Bibliometric analysis of machine learning trends and hotspots in arthroplasty literature over 31 years

Background

Artificial intelligence has demonstrated utility in orthopedic research. Algorithmic models derived from machine learning have demonstrated adaptive learning with predictive application towards outcomes, leading to increased traction in the literature. This study aims to identify machine learning arthroplasty research trends and anticipate emerging key terms.

Methods

Published literature focused on machine learning in arthroplasty from 1992 to 2023 was selected through the Web of Science Core Collection of Clarivate Analytics. Following that, bibliometric indicators were attained and brought in to perform an additional examination using Bibliometrix and VOSviewer to identify historical and present patterns within the literature.

Results

A total of 235 documents were obtained through bibliometric sourcing based on machine learning applications within the arthroplasty literature. Thirty-four countries published articles on the topic, and the United States was demonstrated to be the largest global contributor. Four hundred-five institutions internationally contributed articles, with Harvard Medical School and the University of California system as the most relevant institutes, with 75 and 44 articles produced, respectively. Kwon YM was the most productive author, while Haeberle HS and Ramkumar PN were the most impactful based on h-index. The Thematic map and Co-occurrence visualization helped identify both major and niche themes present in the scientific databases.

Conclusions

Machine learning in arthroplasty research continues to gain traction with a growing annual production rate and contributions from international authors and institutions. Institutions and authors based in the United States are the leading contributors to machine learning applications within arthroplasty research. This research discerns trends that have occurred, are presently ongoing, and are emerging within this field, aiming to inform future hotspot development.

Evaluating the optimal management strategy for intraoperative iatrogenic injury to the medial collateral ligament during primary total knee arthroplasty: A systematic review

INTRODUCTION

Intraoperative iatrogenic MCL injuries during primary TKA are rare complications that lack a gold standard management protocol. This review aims to provide insight into various treatment modalities and evidence-based guidance for improved patient outcomes.

METHODS

A comprehensive search across five databases identified relevant randomized control trials and retrospective cohort studies with reported outcomes. A total of 17 studies were included, and variables such as patient demographics, injury type, management, and Knee Society Scores (KSS) were assessed. The quality of included studies was evaluated using the Critical Appraisal Skills Programme tool.

RESULTS

Mean age of included patients ranged from 60.0 to 71.4 years. The mean Body Mass Index ranged from 26.75 to 34.40 kg/m2. Among the included knees, 298 were categorized as MCL avulsion, and 167 as midsubstance/transection injuries. Primary repair with sutures or bone staples emerged as the most common management. Intraoperative MCL injury was correlated with reduced preoperative range of motion (ROM) and postoperative KSS clinical, functional, and pain scores compared to control groups. Postoperative ROM was comparable between MCL injury and control groups, ranging from 100.0° to 130.0° and 107.0° to 130.0°, respectively.

CONCLUSION

Current evidence supports primary repair as the preferred management for this complication. Factors such as extent of the tear, type of injury, and the surgeon's experience also help to guide treatment. While treatment modalities like allograft or autograft reconstruction show promise, further research with larger sample sizes is needed to enhance future outcomes.

Frailty Among Revision Total Knee Arthroplasty Recipients: Epidemiology and Propensity Score-weighted Analysis of Effect on In-hospital Postoperative Outcomes

BACKGROUND

Frailty has been shown to correlate with worse outcomes after total knee arthroplasty (TKA), although less is known regarding its effect on revision TKA (rTKA). This study examines the epidemiologic characteristics and inpatient outcomes of patients with frailty undergoing rTKA.

METHODS

Discharge data from National Inpatient Sample registry were used to identify all patients aged 50 years or older who underwent rTKA between 2006 and 2015. Patients were stratified into frail and nonfrail groupings, based on the presence of specific International Classification of Diseases-9 diagnostic coding. An analysis comparing the epidemiology, medical comorbidities, and propensity score-weighted postoperative clinical and economic outcomes of the two groups was done.

