Increasing obesity and comorbidity in patients undergoing primary total hip arthroplasty in the U.S.: a 13-year study of time trends

Robot-Assisted Total Hip Arthroplasty is Associated with an Increased Risk of Periprosthetic Fracture

INTRODUCTION

Total Hip Arthroplasty (THA) aims to restore joint function and relieve pain. New technology, such as robot assistance, offers the potential to reduce human error, improve precision, and improve postoperative outcomes. The aim of this study was to compare outcomes between conventional and robot-assisted THA.

METHODS

This is a retrospective cohort study utilizing a national database from 2016 to 2019. Patients undergoing THA, conventional or robot-assisted, were identified via the International Classification of Diseases, Tenth Revision (ICD-10) code. Multivariate regressions were performed to assess outcomes between groups. Negative binomial regressions were performed to assess discharge disposition, readmission, and reoperation. Gamma regressions with log-link were used to assess total charges and lengths of hospital stays. Patient demographics and comorbidities, measured via the Elixhauser comorbidity index, were controlled for in our analyses. A total of 1,216,395 patients undergoing THA, 18,417 (1.51%) with robotic assistance, were identified.

RESULTS

Patients undergoing robot-assisted procedures had increased surgical complications (odds ratio (OR) 1.31 [95% CI (confidence interval) 1.14 to 1.53]; P < 0.001), including periprosthetic fracture (OR 1.63 [95% CI 1.35 to 1.98]; P < 0.001). Notably, these patients also had significantly greater total charges (OR 1.20 [95% CI 1.11 to 1.30]; P < 0.001).

CONCLUSION

Robotic assistance in THA is associated with an increased risk of surgical complications, including periprosthetic fracture, while incurring greater charges.

How Has the Total Hip Arthroplasty Patient Population Changed? A Ten-Year Analysis of Total Hip Arthroplasty Patients From 2013 to 2022: A Retrospective, Single-Center Study

BACKGROUND

Over the past decades, utilization of total hip arthroplasty (THA) has steadily increased. Understanding the demographic trends of THA patients can assist in projecting access to care. This study sought to assess the temporal trends in THA patient baseline characteristics and socioeconomic factors.

METHODS

We retrospectively analyzed 16,296 patients who underwent primary elective THA from January 1, 2013, to December 31, 2022. Demographic data, including age, sex, race, body mass index (BMI), Charlson comorbidity index, insurance, and socioeconomic status, as determined by median income by patients' zip code, were collected. The trends of these data were analyzed using the Mann-Kendall test.

RESULTS

Over the past decade at our institution, patient age (2013: 62.1 years to 2022: 65.1 years, P = .001), BMI (2013: 29.0 to 2022: 29.5, P = .020), and mean Charlson comorbidity index (2013: 2.4 to 2022: 3.1, P = .001) increased. The proportion of Medicare patients increased from 48.4% in 2013 to 54.9% in 2022 (P = .001). The proportion of African American patients among the THA population increased from 11.3% in 2013 to 13.0% in 2022 (P = .012). Over this period, 90-day readmission and 1-year revision rates did not significantly change (2013: 4.8 and 3.0% to 2022: 3.4 and 1.4%, P = .107 and P = .136, respectively). The proportion of operations using robotic devices also significantly increased (2013: 0% to 2022: 19.1%; P < .001).

CONCLUSIONS

In the past decade, the average age, BMI, and comorbidity burden of THA patients have significantly increased, suggesting improved access to care for these populations. Similarly, there have been improvements in access to care for African American patients. Along with these changes in patient demographics, we found no change in 90-day readmission or 1-year revision rates. Continued characterization of the THA patient population is vital to understanding this demographic shift and educating future strategies and improvements in patient care.

Global mapping of institutional and hospital-based (Level II-IV) arthroplasty registries: a scoping review

PURPOSE

Four joint arthroplasty registries (JARs) levels exist based on the recorded data type. Level I JARs are national registries that record primary data. Hospital or institutional JARs (Level II-IV) document further data (patient-reported outcomes, demographic, radiographic). A worldwide list of Level II-IV JARs must be created to effectively assess and categorize these data.

METHODS

Our study is a systematic scoping review that followed the PRISMA guidelines and included 648 studies. Based on their publications, the study aimed to map the existing Level II-IV JARs worldwide. The secondary aim was to record their lifetime, publications' number and frequency and recognise differences with national JARs.

RESULTS

One hundred five Level II-IV JARs were identified. Forty-eight hospital-based, 45 institutional, and 12 regional JARs. Fifty JARs were found in America, 39 in Europe, nine in Asia, six in Oceania and one in Africa. They have published 485 cohorts, 91 case-series, 49 case-control, nine cross-sectional studies, eight registry protocols and six randomized trials. Most cohort studies were retrospective. Twenty-three per cent of papers studied patient-reported outcomes, 21.45% surgical complications, 13.73% postoperative clinical and 5.25% radiographic outcomes, and 11.88% were survival analyses. Forty-four JARs have published only one paper. Level I JARs primarily publish implant revision risk annual reports, while Level IV JARs collect comprehensive data to conduct retrospective cohort studies.

CONCLUSIONS

This is the first study mapping all Level II-IV JARs worldwide. Most JARs are found in Europe and America, reporting on retrospective cohorts, but only a few report on studies systematically.

How are Oral Antibiotics Being Used in Total Joint Arthroplasty? A Review of the Literature

While the role and benefit of perioperative intravenous (IV) antibiotics in patients undergoing total joint arthroplasty (TJA) is well-established, oral antibiotic use in TJA remains a controversial topic with wide variations in practice patterns. With this review, we aimed to better educate the orthopedic surgeon on when and how oral antibiotics may be used most effectively in TJA patients, and to identify gaps in the literature that could be clarified with targeted research. Extended oral antibiotic prophylaxis (EOAP) use in high-risk primary, aseptic revision, and exchange TJA for infection may be useful in decreasing periprosthetic joint infection (PJI) rates. When prescribing oral antibiotics either as EOAP or for draining wounds, patient factors, type of surgery, and type of infectious organisms should be considered in order to optimally prevent and treat PJI. It is important to maintain antibiotic stewardship by administering the proper duration, dose, and type of antibiotics and by consulting infectious disease when necessary.

Trends in Extended Oral Antibiotic Prophylaxis Utilization Following Primary and Revision Total Hip Arthroplasty From 2010 to 2022

BACKGROUND

In patients considered high-risk for infection, extended oral antibiotic (EOA) prophylaxis has been demonstrated to reduce rates of prosthetic joint infection following total hip arthroplasty (THA). Although national guidelines regarding their use have not yet been created, the increase in literature surrounding EOA prophylaxis suggests a potential change in practice patterns. The purpose of this study was to investigate the trends in utilization of EOA prophylaxis following THA from 2010 to 2022 and identify prescription patterns.

METHODS

A total of 646,059 primary THA and 51,879 aseptic revision THA patients were included in this study. Patients who underwent primary or aseptic revision THA between 2010 and 2022 were identified in a national administrative claims database. Rates and duration of EOA prescriptions were calculated. A secondary analysis examined rates of utilization across demographics, including patients considered high risk for infection.

RESULTS

From 2010 to 2022, utilization of EOA increased by 366% and 298% following primary and revision THA, respectively. Of patients prescribed postoperative antibiotics, 30% and 59% were prescribed antibiotics for more than 7 days following primary and revision THA, respectively. Rates of utilization were similar between high-risk individuals and the general population.

CONCLUSIONS

Rates of utilization of EOA prophylaxis after THA have increased significantly since 2010. As current trends demonstrate a wide variation in prescription patterns, including in length of antibiotic duration and in patient population prescribed, guidelines surrounding the use of EOA prophylaxis after THA are necessary to promote antibiotic stewardship while preventing rates of periprosthetic joint infection.

The Use of Oral Antibiotics After Total Joint Arthroplasty: A Critical Analysis Review

» There is conflicting and insufficient evidence that extended oral antibiotic (EOA) therapy prevents infection in high-risk patients undergoing primary total joint arthroplasty (TJA), limiting recommendation for or against the practice.» In the case of aseptic revision TJA, the evidence is also conflicting and limited by underlying confounders, preventing recommendation for use of EOA.» There is fair evidence that use of EOA after debridement antibiotic therapy and implant retention of the prosthesis prolongs infection-free survival, but randomized controlled trials are needed. On the other hand, there is strong evidence that patients undergoing 2-stage revision should receive a period of suppressive oral antibiotics after the second stage.» The optimal duration of EOA in primary TJA, aseptic revision, and debridement antibiotic therapy and implant retention of the prosthesis is unknown. However, there is strong evidence that 3 months of EOA suppression may be appropriate after reimplantation as part of 2-stage exchange arthroplasty.» Complications secondary to EOA are reported to be between 0% and 13.7%, yet are inconsistently reported and poorly defined. The risks associated with antibiotic use, including development of antimicrobial resistance, must be weighed against a possible decrease in infection rate.

Epidemiological Characteristics and Trends of Primary Hip Arthroplasty in Five Tertiary Hospitals: A Multicenter Retrospective Study

OBJECTIVE

The number of primary hip arthroplasty (PHA) has increased sharply in recent years. Whether the epidemiological characteristics and trends of PHA have changed are unknown. This study aims to analyze the epidemiological characteristics and trends of those patients are urgent for public health institutions.

