Impact of Postoperative COVID-19 Infection Status on Outcomes in Elective Primary Total Joint Arthroplasty.

BACKGROUND: Although Coronavirus disease 2019 (COVID-19) infection causes major morbidity and mortality, it is unclear what the impact of postoperative COVID-19 infection is on 30-day outcomes after total joint arthroplasty (TJA). METHODS: There were 2,340 patients who underwent TJA in 2021, identified using the National Surgical Quality Improvement Program database, with 925 total hip arthroplasty (THA) patients (39.5%) and 1,415 total knee arthroplasty (TKA) patients (60.5%), overall. Propensity score matching was implemented using patient demographics and preoperative medical conditions to compare outcomes for postoperative COVID-19-positive and COVID-19-negative patients who underwent TKA or THA. RESULTS: Postoperative COVID-19-positive THA patients were found to have a significantly increased risk of pneumonia (odds ratio [OR] 42.57), sepsis (OR 12.77), readmission (OR 12.06), non-home discharge (OR 3.78), and longer length of stay (hazard ratio 1.62). Postoperative COVID-19-positive TKA patients had an increased risk of 30-day mortality (OR 14.17), superficial infection (OR 3.17), pneumonia (OR 34.68), unplanned intubation (OR 18.31), ventilator use for more than 48 hours (OR 18.31), pulmonary embolism (OR 11.98), urinary tract infection (OR 5.16), myocardial infarction (OR 16.02), deep vein thrombosis (OR 4.69), non-home discharge (OR 1.79), reoperation (OR 3.17), readmission (OR 9.61), and longer length of stay (hazard ratio 1.49). CONCLUSIONS: Patients who contracted COVID-19 within 30 days after TJA were at increased risk of mortalities, medical complications, readmissions, reoperations, and non-home discharges. It is important for orthopedic surgeons to understand these adverse outcomes to better counsel patients and mitigate these risks, particularly in higher risk populations.

Over the Past Decade, Preoperative Anemia Has Become a Greater Predictor of Transfusions After Total Knee Arthroplasty.

BACKGROUND: With advancements in perioperative blood management and the use of tranexamic acid, the rate of transfusions after total knee arthroplasty (TKA) has substantially decreased. As these principles are refined, other modifiable risk factors, such as preoperative anemia, may play an increasingly important role in transfusion risk for patients undergoing TKA. METHODS: A multicenter, national database was utilized to identify patients undergoing TKA from 2010 to 2021. Anemia was defined by World Health Organization definitions as < 12 g/dL for women and < 13 g/dL for men. A predictive model was created using backwards elimination logistic regression to predict transfusion risk, controlling for demographic and medical covariates. The coefficient of anemia was then analyzed for each year. The trend over time was fitted with a best-fit linear regression equation. RESULTS: There were 509,117 patients who underwent TKA, and had a mean age of 67 years (range, 18 to 89). There were 57,716 (11%) patients who were anemic preoperatively, and 15,426 (3%) of patients required a transfusion. Rate of transfusion decreased from 10.6% in 2010 to 0.6% in 2021. The odds ratio associated with anemia as a predictor of transfusion increased from 3.1 (95% confidence interval: 2.1 to 4.6) in 2010 to 14.0 (95% confidence interval: 8.9 to 24) in 2021. CONCLUSIONS: The results of this study demonstrate that the importance of preoperative anemia as a predictor of transfusion has increased over the past decade as rates of transfusion have decreased. As perioperative blood management protocols improve, preoperative anemia should be considered an important focus of intervention to reduce the risk of transfusion prior to TKA. LEVEL OF EVIDENCE: III.

Decreased Risk of Readmission and Complications With Preoperative GLP-1 Analog Use in Patients Undergoing Primary Total Joint Arthroplasty.