RESULTS

From 2006 to the third quarter of 2015, a total of 576,920 patients (17,727 frail) who underwent rTKA were included. The average age in the study's population was 67.2 years, with a female distribution of 57.4%. Frail patients were more likely to exhibit markedly higher rates of almost all modified Elixhauser Comorbities than their nonfrail counterparts. Frail patients were also more likely to undergo different types of revisions, including an increased rate of removal of the prosthesis without replacement. In addition, frail patients displayed increased likelihood of experiencing any postoperative complication, deep vein thrombosis, postoperative anemia, respiratory complications, and wound dehiscence. Frail patients experienced lower rates of discharge home and increased length of stay than the nonfrail cohort.

DISCUSSION

Patients with frailty undergoing rTKA are at markedly higher risk for inpatient postoperative complications and increased length of stay. Understanding the implications of frailty within rTKA is essential for risk assessment and preoperative optimization for this expanding population.

Outcomes of Image-Free Robotic Assisted Total Knee Arthroplasty in Patients Who Have Valgus Knee Deformities

BACKGROUND

Valgus knee deformities pose a unique challenge in total knee arthroplasty (TKA) due to the complexity of achieving ligamentous balance and satisfactory alignment compared to varus or neutral deformities. Robotic-assisted (RA) TKA could aid in achieving improved component alignment and balance.

METHODS

We retrospectively evaluated a matched cohort of patients to compare image-free RA-TKA (n = 44) versus conventional manual (CM) TKA (n = 30) techniques in patients who have valgus deformity of 5 to 15 degrees, including radiographic and patient-reported outcomes measures (PROMs) over a 3-year period. The patient reported outcome measures (PROMs) studied to determine outcomes were: Western Ontario McMaster University Arthritis Index, Knee Society Score-Function Score, and Short Form 12-item Survey.

RESULTS

Overall, the RA-TKA cohort showed faster improvement in PROMs (37.16 ± 1 8.8 versus 25.74 ± 17.7, P = .02), shorter length of stay (1.41 versus 2.29 days, P = .02), and shorter operating room times (120.79 versus 123.67 minutes, P = .02) than CM-TK). Additionally, there was no difference in the use of primary versus varus-valgus constrained polyethylene liners between the cohorts.

CONCLUSIONS

In this investigation, RA-TKA yielded a slightly faster patient recovery, more objective measurements of ligamentous balance, and proved noninferior PROMs compared to CM-TKA for preoperative valgus knee deformities.

Tourniquet-free minimally invasive total knee arthroplasty is associated with early aseptic loosening

BACKGROUND

While tourniquet-free (T-) total knee arthroplasty (TKA) has gained popularity, tourniquet-use during minimally-invasive (MIS)-TKA has not been adequately studied. Traditional techniques employ knee hyper-flexion, compressing vasculature and reducing impact of bleeding, while MIS-TKA embraces the semi-extended knee position, which does not restrict the effects of bleeding on cementation and visualization. We compared the risk of aseptic loosening between patients undergoing T- MIS-TKA compared to T + MIS-TKA.

METHODS

This single-surgeon cohort study included 329 consecutive MIS-TKA (226 T+,103 T-) patients with minimum 3-year follow-up. Aseptic loosening, radiolucent lines (RLL), health related quality of life scores, and complications were recorded. T-test and chi-square test were used to compare continuous and categorical variables, and logistic regression included BMI, age, ASA, patellar-resurfacing, and tourniquet-use.

RESULTS

There were no differences in baseline demographics. One (0.4 %) aseptic loosening occurred with T+, versus 7 (6.8 %) with T- (p = 0.002). No T + and 3 T- patients (2.9 %, p = 0.01) had revision for aseptic loosening. The incidence of RLLs was 16.8 % in T + and 30.1 % in T- (p = 0.008). Logistic regression revealed T + was significantly associated with decreased aseptic loosening and risk of RLL (odds ratio = 16.4, odds ratio = 2.8).

CONCLUSION

In this consecutive series, T- MIS-TKA was associated with increased rates of revision for aseptic loosening as compared to the T + MIS-TKA, even controlling for BMI, age, ASA level, and patellar resurfacing. Radiolucent lines were increased with T- MIS-TKA compared to T + MIS-TKA. Complications, all-cause revision, ROM, and HRQoL scores were similar between tourniquet-use and tourniquet-free cohorts.