METHODS

The data of patients who underwent PHA in five tertiary hospitals from January 2011 to December 2020 were retrospectively reviewed. A total of 21,898 patients were included, most of whom were aged 60-69 years (25.1% males and 31.5% females). According to the hospitalization date, the patients were divided into two groups (Group A and Group B). The patients admitted between January 2011 and December 2015 were designated as Group A (7862), and those admitted between January 2016 and December 2020 were designated as Group B (14036). The patient data of the two groups, including sex, age, disease causes, body mass index (BMI), comorbidities, surgical procedures, hospital stay duration, and hospitalization costs, were analyzed by Pearson chi-Square test, Student t test or Mann-Whitney U test.

RESULTS

More women were included in Group B than in Group A (58.5% vs 52.5%, P < 0.001). The mean age of Group B was less than that of Group A (62.27 ± 14.77 vs 60.69 ± 14.44 years, P < 0.001). Femoral head necrosis was the primary pathogenic factor in both groups, with a higher proportion in Group B than in Group A (55.5% vs 45.5%, P < 0.001). Significant differences were found between the two groups in BMI, comorbidities, surgical procedures, hospital stay duration, and hospitalization costs. Total hip arthroplasty (THA) was the most common surgical procedure in both groups, with a higher proportion in Group B than in Group A (89.8% vs 79.3%, P < 0.001). The proportion of patients with one or more comorbidities was significantly higher in Group B than in Group A (69.2% vs 59.9%, P < 0.001). In addition, Group B had a shorter hospital stay duration and higher hospitalization costs than Group A.

CONCLUSION

Femoral head necrosis was the primary etiology for PHA in this study, followed by femoral neck fracture and hip osteoarthritis. Patients who underwent PHA exhibited a higher percentage of femoral head necrosis; underwent THA more often; and had larger BMIs, more comorbidities, higher medical costs, and younger age in the past decade.

Total Hip Arthroplasty in Patients With Neurological Conditions: A Systematic Review

Background

As operative techniques and implant design have evolved over time, total hip arthroplasty (THA) is increasingly being carried out for patients with neurological impairment. This patient group places unique surgical challenges to the arthroplasty surgeon, which may include contractures, instability, and altered muscular tone. The purpose of this systematic review is to report the patient outcomes, complications, and implant survival following THA for patients with neurological conditions affecting the hip. Thus, we aim to support orthopaedic surgeon decision-making when considering and planning THA for these patients.

Methods

A systematic review was performed as per Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using the PubMed/Medline OVID, Cochrane, and Embase databases. All studies reporting the outcomes of THA in the neurological population which met defined inclusion criteria were included.

Results

From an initial screen of 1820 studies, 45 studies with a total of 36,251 THAs were included in the final selection. All 45 studies reported complication rates, with controls included in 16 for comparison. High complication rates were observed following THA in the neurologically impaired population, most notably dislocation with observed rates up to 10.6%. An improvement was noted in all 36 studies (1811 THAs) which reported upon patient-reported outcomes.

Conclusions

THA may be beneficial in the selected patients with neurological conditions, to reduce pain and improve function. There is an increased risk of complications which require careful consideration when planning the operation and open discussion with prospective patients and caregivers before proceeding with surgery.

Trends of obesity rates between primary total hip arthroplasty patients and the general population from 2013 to 2020

Background

The prevalence of obesity in total hip arthroplasty (THA) patients has been studied in the past. However, there has not been direct comparison against obesity in the general population. This study compared yearly trends in BMI and obesity rates between patients who had undergone primary THA and those from the general patient population.

Methods

We retrospectively reviewed all patients over the age of 18 who underwent primary, elective THA and those who had an annual routine physical exam between January 2013 and December 2020 at our academic tertiary medical center. Baseline demographics were controlled in our statistical models. Significance of yearly trends was determined through a linear regression analysis. Independent samples t-test and Chi-square test were used to compare means and proportions between the two groups, respectively.

Results

A total of 11,250 primary THA patients and 1,039,918 annual physical exam patients were included. Average BMI for the THA group was significantly higher (P < 0.001) each year compared to the annual physicals group (APG). Higher obesity rates were observed in all obesity subgroups (all classes, and class I–III individually) for THA patients each year compared to the APG. Interestingly, while we found a significantly increasing trend in obesity for the general population (P < 0.001), BMI and obesity rates remained stable in the THA population.

Conclusion

While our general patient population showed significant increase in BMI and obesity over time, THA patients had higher, yet stable, BMI. Further investigation is required to determine the role of risk optimization in these findings.

Level III Evidence

Retrospective Cohort Study.

Management of Periprosthetic Acetabular Fractures: A Critical Analysis and Review of the Literature

➢

Periprosthetic acetabular fractures are uncommon and infrequently the focus of studies.

➢

Acetabular fractures are occasionally recognized postoperatively when patients report unremitting groin pain weeks after surgery.

➢

The widespread use of cementless acetabular cups might lead to a higher number of fractures than are clinically detectable.

➢

Appropriate recognition, including mindfulness of preoperative patient and surgical risk factors, is critical to the successful management of acetabular complications.

[Preoperative screening for risk factors]

The demographic change and continuously improving healthcare lead to increasing numbers of older, comorbid patients in elective orthopedic surgery. Perioperative risk assessment is crucial for patient counseling and preoperative planning. Risk factors, such as heart failure, chronic obstructive pulmonary disease, peripheral arterial occlusive disease, anemia, malnutrition, obesity, smoking and insufficiently controlled diabetes mellitus are common in patients undergoing elective orthopedic surgery. A thorough and early screening not only enables the individual assessment of the risk profile but in an elective setting also enables the chance for modification of certain risk factors in order to reduce the individual perioperative risk. Meanwhile, recommendations regarding risk stratification and adjustment of modifiable risk factors are included in national guidelines on the indications for elective total hip arthroplasty.

Are Body Mass Index Cutoffs Creating Racial, Ethnic, and Gender Disparities in Eligibility for Primary Total Hip and Knee Arthroplasty?

BACKGROUND

Unabated increases in the prevalence of obesity among American adults have disproportionately affected women, Black persons, and Hispanic persons. The purpose of this study was to evaluate for disparity in rates of patient eligibility for primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) based on race and ethnicity and gender by applying commonly used body mass index (BMI) eligibility criteria to two large national databases.

METHODS

We retrospectively reviewed data from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database for the years 2015-2019 for primary THA and TKA and the National Health and Nutrition Examination Survey (NHANES) from 2011-2018. Designations of race and ethnicity were standardized between cohorts. BMI cutoffs of <50 kg/m², <45 kg/m², <40 kg/m², and <35 kg/m² were then applied. Rates of eligibility for surgery were examined for each respective BMI cutoff and stratified by age, race and ethnicity, and gender.

RESULTS

143,973 NSQIP THA patients, 242,518 NSQIP TKA patients, and 13,255 NHANES participants were analyzed. Female patients were more likely to be ineligible for surgery across all cohorts for all modeled BMI cutoffs (P < .001 for all). Black patients had relatively lower rates of eligibility across all cohorts for all modeled BMI cutoffs (P < .0001 for all). Hispanic patients had disproportionately lower rates of eligibility only at a BMI cutoff of <35 kg/m².

CONCLUSION

Using BMI cutoffs alone to determine the eligibility for primary THA and TKA may disproportionally exclude women, Black persons, and Hispanic persons. These data raise concerns regarding further disparity and restriction of arthroplasty care to vulnerable populations that are already marginalized.

LEVEL OF EVIDENCE

Retrospective Cohort Study, Level III.

Effects of Hospital and Surgeon Volume on Patient Outcomes After Total Joint Arthroplasty: Reported From the American Joint Replacement Registry

BACKGROUND

The purpose of this study was to evaluate outcomes and complications because it relates to surgeon and hospital volume for patients undergoing primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) using the American Joint Replacement Registry from 2012 to 2017.

METHODS

A retrospective study was conducted on Medicare-eligible cases of primary elective THAs and TKAs reported to the American Joint Replacement Registry database and was linked with the available Centers of Medicaid and Medicare Services claims and the National Death Index data from 2012 to 2017. Surgeon and hospital volume were defined separately based on the median annual number of anatomic-specific total arthroplasty procedures performed on patients of any age per surgeon and per hospital. Values were aggregated into separate surgeon and hospital volume tertile groupings and combined to create pairwise comparison surgeon/hospital volume groupings for hip and knee.

RESULTS

Adjusted multivariable logistic regression analysis found low surgeon/low hospital volume to have the greatest association with all-cause revisions after THA (odds ratio [OR], 1.63, 95% confidence interval [CI], 1.41-1.89, P < 0.0001) and TKA (OR, 1.72, 95% CI, 1.44-2.06, P < 0.0001), early revisions because of periprosthetic joint infection after THA (OR, 2.50, 95% CI, 1.53-3.15, P < 0.0001) and TKA (OR, 2.18, 95% CI, 1.64-2.89, P < 0.0001), risk of early THA instability and dislocation (OR, 2.47, 95% CI, 1.77-3.46, P < 0.0001), and 90-day mortality after THA (OR, 1.72, 95% CI, 1.27-2.35, P = 0.0005) and TKA (OR, 1.47, 95% CI, 1.15-1.86, P = 0.002).