BACKGROUND: There has been considerable interest in the use of GLP-1 receptor analogs (GLP-1 RAs) for weight optimization in patients undergoing elective arthroplasty. As there is limited data regarding the implications of their use, our study aimed to evaluate the association between preoperative GLP-1 RA use and postoperative outcomes in patients undergoing primary total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS: The TrinetX research network was queried to identify all patients undergoing primary THA or TKA between May 2005 and December 2023 across 84 health care organizations. Patients were stratified based on preoperative GLP-1 RA use. Propensity score matching (1:1) was performed to account for baseline differences in demographics, laboratory investigations, and comorbidities. Subsequently, risk ratios were evaluated for postoperative outcomes. RESULTS: A total of 268,504 and 386,356 patients underwent THA and TKA, of which 1,044 and 2,095 used preoperative GLP-1 RAs. After matching, GLP-1 RA use was associated with a decreased 90-day risk of periprosthetic joint infection (2.1 versus 3.6%, RR = 0.58, P = .042) and readmission (1.1 versus 2.0%, RR = 0.53, P = .017) following THA and TKA, respectively. There was no difference in the risk of all other outcomes between comparison groups. CONCLUSIONS: Preoperative GLP-1 RA use is associated with a 42% decreased risk of periprosthetic joint infection and 47% decreased risk of readmission in the 90-day postoperative period following THA and TKA, respectively, with no difference in other risks, including aspiration. Our findings indicate that GLP-1 RAs may be safe to use in patients undergoing elective arthroplasty; however, further studies are warranted to inform the routine use of GLP-1 RAs for weight management in THA and TKA patients.

The Definition of Anemia Matters When Using Preoperative Hemoglobin as a Screening Tool Prior to Total Hip and Knee Arthroplasty.

BACKGROUND: Preoperative anemia is common in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA). Several definitions of anemia have been described, with no clear consensus on the optimal one for preoperative screening. We hypothesized that depending on the definition used preoperatively, the proportion of anemic patients identified who would require a postoperative allogeneic blood transfusion would vary significantly. METHODS: A total of 681,141 patients were identified in a national database who underwent either THA or TKA. Preoperative anemia was classified according to the World Health Organization (WHO) definition, Cleveland Clinic (CC) definition, or race, age, and sex-specific definition described by Beutler et al in 2006. The optimal preoperative (OP) hemoglobin thresholds to predict perioperative transfusions were also calculated using receiver operating characteristic curves. RESULTS: When using the WHO definition, 18% of anemic patients required a transfusion versus 14% (OP definition), 12% (CC definition), and 16% (Beutler definition). Similarly, 0.69% of anemic patients sustained a periprosthetic joint infection within 30 days using the WHO definition versus 0.59% (OP definition), 0.60% (CC definition), or 0.66% (Beutler definition). Using the WHO definition, 5.3% of patients would have sustained a major complication versus 4.5% (OP definition), 4.4% (CC definition), and 5.0% (Beutler definition). CONCLUSIONS: Variation in the definition of anemia for preoperative screening in THA and TKA results in substantial differences in discriminative ability to predict perioperative transfusions. The WHO definition identified the largest proportion of patients who ultimately received a perioperative transfusion.

Compressed Sensing SEMAC MRI of Hip, Knee, and Ankle Arthroplasty Implants: A 1.5-T and 3-T Intrapatient Performance Comparison for Diagnosing Periprosthetic Abnormalities.