The utilization of US-based large data in arthroplasty research: Bibiliometric analysis of trends and hotspots

Background

The accessibility of digital information has expanded orthopaedic surgery with expanded role of Big Databases. The increasing interest have led to creation of large databases with increasing utilization in retrospective studies. The aim of this study is to identify Big Database research and predict future hotspots.

Methods

Big Database publications between 1982 and 2022 were identified from the Web of Science Core Collection of Clarivate Analytics. Bibliometric indicators were obtained and imported for further analysis with VOSviewer and Bibliometrix to identify previous and ongoing trends within this field.

Results

Bibliometric sourcing identified 811 total articles that was associated with major databases. Twenty-eight countries published manuscript in the field with the United States as the largest contributor. The most relevant institutions were Cleveland Clinic and Harvard University. Mont MA was the most productive and influential author. Co-occurrence visualization and thematic map identified niche and major themes within the literature.

Conclusions

Large Database research continue to show an increasing trend since 2011 with contributions globally. United States institutions and authors are the leading contributors in big database research. This study identifies previous, current, and developing trends within this field for future hotspot development.

Improved performance of machine learning models in predicting length of stay, discharge disposition, and inpatient mortality after total knee arthroplasty using patient-specific variables

BACKGROUND

This study aimed to compare the performance of ten predictive models using different machine learning (ML) algorithms and compare the performance of models developed using patient-specific vs. situational variables in predicting select outcomes after primary TKA.

METHODS

Data from 2016 to 2017 from the National Inpatient Sample were used to identify 305,577 discharges undergoing primary TKA, which were included in the training, testing, and validation of 10 ML models. 15 predictive variables consisting of 8 patient-specific and 7 situational variables were utilized to predict length of stay (LOS), discharge disposition, and mortality. Using the best performing algorithms, models trained using either 8 patient-specific and 7 situational variables were then developed and compared.

RESULTS

For models developed using all 15 variables, Linear Support Vector Machine (LSVM) was the most responsive model for predicting LOS. LSVM and XGT Boost Tree were equivalently most responsive for predicting discharge disposition. LSVM and XGT Boost Linear were equivalently most responsive for predicting mortality. Decision List, CHAID, and LSVM were the most reliable models for predicting LOS and discharge disposition, while XGT Boost Tree, Decision List, LSVM, and CHAID were most reliable for mortality. Models developed using the 8 patient-specific variables outperformed those developed using the 7 situational variables, with few exceptions.

CONCLUSION

This study revealed that performance of different models varied, ranging from poor to excellent, and demonstrated that models developed using patient-specific variables were typically better predictive of quality metrics after TKA than those developed employing situational variables.

LEVEL OF EVIDENCE

III.

Assessing the predictive capacity of machine learning models using patient-specific variables in determining in-hospital outcomes after THA

Background

Machine learning is a subset of artificial intelligence using algorithmic modeling to progressively learn and create predictive models. Clinical application of machine learning can aid physicians through identification of risk factors and implications of predicted patient outcomes.

Aims

The aim of this study was to compare patient-specific and situation perioperative variables through optimized machine learning models to predict postoperative outcomes.

Methods

Data from 2016 to 2017 from the National Inpatient Sample was used to identify 177,442 discharges undergoing primary total hip arthroplasty, which were included in the training, testing, and validation of 10 machine learning models. 15 predictive variables consisting of 8 patient-specific and 7 situational specific variables were utilized to predict 3 outcome variables: length of stay, discharge, and mortality. The machine learning models were assessed in responsiveness via area under the curve and reliability.

Results

For all outcomes, Linear Support Vector Machine had the highest responsiveness among all models when using all variables. When utilizing patient-specific variables only, responsiveness of the top 3 models ranged between 0.639 and 0.717 for length of stay, 0.703-0.786 for discharge disposition, and 0.887-0.952 for mortality. The top 3 models utilizing situational variables only produced responsiveness of 0.552-0.589 for length of stay, 0.543-0.574 for discharge disposition, and 0.469-0.536 for mortality.

