (males = 207, females = 748; mean age = 66.1 years, standard deviation [SD] = 7.7). A total of 79 (8.27%) cases required postoperative blood transfusion, and the crossmatch-transfusion ratio was 17.5. Significant predictors for postoperative transfusion included lower preoperative hemoglobin levels (p < 0.001) and advanced age (p < 0.001). Receiver operating characteristic (ROC) curve and Youden's Index analyses identified the preoperative hemoglobin cut-off value for females to be 12.1 g/dL (relative risk (RR): 5.65, p < 0.001) in predicting postoperative blood transfusion requirement, and 12.4 g/dL (RR: 11.71, p < 0.001) for males. For age, the identified cut-off value was 68 years (RR: 3.18, p < 0.001). The largest decline in hemoglobin levels was noted on postoperative day (POD) 3 (31.8%), and smallest on POD 1 (18.8%). The postoperative transfusion requirements in TKA are low and do not justify routine perioperative blood investigations. However, these investigations should be reserved for patients with the identified risk factors, in particular advancing age (68 years and above) and lower preoperative hemoglobin (below or equal to 12.1 and 12.4 g/dL for females and males, respectively). In the event that postoperative hemoglobin level needs to be checked, it should be performed beyond the first POD.

Association between preoperative hemoglobin and postoperative moderate and severe anemia among patients undergoing primary total knee arthroplasty: a single-center retrospective study

BACKGROUND

Postoperative moderate and severe anemia (PMSA) has been a serious perioperative complication in primary total knee arthroplasty (TKA). However, the ideal cutoff values to predict PMSA is still undetermined. The aim of this study was (1) to identify the risk factors associated with PMSA and (2) to establish the cutoff values of preoperative hemoglobin (HB) associated with increased PMSA in primary TKA.

METHODS

We identified 474 patients undergoing primary TKA and separated those in which PMSA (HB was less than 110 g/L on postoperative day 1 and 3) was developed from those without PMSA. Multivariate logistic regression model was used to identify independent risk factors for PMSA. Area under the receiver-operator curve (AUC) was used to determine the best-supported preoperative HB cutoff across all the patients.

RESULTS

The PMSA rate in primary TKA was 53.2%. Significant risk factors were lower preoperative HB (OR [odds ratio] = 1.138, 95% CI [confidence interval] = 1.107-1.170, p < 0.001) and more intraoperative blood loss (OR = 1.022, 95% CI 1.484-4.598, p < 0.001). A preoperative HB cutoff value that maximized the AUC was 138.5 g/L for men (sensitivity: 79.4%, specificity: 75.0%) and 131.5 g/L for women (sensitivity: 74.7%, specificity: 80.5%), respectively.

CONCLUSION

We should recognize and consider the related risk factors to establish specific, personalized risk assessment for PMSA, including preoperative HB and intraoperative blood loss. Of these, preoperative HB was a referable tool to predict PMSA in primary TKA.

A break-even analysis of tranexamic acid for prevention of periprosthetic joint infection following total hip and knee arthroplasty

Purpose

Despite the commonplace use of tranexamic acid in total joint arthroplasty, much of the current data regarding its cost-effectiveness examines savings directly related to its hemostatic properties, without considering its protective effect against periprosthetic joint infections. Using break-even economic modeling, we calculated the cost-effectiveness of routine tranexamic acid administration for infection prevention in total joint arthroplasty.

Materials and methods

The cost of intraoperative intravenous tranexamic acid, the cost of revision arthroplasty for periprosthetic joint infections, and the baseline rates of periprosthetic joint infections in patients who did not receive intraoperative tranexamic acid were obtained from the literature and institutional purchasing records. Break-even economic modeling incorporating these variables was performed to determine the absolute risk reduction in infection rate to make routine intraoperative tranexamic acid use economically justified. The number needed to treat was calculated from the absolute risk reduction.

Results

Routine use of intraoperative tranexamic acid is economically justified if it prevents at least 1 infection out of 3125 total joint arthroplasties (absolute risk reduction = 0.032%). Cost-effectiveness was maintained with varying costs of tranexamic acid, infection rates, and periprosthetic joint infection costs.

Conclusion

The routine use of intraoperative tranexamic acid is a highly cost-effective practice for infection prevention in primary and revision total joint arthroplasty. The use of tranexamic acid is warranted across a wide range of costs of tranexamic acid, initial infection rates, and costs of periprosthetic joint infection treatment.

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.

Simultaneous Bilateral Primary Total Knee Arthroplasty With TXA and Restrictive Transfusion Protocols: Still a 1 in 5 Risk of Allogeneic Transfusion

BACKGROUND

Historically, there was up to a 60% risk of blood transfusion for patients undergoing simultaneous bilateral total knee arthroplasty (SBTKA). As such, the goal of this study was to analyze the rate and risk factors for allogeneic blood transfusions in patients undergoing SBTKA with tranexamic acid (TXA).

METHODS

We retrospectively identified 475 patients who underwent SBTKA with a double dose TXA regimen at a single institution from 2016 to 2019. Mean age was 65 years. Two hundred fifty-seven patients (54%) were female. Mean body mass index was 30 kg/m². Drains were utilized in 143 patients (30%). Mean preoperative hemoglobin (Hgb) was 13.7 g/dL. Multivariate logistic regression analysis adjusting for age ≥70 years, sex, body mass index, drain use, and preoperative Hgb of <12.5 g/dL was utilized to identify risk factors for transfusion.

RESULTS

One hundred six patients (22%) received an allogeneic transfusion, including 28 patients (6%) who received ≥2 units. Multivariate analysis showed that preoperative Hgb <12.5 (OR = 3.99, P < .0001), female sex (OR = 2.34, P = .002), and drain use (OR = 2.13, P = .004) were risk factors for transfusion. Forty-two patients (42/83, 51%) with a preoperative Hgb <12.5 received a transfusion compared with 64 patients (64/392, 16%) with a Hgb ≥12.5 (P < .001).

CONCLUSION

Patients undergoing SBTKA with contemporary blood management still have a 1 in 5 rate of allogeneic transfusion. Drain use independently increases transfusion risk by 2-fold and should be avoided. Patients with a preoperative Hgb <12.5 have a transfusion rate of 50% and, as such, should either not undergo SBTKA or have extensive perioperative blood optimization.