CONCLUSION

Our findings demonstrate considerably greater THA and TKA complications when performed at low-volume hospitals by low-volume surgeons. Given the data from previous literature including this study, a continued push through healthcare policies and healthcare systems is warranted to direct THA and TKA procedures to high-volume centers by high-volume surgeons because of the evident decrease in complications and considerable costs associated with all-cause revisions, periprosthetic joint infection, instability, and 90-day mortality.

LEVEL OF EVIDENCE

III.

Extended Postoperative Prophylactic Antibiotics for Primary and Aseptic Revision Total Joint Arthroplasty: A Systematic Review

INTRODUCTION

Limited literature is available about the effects of extended (>24 hours) antibiotic use after primary and aseptic revision total joint arthroplasty (TJA) on rates of periprosthetic joint infection (PJI). The purpose of this study was to systematically review the outcomes of extended prophylactic antibiotic use.

METHODS

A systematic search on PubMed and EMBASE databases was done in August 2021 following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Articles that met inclusion criteria were screened by two separate authors. Basic patient demographics, route of delivery, type, dose, frequency of the antibiotic, rates of PJI, and length of stay were extracted.

RESULTS

A total of 11 articles published from 1979 to 2021 were included in the final analysis. Two studies evaluated aseptic revisions, seven evaluated primary TJA, and two studies evaluated both. Five studies were randomized controlled trials, one multicenter nonrandomized trial, and five retrospective cohort studies. All 11 studies used a cephalosporin or a penicillin antibiotic in both the control and cohort groups. Five studies used intravenous (IV) antibiotics, one study used oral (PO) antibiotics, and the other five studies used both IV and PO antibiotics. Length of stay was reported in three studies, all using IV antibiotics. All 11 studies evaluated rates of PJI, while four studies evaluated included rates of superficial surgical site infections. Four studies showed a statistically significant decrease in PJI when compared with a control group, while seven studies showed no statistically significant difference.

CONCLUSION

There is conflicting evidence regarding the benefit of extended (>24 hours) antibiotics, IV or PO, after TJA. As of now, current guidelines do not support the use of extended antibiotics; future prospective clinical trials are needed to help support these claims.

Projected Prevalence of Obesity in Primary Total Hip Arthroplasty: How Big Will the Problem Get?

BACKGROUND

Obesity is associated with higher rates of adverse outcomes following primary total hip arthroplasty (THA). The purpose of this study is to utilize 3 national databases to develop projections of obesity within the general population and primary THA patients in the United States through 2029.

METHODS

Data from the National Surgical Quality Improvement Program (NSQIP), the Behavior Risk Factor Surveillance System (BRFSS), and the National Health and Nutrition Examination Survey were queried for years 1999-2019. Current Procedural Terminology code 27130 was used to identify primary THA patients in NSQIP. Individuals were categorized according to body mass index (kg/m²) by year: normal weight (≤24.9); overweight (25.0-29.9); obese (30.0-39.9); and morbidly obese (≥40). Multinomial logistic regression was used to project categorical body mass index data for years 2020-2029.

RESULTS

A total of 8,222,013 individuals were included (7,986,414 BRFSS, 235,599 NSQIP THA). From 2011 to 2019, the prevalence of normal weight and overweight individuals declined in the general population (BRFSS) and in primary THA. Prevalence of obese/morbidly obese individuals increased in the general population from 31% to 36% and in primary THA from 42% to 49%. Projection models estimate that by 2029, 46% of the general population will be obese/morbidly obese and 55% of primary THA will be obese/morbidly obese.

CONCLUSION

By 2029, we estimate ≥55% of primary THA to be obese/morbidly obese. Increased resources dedicated to care pathways and research focused on improving outcomes in obese arthroplasty patients will be necessary as this population continues to grow.

LEVEL OF EVIDENCE

Level III, Retrospective Cohort Study.

Documented and Undocumented Psychiatric Conditions Affect the Length of Stay and Discharge Disposition Following Total Hip Arthroplasty

BACKGROUND

Despite increased efforts toward patient optimization, some patients have undocumented conditions that can affect costs and quality metrics for institutions and physicians. This study evaluates the effect of documented and undocumented psychiatric conditions on length of stay (LOS) and discharge disposition following total hip arthroplasty (THA).

METHODS

A retrospective review of all primary THAs from 2015 to 2020 at a high-volume academic orthopedic specialty hospital was conducted. Patients were separated into 3 cohorts: patients with a documented psychiatric diagnosis (+Dx), patients without a documented psychiatric diagnosis but with an actively prescribed psychiatric medication (-Dx), and patients without a psychiatric diagnosis or medication (control). Patient demographics, LOS, and discharge disposition were assessed.

RESULTS

A total of 5309 patients were included; 3048 patients had no recorded psychiatric medications (control); 2261 patients took at least 1 psychiatric medication, of which 1513 (65.9%) and 748 (34.1%) patients were put in the -Dx and +Dx cohorts, respectively. American Society of Anesthesiologists class differed between groups (P < .001). The -Dx and +Dx groups had increased LOS (3.15 ± 2.37 [75.6 ± 56.9] and 3.12 ± 2.27 [74.9 ± 54.5] vs 2.42 ± 1.70 [57.6 ± 40.8] days (hours), P < .001) and were more likely to be discharged to a secondary facility (23.0% and 21.7% vs 13.8%, P < .001) than the control group. Outcomes did not significantly differ between the -Dx and +Dx cohorts.

CONCLUSION

Most THA patients' psychiatric diagnoses were not documented. The presence of psychiatric medications was associated with longer LOS and a greater likelihood of discharge to secondary facilities. This has implications for both cost and quality metrics. Review of medications can help identify and optimize these patients before surgery.

LEVEL III EVIDENCE

Retrospective Cohort Study.

[Risk management in orthopedic surgery : Stratification and adjustment of patient-individual risk factors]

Preoperative identification of patients at risk of postoperative complications enables better patient education and surgical planning for the orthopedic surgeon. In addition to demographic and intervention-specific factors, a variety of instruments are available for individual risk assessment. The concept of frailty seems to be promising to identify patients at risk. Modifiable risk factors such as malnutrition, anemia, obesity, smoking, and insufficiently controlled diabetes mellitus are common in elective orthopedic patients. With the use of screening protocols, modifiable risk factors can be identified and optimized preoperatively in order to reduce the individual risk of complications. Recommendations regarding preoperative risk stratification and modification prior to elective hip replacement have meanwhile been incorporated in national guidelines.

Diagnosis and Management of Intraoperative Fractures in Primary Total Hip Arthroplasty

Intraoperative periprosthetic fractures are challenging complications that may affect implant stability and survivorship. Periprosthetic acetabular fractures are uncommon and infrequently are the focus of studies. Acetabular fractures are occasionally recognized after patients report unremitting groin pain weeks postoperatively. The widespread use of cementless acetabular cups might lead to higher number of fractures than is clinically detectable. Conversely, the incidence of intraoperative periprosthetic femoral fractures are more common and encompass a broad spectrum, ranging from a small cortical perforation to displaced fractures with an unstable prosthesis. Appropriate recognition, including mindfulness of preoperative patient and surgical risk factors, is critical to the successful management of acetabular and femoral complications. This comprehensive review article focuses on the incidence, patient and surgical risk factors, diagnosis, management, and clinical outcomes associated with intraoperative acetabular and femur fractures in primary total hip arthroplasty.

Hospital Frailty Risk Score Outperforms Current Risk Stratification Models in Primary Total Hip and Knee Arthroplasty

BACKGROUND

Models for risk stratification and prediction of outcome, such as the Charlson Comorbidity Index (CCI), the Elixhauser Comorbidity Method (ECM), the 5-factor modified Frailty Index (mFI-5), and the Hospital Frailty Risk Score (HFRS) have been validated in orthopedic surgery. The aim of this study is to compare the predictive power of these models in total hip and knee replacement.

METHODS

In a retrospective analysis of 8250 patients who had undergone total joint replacement between 2011 and 2019, CCI, ECM, mFI-5, and HFRS were calculated for each patient. Receiver operating characteristic curve plots were generated and the area under the curve (AUC) was compared between each score with regard to adverse events such as transfusion, surgical, medical, and other complications. Multivariate logistic regression models were used to assess the relationship among risk stratification models, demographic factors, and postoperative adverse events.

RESULTS

In prediction of surgical complications, HFRS performed best (AUC: 0.719, P < .001), followed by ECM (AUC: 0.578, P < .001), mFI-5 (AUC: 0.564, P = .003), and CCI (AUC: 0.555, P = .012). With regard to medical complications, other complications, and transfusion, HFRS also was superior to ECM, mFI-5, and CCI. Multivariate logistic regression analyses revealed HFRS as an independent risk stratification model associated with all captured adverse events (P ≤ .001).

CONCLUSION

The HFRS is superior to current risk stratification models in the context of total joint replacement. As the HRFS derives from routinely collected administrative data, healthcare providers can identify at-risk patients without additional effort or expense.

Occlusion of an Aortobifemoral Graft after Revision Total Hip Arthroplasty

With the aging population, the demand for total hip arthroplasty is rising. Improvements in arthroplasty techniques and design allow for total hip arthroplasty to be increasingly performed in older patients and those with multiple comorbidities. Complications are rare in young and healthy patients; however, there is greater risk in patients with multiple medical comorbidities and those who have had prior revision procedures. Large-vessel thrombosis is an especially rare, but potentially devastating, complication, particularly in patients with existing major-vessel bypass grafts. Only 3 case reports of major-vessel graft occlusion after total hip arthroplasty have been reported in the literature, and none after revision. In this article, we report a case of occlusion of an aortobifemoral graft after revision total hip arthroplasty for periprosthetic joint infection.