Conclusions

Linear Support Vector Machine was the most responsive machine learning model of the 10 algorithms trained, while decision list was most reliable. Responsiveness was observed to be consistently higher with patient-specific variables than situational variables, emphasizing the predictive capacity and value of patient-specific variables. The current practice in machine learning literature generally deploys a single model, it is suboptimal to develop optimized models for application into clinical practice. The limitation of other algorithms may prohibit potential more reliable and responsive models.Level of Evidence III.

Anterior Knee Pain After Total Knee Arthroplasty: A Critical Review of Peripatellar Variables

» Despite the widespread success of total knee arthroplasty (TKA), postoperative anterior knee pain (AKP) remains a common occurrence and source of dissatisfaction with several readily discernible and diagnosable causes of AKP after TKA, including component malpositioning, infection, wear and osteolysis, instability, and loosening, among others.» In the setting of the well-appearing but painful TKA, potential intraoperative contributors to AKP have been extensively investigated, but remain controversial and include patellar resurfacing, patellar denervation, and patellofemoral joint overstuffing or understuffing.» Intraoperative management of peripatellar soft tissues has comparatively attained substantially less attention recently, and persistent controversy exists in the literature to make informed decisions on soft-tissue management and identify potential contributors to AKP.» Further investigations and research is needed, including exploration of multifactorial or alternative etiologies, specifically ones related to less obvious soft-tissue-related factors, needed to better understand and ultimately avoid AKP after TKA.

Epidemiology of primary and revision total knee arthroplasty: analysis of demographics, comorbidities and outcomes from the national inpatient sample

INTRODUCTION

Primary total knee arthroplasty (TKA) is a preferred treatment for end-stage knee osteoarthritis. In the setting of a failed TKA, revision total knee arthroplasty (rTKA) acts as a salvage procedure and carries a higher risk compared to primary TKA. Given increased interest in postoperative outcomes from these procedures, a thorough understanding of the demographics, comorbidities, and inpatient outcomes is warranted. This study aimed to report the epidemiological data of demographics, comorbidity profiles and outcomes of patients undergoing TKA and rTKA.

METHODS

A retrospective review of NIS registry discharge data from 2006 to 2015 third quarter was performed. This study included adults aged 40 and older who underwent TKA or rTKA. A total of 5,901,057 TKA patients and 465,968 rTKA patients were included in this study. Simple descriptive statistics were used to present variables on demographics, medical comorbidities, and postoperative complications.

RESULTS

A total of 5,901,057 TKA and 465,968 rTKA discharges were included in this study, with an average age of 66.30 and 66.56 years, and the major payor being Medicare, accounting for 55.34% and 59.88% of TKA and rTKA cases, respectively. Infection (24.62%) was the most frequent reason for rTKA, and was followed by mechanical complications (18.62%) and dislocation (7.67%). The most common medical comorbidities for both groups were hypertension, obesity, and diabetes. All types of inpatient complications were reported in 22.21% TKA and 28.78% of rTKA cases. Postoperative anemia was the most common complication in both groups (20.34% vs. 25.05%).

CONCLUSIONS

Our data demonstrated a 41.9% increase in patients receiving TKA and 28.8% increase in rTKA from the years 2006 to 2014. The data showed a 22.21% and a 28.78% "complication" rate with TKA and rTKA, with postoperative anemia being the most common complication. The top 3 medical comorbidities were hypertension, obesity, and diabetes for both groups and with increased focus on perioperative optimization, future analyses into preoperative medical optimization, and improved primary arthroplasty protocol may result in improved postoperative outcomes.

Cannabis use disorder is associated with shorter length of stay and increased home discharge after primary total joint arthroplasty: a propensity-weighted analysis

INTRODUCTION

Increased legalization of cannabis use across the United States has been correlated with increased cannabis use in the clinical setting. However, little is known regarding the characteristics and postoperative outcomes after primary joint arthroplasty (TJA) for patients with cannabis use disorder (CUD).