BACKGROUND. The utility of 3-T MRI for diagnosing joint disorders is established, but its performance for diagnosing abnormalities around arthroplasty implants is unclear. OBJECTIVE. The purpose of this study was to compare 1.5-T and 3-T compressed sensing slice encoding for metal artifact correction (SEMAC) MRI for diagnosing peri-prosthetic abnormalities around hip, knee, and ankle arthroplasty implants. METHODS. Forty-five participants (26 women, 19 men; mean age ± SD, 71 ± 14 years) with symptomatic lower extremity arthroplasty (hip, knee, and ankle, 15 each) prospectively underwent consecutive 1.5- and 3-T MRI examinations with intermediate-weighted (IW) and STIR compressed sensing SEMAC sequences. Using a Likert scale, three radiologists evaluated the presence or absence of periprosthetic abnormalities, including bone marrow edema-like signal, osteolysis, stress reaction/fracture, synovitis, and tendon abnormalities and collections; image quality; and visibility of anatomic structures. Statistical analysis included nonparametric comparison and interchangeability testing. RESULTS. For diagnosing periprosthetic abnormalities, 1.5-T and 3-T compressed sensing SEMAC MRI were interchangeable. Across all three joints, 3-T MRI had lower noise than 1.5-T MRI (median IW and STIR scores at 3 T vs 1.5 T, 4 and 4 [range, 2-5 and 3-5] vs 3 and 3 [range, 2-5 and 2-4]; p < .01 for both), sharper edges (median IW and STIR scores at 3 T vs 1.5 T, 4 and 4 [both ranges, 2-5] vs 3 and 3 [range, 2-4 and 2-5]; p < .02 and p < .05), and more effective metal artifact reduction (median IW and STIR scores at 3 T vs 1.5 T, 4 and 4 [range, 3-5 and 2-5] vs 4 and 4 [both ranges, 3-5]; p < .02 and p = .72). Agreement was moderate to substantial for image contrast (IW and STIR, 0.66 and 0.54 [95% CI, 0.41-0.91 and 0.29-0.80]; p = .58 and p = .16) and joint capsule visualization (IW and STIR, 0.57 and 0.70 [range, 0.32-0.81 and 0.51-0.89]; p = .16 and p = .19). The bone-implant interface was more visible at 1.5 T (median IW and STIR scores, 4 and 4 [both ranges, 2-5] at 1.5 T vs 3 and 3 [both ranges, 2-5] at 3 T; p = .08 and p = .58), but periprosthetic tissues had superior visibility at 3 T (IW and STIR, 4 and 4 [both ranges, 3-5] at 3 T vs 4 and 4 [ranges, 2-5 and 3-5] at 1.5 T; p = .07 and p = .19). CONCLUSION. Optimized 1.5-T and 3-T compressed sensing SEMAC MRI are interchangeable for diagnosing periprosthetic abnormalities, although metallic artifacts are larger at 3 T. CLINICAL IMPACT. With compressed sensing SEMAC MRI, lower extremity arthroplasty implants can be imaged at 3 T rather than 1.5 T.

Racial and Ethnic Disparities in Short-Stay Total Knee Arthroplasty.

BACKGROUND: The purpose of this study was to understand racial and ethnic disparities in hospital-based, Medicare-defined outpatient total knee arthroplasty (TKA). We aimed to determine the following: 1) whether there are differences in preoperative characteristics or postoperative outcomes in outpatient TKA between racial/ethnic groups and 2) trends in outpatient TKA volume, based on race/ethnicity. METHODS: This was a retrospective cohort study of a large national database. Outpatient TKAs performed between 2012 and 2018 were identified. Patient demographics, comorbidities, and 30-day postoperative outcomes were compared between White, Black, Asian, and Hispanic patients. RESULTS: Of 54,183 outpatient patients, 85.6% were White, 7.4% Black, 2.6% Asian, and 4.1% Hispanic. Black patients had the highest body mass index, and there were higher rates of diabetes among all minority groups (P < .001). All minority groups were more likely to be discharged to a rehabilitation or a skilled care facility compared to White patients (P < .001). Annual percentage increases in outpatient TKA were most pronounced for Asians and Hispanics and least pronounced among Blacks, when compared to White patients. CONCLUSION: The outcomes of outpatient TKA are impacted by risk factors that reflect underlying disparities in healthcare. As joint arthroplasties have come off the inpatient-only list and procedures move to ambulatory settings, these disparities will likely magnify and impact outcomes, costs, and access points. Extensive preoperative optimization and interventions that target medical and social factors may help to reduce these disparities in TKA and increase access among minority patients. LEVEL OF EVIDENCE: III, retrospective cohort study.