Hospital Frailty Risk Score Predicts Adverse Events in Primary Total Hip and Knee Arthroplasty

BACKGROUND

The Hospital Frailty Risk Score (HFRS) is a validated geriatric comorbidity measure derived from routinely collected administrative data. The purpose of this study is to evaluate the utility of the HFRS as a predictor for postoperative adverse events after primary total hip (THA) and knee (TKA) arthroplasty.

METHODS

In a retrospective analysis of 8250 patients who had undergone THA or TKA between 2011 and 2019, the HFRS was calculated for each patient. Reoperation rates, readmission rates, complication rates, and transfusion rates were compared between patients with low and intermediate or high frailty risk. Multivariate logistic regression models were used to assess the relationship between the HFRS and postoperative adverse events.

RESULTS

Patients with intermediate or high frailty risk showed a higher rate of reoperation (10.6% vs 4.1%, P < .001), readmission (9.6% vs 4.3%, P < .001), surgical complications (9.1% vs 1.8%, P < .001), internal complications (7.3% vs 1.1%, P < .001), other complications (24.4% vs 2.0%, P < .001), Clavien-Dindo grade IV complications (4.1% vs 1.5%, P < .001), and transfusion (10.4% vs 1.3%, P < .001). Multivariate logistic regression analyses revealed a high HFRS as independent risk factor for reoperation (odds ratio [OR] = 2.1; 95% confidence interval [CI], 1.46-3.09; P < .001), readmission (OR = 1.78; 95% CI, 1.21-2.61; P = .003), internal complications (OR = 3.72; 95% CI, 2.28-6.08; P < .001), surgical complications (OR = 3.74; 95% CI, 2.41-5.82; P < .001), and other complications (OR = 9.00; 95% CI, 6.58-12.32; P < .001).

CONCLUSION

The HFRS predicts adverse events after THA and TKA. As it derives from routinely collected data, the HFRS enables hospitals to identify at-risk patients without extra effort or expense.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

Ten-year risk of complication and mortality after total hip arthroplasty in morbidly obese patients: a population study

Background

The relationship between morbid obesity and long-term patient outcomes after primary total hip arthroplasty (THA) has been understudied. The purpose of this study was to determine the association between morbid obesity and 10-year complications (revision surgery, reoperation, dislocation) and mortality in patients undergoing primary THA.

Methods

We conducted a population-based cohort study of patients aged 45–74 years who underwent primary THA for osteoarthritis between 2002 and 2007 using Ontario administrative health care databases. Patients were followed for 10 years. We estimated risk ratios (RRs) of mortality, reoperation, revision and dislocation in patients with body mass index (BMI) greater than 45 kg/m2 (morbidly obese patients) compared with patients with a BMI of 45 kg/m2 or less (nonmorbidly obese patients).

Results

There were 22 251 patients in the study cohort, of whom 726 (3.3%) were morbidly obese. Morbid obesity was associated with higher 10-year risk of death (RR 1.38, 95% confidence interval [CI] 1.18–1.62). Risks of revision (RR 1.43, 95% CI 0.96–2.13) and dislocation (RR 2.38, 95% CI 1.38–4.10) were higher in morbidly obese men than in nonmorbidly obese men; there were no associations between obesity and revision or dislocation in women. Risk of reoperation was higher in morbidly obese women than in nonmorbidly obese women (RR 1.59, 95% CI 1.05–2.40); there was no association between obesity and reoperation in men.

Conclusion

Morbidly obese patients undergoing primary THA are at higher risk of long-term mortality and complications. There were differences in complication risk by sex. The results of this study should inform perioperative counselling of patients considering THA.

Declining early mortality after hip and knee arthroplasty

BACKGROUND

We aimed to measure the period effect (change over time) in 30-day mortality after total hip arthroplasty (THA) and total knee arthroplasty (TKA) using data from the Australian Orthopaedic Association National Joint Replacement Registry.

METHODS

We performed an observational study using national registry data from all hospitals performing THA and TKA in Australia including people undergoing primary elective conventional THA and TKA for osteoarthritis from 2003 to 2017, inclusive. Data from the Australian Orthopaedic Association National Joint Replacement Registry, the National Death Index and the Australian Bureau of Statistics were used to generate unadjusted 30-day mortality, the incident rate ratio for mortality adjusted for age and gender, and the standardized mortality ratio at 30 days for each year separately.

RESULTS

For the years 2003 and 2017, respectively, for THA, the unadjusted 30-day mortality was 0.23% and 0.06%, and the standardized mortality ratio was 1.11 (95% CI: 0.73, 1.49) and 0.38 (95% CI: 0.16, 0.59). The incident rate ratio was significantly higher than the reference year (2017) from 2003 to 2010, and for 2012, 2013 and 2016, decreasing over time. For the years 2003 and 2017, respectively, for TKA, the unadjusted 30-day mortality was 0.17% and 0.08%, and the standardized mortality ratio was 0.84 (95% CI: 0.55, 1.13) and 0.61 (95% CI: 0.38, 0.83). The incident rate ratio was significantly higher than the reference year (2017) from 2003 to 2009 inclusive, decreasing over time.

CONCLUSIONS

Thirty-day mortality after THA and TKA declined from 2003 to 2017. This may be due to improvements in intra-operative and post-operative patient management.

Have We Actually Reduced Our 30-Day Short-Term Surgical Site Infection Rates in Primary Total Hip Arthroplasty in the United States?

BACKGROUND

The purpose of this study is to track the 30-day postoperative annual rates and trends of (1) overall, (2) deep, and (3) superficial surgical site infections (SSIs) following total hip arthroplasty (THA) using a large nationwide database.

METHODS

The National Surgical Quality Improvement Program database was queried for all THA cases performed between 2012 and 2016. After an overall 5-year correlation and trends analysis, univariate analysis was performed to compare the most recent year, 2016, with the preceding 4 years. Correlation coefficients and chi-squared tests were used to determine correlation and statistical significance.

RESULTS

The lowest incidence of SSIs was in the most recent year, 2016 (0.81%), while the greatest incidence was in the earliest year, 2012 (1.12%), marking a 31% decrease (P < .01). The lowest rate was in the most recent year, 2016 (0.23%), marking a 26% decrease from 2012. The lowest superficial SSI incidence occurred in the most recent year, 2016 (0.58%), while greatest incidence was in 2012 (0.83%), marking a 31% decrease over time (P < .05). There was an inverse correlation among overall, deep, and superficial SSI rates with operative year.

CONCLUSION

The findings from this study suggest a decreasing trend in SSIs within 30 days following THA. Furthermore, deep SSIs, which can pose substantial threats to implant survivorship, have also decreased throughout the years. These results highlight that potentially through improved medical and surgical techniques, we are winning the fight against short-term infections, but that more can still be done.

Trends in total knee and hip arthroplasty recipients: a retrospective cohort study

Background

Arthroplasty is one of the most commonly performed procedures in the USA with projections of continuous growth. As this field undergoes continuous changes, the goal of this study was to provide an analysis of patient-related and healthcare system-related trends. This is important as it allows practitioners, administrators and policy makers to allocate needed resources appropriately.

Methods

The study included total knee arthroplasty (TKA) and total hip arthroplasty (THA) procedures from 2006 to 2016. Demographic information, comorbidities and complications were extracted and analyzed from the Premier Healthcare database.

Results

The surgical volume increased annually over the observation period by an average of 5.54% for TKA and 7.02% for THA, respectively. The average age of the patient population and the types of anesthesia used remained relatively consistent over time. Comorbidity burden increased, especially for obesity (16.52% in 2006 and 29.77% in 2016 for TKA, 11.15% in 2006 and 20.92% in 2016 for THA), obstructive sleep apnea (OSA) (6.82% in 2006 and 17.03% in 2016 for TKA, 4.69% in 2006 and 12.72% in 2016 for THA) and renal insufficiency (2.81% in 2006 and 7.01% in 2016 for TKA, 2.78% in 2006 and 6.43% in 2016 for THA). Minor trends of increases were also observed in the prevalence of liver disease, depression and hypothyroidism. All postoperative complications were trending lower except for acute renal failure, where an increase was noted (4.39% in 2006 and 8.10% in 2016 for TKA, 4.99% in 2006 and 8.42% in 2016 for THA).

Discussion

Significant trends in the care of patients who undergo TKA and THA were identified. Individuals undergoing these procedures presented with a higher prevalence of comorbidities. Despite these trajectories, complications declined over time. These data can be used to inform future research and to allocate resources to address changes in populations cared for and complications encountered.