Perioperative Blood Transfusions Are Associated with a Higher Incidence of Thromboembolic Events After TKA: An Analysis of 333,463 TKAs

BACKGROUND

Given the morbidity, mortality, and financial burden associated with venous thromboembolism (VTE) after TKA, orthopaedic providers continually seek to identify risk factors associated with this devastating complication. The association between perioperative transfusion status and VTE risk has not been thoroughly explored, with previous studies evaluating this relationship being limited in both generalizability and power.

QUESTIONS/PURPOSES

Therefore, we sought to determine whether perioperative transfusions were associated with an increased risk of (1) pulmonary embolism (PE) or (2) deep vein thrombosis (DVT) after primary TKA in a large, multi-institutional sample.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database was implemented for our analysis. The definitions of complications, such as DVT and PE, and risk adjustment validation is monitored by the central ACS NSQIP office to ensure participating hospitals are adhering to the same guidelines to log patients. Additionally, both preoperative and intraoperative/72 hour postoperative transfusion status is included for all patients. Therefore, ACS NSQIP was determined to be the most appropriate database for our analysis. All patients who underwent primary TKA between 2011 and 2018 were identified using Current Procedural Terminology code 27447. Primary TKAs designated as "non-elective" were excluded, thereby providing a cohort composed solely of patients undergoing unilateral primary elective TKA for further analysis. The final analysis included 333,463 patients undergoing TKA (mean age 67 ± 9 years, 62% female). Preoperative transfusions were received by < 0.01% (48 of 333,463) of the patients, while 4% (14,590 of 333,463) received a transfusion within the interim between the start of surgery up to 72 hours postoperatively. All missing values were imputed through multiple imputation by chained equation to avoid variable availability-based selection and the subsequent listwise deletion-associated bias in the estimate of parameters. A multivariable logistic regression analysis was conducted using variables identified in a univariate model to calculate adjusted odds ratios and 95% confidence intervals for risk factors associated with symptomatic DVT and/or PE. For variables that maintained significance in the multivariable model, an additional model without confounders was used to generate fully adjusted ORs and 95% CIs. A propensity score matched comparison between recipients versus nonrecipients (1:1) of transfusion (preoperative and intraoperative/72 hours postoperative) was then conducted to evaluate the independent association between DVT/PE development and patients' transfusion status. Significance was determined at a p value < 0.05.

RESULTS

Adjusted multivariable regression analysis accounting for patient age, sex, race, BMI, American Society of Anesthesiologists (ASA) class and baseline comorbidities demonstrated the absence of an association between preoperative (OR 1.75 [95% CI 0.24 to 12.7]; p = 0.58) or intraoperative/72 hours postoperative (OR 1.12 [95% CI 0.93 to 1.35]; p = 0.23) transfusions and higher odds of developing PE. Similar findings were demonstrated after propensity score matching. Although multivariable regression demonstrated the absence of an association between preoperative transfusion and the odds of developing DVT within the 30-day postoperative period (OR 1.85 [95% CI 0.43 to 8.05]; p = 0.41), intraoperative/postoperative transfusion was associated with higher odds of DVT development (OR 3.68 [95% CI 1.14 to 1.53]; p < 0.001) relative to transfusion naïve patients. However, this significance was lost after propensity score matching.

CONCLUSION

After controlling for various potential confounding variables such as ASA Class, age, anesthesia type, and BMI, the receipt of an intra- or postoperative transfusion was found to be associated with an increased risk of DVT. Our findings should encourage orthopaedic providers to strictly adhere to blood management protocols, further tighten transfusion eligibility, and adjust surgical approach and implant type to reduce the incidence of transfusion among patients with other DVT risk factors. Additionally, our findings should encourage a multidisciplinary approach to VTE prophylaxis and prevention, as well as to blood transfusion guideline adherence, among all providers of the care team.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Is There a Synergistic Effect of Topical Plus Intravenous Tranexamic Acid Versus Intravenous Administration Alone on Blood Loss and Transfusions in Primary Total Hip and Knee Arthroplasties?

Background

The optimal route and dosing regimen of tranexamic acid (TXA) in primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) remain unclear. As such, we sought to analyze if there was a synergistic effect of intravenous (IV) and topical TXA on blood loss and transfusions.

Methods

We retrospectively analyzed 6720 primary TKAs and 6559 THAs performed from February 1, 2016 to December 31, 2019 at a single institution in patients who received a double IV dose (6159 TKAs and 6276 THAs) compared with a combined single IV and topical dose (561 TKAs and 283 THAs) of TXA. Multivariate logistic regression models, adjusting for age, body mass index, American Society of Anesthesiologists class, preoperative hemoglobin, and TXA administration, were performed for significant variables from a univariate analysis.

Results

In the TKA cohort, the mean total blood loss was statistically similar for double IV (305 mL, 95% confidence interval [CI] = 301-310 mL) TXA compared with combined TXA (310 mL, 95% CI = 299-321 mL) (P = .43). Furthermore, there was no difference in the rate of transfusion (odds ratio = 1.23, 95% CI = 0.57-2.67, P = .598). In the THA cohort, there was statistically higher blood loss with double IV (328 mL, 95% CI = 323-333 mL) TXA than in the combined group (295 mL, 95% CI = 280-310 mL) (P < .001). The rate of transfusion was statistically similar at ~2% (P = .970).

Conclusions

A double IV TXA dose and a combined single IV and topical TXA dose were equally effective in minimizing blood transfusions (~2%) at primary TKA and THA. We did not find a synergistic effect when combining a systemic IV TXA with a topical TXA.

Level of Evidence

Level III.

