Comparison of Estimated Glomerular Filtration Rate Using Five Equations to Predict Acute Kidney Injury Following Total Joint Arthroplasty

Introduction: Primary total joint arthroplasty (TJA) is one of the most common procedures in the United States, and as the incidence of this surgery increases, identifying methods for improving outcomes and reducing complications is essential. Acute kidney injury (AKI) following TJA is a potential source of morbidity and mortality. Estimated glomerular filtration rate (eGFR) is used as an indicator of renal function. Several equations are commonly used to calculate eGFR. The purpose of this study was 1) to evaluate the agreement between five equations in calculating eGFR, and 2) to confirm which equation can best predict AKI in patients undergoing TJA. Methods: 497,261 cases of TJA were queried from the National Surgical Quality Improvement Program (NSQIP) from 2012 to 2019. Preoperative eGFR was calculated using the Cockcroft-Gault, Modification of Diet in Renal Disease (MDRD) II, re-expressed MDRD II, Chronic Kidney Disease Epidemiology Collaboration, and Mayo quadratic (Mayo) equations. The primary outcome measure was acute kidney injury (AKI). These cohorts were compared based on demographic and preoperative factors. Multivariate regression analysis was used to evaluate independent associations between preoperative eGFR and postoperative renal outcomes. Results: Seven hundred seventy-seven (0.16%) patients experienced AKI after TJA. The Cockcroft-Gault equation yielded the highest mean eGFR (98.6 ± 32.7), while the Re-expressed MDRD II equation yielded the lowest mean eGFR (75.1 ± 28.8). Multivariate regression analysis showed that a decrease in preoperative eGFR was independently associated with an increased risk of postoperative AKI in all five equations. The Akaike information criterion (AIC) was the lowest in the Mayo equation (6546). Conclusions: Preoperative decrease in eGFR in all five equations was independently associated with increased risk of postoperative AKI. The Mayo equation had the highest predictive ability of acquiring postoperative AKI following TJA

Predictive Factors and Outcomes in Patients With Severe Postoperative Anemia Following Total Joint Arthroplasty

Background: Perioperative allogenic blood transfusions (ABT) have demonstrated associations with poor outcomes and increased complication rates following total joint arthroplasty (TJA). Recent strides in blood conservation methods have been made, including multimodal blood management, tranexamic acid (TXA) use, and restrictive transfusion strategies in order to reduce risk associated with transfusion. While the literature on transfusions and outcomes is extensive, the consequences of low postoperative hemoglobin is less well defined. This study aimed to identify factors and consequences associated with severe anemia (hemoglobin \u3c8g/dL) following primary TJA. Methods: A retrospective review was conducted of all the elective primary TJA at a single tertiary care medical center from January 2017 to December 2018. One thousand six hundred and thirty-five cases were stratified based on the development of severe postoperative anemia, and compared based on patient preoperative hemoglobin, comorbidities, demographics, intraoperative variables, and postoperative outcomes. Logistic regression was used to identify independent predictors of severe postoperative anemia. Results: Surgical duration (per 30 minute increase) (OR, 2.03; 95% CI, 1.59-2.58), preoperative hemoglobin (per 1g/dL decrease) (odds ratio [OR], 2.96; 95% confidence interval [CI], 2.38-6.38), and THA vs. TKA (OR, 2.06; 95% CI 1.26-3.37) were independently associated with severe postoperative anemia. Use of TXA (OR, 0.42; 0.20-0.85), and body mass index (per 1kg/m2 increase) (OR, 0.90; 95% CI, 0.86-0.95) were protective against it. Severe postoperative anemia was associated with acute kidney injury (AKI), longer length of stay (LOS), and 90-day emergency department visits/readmissions. Conclusions: Longer duration of surgery, lower preoperative hemoglobin, and THA are all associated with severe postoperative anemia, and lead to complications of AKI, increased LOS, and higher readmission rates. As the incidence of fast-track TJA and outpatient surgery steadily increase, reducing the extent of postoperative anemia is essential for patient outcomes

Comparing five equations to calculate estimated glomerular filtration rate to predict acute kidney injury following total joint arthroplasty.