Body mass index is associated with risk of reoperation and revision after primary total hip arthroplasty: a study of the Swedish Hip Arthroplasty Register including 83,146 patients

Background and purpose - The prevalence of obesity is on the rise, becoming a worldwide epidemic. The main purpose of this register-based observational study was to investigate whether different BMI classes are associated with increased risk of reoperation within 2 years, risk of revision within 5 years, and the risk of dying within 90 days after primary total hip arthroplasty (THA). We hypothesized that increasing BMI would increase these risks. Patients and methods - We analyzed a cohort of 83,146 patients who had undergone an elective THA for primary osteoarthritis between 2008 and 2015 from the Swedish Hip Arthroplasty Register (SHAR). BMI was classified according to the World Health Organization (WHO) into 6 classes: < 18.5 as underweight, 18.5-24.9 as normal weight, 25-29.9 as overweight, 30-34.9 as class I obesity, 35-39.9 as class II obesity, and ≥ 40 as class III obesity. Results - Both unadjusted and adjusted parameter estimates showed increasing risk of reoperation at 2 years and revision at 5 years with each overweight and obesity class, mainly due to increased risk of infection. Uncemented and reversed hybrid fixations and surgical approaches other than the posterior were all associated with increased risk. Obesity class III (≥ 40), male sex, and increasing ASA class were associated with increased 90-day mortality. Interpretation - Increasing BMI was associated with 2-year reoperation and 5-year revision risks after primary THA where obese patients have a higher risk than overweight or normal weight patients. As infection seems to be the main cause, customizing preoperative optimization and prophylactic measures for obese patients may help reduce risk.

The Effect of Patient Characteristics on 1 to 2-Year and Minimum 5-Year Outcomes After Total Ankle Arthroplasty

BACKGROUND

Total ankle arthroplasty has shown durable improvements in patient-reported outcomes. However, the impact of common comorbidities and patient factors has not been fully characterized. The purpose of this study was to identify patient comorbidities and characteristics that impact outcomes after total ankle arthroplasty.

METHODS

Patients who underwent a total ankle arthroplasty between January 2007 and December 2016 were enrolled into a prospective study at a single academic center. Patients completed outcome measures before the surgical procedure and at the time of follow-up: a visual analog scale (VAS) for pain, the 36-item Short Form Survey (SF-36), and the Short Musculoskeletal Function Assessment (SMFA). Patient and operative factors, along with prevalent preoperative comorbidities, were analyzed for association with preoperative to postoperative changes in 1 to 2-year and minimum 5-year outcomes. Comorbidities that met a significance threshold of p < 0.05 in adjusted analyses were incorporated into multivariable outcome models.

RESULTS

A total of 668 patients with a mean 1 to 2-year follow-up (and standard deviation) of 1.6 ± 0.5 years (range, 10 months to 2 years and 2 months) were included. Patients' pain and function significantly improved across all outcomes (p < 0.05). However, depression, staged bilateral ankle arthroplasty, increased length of stay, a prior surgical procedure, increased American Society of Anesthesiologists (ASA) score, and particular implant types were associated with significantly smaller improvements in at least 1 patient-reported outcome after total ankle arthroplasty in the 1 to 2-year follow-up, although the effects were relatively small. At a minimum 5-year follow-up, smoking, depression, implant type, and staged bilateral ankle arthroplasty were associated with worse outcomes, and a prior surgical procedure, a simultaneous bilateral surgical procedure, and obesity were associated with improved outcomes.

CONCLUSIONS

Patients who underwent total ankle arthroplasty had significant improvement in patient-reported outcomes, although several factors were associated with a small, but significant, negative impact on improvement, including depression, increased ASA score, current smoking, increased length of stay, a prior surgical procedure, and staged bilateral total ankle arthroplasty. Current smoking, obesity, and depression are potentially modifiable risk factors that could be improved prior to total ankle arthroplasty. Patients with these characteristics should be counseled on their risk of limited improvement in ankle pain and disability after total ankle arthroplasty.

LEVEL OF EVIDENCE

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

Possible Implications for Bundled Payment Models of Comorbidities and Complications as Drivers of Cost in Total Ankle Arthroplasty

BACKGROUND:

The Comprehensive Care for Joint Replacement (CJR) model provides bundled payments for in-hospital and 90-day postdischarge care of patients undergoing total ankle arthroplasty (TAA). Defining patient factors associated with increased costs during TAA could help identify modifiable preoperative patient factors that could be addressed prior to the patient entering the bundle, as well as determine targets for cost reduction in postoperative care.

METHODS:

This study is part of an institutional review board-approved single-center observational study of patients undergoing TAA from January 1, 2012, to December 15, 2016. Patients were included if they met CJR criteria for inclusion into the bundled payment model. All Medicare payments beginning at the index procedure through 90 days postoperatively were identified. Patient, operative, and postoperative characteristics were associated with costs in adjusted, multivariable analyses. One hundred thirty-seven patients met inclusion criteria for the study.

RESULTS:

Cerebrovascular disease (intracranial hemorrhages, strokes, or transient ischemic attacks) was initially associated with increased costs (mean, $5595.25; 95% CI, $1710.22-$9480.28) in adjusted analyses ( P = .005), though this variable did not meet a significance threshold adjusted for multiple comparisons. Increased length of stay, discharge to a skilled nursing facility (SNF), admissions, emergency department (ED) visits, and wound complications were significant postoperative drivers of payment.

CONCLUSION:

Common comorbidities did not reliably predict increased costs. Increased length of stay, discharge to an SNF, readmission, ED visits, and wound complications were postoperative factors that considerably increased costs. Lastly, reducing the rates of SNF placement, readmission, ED visitation, and wound complications are targets for reducing costs for patients undergoing TAA.

LEVEL OF EVIDENCE:

Level II, prognostic prospective cohort study.

Obesity and racial characteristics drive utilization of total joint arthroplasty at a younger age

BACKGROUND

Obesity is a growing public health problem. Obesity increases the risk of requiring total joint arthroplasty (TJA). The purpose of this study was to examine the effect of obesity on the propensity for TJA in patients at our institution. We hypothesized that obese patients would be younger and more likely to be races other than non-Hispanic whites when compared to a normal weight cohort.

METHODS

568 consecutive patients undergoing primary TJA were reviewed. Demographic data and World Health Organization Body Mass Index (BMI) class were compared statistically, with age at time of TJA used as the main outcome of interest.

RESULTS

The average age at TKA was 68.3 years, while the average age at THA was 67.5 years (p = 0.447 between procedure groups). Increased BMI class was associated with decreased age at TJA: normal weight patients were 12.2 and 11.4 years older than class III obese patients at the time of TKA and THA, respectively (p < 0.001). Among TKA patients, obese patients, when compared to non-obese patients, were significantly less likely to be non-Hispanic whites (p = 0.016). Among THA patients, class III obese patients were significantly less likely to be non-Hispanic whites (p = 0.007).

CONCLUSIONS

Obesity is a risk factor for both TKA and THA at a younger age. For patients in the study, for each unit increase in BMI, the age at TKA decreased by 0.56 years and age at THA decreased by 0.52 years. Obese patients were less likely to be non-Hispanic whites than normal weight patients.

Extended Oral Antibiotic Prophylaxis in High-Risk Patients Substantially Reduces Primary Total Hip and Knee Arthroplasty 90-Day Infection Rate

BACKGROUND

Total joint arthroplasty (TJA) episodic payment models shift risk and cost of periprosthetic joint infection (PJI) to surgeons and hospitals, causing some to avoid treating high-risk patients. Furthermore, there are little data to support optimization of host factors preoperatively to decrease PJI, and recent literature supports using extended antibiotic prophylaxis following reimplantation TJA. The purpose of this study was to evaluate whether extended oral antibiotic prophylaxis minimized PJI after primary TJA in high-risk patients.

METHODS

A retrospective cohort study was performed of 2,181 primary total knee arthroplasties (TKAs) and primary total hip arthroplasties (THAs) carried out from 2011 through 2016 at a suburban academic hospital with modern perioperative and infection-prevention protocols. Beginning in January 2015, extended oral antibiotic prophylaxis for 7 days after discharge was implemented for patients at high risk for PJI. The percentages of patients diagnosed with PJI within 90 days were identified and compared between groups that did and did not receive extended oral antibiotic prophylaxis, with p ≤ 0.05 indicating significance.

RESULTS

The 90-day infection rates were 1.0% and 2.2% after the TKAs and THAs, respectively. High-risk patients without extended antibiotic prophylaxis were 4.9 (p = 0.009) and 4.0 (p = 0.037) times more likely to develop PJI after TKA and THA, respectively, than high-risk patients with extended antibiotic prophylaxis.

CONCLUSIONS

Extended postoperative antibiotic prophylaxis led to a statistically significant and clinically meaningful reduction in the 90-day infection rate of selected patients at high risk for infection. We encourage further study and deliberation prior to adoption of a protocol involving extended oral antibiotic prophylaxis after high-risk TJA, with the benefits weighed appropriately against potential adverse consequences such as increasing the development of antimicrobial resistance.

LEVEL OF EVIDENCE

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

The Association of Body Mass Index with Risk of Long-Term Revision and 90-Day Mortality Following Primary Total Hip Replacement: Findings from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man

BACKGROUND

The influence of obesity on outcomes following total hip replacement is unclear. Restriction of total hip replacement on the basis of body mass index (BMI) has been suggested. The purpose of this study was to assess the influence of BMI on the risk of revision and 90-day mortality.

METHODS

This was a population-based, longitudinal cohort study of the National Joint Registry (NJR) for England, Wales, Northern Ireland and the Isle of Man. Using data recorded from April 2003 to December 2015, linked to Office for National Statistics data, we ascertained revision and 90-day mortality rates following primary total hip replacement by BMI category. The probability of revision was estimated using Kaplan-Meier methods. Associations of BMI with revision and mortality were explored using adjusted Cox proportional hazards regression models.