The Effect of Hypotensive Anesthesia on Hemoglobin Levels during Total Knee Arthroplasty

Introduction: Hypotensive epidural anesthesia (HEA) is used in total joint arthroplasty as a safe and effective blood-saving modality. In order to maintain the blood pressure and heart rate patients, receive 1000 to 1500 mL of lactated Ringer’s solution during surgery. While HEA reduces the intraoperative blood loss, the effect of intravenous fluid loading on hemoglobin levels is not fully understood. The current study investigates the effect of HEA on perioperative hemoglobin levels. Materials and Methods: The study included 35 patients operated on by a single surgeon undergoing primary total knee arthroplasty under HEA. Intraoperatively, at least 300 mL of intravenous fluid were given every 15 min over the first 60 min after HEA. Blood samples were drawn before entering the operating room, after HEA, as well as after inflation of the tourniquet, every 15 min thereafter, as well as in the recovery room and on postoperative days one and two. In addition, fluid in- and outtake was recorded. Results: Patients received a mean 1275 mL during the 60 min of tourniquet time. The mean arterial pressure (MAP) 5 min after HEA dropped to 60 mmHg and reached a constant level of around 58 mmHg 15 min after HEA. The average hemoglobin level dropped from 13.9 g/dL prior to HEA, to 12.5 g/dL immediately after HEA (p < 0.001). Intraoperatively the hemoglobin level dropped further and reached 11.8 g/dL at 60 min in the absence of blood loss. Conclusions: Hypotensive epidural anesthesia and the resulting fluid substitution resulted in an average hemoglobin drop of 2.1 g/dL within the first 60 min. This needs to be taken into account when evaluating the need for blood transfusions after primary joint replacement surgery under HEA.

Perioperative Allogeneic Red Blood Cell Transfusion and Wound Infections: An Observational Study

BACKGROUND

It remains unclear whether the benefits of performing perioperative allogeneic red blood cell (RBC) transfusion outweigh the risks of postoperative wound infection. The aim of this study was to assess the impact of perioperative RBC transfusion as well as dose-response relationship on wound infections in surgical patients in a large cohort.

METHODS

As a retrospective observational study, the national Hospital Quality Monitoring System database was used to retrieve information about in-hospital surgical patients without limitations on surgical types in the People's Republic of China between 2013 and 2018. Patients were divided into the perioperative RBC transfusion and non-RBC transfusion groups, and wound infection rates (the primary end point) were compared. Secondary end points included in-hospital mortality, nosocomial infections, and length of hospital stay. Furthermore, patients who underwent RBC transfusion were subdivided into 6 groups based on the volume of transfused RBCs to investigate the dose-response relationship between RBC transfusions and wound infections. The association between RBC transfusion and patient outcomes were analyzed using multivariable logistic regression models adjusted for potential confounders.

RESULTS

A total of 1,896,584 patients from 29 provinces were included, among whom 76,078 (4.0%) underwent RBC transfusions; the overall wound infection rate was 0.7%. After adjusting for confounding factors, perioperative RBC transfusion was associated with higher odds of wound infection (odds ratio [OR] = 2.24, 95% confidence interval [CI], 2.09-2.40; P < .001). As the volume of transfused RBCs increased, so did the odds of wound infection with a clear dose-response relationship (OR of >0 and ≤1 U, >1 and ≤2 U, >2 and ≤4 U, >4 and ≤8 U, >8 U transfusion compared with no RBC transfusion were 1.20, 95% CI, 0.76-1.91; 1.27, 95% CI, 1.10-1.47; 1.70, 95% CI, 1.49-1.93; 2.12, 95% CI, 1.83-2.45 and 3.65, 95% CI, 3.13-4.25, respectively). RBC transfusion was also found to be associated with higher odds of in-hospital mortality, nosocomial infection, and longer hospital stay.

CONCLUSIONS

RBC transfusion was associated with an increased odd of postoperative wound infection in surgical patients, and a significant dose-related relationship was also observed. While there are still essential confounders not adjusted for and the results do not necessarily indicate a causal relationship, we still recommend to lessen perioperative blood loss and optimize blood conservation strategies.

Reduction of Blood Loss by Intra-articular Injection of Tranexamic Acid Combined with Knee and Hip Flexion at 45° During Primary Total Knee Arthroplasty: A Randomized Controlled Trial

Objective

To explore the hemostatic effect of intra‐articular administration of tranexamic acid (TXA) combined with knee flexion in total knee arthroplasty (TKA).

Methods

This randomized controlled trial was conducted at the Third Affiliated Hospital of Southern Medical University (Guangzhou, China) from January 2017 to February 2018. The patients were randomized 1:1 to the TXA group (TXA 500 mg into the joint after closure, knee, and hip flexed at 45° for 4 h) or the control group (physiological saline, with limb fully extended). The primary endpoint was postoperative hemoglobin reduction. The postoperative levels of hemoglobin were measured at four time points: 6 h after operation, and on the first, second, and third postoperative days. Calculated blood loss (CBL) at 3 days, transfusion rate, range of motion (ROM), VAS pain score, and knee circumference increment were the secondary endpoints. Ninety‐four (47/group) patients were analyzed.

Results

Postoperatively, there were statistically significant differences between the TXA and control groups in CBL (791 ± 212 mL vs 1175 ± 273 mL, P < 0.05). Hemoglobin reduction was significantly lower in the TXA group (2.0 ± 0.9 g/dL vs 4.5 ± 0.7 g/dL, P < 0.05). Based on the transfusion criteria, 3 out of 47 (6.4%) patients in the TXA group and 13 out of 47 (27.6%) patients in the control group received blood transfusions (P = 0.006). ROM (90.8° ± 6.2° vs 87.6° ± 6.4°, P = 0.004), VAS pain score (4.1 ± 1.1 vs 4.8 ± 1.3, P = 0.004), and KCI (2.4 ± 0.9 cm vs 3.2 ± 1.0 cm, P = 0.01) were better in the TXA group compared with thecontrols. There was no deep venous thrombosis (DVT), wound infection or other adverse events in either group. In the control group, 2 patients had a fever after blood transfusion.

Conclusion

Intra‐articular injection of TXA combined with knee and hip flexion at 45° can effectively attenuate CBL and hemoglobin reduction during primary TKA, without an additional adverse event.

Use of bone wax reduces blood loss and transfusion rates after total knee arthroplasty

BACKGROUND

Unnecessary costs and complications can be reduced by minimizing blood loss and allogeneic blood transfusion in cases of total knee arthroplasty (TKA). This study evaluated the effectiveness of bone wax in reducing blood loss and transfusion rates after TKA.

METHODS

A total of 674 consecutive TKAs performed for degenerative osteoarthritis were retrospectively reviewed. Propensity score-matching and inverse probability of treatment weighting analyses were performed for demographics, comorbidities, use of medications, preoperative laboratory findings and radiologic prosthetic coverage of osteotomy surface. In the bone wax group, bone wax (2.5 g) was applied to the uncovered bone section around the prostheses along with the topical administration of tranexamic acid, whereas hemostasis was achieved in the control group with the topical administration of tranexamic acid. Intergroup comparisons of estimated blood loss, decreases in hemoglobin (Hb) levels, and transfusion rates were performed.