BACKGROUND: Acute kidney injury (AKI) following total joint arthroplasty (TJA) is associated with increased morbidity and mortality. Estimated glomerular filtration rate (eGFR) is used as an indicator of renal function. The purpose of this study was (1) to assess each of the five equations that are used in calculating eGFR, and (2) to evaluate which equation may best predict AKI in patients following TJA. METHODS: The National Surgical Quality Improvement Program (NSQIP) was queried for all 497,261 cases of TJA performed from 2012 to 2019 with complete data. The Modification of Diet in Renal Disease (MDRD) II, re-expressed MDRD II, Cockcroft-Gault, Mayo quadratic, and Chronic Kidney Disease Epidemiology Collaboration equations were used to calculate preoperative eGFR. Two cohorts were created based on the development of postoperative AKI and were compared based on demographic and preoperative factors. Multivariate regression analysis was used to assess for independent associations between preoperative eGFR and postoperative renal failure for each equation. The Akaike information criterion (AIC) was used to evaluate predictive ability of the five equations. RESULTS: Seven hundred seventy-seven (0.16%) patients experienced AKI after TJA. The Cockcroft-Gault equation yielded the highest mean eGFR (98.6 ± 32.7), while the Re-expressed MDRD II equation yielded the lowest mean eGFR (75.1 ± 28.8). Multivariate regression analysis demonstrated that a decrease in preoperative eGFR was independently associated with an increased risk of developing postoperative AKI in all five equations. The AIC was the lowest in the Mayo equation. CONCLUSIONS: Preoperative decrease in eGFR was independently associated with increased risk of postoperative AKI in all five equations. The Mayo equation was most predictive of the development of postoperative AKI following TJA. The mayo equation best identified patients with the highest risk of postoperative AKI, which may help providers make decisions on perioperative management in these patients

Comparison of Estimated Glomerular Filtration Rate Using Five Equations to Predict Acute Kidney Injury Following Hip Fracture Surgery

Introduction: Hip fractures are a common injury and a source of disability and mortality in the aging population. Acute kidney injury (AKI) is a common and potentially serious complication following hip fracture surgery. Estimated glomerular filtration rate (eGFR) is used as an indicator of renal function. Several equations are commonly used to calculate eGFR. The purpose of this study was 1) to evaluate the agreement between five equations in calculating eGFR, and 2) to confirm which equation can best predict AKI in patients undergoing hip fracture surgery. Methods: 146,702 cases of surgical stabilization of hip fracture were queried from the National Surgical Quality Improvement Program (NSQIP) from 2012 to 2019. Preoperative eGFR was calculated using the Cockcroft-Gault, Modification of Diet in Renal Disease (MDRD) II, re-expressed MDRD II, Chronic Kidney Disease Epidemiology Collaboration, and Mayo quadratic (Mayo) equations. The primary outcome measure was AKI. Cases were stratified into two cohorts based on the development of postoperative AKI. These cohorts were compared based on demographic and preoperative factors. Multivariate regression analysis was used to evaluate independent associations between preoperative eGFR and postoperative renal outcomes. Results: Six hundred ninety-nine (0.73%) patients acquired AKI after hip fracture surgery. The Mayo equation yielded the highest mean eGFR (83.8 ± 23.6), while the Re-expressed MDRD II equation yielded the lowest mean eGFR (68.3 ± 35.6). Multivariate regression analysis showed that a decrease in preoperative eGFR was independently associated with an increased risk of postoperative AKI in all five equations. The Akaike information criterion (AIC) was the lowest in the Mayo equation (5116). Conclusions: Preoperative decrease in eGFR in all five equations was independently associated with increased risk of postoperative AKI. The Mayo equation had the highest predictive ability of acquiring postoperative AKI following hip fracture surgery

Blood Transfusions in Revision Surgery for Prosthetic Hip and Knee Infection

Background: Surgery for prosthetic joint infection (PJI) can often have significant blood loss necessitating allogeneic blood transfusion (ABT). ABT is associated with higher rates of morbidity and death in revision TJA, particularly in the treatment of PJI. It is important to understand how the rates of ABT differ among the various surgical treatments of PJI. We compared ABT rates by procedure type among patients treated for PJI a multimodal blood conservation protocol. Methods: We retrospectively reviewed 143 operative cases of revision arthroplasty for hip and knee PJI involving 102 patients at a single institution between 2016 and 2018. Procedures were categorized as 1. irrigation and debridement (I&D) with modular component exchange (“modular component exchange”), 2. explantation with I&D and placement of antibiotic spacer (“explantation”), 3. I&D with antibiotic spacer exchange (“spacer exchange”), or 4. antibiotic spacer removal and prosthetic reimplantation (“reimplantation”). ABT rates and number of units transfused were assessed for the four procedures. Factors associated with ABT were assessed with a multilevel mixed-effects regression model. Results: Seventy-seven cases (54%) received ABT. The highest rates of ABT occurred during explantations (74%) and spacer exchanges (72%), followed by reimplantations (36%) and modular component exchanges (33%). After adjusting for perioperative variables, lower preoperative hemoglobin level was associated with higher odds of ABT (odds ratio [OR], 1.9 [per 1-g/dL decrease]; 95% confidence interval [CI]: 1.5–2.5). Explantation (OR, 14; 95% CI: 4.0–50), reimplantation (OR, 4.3; 95% CI: 1.1–16), and spacer exchanges (OR, 5.6; 95% CI: 1.1–28) were associated with greater odds of ABT. Antibiotic spacer exchanges (OR, 26; 95% CI: 2.1-315) and explantations (OR, 11; 95% CI: 2.1-61) were associated with greater odds of multiple unit transfusions. Discussion: Despite a restrictive transfusion protocol, ABT rates remain high in the surgical treatment of PJI. Antibiotic spacer exchange and explantation procedures had high rates of multiple unit transfusions, and additional units of blood should be made available. Preoperative anemia should be treated when possible, and further refinement of blood management protocols in prosthetic joint infection is necessary