RESULTS

We investigated revision and 90-day mortality among 415,598 and 413,741 primary total hip replacements, respectively. Each data set accounts for approximately 52% of the total number of recorded operations in the NJR. Thirty-eight percent of the patients were classified as obese. At 10 years, class-III obese patients had the highest cumulative probability of revision (6.7% [95% confidence interval (CI), 5.5% to 8.2%]), twice that of the underweight group (3.3% [95% CI, 2.2% to 4.9%]). When the analysis was adjusted for age, sex, American Society of Anesthesiologists [ASA] grade, year of operation, indication, and fixation type, compared with patients with normal BMI, significantly elevated hazard ratios (HRs) for revision were observed for patients in the BMI categories of class-I obese (≥30 to <35 kg/m) (HR, 1.14 [95% CI, 1.07 to 1.22]), class-II obese (≥35 to <40 kg/m) (HR, 1.30 [95% CI, 1.19 to 1.40]), and class-III obese (≥40 to ≤60 kg/m) (HR, 1.43 [95% CI, 1.27 to 1.61]) (p < 0.0005 for all). Underweight patients had a substantially higher cumulative probability of 90-day mortality (1.17%; 95% CI, 0.86% to 1.58%) compared with patients with normal BMI (0.43%; 95% CI, 0.39% to 0.48%). The risk of 90-day mortality was significantly higher for the underweight group (HR, 2.09 [95% CI, 1.51 to 2.89]; p < 0.0005) and significantly lower for patients who were categorized as overweight (HR, 0.70; 95% CI, 0.61 to 0.81; p < 0.0005), class-I obese (HR, 0.69 [95% CI, 0.59 to 0.81]; p < 0.0005), and class-II obese (HR, 0.79 [95% CI, 0.63 to 0.98]; p = 0.049) compared with patients with normal BMI.

CONCLUSIONS

Although long-term revision rates following total hip replacement were higher among obese patients, we believe that the rates remained acceptable by contemporary standards and were balanced by a lower risk of 90-day mortality.

LEVEL OF EVIDENCE

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

Cemented conical stems can be removed more easily than cylindrical stems, regardless of cone angle in revision knee arthroplasty

BACKGROUND

According to literature, more than 30% of revised knee arthroplasties will require at least one re-revision. Practical experience has shown that there are considerable product-specific differences in the explantability of cemented long-stem prostheses. In the registers of successful implants, stem geometry varies considerably between the manufacturers. However, comparative data on explantability of the respective stems are missing. Objective of the present study was to identify a correlation between the geometry of a smooth cemented long stem and the necessary explantation energy required until failure of the implant-cement interface occurs.

METHODS

Eight cemented stems with different conical profile angles (0°-3°) were explanted in a reproducible biomechanical setup each six times to evaluate the correlation between the stem design and the required explantation energy.

RESULTS

The average explantation energy was highest in the case of the cylindrical stem, at 18.1 ± 3.6 J. At a cone angle of 0.25°, it was just 12.1 ± 2.1 J (p < 0.001) and dropped beyond 0.5° to an average of 5.7 ± 1.8 J (p < 0.001). Between 0.5° and 3°, no significant difference in the required extraction energy was observed.

CONCLUSIONS

Whereas smooth conical stems can mostly be removed easily, an early decision in favour of osteotomy or fenestration can be taken in the case of cylindrical cemented stems.

Trends in Inpatient Resource Utilization and Complications Among Total Joint Arthroplasty Recipients: A Retrospective Cohort Study

Introduction:

Joint arthroplasty practice is highly dynamic to adapt to economic changes and advances in medicine. This study provides updates of the current perioperative practice on healthcare resource utilization.

Methods:

The study included total knee arthroplasty, total hip arthroplasty, and total shoulder arthroplasty within the healthcare cost and utilization project New York State database from 2007 to 2013 (ie, 202,100, 127,872, and 8858 cases, respectively).

Results:

A higher proportion of sicker patients were prevalent over time. The length of stay decreased continuously. However, total hospital charges increased after adjusting for inflation. The incidence of wound infection and transfusion decreased steadily over time, whereas acute renal failure has been on the rise. There was an increased utilization of echocardiography, while decreased among other resources.

Discussion:

Total knee arthroplasty, total hip arthroplasty, and total shoulder arthroplasty changed toward sicker patients with shorter length of stay, fewer complications, and less resource utilization. However, overall costs increased over time.

Patient Risk Factors Do Not Impact 90-Day Readmission and Emergency Department Visitation After Total Ankle Arthroplasty: Implications for the Comprehensive Care for Joint Replacement (CJR) Bundled Payment Plan

BACKGROUND

The Comprehensive Care for Joint Replacement (CJR) model provides bundled payments for in-hospital care and care within 90 days following discharge for Medicare beneficiaries undergoing lower-extremity joint replacement involving the hip, knee, or ankle (total hip arthroplasty, total knee arthroplasty, or total ankle arthroplasty [TAA]). The study hypothesis was that patient comorbidities are associated with readmissions, emergency department (ED) utilization, and subspecialist wound-healing consultation, which are examples of costly contributors to postoperative health-care spending.

METHODS

The medical records for 1,024 patients undergoing TAAs between June 2007 and December 2016 at a single academic center in the southeastern United States were reviewed for the outcomes of readmissions, ED visitations, and subspecialist wound-healing consultation within the 90-day post-discharge period. All patients undergoing TAA (n = 1,365) were eligible. Of the 1,037 patients who consented to participation in the study and underwent TAA, 1,024 (98.7%) completed the study. Medical comorbidities according to the Elixhauser and Charlson-Deyo comorbidity indices that were present prior to TAA were recorded. Univariate and multivariable tests of significance were used to relate patient and operative characteristics to outcomes.

RESULTS

Four hundred and ninety-six (48.4%) of the 1,024 patients were female, and 964 (94.1%) were white/Caucasian, with an average age (and standard deviation) of 63 ± 10.5 years. Hypertension, obesity, solid tumor, depression, rheumatic disease, cardiac arrhythmia, hypothyroidism, diabetes mellitus, and chronic pulmonary disease had a prevalence of >10%. Fifty-three (5.2%) of the 1,024 patients were readmitted for any cause. Thirty-six (3.5%) of the 1,024 returned to the ED but were not admitted to the hospital. Readmission or ED visitation was most commonly for a wound complication, followed by deep venous thrombosis (DVT) and pulmonary embolism (PE) evaluation, while urgent medical evaluations composed the majority of non-TAA-related ED visitations. No patient comorbidities were significantly associated with 90-day readmission, ED visitation, or wound complications in multivariable models.

CONCLUSIONS

Patient comorbidities were not associated with 90-day hospital readmissions or ED visitation for patients undergoing TAA. Readmissions were dominated by evaluation of wound compromise as well as DVT and PE. These data suggest that there may be considerable differences between TAA and total hip arthroplasty or total knee arthroplasty that cause surgeons to question the inclusion of TAA in CJR bundled payment models.

LEVEL OF EVIDENCE

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

Impact of comorbid conditions on outcomes of hip and knee replacement surgery: a systematic review and meta-analysis

OBJECTIVE

To systematically perform a meta-analysis of the association between different comorbid conditions on safety (short-term outcomes) and effectiveness (long-term outcomes) in patients undergoing hip and knee replacement surgery.

DESIGN

Systematic review and meta-analysis.

METHODS

Medline, Embase and CINAHL Plus were searched up to May 2017. We included all studies that reported data to allow the calculation of a pooled OR for the impact of 11 comorbid conditions on 10 outcomes (including surgical complications, readmissions, mortality, function, health-related quality of life, pain and revision surgery). The quality of included studies was assessed using a modified Newcastle-Ottawa Scale. Continuous outcomes were converted to ORs using the Hasselblad and Hedges approach. Results were combined using a random-effects meta-analysis.

OUTCOMES

The primary outcome was the adjusted OR for the impact of each 11 comorbid condition on each of the 10 outcomes compared with patients without the comorbid condition. Where the adjusted OR was not available the secondary outcome was the crude OR.

RESULTS

70 studies were included with 16 (23%) reporting on at least 100 000 patients and 9 (13%) were of high quality. We found that comorbidities increased the short-term risk of hospital readmissions (8 of 11 conditions) and mortality (8 of 11 conditions). The impact on surgical complications was inconsistent across comorbid conditions. In the long term, comorbid conditions increased the risk of revision surgery (6 of 11 conditions) and long-term mortality (7 of 11 conditions). The long-term impact on function, quality of life and pain varied across comorbid conditions.

CONCLUSIONS

This systematic review shows that comorbidities predominantly have an impact on the safety of hip and knee replacement surgery but little impact on its effectiveness. There is a need for high-quality studies also considering the severity of comorbid conditions.

Does Prior Bariatric Surgery Affect Implant Survivorship and Complications Following Primary Total Hip Arthroplasty/Total Knee Arthroplasty?

BACKGROUND

The purpose of this study is to evaluate the impact of prior bariatric surgery on survivorship, outcome, and complications following primary total hip arthroplasty (THA)/total knee arthroplasty (TKA).

METHODS

Using the Medicare 5% part B data from 1999 to 2012, we analyzed patients who underwent primary THA (n = 47,895) and primary TKA (n = 86,609). Patients with prior bariatric surgery before arthroplasty were compared to patients with other common metabolic conditions. Kaplan-Meier risk of revision THA/TKA for those with and without bariatric surgery and each of the metabolic bone conditions was calculated. The risk for infection was also evaluated. Regression analysis was used to determine the relative risk of revision at various time intervals for those with and without each of the metabolic conditions. Analysis was also adjusted for the metabolic conditions, age, gender, socioeconomic status, and Charlson comorbidity index.