RESULTS

The mean estimated blood loss and volume of postoperative drainage were reduced in the bone wax group. The maximum decreases in Hb levels on postoperative days 1, 3, 5, and 7 were 1.8 ± 0.7 ml, 2.5 ± 0.8 ml, 2.7 ± 0.8 ml, and 2.8 ± 0.8 ml in the bone wax group and 2.1 ± 1.0 ml, 3.0 ± 1.2 ml, 3.1 ± 1.1 ml, and 3.2 ± 1.1 ml in the control group, respectively. The postoperative transfusion rates decreased markedly from 8.8% to 2.0% when bone wax was used.

CONCLUSIONS

The use of bone wax significantly reduced blood loss, decreased Hb levels, and the risk of transfusion.

LEVEL OF EVIDENCE

Level III, Therapeutic studies.

Tranexamic Acid Reduces the Rate of Periprosthetic Joint Infection After Aseptic Revision Arthroplasty

BACKGROUND

Revision total joint arthroplasty (TJA) has a higher rate of periprosthetic joint infection (PJI) compared with primary TJA, possibly as the result of increased allogeneic blood transfusion. Tranexamic acid (TXA) is gaining popularity in revision TJA to minimize blood loss and the need for transfusion; however, its effect on PJI reduction has yet to be investigated. The hypothesis of this study was that the administration of TXA during revision arthroplasty is protective against subsequent PJI.

METHODS

A prospectively maintained institutional database was used to identify patients who underwent revision TJA for aseptic failure from 2009 to 2018 and had a minimum follow-up of 90 days. Patients who developed PJI following revision arthroplasty were identified. All patients with PJI met Musculoskeletal Infection Society (MSIS) criteria. A multivariate analysis was performed to identify variables independently associated with PJI after aseptic revision TJA.

RESULTS

Overall, 1,731 patients who underwent aseptic revision were identified; of these patients, 83 (4.8%) developed PJI. Patients who received TXA had significantly lower rates (p = 0.029) of PJI postoperatively at 3.30% compared with those who did not receive TXA at 5.73%. After controlling for relevant confounding variables, TXA remained a significant independent factor that protected against PJI (odds ratio [OR], 0.47 [95% confidence interval (CI), 0.23 to 0.90]; p = 0.030). Female sex was also identified as a significant independent factor that protected against PJI (OR, 0.52 [95% CI, 0.30 to 0.88]; p = 0.016). However, preoperative anemia was independently associated with an increased risk of subsequent PJI (OR, 2.37 [95% CI, 1.34 to 4.16]; p = 0.003).

CONCLUSIONS

Based on this study conducted at a single institution, the use of TXA during aseptic revision arthroplasty was independently associated with a reduced risk of subsequent acute PJI after adjusting for multiple patient characteristics and surgical factors.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Effects of intravenous iron monotherapy for patients with iron deficient anemia undergoing total knee arthroplasty

Background

Unnecessary costs and complications can be reduced by increasing hemoglobin (Hb) levels and minimizing blood transfusions in patients who underwent total knee arthroplasty (TKA). This study aimed to determine the effects of intravenous iron monotherapy before TKA on preoperative iron deficient anemia and postoperative transfusion rates.

Methods

This prospective cohort study included 45 patients scheduled for TKA in the experimental group (Group I) and 221 patients who underwent TKA in 2015 and 2018 in the control group (Group C). One thousand milligrams of ferric carboxymaltose was administrated 1 month before TKA in group I. Intergroup comparison of the rate and total volume of transfusion, perioperative changes in Hb and analysis of iron metabolism variables in group I were performed. Subgroup analysis of Group I was conducted according to the response to iron monotherapy.

Results

Although Hb levels increased after intravenous iron monotherapy in Group I, postoperative transfusion rates in Groups I and C were 17.8% and 18.6%, respectively, without significant intergroup differences in the rate and total units of transfusion. Ferritin level and transferrin saturation were corrected in both subgroups of Group I. Only 17 patients (37.78%) showed response to iron monotherapy, with an Hb increase of 1.0 g/dL or more. Subgroup analysis showed lower proportions of coexisting chronic diseases, including chronic kidney disease in responders.

Conclusion

IV iron monotherapy was shown to be insufficient in successfully treating preoperative iron-deficient anemia to reduce postoperative allogenic blood transfusion in patients who underwent TKA. As preoperative anemia should be managed due to the high rates of postoperative transfusion for this surgery, clinicians should consider the complex interplay among the causal factors of anemia, apart from ID, in patients with preoperative anemia who are scheduled for TKA.

The Impact of Intraoperative Hypothermia on Blood Loss and Allogenic Blood Transfusion in Total Knee and Hip Arthroplasty: A Retrospective Study

Background

Total joint arthroplasty (TJA) usually leads to substantial blood loss, which may cause allogenic blood transfusion. Hypothermia occurring during operation has been reported to increase blood loss and transfusion rates in nonorthopedic cohorts. However, the relationship between intraoperative hypothermia and blood loss remains controversial in patients undergoing orthopedic surgeries. The aims of this study were to investigate the incidence of hypothermia and identify the impact of intraoperative body temperature and hypothermia on blood loss and transfusion rates in total knee and hip arthroplasty (TKA and THA, respectively).

Methods

This retrospective study enrolled 616 consecutive patients, who underwent primary unilateral TKA or THA at our institution during the period from April 2012 to July 2014. The occurrence of a temperature below 36°C during the operation was documented to identify the incidence of hypothermia. Univariate analysis was performed to find the risk factors for hypothermia. Multiple regression analysis and multivariate logistic regression analysis were employed to explore the association of intraoperative temperature and hypothermia with intraoperative blood loss and perioperative blood transfusion.

Results

The incidence of intraoperative hypothermia was 13.5%, 14.0%, and 13.1% in TJA, TKA, and THA, respectively. Intraoperative temperature (P = 0.045, P = 0.006) and hypothermia (P = 0.042, P < 0.001) were associated with intraoperative blood loss and perioperative transfusion in TKA. Intraoperative temperature (P = 0.002) was negatively related to the amount of blood loss, and hypothermia (P = 0.031) was the independent risk factor for transfusion in THA.