Preoperative International Normalized Ratio Thresholds in Hip Fracture: An Analysis of the National Surgical Quality Improvement Program

Background: Hip fractures are one of the most common orthopaedic injuries among the elderly, and as life expectancy continues to rise, the incidence of hip fractures has increased. The international normalized ratio (INR) is routinely obtained preoperatively to assess a patient’s readiness for surgery to evaluate bleeding risk. We aimed to 1) assess the relationship between preoperative INR in hip fracture patients and postoperative complication rates and 2) establish an INR threshold under which patients would be safe to proceed to surgery without INR correction. Methods: We retrospectively reviewed cases of hip fracture surgical stabilization in the American College of Surgeons National Surgical Quality Improvement Program from January 1, 2012 to December 31, 2018. Cases were stratified into four groups based on preoperative INR levels: 1) \u3c 1.4, 2) ≥1.4 and Results: Thirty-five thousand nine hundred-ten cases were identified, with 33,484 (93.2%) performed on patients with preoperative INR \u3c 1.4, 867 (2.4%) on INR ≥1.4 and Conclusions: In this study we found a threshold of INR\u3c 1.6 to be safe for patients prior to undergoing hip fracture surgery. Below this value patients avoid an increased risk of both transfusions and 30-day mortality seen at higher INR values. These findings may allow for adjustments to preoperative protocols and improve outcomes of hip fracture surgery in this population

Predictors of Hospice Discharge Following Surgical Fixation of Hip Fracture

Introduction: Each year, over 300,000 people over the age of 65 are hospitalized for hip fractures, and even with co-management of patients perioperatively with a geriatric team, hip fractures in the elderly are associated with significant morbidity and mortality. Given the extreme morbidity and mortality faced by elderly patients in the post-injury period, recommendations have been put forth for the integration of palliative and even hospice care, to help improve patients’ quality of life. Our objectives were to 1) determine the proportion of patients discharged to hospice following hip fracture surgery and their 30-day mortality rates of these patients, and 2) identify the independent predictors of discharge to hospice. Methods: We retrospectively queried the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) for all hip fractures surgeries between the years of 2016 and 2018. Included cases were stratified into two cohorts: cases involving a discharge to hospice and non-hospice discharge. Variables assessed included patient demographics, comorbidities, perioperative characteristics, and postoperative outcomes. Differences between hospice and non-hospice patients were compared using chi-squared analysis or Fisher\u27s exact test for categorical variables and Student’s t-tests for continuous variables. A binary logistic regression model was used to assess independent predictors of hospice discharge with 30-day mortality. Results: Overall, 31,531 operatively treated hip fractures were identified, of which 281 (0.9%) involved a discharge to hospice. Patients discharged to hospice had a 67% 30-day mortality rate in comparison to 5.6% of patients not discharged to hospice (p \u3c 0.001). Disseminated cancer, dependent functional status, \u3e10% weight loss over six months preoperatively, and preoperative cognitive deficit were the strongest predictors of hospice discharge with 30-day mortality following hip fracture surgery. Conclusions: Current hospice utilization in hip fracture patients remains low, but 30-day mortality in these patients is high. An awareness of the associations between patient characteristics and discharge to hospice with 30-day mortality is important for surgeons to consider when discussing postoperative expectations and outcomes with these patients

Comparing Pain and Pain Coping Mechanisms in Patients Undergoing Total Joint Arthroplasty as Part of a Mission Trip to Those in the United States.