RESULTS

The prevalence of patients with prior bariatric surgery within 24 months of primary THA/TKA was 0.1%. Benchmarked against other common chronic metabolic conditions, bariatric surgery prior to THA was not associated with an increased risk for revision surgery at all measured intervals but positively correlated with increased risk for developing infections. Conversely, patients undergoing primary TKA following bariatric surgery were at increased risk for revision compared to controls but not at increased risk for infection.

CONCLUSION

The impact of bariatric surgery prior to elective THA/TKA remains unclear. These patients remain at increased risk for infections following THA and revisions following TKA.

Older Adults Undergoing Total Hip or Knee Arthroplasty: Chronicling Changes in Their Multimorbidity Profile in the Last Two Decades

BACKGROUND

Despite the ubiquitous use of total hip arthroplasty (THA) and total knee arthroplasty (TKA) in older adults, little is known about the multimorbidity (MM) profile of this patient population. This study evaluates the temporal trends of MM, hypothesizing that patients with MM have had an increasingly greater representation in THA and TKA patients over time.

METHODS

Data on a US representative sample of older adults from the linked Health and Retirement Study and Medicare data from 1993 to 2012 were used. The Health and Retirement Study is a biennial survey that collects data on a broad array of measures, including self-reported chronic conditions and geriatric syndromes, which were used to account for MM. Medicare data were used to identify fee-for-service Medicare beneficiaries who underwent THA (n = 479) or TKA (n = 998) during the study years, which were grouped into 3 periods: 1993-1999, 2000-2006, and 2007-2012. Multivariable logistic regression analysis was conducted to obtain age-, gender-, and race-adjusted time trends for MM.

RESULTS

Compared to the earliest study period, and for both THA and TKA patients, there were significantly fewer patients with stroke and/or poor cognitive performance in the most recent study period. In addition, more TKA than THA patients presented with 2+ chronic conditions. Nearly 70% presented with co-occurring chronic conditions and geriatric syndromes, and this percentage did not change significantly over time.

CONCLUSION

The high representation of THA and TKA patients presenting with co-occurring chronic conditions and geriatric syndromes in this patient population warrants detailed exploration of the effects of geriatric syndromes on postoperative outcomes.

Common Medical Comorbidities Correlated With Poor Outcomes in Hip Periprosthetic Infection

BACKGROUND

Periprosthetic infection has been linked to risk factors such as diabetes, obesity, and smoking among others. This study examined the relationship between common patient comorbidities and hip periprosthetic infection outcomes.

METHODS

We retrospectively reviewed the records of 149 culture-positive periprosthetic hip infections at our tertiary care center that underwent treatment between 2005 and 2015. Baseline characteristics and common comorbidities were analyzed with relation to rates of successfully treated infection, total surgeries for infection, and cumulative length of hospitalization using multivariate analysis.

RESULTS

Patients with coronary artery disease or anemia had significantly lower rate of successfully treated infection. Patients with anemia or chronic pulmonary disease underwent significantly more surgery, and patients with chronic pulmonary disease, psychiatric disease, anemia, or diabetes spent significantly longer time in hospital.

CONCLUSION

Potentially modifiable cardiovascular, respiratory, and psychiatric diseases were associated with a decreased rate of successfully treated infection, more surgery, and longer hospitalization in treatment for hip periprosthetic infection in multivariate analysis.

Obesity Epidemic: Is Its Impact on Total Joint Arthroplasty Underestimated? An Analysis of National Trends

BACKGROUND

Obesity is a well-established risk factor for total joint arthroplasty (TJA) and a number of complications including prosthetic joint infection. The annual changes in the prevalence of obesity among primary, revision, and infected TJA has not been studied at a national level. Given the higher costs of complications of TJA, it is important to understand the association of obesity with the annual trends of revision and infected TJA.

QUESTIONS/PURPOSES

(1) Is the prevalence of obesity increasing among patients undergoing THA/TKA? (2) Is the prevalence of obesity increasing among patients undergoing revision THA/TKA? (3) Is the prevalence of obesity increasing among patients with infected THA/TKA?

METHODS

Annual volumes of primary, revision, and infected THA and TKA from 1998 to 2011 were obtained from the Nationwide Inpatient Sample. Using mathematical equations, the prevalence of obesity was estimated from relative risks and national obesity prevalence. National obesity prevalence was obtained from public health sources and the relative risk estimates were obtained from previously published meta-analyses and population-based studies. Annual prevalence of obesity was obtained by dividing the number of obese primary/revision/infected procedures in each year by the total number of corresponding procedures in that year. Annual changes in the prevalence of obesity were analyzed using linear regression.

RESULTS

The prevalence of obesity is increasing among patients undergoing THA (1998: 60,264 of 154,337 [39%], 2011: 160,241 of 305,755 [52%], increase of 1.05%/year [confidence interval {CI}, 0.95%-1.15%], p < 0.001) and TKA (1998: 143,681 of 251,309 [57%], 2011: 448,712 of 644,243 [70%], increase of 0.97%/year [CI, 0.87%-1.07%], p < 0.001). There was an increasing prevalence of obesity with THA revisions (1998: 16,322 of 34,139 [48%], 2011: 33,304 of 54,453 [61%], increase of 1.04%/year [CI, 0.94%-1.15%], p < 0.001) and in TKA revisions (1998: 16,837 of 26,539 [63%], 2011: 52,151 of 69,632 [75%], increase of 0.89%/year [CI, 0.79%-0.99%], p < 0.001). There was an increasing prevalence of obesity with THA infections (1998: 2068 of 3018 [69%], 2011: 6856 of 8687 [79%], increase of 0.80%/year [CI, 0.71%-0.89%], p < 0.001) and in TKA infections (1998: 3563 of 4684 [76%], 2011: 14,178 of 16,774 [85%], increase of 0.65%/year [CI, 0.57%-0.73%], p < 0.001).

CONCLUSIONS

The prevalence of obesity has increased in patients undergoing primary, revision, and infected TJA in United States. The obesity epidemic appears to be related to the growing trends of revision and infection after TJA. With the obesity rates expected to grow further, the revision and infection burden associated with obesity may increase in the future.

LEVEL OF EVIDENCE

Level II, prognostic study.

Is decreasing mortality in total hip and knee arthroplasty patients dependent on patients' comorbidity?

Background and purpose - Mortality after primary total hip and knee arthroplasty (THA and TKA) has declined, and the proportion of THA and TKA patients with comorbid conditions has increased. We therefore wanted to examine changes in comorbidity burden over time and the impact of comorbid on mortality following primary total hip and knee arthroplasty in patients with osteoarthritis. Patients and methods - We used the Danish arthroplasty registers to identify THA and TKA patients from 1996 through 2013. From administrative databases, we collected data on pre-surgery hospital history for all patients, which were used to calculate the Charlson comorbidity index (CCI). Patients were divided into 4 groups: CCI-none, CCI-low, CCI-moderate, and CCI-high. We calculated the relative risk (RR) of mortality within 90 days after surgery with a 95% confidence interval (CI), with stratification according to CCI group and year of surgery. Results - 99,962 THAs and 63,718 TKAs were included. The proportion of THAs with comorbidity increased by 3-4% in CCI-low, CCI-moderate, and CCI-high patients, from 1996-1999 to 2010-2013. The overall 90-day mortality risk declined for both procedures. Compared to CCI-none, THA patients with low, moderate, and high comorbidity burdens had an RR of 90-day mortality of 1.9 (95% CI: 1.6-2.4), 1.9 (CI: 1.5-2.5), and 3.3 (CI: 2.6-4.2), respectively. Similar increases in proportions and RRs were observed in TKAs. Interpretation - Despite the fact that the proportion of THA and TKA patients with comorbidities has increased over the past 18 years, the overall mortality has declined. The mortality risk depended on the comorbidity burden and did not decline during the study period for THA and TKA patients with a moderate or high comorbidity burden at the time of surgery.

Obesity in total hip arthroplasty

Aims

The purpose of our study is to summarise the current scientific findings regarding the impact of obesity on total hip arthroplasty (THA); specifically the influence of obesity on the timing of THA, incidence of complications, and effect on clinical and functional outcomes.

Materials and Methods

We performed a systematic review that was compliant with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify prospective studies from the PubMed/Medline, Embase, and Cochrane Library databases that evaluated primary THA in obese (body mass index (BMI) ≥ 30 kg/m2) patients.

Results

There were 17 articles included in the review, which encompassed 13 722 THA patients. Analysis of the included studies showed that, when compared with non-obese patients, obesity was associated with younger age at time of primary THA, and an increased incidence of complications (up to four-fold). Results were mixed on the influence of obesity on the outcomes of primary THA, with three studies showing a detrimental effect on outcomes of a BMI ≥ 30 kg/m2, while eight studies showed no effect.

Conclusion

Obesity is associated with significantly younger age at time of primary THA and obese patients are likely to experience a higher rate of peri-operative complications. More investigation is needed into the effect of obesity on clinical outcomes, as the current literature is mixed. Cite this article: Bone Joint J 2017;99-B(1 Supple A):31–6.

Characteristics of hip involvement in patients with ankylosing spondylitis in Korea

BACKGROUND/AIMS

To evaluate the clinical course of hip arthritis and the risk factors for hip joint replacement in patients with ankylosing spondylitis (AS).