Conclusion

Intraoperative hypothermia is associated with increased blood loss and transfusion rates in TJA. Efforts should be made to maintain normothermia during operation in these patients.

Should we routinely perform a post-operative hemoglobin check following unicompartmental knee arthroplasty?

OBJECTIVES

To study the significance of checking post-operative hemoglobin and hematocrit following unicompartmental knee arthroplasty (UKA).

SETTING

Single center. Multiple surgeons.

DESIGN

Retrospective case series. Level of evidence IV.

MATERIALS AND METHODS

Following institutional approval, a retrospective analysis of all patients undergoing UKA at our level one academic university hospital was conducted. Operative records of all patients undergoing primary UKA were reviewed between March 2016 and March 2019. Patients' pre-operative hemoglobin and hematocrit, BMI, co-morbidities, application of tourniquet, tourniquet time, administration of tranexamic acid, need for post-operative blood transfusion, hospital length of stay, complications, and re-admission were all recorded. Blood loss was estimated using the post-operative hematocrit.

RESULTS

A total number of 155 patients were included. There were 70 females (45%) and 85 males (55%). The mean age was 66 ± 10 years. Median pre-op blood volume was 4700 mLs (interquartile range (IQR); 4200-5100). Median blood loss was 600 mLs (IQR; 400-830). Mean pre-op hemoglobin was 135 ± 14 g/L and mean post-op hemoglobin was 122 ± 13 g/L. No patient had a post-op hemoglobin under 80 g/L (range 93-154). No patients in our study needed transfusion.

CONCLUSION

The results of our study indicated that post-operative hemoglobin and hematocrit check proved unnecessary in all of our patients and could have been omitted from post-operative routines. We conclude that routine post UKA check of hemoglobin and hematocrit can be avoided and be saved for special circumstances depending on patient's physiology.

Treating Preoperative Anemia to Improve Patient Outcomes After Orthopaedic Surgery

For patients undergoing orthopaedic surgery, preoperative risk modification and control of comorbidities can maximize safety and improve outcomes. Anemia is common among orthopaedic patients, and its prevalence increases with patient age. Although surgeons are well versed in intraoperative blood conservation, preoperative anemia treatment is often deferred to primary care physicians, who may not understand the importance of a thorough assessment and treatment. Orthopaedic surgeons should understand the causes and treatments of anemia to advocate that patients receive appropriate preoperative care. Mean corpuscular volume and reticulocyte count can help determine the cause of anemia and assess the bone marrow's ability to produce red blood cells. These values can be used to aid in diagnosis and treatment plans. Iron deficiency anemia, the most common type, is a microcytic anemia easily treated with iron supplementation. In cases of trauma, anemia can be related to acute blood loss and underlying conditions. Fracture patterns and preexisting comorbidities should be assessed. The role of intravenous iron supplementation in this setting has not been clearly shown. Patients needing urgent procedures that might involve substantial blood loss should receive transfusions if they have hemoglobin levels <8 g/dL or symptomatic anemia.

Efficacy and Safety of Tranexamic Acid Combined with Rivaroxaban in Primary Total Knee Arthroplasty: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Tranexamic acid (TXA) combined with rivaroxaban (RA) has been widely used in total knee replacement (TKA). This meta-analysis explored the clinical effects of TXA combined with RA on reducing bleeding and preventing venous thrombosis in patients with unilateral TKA.

METHODS

Five controlled clinical studies that met the inclusion criteria were collected from PubMed, Embase and Cochrane libraries. Fixed effect model and random effect model were used to compare the TXA + RA group with the RA group in 731 patients.

RESULTS

Decrease of hemoglobin (Hb), total blood loss, transfusion rate and wound complications of the TXA + RA group is lower than the RA group, the difference was statistically significant (p < 0.05). Deep venous thrombosis (DVT) occurs in the TXA + RA group and the RA group showed no statistically significant difference (p > 0.05). There was no obvious difference of two ways of drug given that intra-articular (IA) and intravenous (IV) effect on Hb decrease, total blood loss, transfusion rate, wound complications, DVT (p > 0.05).

CONCLUSION

The application of TXA combined with RA in the TKA can effectively reduce blood loss without increasing the risk of DVT. However, it should be noted that TXA combined with RA after TKA has a potential increased risk of wound complications.

The incidence and risk factors for allogenic blood transfusion in total knee and hip arthroplasty

Background

Excessive blood loss in total joint arthroplasty (TJA) usually leads to an allogenic blood transfusion, which may cause adverse outcomes, prolonged length of hospitalization, and increased costs. The purpose of this study was to determine the incidence and risk factors for intraoperative and postoperative allogenic transfusion in patients undergoing primary unilateral total knee and hip arthroplasty (TKA and THA).

Methods

We conducted a retrospective study and enrolled consecutive patients undergoing primary unilateral TKA and THA at our institution between January 2010 and July 2014 (n = 1534). Information about allogenic transfusion was collected from medical records to determine the incidence. We performed univariate analysis and multivariate logistic regression analysis to identify the independent risk factors.

Results

Total, intraoperative, and postoperative transfusion rates were 17.9%, 7.9%, and 11.3%, respectively. The preoperative lower level of hemoglobin (Hb) (P < 0.001) and increased amount of intraoperative blood loss (P < 0.001) were independently associated with transfusion in TKA. The independent risk factors for transfusion in THA were female (P = 0.023), preoperative lower Hb level (P < 0.001), prolonged operation time (P < 0.001), and increased intraoperative blood loss (P < 0.001).

Conclusions

Given the high prevalence and potential risk of transfusion in TJA, interventions for identified risk factors should be used during the perioperative period.

Perioperative allogenic blood transfusion increases the incidence of postoperative deep vein thrombosis in total knee and hip arthroplasty

Background

Excessive blood loss caused by total joint arthroplasty (TJA) often increases the requirement for blood transfusion, which is associated with adverse outcomes. The purpose of this study was to determine the relationship between perioperative transfusion and postoperative DVT in TJA.