Preoperative Anemia is an Independent Risk Factor for Increased Complications and Mortalities After Total Knee Arthroplasty Regardless of Postoperative Transfusions.

BACKGROUND: Preoperative anemia is associated with adverse events following total knee arthroplasty (TKA). It remains unknown if this effect is due to comorbid conditions, adverse events associated with transfusions, or the anemia itself. We used propensity-score matching to isolate the effect of anemia on postoperative complications following TKA, regardless of blood transfusions. METHODS: Patients undergoing primary TKA from 2010 to 2020 without receiving a perioperative blood transfusion, were identified using a large national database. A 1:1 propensity score matching was used to create cohorts of anemic and nonanemic patients matched on Charlson Comorbidity Index (CCI), American Society of Anesthesiology (ASA) classification, age, sex, and prevalence of bleeding disorders. There were 43,370 patients were included in each group (mean age 68 [range, 29 to 99; 44% male]). The 1:1 matching yielded groups with similar CCI, ASA classification, age, sex, and prevalence of bleeding disorders (all, P > .9). RESULTS: Anemic patients had a higher incidence of major complications (4.1 versus 2.8%; P < .001), 30-day mortality rate (0.2 versus 0.1%; P < .001), and extended lengths of stay (LOS) (8.3 versus 6.6%; P < .001). Anemic patients also had increased 30-day rates of wound infection requiring hospital admission, renal failure, reintubation, myocardial infarction, and pneumonia (all, P < .001). CONCLUSION: In matched cohorts of anemic versus nonanemic patients undergoing TKA, all who had no postoperative blood transfusion, anemic patients had higher rates of complications, extended LOS, and mortalities. Thus, anemia should be considered an independent risk factor for complications following TKA.

Body Mass Index and Revision Total Knee Arthroplasty: Does Cause for Revision Vary by Underweight or Obese Status?

BACKGROUND: Body mass index (BMI) impacts risk for revision total knee arthroplasty (rTKA), but the relationship between BMI and cause for revision remains unclear. We hypothesized that patients in different BMI classes would have disparate risk for causes of rTKA. METHODS: There were 171,856 patients who underwent rTKA from 2006 to 2020 from a national database. Patients were classified as underweight (BMI < 19), normal-weight, overweight/obese (BMI 25 to 39.9), or morbidly obese (BMI > 40). Multivariable logistic regressions adjusted for age, sex, race/ethnicity, socioeconomic status, payer status, hospital geographic setting, and comorbidities were used to examine the effect of BMI on risk for different rTKA causes. RESULTS: Compared to normal-weight controls, underweight patients were 62% less likely to undergo revision due to aseptic loosening, 40% less likely due to mechanical complications, 187% more likely due to periprosthetic fracture, 135% more likely due to periprosthetic joint infection (PJI). Overweight/obese patients were 25% more likely to undergo revision due to aseptic loosening, 9% more likely due to mechanical complications, 17% less likely due to periprosthetic fracture, and 24% less likely due to PJI. Morbidly obese patients were 20% more likely to undergo revision due to aseptic loosening, 5% more likely due to mechanical complications, and 6% less likely due to PJI. CONCLUSION: Mechanical reasons were more likely to be the cause of rTKA in overweight/obese and morbidly obese patients, compared to underweight patients, for whom revision was more likely to be infection or fracture related. Increased awareness of these differences may promote patient-specific management to reduce complications. LEVEL OF EVIDENCE: III.

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 < .001) and more femoral rollback (n = 2, P < .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.

Increased Patient-Level Payment After Removal of Total Knee Arthroplasty From the Inpatient-Only List.