METHODS

In this retrospective analysis, we evaluated 488 AS patients at a single tertiary hospital. At baseline and the most recent visit to the outpatient clinic from the patients with hip arthritis in AS, radiographic hip arthritis was evaluated using the Bath Ankylosing Spondylitis Radiology Hip Index (BASRI-h). Also the average of the hip joint space width (interbone distance) at three distinct sites between the acetabulum and femoral head was recorded.

RESULTS

Among 488 patients with AS, 60 patients (12.3%) had hip arthritis. Erythrocyte sedimentation rate were associated with hip involvement (odds ratio, 1.01; 95% confidence interval [CI], 1.00 to 1.02; p = 0.004). Long disease duration and advanced axial disease were associated with severe hip arthritis (3 ≥ BASRI-h) at baseline. BASRI-h and interbone distance did not significantly change in patients with hip involvement during the follow-up period of 81.4 ± 35.7 months. Five patients had hip joint replacement surgery during follow-up period. The body mass index (BMI) and BASRI-h at baseline were associated with joint replacement surgery (hazard ratio [HR], 1.30; 95% CI, 1.00 to 1.67; p = 0.049 and HR, 20.64; 95% CI, 2.39 to 178.11; p = 0.006, respectively).

CONCLUSIONS

Most of the patients with hip arthritis in AS showed no significant radiographic progression during the follow-up period. High BMI and advanced hip arthritis at baseline were associated with hip joint replacement surgery in patients with AS.

Influence of different sizes of composite femora on the biomechanical behavior of cementless hip prosthesis

BACKGROUND

For the biomechanical evaluation of cementless stems different sizes of composite femurs have been used in the literature. However, the impact of different specimen sizes on test results is unknown.

METHODS

To determine the potential effect of femur size the biomechanical properties of a conventional stem (CLS Spotorno) were examined in 3 different sizes (small, medium and large composite Sawbones®). Primary stability was tested under physiologically adapted dynamic loading conditions measuring 3-dimensional micromotions. For the small composite femur the dynamic load needed to be adapted since fractures occurred when reaching 1700N. Additionally, surface strain distribution was recorded before and after implantation to draw conclusions about the tendency for stress shielding.

FINDINGS

All tested sizes revealed similar micromotions only reaching a significant different level at one measurement point. The highest micromotions were observed at the tip of the stems exceeding the limit for osseous integration of 150μm. Regarding strain distribution the highest strain reduction after implantation was registered in all sizes at the level of the lesser trochanter.

INTERPRETATION

Specimen size seems to be a minor influence factor for biomechanical evaluation of cementless stems. However, the small composite femur is less suitable for biomechanical testing since this size failed under physiological adapted loads. For the CLS Spotorno osseous integration is unlikely at the tip of the stem and the tendency for stress shielding is the highest at the level of the lesser trochanter.

Should We Think Twice About Psychiatric Disease in Total Hip Arthroplasty?

BACKGROUND

Psychiatric disease (PD) is common, and the effect on complications in total hip arthroplasty (THA) is poorly understood. The purpose of this study was to evaluate the medical and surgical postoperative complication profile in patients with PD, and we hypothesize that they will be significantly increased compared with control group.

METHODS

A search of the entire Medicare database from 2005 to 2011 was performed using International Classification of Disease version 9 codes to identify 86,976 patients who underwent primary THA with PD including bipolar (5626), depression (82,557), and schizophrenia (3776). A cohort of 590,689 served as a control with minimum 2-year follow-up. Medical and surgical complications at 30-day, 90-day, and overall time points were compared between the 2 cohorts.

RESULTS

Patients with PD were more likely to be younger (age < 65 years; odds ratio [OR] = 4.51, P < .001), female (OR = 2.02, P < .001) and more medically complex (significant increase in 28/28 Elixhauser medical comorbidities, P < .001). There was a significant increase (P < .001) in 13/14 (92.8%) recorded postoperative medical complications rates at the 90-day time point. In addition, there was a statistically significant increase in periprosthetic infection (OR = 2.26, P < .001), periprosthetic fracture (OR = 2.09, P < .001), dislocation (OR = 2.30, P < .001), and THA revision (OR = 1.93, P < .001) at overall follow-up.

CONCLUSION

Patients with PD who undergo elective primary THA have significantly increased medical and surgical complication rates in the global period and short-term follow-up, and these patients need to be counseled accordingly.

Patient Comorbidity Status and Incremental Total Hospitalization Costs in Elective Orthopedic Procedures

This study examined the correlation between patient comorbidity status, hospitalization length of stay (LOS), and cost for total knee arthroplasty (TKA), total hip arthroplasty (THA), and 1- to 3-level lumbar spinal fusion procedures. Using the Premier Perspective Database, adults older than 18 years who underwent primary unilateral TKA, THA, or spinal fusion between January 1, 2008, and June 30, 2014, were identified. Generalized linear models controlling for age, sex, region, hospital size, academic status, payor, and procedure year predicted the incremental total hospitalization cost among the sickest patients (Charlson Comorbidity Index [CCI] ≥3) vs healthy controls (CCI=0). The study cohort included 536,582 TKAs, 275,953 THAs, and 177,493 spinal fusion procedures. The percentages of patients with a CCI of 3 or greater were 5.4%, 4.7%, and 4.3%, for TKA, THA, and spinal fusion procedures, respectively. Mean (SD) LOS was longer by 0.9 (1.5), 1.4 (2.3), and 2.3 (3.8) days for patients with a CCI of 3 or greater vs 0 for TKA, THA, and spinal fusion procedures, respectively. Unadjusted total hospitalization costs were $17,512 for TKA, $18,915 for THA, and $32,932 for spinal fusion procedures; generalized linear models showed an incremental total hospitalization cost for CCI scores of 3 or greater of $2211, $3041, and $3922 vs CCI equal to 0 for each procedure type, respectively. Although representing a relatively small proportion of all patients undergoing elective orthopedic procedures, highly comorbid patients were associated with a greater total hospitalization cost burden. With the average patient comorbidity burden growing nationally, this study warrants further examination of improved standards of care for comorbid patients undergoing elective orthopedic procedures. [Orthopedics. 2016; 39(4):237-246.].

Reducing the distal profile of dual mobility liners can mitigate soft-tissue impingement and liner entrapment without affecting mechanical performance

Soft-tissue impingement with dual mobility liners can cause anterior hip pain and intra-prosthetic dislocation. The hypothesis of this study was that reducing liner profile below the equator (contoured design) can mitigate soft-tissue impingement without compromising inner-head pull-out resistance and hip joint stability. The interaction of conventional and contoured liners with anterior soft tissues was evaluated in cadaver specimens via visual observation and fluoroscopic imaging. Resistance to inner-head pull-out was evaluated via finite element analyses, and hip joint stability was evaluated by rigid-body mechanics simulation of dislocation in two modes (A, B). Cadaveric experiments showed that distal portion of conventional liners impinge on anterior hip capsule and cause iliopsoas tenting at low flexion angles (≤30°). During hip extension, the rotation imparted to the liner from posterior engagement with femoral neck was impeded by anterior soft-tissue impingement. The iliopsoas tenting was significantly reduced with contoured liners (p ≤ 0.04). Additionally, the contoured and conventional liners had identical inner-head pull-out resistance (901 N vs. 909 N), jump distance (9.4 mm mode-A, 11.7 mm mode-B) and impingement-free range of motion (47° mode-A, 29° mode-B). Thus, soft-tissue impingement with conventional dual mobility liners may be mitigated by reducing liner profile below the equator, without affecting mechanical performance. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:889-897, 2016.

Comparative Risk of Transfusion and Incremental Total Hospitalization Cost for Primary Unilateral, Bilateral, and Revision Total Knee Arthroplasty Procedures

BACKGROUND

This study evaluated the comparative risk of autologous and allogenic blood transfusion, inhospital complications, and incremental total hospitalization costs for primary unilateral, simultaneous bilateral, and revision total knee arthroplasty (TKA) procedures.

METHODS

Using the Premier Perspective database, we identified adults who underwent primary unilateral, simultaneous bilateral, or revision TKA procedures. Logistic regression, controlling for patient and hospital characteristics, was used to determine the risk of autologous or allogeneic blood transfusion. Controlling for the same factors, generalized linear models predicted incremental total hospitalization cost associated with transfusion.

RESULTS

Between January 2008 and June 2014, 513,558 primary unilateral, 33,977 bilateral, and 32,494 revision TKA patients met selection criteria. The overall percentage receiving a transfusion was 14.1% for unilateral, 36.3% for bilateral, and 20.0% for revision procedures. Logistic regression showed patients aged >65 years, female gender, Northeastern location, large hospitals, and higher Charlson score to be significantly associated with higher transfusion risk. Although overall risk of transfusion decreased over the study period, patients with Charlson score ≥3 were at 2.27 (primary unilateral), 1.88 (bilateral), and 2.44 (revision) greater odds of transfusion compared with healthy controls (Charlson score = 0). Generalized linear models showed an incremental total hospitalization cost among those receiving a transfusion of $2477, $4235, and $8594, respectively, compared with those without transfusion.

CONCLUSIONS

Transfusion risk remains a significant burden in select patient populations and procedures. The incremental cost of receiving a transfusion is significant, including not only direct costs but also staff time and increased hospital resource use.