Methods

This retrospective study reviewed medical records of 715 patients, who consecutively underwent primary unilateral total knee arthroplasty (TKA) or total hip arthroplasty (THA) at our institution between September 2015 and March 2017. Demographic, clinical and surgical parameters were introduced into the univariate analysis to find risk factors for DVT within postoperative 30 days. In order to identify if allogenic blood transfusion was independently associated with DVT, a multivariate logistic regression analysis was conducted to adjust for gender, age, body mass index (BMI), diagnosis, and type of surgery.

Results

The incidence of perioperative allogenic blood transfusion was 12.4% (n = 89). Fifty-seven patients (8.0%) developed DVT after surgery. Univariate analysis demonstrated that there were differences between DVT group and non-DVT group in gender (P = 0.045), age (P < 0.001), BMI (P = 0.026), primary diagnosis (P = 0.001), type of surgery (P < 0.001), and transfusion rates (P = 0.040). After adjustment by using multivariate logistic regression analysis, transfusion appeared to be the independent risk factor for DVT in TJA (P = 0.001; OR = 3.9, 95%CI 1.8–8.4).

Conclusion

We found that perioperative allogenic blood transfusion was significantly associated with DVT following TJA. In order to reduce the risk of DVT and other adverse outcomes, methods to decrease transfusion rates should be used in clinical practice.

Impact of Co-Morbidities on the Cost of Care in Primary Elective Joint Arthroplasty

BACKGROUND

The Comprehensive Care for Joint Replacement model is the newest iteration of the bundled payment methodology introduced by the Centers for Medicare and Medicaid Services. Comprehensive Care for Joint Replacement model, while incentivizing providers to deliver care at a lower cost, does not incorporate any patient-level risk stratification. Our study evaluated the impact of specific medical co-morbidities on the cost of care in total joint arthroplasty (TJA) patients.

METHODS

A retrospective study was conducted on 1258 Medicare patients who underwent primary elective TJA between January 2015 and July 2016 at a single institution. There were 488 males, 552 hips, and the mean age was 71 years. Cost data were obtained from the Centers for Medicare and Medicaid Services. Co-morbidity information was obtained from a manual review of patient records. Fourteen co-morbidities were included in our final multiple linear regression models.

RESULTS

The regression models significantly predicted cost variation (P < .001). For index hospital costs, a history of cardiac arrhythmias (P < .001), valvular heart disease (P = .014), and anemia (P = .020) significantly increased costs. For post-acute care costs, a history of neurological conditions like Parkinson's disease or seizures (P < .001), malignancy (P = .001), hypertension (P = .012), depression (P = .014), and hypothyroidism (P = .044) were associated with increases in cost. Similarly, for total episode cost, a history of neurological conditions (P < .001), hypertension (P = .012), malignancy (P = .023), and diabetes (P = .029) were predictors for increased costs.

CONCLUSION

The cost of care in primary elective TJA increases with greater patient co-morbidity. Our data provide insight into the relative impact of specific medical conditions on cost of care and may be used in risk stratification in future reimbursement methodologies.

Association between Allogeneic Blood Transfusion and Wound Infection after Total Hip or Knee Arthroplasty: A Retrospective Case-Control Study

Background: To assess using a retrospective case control study, whether patients undergoing primary, elective total hip or knee arthroplasty who receive blood transfusion have a higher rate of post-operative infection compared to those who do not.

Materials and Methods: Data on elective primary total hip or knee arthroplasty patients, including patient characteristics, co-morbidities, type and duration of surgery, blood transfusion, deep and superficial infection was extracted from the Alberta Bone and Joint Health Institute (ABJHI). Logistic regression analysis was used to compare deep infection and superficial infection in blood-transfused and non-transfused cohorts.

Results: Of the 27892 patients identified, 3098 (11.1%) received blood transfusion (TKA 9.7%; THA 13.1%). Overall, the rate of superficial infection (SI) was 0.5% and deep infection (DI) was 1.1%. The infection rates in the transfused cohort were SI 1.0% and DI 1.6%, and in the non-transfused cohort were SI 0.5% and DI 1.0%. The transfused cohort had an increased risk of superficial infection (adjusted odds ratio (OR) 1.9 [95% CI 1.2-2.9, p-value 0.005]) as well as deep infection (adjusted OR 1.6 [95% CI 1.1-2.2, p-value 0.008]).

Conclusion: The odds of superficial and deep wound infection are significantly increased in primary, elective total hip and knee arthroplasty patients who receive blood transfusion compared to those who did not. This study can potentially help in reducing periprosthetic hip or knee infections.

Preoperative Hemoglobin Predicts Postoperative Transfusion Despite Antifibrinolytics During Total Knee Arthroplasty

Current antifibrinolytics have decreased perioperative blood loss; however, some patients still require transfusions postoperatively. The authors sought to determine the risk factors associated with postoperative transfusions and to establish a "cutoff" preoperative hemoglobin threshold value specific to total knee arthroplasty (TKA) that would identify patients who would benefit from blood conservation programs. The institutional database was queried for primary TKA patients. Preoperative patient demographics and hemoglobin values were determined in addition to intraoperative and postoperative variables, including transfusion rate. Patients were stratified by whether they received a transfusion perioperatively, and risk factors were identified through univariable and multivariable analysis. Optimal cutoff values for hemoglobin were identified by concurrently maximizing the sensitivity and specificity for predicting the risk of a postoperative transfusion event. Men and women were analyzed independently. A total of 532 primary TKAs were included for analysis, and 33 patients (6.2%) required a transfusion. Advanced age (P=.019), low pre-operative hemoglobin value (P<.001), and failure to receive tranexamic acid (P<.001) were associated with increased risk of postoperative transfusion. A preoperative hemoglobin value of 12.5 g/dL was identified as the optimal cutoff for predicting postoperative transfusion requirements across all patients, with a sensitivity of 84.8% and a specificity of 76.4%. Preoperative anemia remains predictive of transfusion following TKA despite current antifibrinolytics. Patients with a preoperative hemoglobin value of less than 12.5 g/dL who are not receiving intravenous tranexamic acid are particularly at risk and should be considered for blood conservation programs. [Orthopedics. 2019; 42(2):103-109.].

Preoperative Comorbidities and Postoperative Complications Do Not Influence Patient-Reported Satisfaction Following Humeral Head Resurfacing: Mid- to Long-term Follow-up of 106 Patients

Background

Humeral head resurfacing (HHR) has emerged as an alternative treatment for glenohumeral osteoarthritis. We investigated the outcomes of HHR using validated patient-reported outcome (PRO) measures.