BACKGROUND: Access to total joint arthroplasty can be difficult in low-resource settings. Service trips are conducted to provide arthroplasty care to populations in need around the world. This study aimed to compare the pain, function, surgical expectations, and coping mechanisms of patients from one such service trip to the United States. METHODS: In 2019, the Operation Walk program conducted a service trip in Guyana during which 50 patients had hip or knee arthroplasties. Patient demographics, patient-reported outcome measures, questionnaires assessing pain attitudes and coping, and pain visual analog scales were collected preoperatively and at 3 months postoperatively. These outcomes were compared with a matched cohort of elective total joint arthroplasty at a US tertiary care medical center. There were 37 patients matched between the 2 cohorts. RESULTS: The mission cohort had significantly lower preoperative self-reported function scores than the US cohort (38.3 versus 47.5, P = .003), as well as a significantly larger improvement at 3 months (42.4 versus 26.4, P = .014). The mission cohort had significantly higher initial pain (8.0 versus 7.0, P = .015), but there were no differences with regard to pain at 3 months (P = .420) or change in pain (P = .175). The mission cohort had significantly greater preoperative scores in pain attitude and coping responses. CONCLUSION: Patients in low-resource settings were more likely to have preoperative functional limitations and pain, and they coped with pain through prayer. Understanding the key differences between these 2 types of populations and how they approach pain and functional limitations may help improve care for each group. LEVEL OF EVIDENCE: II, prospective study

Ultracongruent Designs Compared to Posterior-Stabilized and Cruciate-Retaining Tibial Inserts - What Does the Evidence Tell Us? A Systematic Review and Meta-Analysis.

BACKGROUND: Posterior-stabilized (PS) and cruciate-retaining (CR) have been the most common tibial designs used in total knee arthroplasty. Ultra-congruent (UC) inserts are becoming popular because they preserve bone without relying on the posterior cruciate ligament balance and integrity. Despite increasing use, there is no consensus on how UC inserts perform versus PS and CR designs. METHODS: A comprehensive literature search of 5 online databases was performed for articles from January 2000 to July 2022 comparing the kinematic and clinical outcomes of PS or CR tibial inserts to UC inserts. There were nineteen studies included. There were 5 studies comparing UC to CR and 14 comparing UC to PS. Only one randomized controlled trial (RCT) was rated good quality . RESULTS: For CR studies, pooled analyses showed no difference in knee flexion (n = 3, P = .33) or Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores (n = 2, P = .58). For PS studies, meta-analyses showed better anteroposterior stability (n = 4, P \u3c .001) and more femoral rollback (n = 2, P \u3c .001) for PS but no difference in knee flexion (n = 9, P = .55) or medio-lateral stability (n = 2, P = .50). There was no difference with WOMAC (n = 5, P = .26), Knee Society Score (n = 3, P = .58), Knee Society Knee Score (n = 4, P = .76), or Knee Society Function Score (n = 5, P = .51). CONCLUSION: Available data demonstrates there are no clinical differences between CR or PS and UC inserts in small short-term studies ending around 2 years after surgery. More importantly, high-quality research comparing all inserts is lacking, demonstrating a need for more uniform and longer-term studies beyond 5 years after surgery to justify increased UC usage

Predictors of Hospice Discharge After Surgical Fixation of Hip Fractures.

BACKGROUND: Each year, over 300,000 people older than 65 years are hospitalized for hip fractures. Given the notable morbidity and mortality faced by elderly patients in the postinjury period, recommendations have been put forth for integrating palliative and, when needed, hospice care to improve patients\u27 quality of life. Our objective was to (1) understand the proportion of patients discharged to hospice after hip fracture surgery and their 30-day mortality rates and (2) identify the independent predictors of discharge to hospice. METHODS: We retrospectively queried the American College of Surgeons National Surgical Quality Improvement Program for all hip fracture surgeries between the years of 2016 and 2018. Included cases were stratified into two cohorts: cases involving a discharge to hospice and nonhospice discharge. Variables assessed included patient demographics, comorbidities, perioperative characteristics, and postoperative outcomes. Differences between hospice and nonhospice patients were compared using chi-squared analysis or the Fisher exact test for categorical variables and Student t -tests for continuous variables. A binary logistic regression model was used to assess independent predictors of hospice discharge with 30-day mortality. RESULTS: Overall, 31,531 surgically treated hip fractures were identified, of which only 281 (0.9%) involved a discharge to hospice. Patients discharged to hospice had a 67% 30-day mortality rate in comparison with 5.6% of patients not discharged to hospice ( P \u3c 0.001). Disseminated cancer, dependent functional status, \u3e10% weight loss over 6 months preoperatively, and preoperative cognitive deficit were the strongest predictors of hospice discharge with 30-day mortality after hip fracture surgery. CONCLUSIONS: Current hospice utilization in hip fracture patients remains low, but 30-day mortality in these patients is high. An awareness of the associations between patient characteristics and discharge to hospice with 30-day mortality is important for surgeons to consider when discussing postoperative expectations and outcomes with these patients. LEVEL OF EVIDENCE: Level III, retrospective comparative study