BACKGROUND: In January 2018, the Centers for Medicare and Medicaid Services removed total knee arthroplasty (TKA) from the Inpatient Only (IPO) list. This study aimed to compare patient-level payments in TKA cases with a length of stay (LOS) <2 midnights before and after removal of TKA from IPO list. METHODS: In this retrospective cohort study, all Medicare patients who received a primary elective TKA from 2016-2019 with a LOS <2 midnights at an academic tertiary center were identified. Total and itemized charges and patient-level payments were compared between eligible TKA cases performed in 2016-2017 and those in 2018-2019. There were 351 eligible TKA cases identified: 151 in 2016-2017 and 200 in 2018-2019. RESULTS: The percentage of patients making any out-of-pocket payment increased in 2018-2019 from 2016-2017 (51.0% versus 10.6%), as did median patient-level payment ($7.30 [range, $0.00-$3,389] versus $0.00 [range, $0.00-$1,248], P < .001 for both). A greater proportion of patients in 2018-2019 paid $1-$50 than in 2016-2017 (37.5% versus 1.3%, P < .001) with no change in the proportion of patients who made payments >$50. Total charges were less in 2018-2019 than in 2016-2017 (P = .001). Charges for drugs, laboratory tests, admissions/floor, and therapies decreased in 2018-2019, whereas charges for the operating room and radiology increased (P < .001 for all). CONCLUSION: Patients receiving outpatient TKA in 2018-2019 were more likely to have out-of-pocket payments than patients with comparable hospital stay who were designated as inpatients, although most of these payments were less than $50.

Effects of Ramelteon on the Prevention of Postoperative Delirium in Older Patients Undergoing Orthopedic Surgery: The RECOVER Randomized Controlled Trial.

OBJECTIVES: Postoperative delirium, associated with negative consequences including longer hospital stays and worse cognitive and physical outcomes, is frequently accompanied by sleep-wake disturbance. Our objective was to evaluate the efficacy and short-term safety of ramelteon, a melatonin receptor agonist, for the prevention of postoperative delirium in older patients undergoing orthopedic surgery. DESIGN: A quadruple-masked randomized placebo-controlled trial (Clinical Trials.gov NCT02324153) conducted from March 2017 to June 2019. SETTING: Tertiary academic medical center. PARTICIPANTS: Patients aged 65 years or older, undergoing elective primary or revision hip or knee replacement. INTERVENTION: Ramelteon (8 mg) or placebo MEASUREMENTS: Eighty participants were randomized to an oral gel cap of ramelteon or placebo for 3 consecutive nights starting the night before surgery. Trained research staff conducted delirium assessments for 3 consecutive days starting on postoperative day (POD) 0, after recovery from anesthesia, and on to POD2. A delirium diagnosis was based upon DSM-5 criteria determined by expert panel consensus. RESULTS: Of 80 participants, five withdrew consent (one placebo, four ramelteon) and four were excluded (four ramelteon) after randomization. Delirium incidence during the 2 days following surgery was 7% (5 of 71) with no difference between the ramelteon versus placebo: 9% (3 of 33) and 5% (2 of 38), respectively. The adjusted odds ratio for postoperative delirium as a function of assignment to the ramelteon treatment arm was 1.28 (95% confidence interval: 0.21-7.93; z-value 0.27; p-value = 0.79). Adverse events were similar between the two groups. CONCLUSION: In older patients undergoing elective primary or revision hip or knee replacement, ramelteon was not efficacious in preventing postoperative delirium.

Temporal Association of Pain Catastrophizing and Pain Severity Across the Perioperative Period: A Cross-Lagged Panel Analysis After Total Knee Arthroplasty.