Methods

A retrospective review was performed on 213 patients who underwent HHR. A PRO follow-up was performed by administering a questionnaire including the American Shoulder and Elbow Society (ASES) score, Brophy activity survey, short form of the Disabilities of the Arm, Shoulder and Hand (quickDASH) survey, and general shoulder function. PRO scores were stratified by comorbidities and complications.

Results

Survey responses were received from 106 patients (51%), with a mean follow-up of 5.6 ± 1.8 years (range: 9 months to 6.1 years). Preoperative comorbidities were associated with significantly higher quickDASH scores. Postoperative complications were associated with significantly higher rates of current pain, higher visual analog scale scores, night pain, lower subjective shoulder values, and lower ASES pain and total scores. No differences in patient satisfaction were identified between the cohorts with and without preoperative comorbidities and between the cohorts with and without postoperative complications.

Conclusion

In our cross-sectional analysis of mid- to long-term outcomes following HHR, preoperative comorbidities, or postoperative complications had no impact on patient-perceived postoperative satisfaction or most PROs. HHR is clinically viable in a wide variety of patients. Future work is necessary to compare the efficacy of HHR compared with more traditional total shoulder arthroplasty and stemmed hemiarthroplasty regarding long-term outcomes and appropriate indications.

Preoperative Patient Profile in Total Hip and Knee Arthroplasty: Predictive of Increased Medicare Payments in a Bundled Payment Model

BACKGROUND

The shift toward value-based bundled payment models in total joint arthroplasty highlights the need for identification of modifiable risk factors for increased spending as well as opportunities to mitigate perioperative treatment of chronic disease. The purpose of this study was to identify preoperative comorbidities that result in an increased financial burden using institutional data at a single institution.

METHODS

We conducted a retrospective review of total joint arthroplasty patients and collected payment data from the Center for Medicare and Medicaid Services for each patient up to 90 days after surgery in accordance with the regulations of the Comprehensive Care for Joint Replacement initiative. Statistical analysis and comparison of preoperative profile and Medicare payments as a surrogate for cost were completed.

RESULTS

Six hundred ninety-four patients were identified over a 4-year time period who underwent surgery before adoption of the Comprehensive Care for Joint Replacement but that met criteria for inclusion. The median total payment per patient episode of care was $20,048. Preoperative diagnosis of alcoholism, anemia, diabetes, and obesity was found to have a statistically significant effect on total payments. The model predicted a geometric mean increase from $1425 to $9308 for patients bearing these comorbidities.

CONCLUSION

With Medicare payments as a surrogate for cost, we demonstrate that specific patient comorbidities and a cumulative increase in comorbidities predict increased costs. This study was based on institutional data rather than administrative data to gain actionable information on an institutional level and highlight potential flaws in research based on administrative data.

No benefit of autologous transfusion drains in total knee arthroplasty

PURPOSE AND HYPOTHESIS

Autologous blood transfusion drains are commonly used to reduce allogeneic blood transfusion rate after total knee arthroplasty. There is conflicting evidence as to whether autologous transfusion drains (ABT drains) were effective when restrictive transfusion triggers were used. The aim of our study was to ascertain where, as a part of a blood management protocol, autologous blood transfusion drains reduce the allogeneic blood transfusion rate after total knee arthroplasty.

METHODS

Two-hundred total knee arthroplasty patients were included in the prospective randomized controlled study. After implantation, a Redon drain without vacuum assistance (control, n = 100) or an autologous blood transfusion drain (ABT group, n = 100) was used. Demographic and operative data were collected. The blood loss, total blood loss, blood values and transfusion rate were documented.

RESULTS

The blood loss in the drains was significantly increased for the ABT group (409 vs. 297 ml, p < 0.001). There was a non-significant trend towards a higher total blood loss for ABT patients (1844 vs. 1685 ml, n.s.). The allogeneic blood transfusion rate was similar for both groups (8 vs. 9%, n.s.). Similarly, the number of transfused blood units was comparable between both groups (0.2U/patient vs. 0.17U/patient n.s.).

CONCLUSION

In combination with restrictive blood transfusion triggers, ABT drains had no positive effect on the allogeneic blood transfusion rate. The blood loss in ABT drains was higher. As a consequence, the use of ABT drains was discontinued.

LEVEL OF EVIDENCE

I.

Perioperative Blood Management Strategies for Total Knee Arthroplasty

Total knee arthroplasty (TKA) often causes a significant amount of blood loss with an accompanying decline in hemoglobin and may increase the frequency of allogeneic blood transfusion rates. Unfortunately, allogeneic blood transfusions have associated risks including postoperative confusion, infection, cardiac arrhythmia, fluid overload, increased length of hospital stay, and increased mortality. Other than reducing the need for blood transfusions, reducing perioperative blood loss in TKA may also minimize intra-articular hemorrhage, limb swelling, and postoperative pain, and increase the range of motion during the early postoperative period. These benefits improve rehabilitation success and increase patients' postoperative satisfaction. Preoperative anemia, coupled with intraoperative and postoperative blood loss, is a major factor associated with higher rates of blood transfusion in TKA. Thus, treatment of preoperative anemia and prevention of perioperative blood loss are the primary strategies for perioperative blood management in TKA. This review, combined with current evidence, analyzes various methods of blood conservation, including preoperative, intraoperative, and postoperative methods, in terms of their effectiveness, safety, and cost. Because many factors can be controlled to reduce blood loss and transfusion rates in TKA, a highly efficient, safe, and cost-effective blood management strategy can be constructed to eliminate the need for transfusions associated with TKA.

Extremely Low Transfusion Rates: Contemporary Primary Total Hip and Knee Arthroplasties

BACKGROUND

Considerable blood loss which requires transfusion is frequently reported after total hip and knee arthroplasties (THA and TKA). The purpose of this study is to review the transfusion rates in contemporary THA and TKA with optimized perioperative protocols including minimized surgical trauma and optimal perioperative patient care.

METHODS

This retrospective study included 1442 consecutive patients receiving either a primary THA or a TKA from the same high-volume surgeon between January 2008 and December 2015. Demographics and surgical data were collected from patients' journals. Estimated blood loss, decline in hemoglobin, and use of transfusion were registered.