OBJECTIVE: Although numerous studies show that preoperative pain catastrophizing is a risk factor for pain after total knee arthroplasty (TKA), little is known about the temporal course of the association between perioperative pain catastrophizing and pain severity. The present study investigated temporal changes and their dynamic associations between pain catastrophizing and pain severity before and after TKA. DESIGN: A secondary data analysis of a larger observational parent study featuring prospective repeated measurement over 12 months. SETTING: Dual-site academic hospital. SUBJECTS: A total of 245 individuals who underwent TKA. METHODS: Participants completed pain catastrophizing and pain severity questionnaires at baseline, 6 weeks, and 3, 6, and 12 months after TKA. Cross-lagged panel analysis was conducted with structural equation modeling including age, sex, race, baseline anxiety, and depressive symptoms as covariates. RESULTS: Reduction in pain catastrophizing from baseline to 6 weeks after TKA was associated with lower pain severity at 3 months after TKA (standardized ß = 0.14; SE = 0.07, P = 0.046), while reduction in pain severity at 6 weeks after TKA was not associated with pain catastrophizing at 3 months after TKA (P = 0.905). In the chronic postsurgical period (>3 months), pain catastrophizing at 6 months after TKA predicted pain severity at 12 months after TKA (ß = 0.23, P = 0.009) with controlling for auto-correlation and covariates, but not vice versa. CONCLUSIONS: We provide evidence that changes in pain catastrophizing from baseline to 6 weeks after TKA are associated with subsequent pain severity. Future studies are warranted to determine whether targeting pain catastrophizing during the perioperative period may improve clinical outcomes for individuals undergoing TKA.

A Fall Within 3 Months Before Total Joint Arthroplasty is Associated With Adverse Outcomes in Elderly Patients.

BACKGROUND: Falls are associated with morbidity and death in the elderly. The consequences of falls after total joint arthroplasty (TJA) are known, but the consequences of preoperative falls are unclear. We assessed associations between preoperative fall history and hospital readmission rates and discharge disposition after primary TJA. METHODS: We queried the National Surgical Quality Improvement Program Geriatric Pilot Project for cases of primary total hip arthroplasty (THA) (n = 3671) and total knee arthroplasty (TKA) (n = 6194) performed between 2014 and 2018 for patients aged ≥65 years. Patient characteristics, comorbidities, functional status indicators, and 30-day outcomes were compared among patients with falls occurring within 3 months, from >3 to 6 months, and from >6 to 12 months before surgery, and patients with no falls in the year before surgery. The timing of falls was assessed for independent associations with hospital readmission and discharge to a skilled care facility (SCF). Alpha = 0.05. RESULTS: Patients who fell within 3 months before surgery had greater odds of SCF discharge (for THA, odds ratio [OR] 2.5, 95% confidence interval [CI] 1.8-3.4; for TKA, OR 1.8, 95% CI 1.4-2.3) and hospital readmission (for THA, OR 1.8, 95% CI 1.1-3.0; for TKA, OR 2.4, 95% CI 1.6-3.5) compared with the no-fall cohort. No such associations were observed for the other two fall cohorts. CONCLUSION: Falls within 3 months before primary TJA are associated with SCF discharge and readmission for patients aged ≥65 years. Fall history screening should be included in preoperative evaluation. LEVEL OF EVIDENCE: III.

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

BACKGROUND: As the incidence of total joint arthroplasty (TJA) increases, identifying methods for cost reduction is essential. Basic metabolic panels (BMPs) are obtained routinely after TJA. We aimed at assessing the prevalence of intervention secondary to abnormal BMPs after primary TJA and at identifying predictors of the need for postoperative BMPs. METHODS: We reviewed 802 cases (758 patients) of primary lower-extremity TJA performed from January 1 through December 31, 2018, at our tertiary care medical center. Patient characteristics, preoperative and postoperative BMPs, comorbidities, current medications, and in-hospital interventions were recorded. Age-adjusted Charlson Comorbidity Index (AA-CCI) values were calculated. Institutional costs of 1 BMP and of all BMPs not prompting intervention were calculated. We used multiple regression to identify independent predictors of in-hospital interventions secondary to abnormal postoperative BMPs. RESULTS: Our institutional BMP cost was $36. A total of 1032 postoperative BMPs were ordered; 958 (93%) prompted no intervention. This equated to $34,488 of avoidable BMP costs. We identified 27 cases (3.4%) requiring intervention secondary to abnormal BMPs. Independent predictors of intervention were preoperative renal dysfunction (ie, abnormal creatinine or glomerular filtration rate <60 mL/min) (odds ratio [OR], 7.8; 95% confidence interval [CI], 2.8-22), number of current nephrotoxic medications (OR, 1.9; 95% CI, 1.3-2.9), and AA-CCI value (OR, 1.2; 95% CI, 1.0-1.5). CONCLUSION: Routine postoperative BMPs are unwarranted for most patients undergoing primary TJA. Testing may be reserved for those with renal dysfunction, those taking multiple nephrotoxic medications, or those with a high AA-CCI value.

Moving Forward in Osteonecrosis: What Research Is Telling Us.

Osteonecrosis may afflict over 20 million patients worldwide. Prevention and treatment of osteonecrosis is dependent on a better understanding of the pathogenesis of the disease. Treatments range from observation with behavior modification to total joint replacement. As osteonecrosis patients are often relatively young, treatment options sparing the joint and reducing or delaying the need for joint replacement are essential. The results of joint sparing procedures are generally better if performed at early, precollapse stages. Approaches to treatment of early-stage disease are based upon the clinician's acceptance of one of the many hypotheses regarding the underlying pathophysiologic mechanisms involved. These mechanisms have been categorized as direct effects on cells or tissues, vascular interruption, intravascular occlusion, and intraosseous extravascular compression. While there has been a substantial increase in research regarding osteonecrosis, many questions remain to be answered concerning risk factors, pathophysiology, and nonsurgical and surgical interventions.

Augmented Reality for Acetabular Component Placement in Direct Anterior Total Hip Arthroplasty.

BACKGROUND: Malposition of the acetabular component of a hip prosthesis can lead to poor outcomes. Traditional placement with fluoroscopic guidance results in a 35% malpositioning rate. We compared the (1) accuracy and precision of component placement, (2) procedure time, (3) radiation dose, and (4) usability of a novel 3-dimensional augmented reality (AR) guidance system vs standard fluoroscopic guidance for acetabular component placement. METHODS: We simulated component placement using a radiopaque foam pelvis. Cone-beam computed tomographic data and optical data from a red-green-blue-depth camera were coregistered to create the AR environment. Eight orthopedic surgery trainees completed component placement using both methods. We measured component position (inclination, anteversion), procedure time, radiation dose, and usability (System Usability Scale score, Surgical Task Load Index value). Alpha = .05. RESULTS: Compared with fluoroscopic technique, AR technique was significantly more accurate for achieving target inclination (P = .01) and anteversion (P = .02) and more precise for achieving target anteversion (P < .01). AR technique was faster (mean ± standard deviation, 1.8 ± 0.25 vs 3.9 ± 1.6 minute; P < .01), and participants rated it as significantly easier to use according to both scales (P < .05). Radiation dose was not significantly different between techniques (P = .48). CONCLUSION: A novel 3-dimensional AR guidance system produced more accurate inclination and anteversion and more precise anteversion in the placement of the acetabular component of a hip prosthesis. AR guidance was faster and easier to use than standard fluoroscopic guidance and did not involve greater radiation dose.

Routine Preoperative Nutritional Screening in All Primary Total Joint Arthroplasty Patients Has Little Utility.