RESULTS

One (0.0013%) THA and 3 (0.0044%) TKAs required blood transfusion postoperatively. Average measured bleeding was 253 mL ± 142 and 207 mL ± 169 in THA and TKA, respectively. Average decline in hemoglobin was 23.5 g/L ± 11.4 and 22.9 g/L ± 11.6 for THA and TKA, respectively.

CONCLUSION

In contemporary THA and TKA, perioperative protocols and patient optimization can decrease the rate of blood transfusion to near zero.

What Should Define Preoperative Anemia in Primary THA?

BACKGROUND

The use of tranexamic acid (TXA) in THA decreases the risk of transfusion after surgery. However, nearly 10% of patients still undergo a transfusion, which has been independently associated with an increased risk of complications. Preoperative anemia has been proven to be a strong predictor of transfusion after THA, but the ideal "cutoff" values in today's population that maximize sensitivity and specificity to predict transfusion have yet to be established.

QUESTIONS/PURPOSES

(1) Which preoperative factors are associated with postoperative transfusion in the setting of TXA use? (2) If preoperative hemoglobin (Hgb) remains associated with transfusion, what are the best-supported preoperative Hgb cutoff values associated with increased transfusion after THA?

METHODS

A retrospective chart analysis was performed from January 1, 2013, to January 1, 2015, on 558 primary THAs that met prespecified inclusion criteria. A multivariable logistic regression analysis model was used to identify independent factors associated with transfusion. Area under the receiver-operator curve (AUC) was used to determine the best-supported preoperative Hgb cut point across all participants, as well as adjusted by sex and TXA use. Overall, 60 patients with a blood transfusion were included and compared with 498 control subjects (11% risk of transfusion).

RESULTS

After controlling for potential confounding variables such as age, sex, American Society of Anesthesiologist score, intravenous TXA (IV TXA) use, and preoperative Hgb, we found that patients with lower preoperative Hgb (g/dL per 1-unit decrease, odds ratio [OR], 2.6; 95% CI, 2.0-3.5; p < 0.001), female sex (vs male, OR, 4.2; 95% CI, 1.7-10.3; p = 0.002), and those unable to receive IV TXA (topical TXA/no TXA, OR, 13.5; 95% CI, 6.3-28.6; p < 0.001) were more likely to receive a transfusion. Of these, preoperative Hgb was found to be the variable most highly associated with transfusion (AUC, 0.876). A preoperative Hgb cutoff value of 12.6 g/dL maximized the AUC (0.876) for predicting transfusion across all patients unadjusted for baseline characteristics (sensitivity = 83, specificity = 84) with values of 12.5 g/dL (sensitivity = 85, specificity = 77) and 13.5 g/dL (sensitivity = 92, specificity = 77) for women and men, respectively.

CONCLUSIONS

The 1968 WHO definitions of anemia (preoperative Hgb < 13 g/dL for men and < 12 g/dL for women) used currently may underestimate patients at risk of transfusion after THA today. Further studies are needed to see if blood conservation referral decreases the risk of transfusion with preoperative treatment of anemia.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Is There a Role for Preoperative Iron Supplementation in Patients Preparing for a Total Hip or Total Knee Arthroplasty?

BACKGROUND

Several treatment modalities exist for the treatment of perioperative anemia. We determined the effect of oral iron supplementation on preoperative anemia, and the use of blood-conserving interventions before total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

A total of 3435 total joint arthroplasties (1461 THAs and 1974 TKAs) were analyzed during 2 phases of a blood conservation program. The first phase used erythropoietin alfa (EPO) or intravenous (IV) iron for patients at risk for perioperative anemia. The second phase included these interventions, as well as preoperative iron supplementation. The effect on preoperative hemoglobin (Hb) and serum ferritin, as well as EPO and IV iron utilization, was determined.

RESULTS

Oral iron therapy increased preoperative Hb level by 6 g/L (P < .001) and 7 g/L (P < .001) in the hip and knee cohorts, respectively. Serum ferritin level rose by 80 μg/L (P < .001) and 52 μg/L (P < .001) in the hip and knee cohorts, respectively. The number of patients with an Hb level <130 g/L was significantly reduced (P < .001 for both cohorts), as were patients with serum ferritin levels <35 μg/L (P = .002 for hip and P < .001 for knee cohorts). Utilization of EPO reduced from 16% to 6% (P < .001) and 18% to 6% (P < .001) in the hip and knee cohorts, respectively. Utilization of IV iron reduced from 4% to 2% (P = .05) and 5% to 2% (P < .001) in the hip and knee cohorts, respectively.

CONCLUSION

Oral iron therapy reduced the burden of perioperative anemia and reduced utilization of other blood-conserving therapies before THA and TKA. Future research should delineate the cost-effectiveness of oral iron therapy.

Quantifying Blood Loss and Transfusion Risk After Primary vs Conversion Total Hip Arthroplasty

BACKGROUND

Primary total hip arthroplasty (THA) and conversion THA may result in substantial blood loss, sometimes necessitating transfusion. Despite the complexities of the latter, both are grouped in the same category for quality assessment and reimbursement. This study's purpose was to compare both blood loss and transfusion risk in primary and conversion THA and identify their associated predictors.

METHODS

A total of 1616 patients who underwent primary and conversion THA at a single hospital from 2009-2013 were reviewed (primary THA = 1575; conversion THA = 41). Demographics, comorbidities, and perioperative data were collected from electronic records. Blood loss was calculated using a validated method. Transfusion triggers were based on standardized criteria. Separate multivariable regression models for blood loss and transfusion were performed.

RESULTS

Conversion THA patients were younger (P = .002), had lower age-adjusted Charlson scores (P = .006), longer surgeries (P < .001), higher blood loss (P < .001), and more transfusions (P < .001). Primary and conversion THA groups were different in terms of surgical approach (P < .001), anesthesia type (P = .002), and venous thromboembolism prophylaxis (P = .01). Compared to primary THA, conversion THA had an average 478.9 mL higher blood loss (P = .003) and increased adjusted odds ratio of 3.2 (P = .019) for transfusion.

CONCLUSION

Conversion THA leads to higher blood loss and transfusion compared with primary THA. These differences were quantified in the present study and showed consistent results between the 2 metrics. The differences between these procedures should be addressed during quality assurance because conversion THA is associated with higher resource utilization, which is important in the allocation of resources and tiered reimbursement strategies.