BACKGROUND: Nutritional optimization before total joint arthroplasty (TJA) may improve patient outcomes and decrease costs. However, the utility of serologic laboratory markers, including albumin, transferrin, and total lymphocyte count (TLC), as primary indicators of nutrition is unclear. We analyzed the prevalence of abnormal nutritional values before TJA and identified factors associated with them. METHODS: We retrospectively reviewed 819 primary cases of TJA performed at 1 institution from January to December 2018. Patient demographic characteristics were assessed for associations with abnormal preoperative nutritional values (albumin <3.5 g/dL, transferrin <200 mg/dL, and TLC <1.5 cells/µL3). Associations of comorbidities, American Society of Anesthesiologists Physical Status classification, and age-adjusted Charlson Comorbidity Index (CCI) with abnormal values were assessed with logistic regression. RESULTS: Values were abnormal for albumin in 21 cases (2.6%), transferrin in 26 cases (5.6%), and TLC in 185 cases (25%). Thirteen cases (1.7%) had abnormal values for 2 markers. Age was associated with abnormal albumin and TLC, and race with abnormal transferrin. Congestive heart failure, chronic kidney disease, pancreatic insufficiency, gastroesophageal reflux disease, osteoporosis, dementia, and CCI were associated with abnormal albumin; Parkinson disease and American Society of Anesthesiologists Physical Status with abnormal transferrin; and dementia, body mass index, cancer history, and CCI with abnormal TLC. CONCLUSION: We report low prevalence of and a low concordance rate among abnormal nutritional values before primary TJA. Our results suggest that routine testing of all healthy patients is not warranted before TJA.

Preoperative Patient Education Class During an Orthopedic Mission Trip: Effects on Knowledge, Anxiety, and Informed Consent.

BACKGROUND: Patient knowledge about arthritis and risks, benefits, and outcomes of joint arthroplasty in developing countries is unknown. We evaluated the effectiveness of a preoperative class on improving knowledge and decreasing anxiety during a surgical mission trip offering total joint arthroplasty. METHODS: A team of US health care providers taught a preoperative class to 41 patients selected for total joint arthroplasty during a surgical mission trip to Guyana. Participants completed a 32-point survey about arthritis; indications, risks, and benefits of joint arthroplasty; and postoperative, in-patient rehabilitation expectations. The State-Trait Anxiety Inventory was used to measure participant anxiety. Participants completed identical surveys before and after class. Matched-pairs Student t tests were used to compare means between preclass and postclass surveys. Significance was accepted at P < .05. RESULTS: Seventy-eight percent of patients (31 of 41) scored less than 12 of 32 possible points (40%) on the preclass knowledge questionnaire. Mean ± standard deviation knowledge scores improved from 14.0 ± 4.5 before the class to 16.5 ± 6.5 after the class (P = .008). Anxiety scores (n = 33) improved from 35 ± 13 before the class to 33 ± 12 after the class (P = .047). CONCLUSION: On this surgical mission trip, underserved patients' knowledge about total joint arthroplasty increased only modestly after taking a preoperative class. Greater understanding of how to educate patients and reduce their anxiety on medical missions is needed.

Humanitarian Needs: The Arthroplasty Community and the COVID-19 Pandemic.

BACKGROUND: As the world struggles with the COVID-19 pandemic, health care providers are on the front lines. We highlight the value of engaging in humanitarian medical work, contributions of the hip and knee arthroplasty community to date, and future needs after the resolution of the pandemic. We sought to understand how the arthroplasty community can contribute, based on historical lessons from prior pandemics and recessions, current needs, and projections of the COVID-19 impact. METHODS: We polled members of medical mission groups led by arthroplasty surgeons to understand their current efforts in humanitarian medical work. We also polled orthopedic colleagues to understand their role and response. Google Search and PubMed were used to find articles relevant to the current environment of the COVID-19 pandemic, humanitarian needs after previous epidemics, and the economic effects of prior recessions on elective surgery. RESULTS: Hip and knee arthroplasty surgeons are not at the center of the pandemic but are providing an invaluable supportive role through continued care of musculoskeletal patients and unloading of emergency rooms. Others have taken active roles assisting outside of orthopedics. Arthroplasty humanitarian organizations have donated personal protective equipment and helped to prepare their partners in other countries. Previous pandemics and epidemics highlight the need for sustained humanitarian support, particularly in poor countries or those with ongoing conflict and humanitarian crises. CONCLUSION: There are opportunities now to make a difference in this health care crisis. In the aftermath, there will be a great need for humanitarian work both here and throughout the world.