METHODS

This retrospective cohort study used data from the National Inpatient Sample of patients undergoing primary TJA between 2006 to 2015. Patients were grouped based on presence of concomitant CUD. Patient demographic characteristics and outcome data between groups were analyzed. Propensity score methodology was used to compare immediate in-hospital complications and economic outcomes.

RESULTS

A total of 8,740,798 TJAs were included. The prevalence of CUD increased nearly five-fold from 0.05% to 0.26% during this time (P < 0.0001). CUD patients were significantly younger, more likely to be male, most frequently of non-Hispanic Black race, and had higher rates of Medicaid insurance. Patients with CUD had a significantly shorter length of hospital stay (3.04 vs. 3.24 days, P = 0.0297), while incurring significantly higher daily ($22,614 vs. $17,955, P < 0.0001) and total charges during admission ($58,507 vs. $50,924, P < 0.0001), compared to patients without CUD. When compared with the control group, CUD was associated with significantly greater odds of home discharge (odds ratio (OR): 1.45, P = 0.0007), and significantly lower odds of rehab discharge (OR: 0.70, P = 0.0013). There were no differences in overall complication profile or in the vast majority of individual in-hospital complications between groups.

CONCLUSION

While CUD is correlated to shorter length of stay and increased home discharge after TJA, it does not show a strong effect on complications in an inpatient postoperative setting. It is important for clinicians to appreciate the demographic profile and expected clinical and economic outcomes for patients with CUD undergoing TJA, particularly in the context of evolving laws surrounding cannabis use.

Epidemiology of total hip arthroplasty: demographics, comorbidities and outcomes

BACKGROUND

Primary THA (THA) is a successful procedure for end-stage hip osteoarthritis. In the setting of a failed THA, revision total hip arthroplasty (rTHA) acts as a salvage procedure. This procedure has increased risks, including sepsis, infection, prolonged surgery time, blood loss, and increased length of stay. Increasing focus on understanding of demographics, comorbidities, and inpatient outcomes can lead to better perioperative optimization and post-operative outcomes. This epidemiological registry study aimed to compare the demographics, comorbidity profiles, and outcomes of patients undergoing THA and rTHA.

METHODS

A retrospective review of discharge data reported from 2006 to the third quarter of 2015 using the National Inpatient Sample registry was performed. The study included adult patients aged 40 and older who underwent either THA or rTHA. A total of 2,838,742 THA patients and 400,974 rTHA patients were identified.

RESULTS

The primary reimbursement for both THA and rTHA was dispensed by Medicare at 53.51% and 65.36% of cases respectively. Complications arose in 27.32% of THA and 39.46% of rTHA cases. Postoperative anemia was the most common complication in groups (25.20% and 35.69%). Common comorbidities in both groups were hypertension and chronic pulmonary disease. rTHA indications included dislocation/instability (21.85%) followed by mechanical loosening (19.74%), other mechanical complications (17.38%), and infection (15.10%).

CONCLUSION

Our data demonstrated a 69.50% increase in patients receiving THA and a 28.50% increase in rTHA from the years 2006 to 2014. The data demonstrated 27.32% and 39.46% complication rate with THA and rTHA, with postoperative anemia as the most common cause. Common comorbidities were hypertension and chronic pulmonary disease. Future analyses into preoperative optimizations, such as prior consultation with medical specialists or improved primary hip protocol, should be considered to prevent/reduce postoperative complications amongst a progressive expansion in patients receiving both THA and rTHA.

Ultrasonography for the Busy Orthopaedic Surgeon: The Lower Extremity

Ultrasonography has the potential to become a fundamental component of the diagnosis and management of musculoskeletal conditions and injuries. Moreover, in the context of modern healthcare systems that are focused on optimizing value, ultrasonography has the advantage of minimizing costs when compared with other advanced imaging modalities. Because of its low cost, lack of radiation exposure, speed, and capability to diagnose dynamic conditions, more orthopaedic surgeons are routinely integrating musculoskeletal ultrasonography into their daily practice. It is important to provide a comprehensive review of and approach to common musculoskeletal conditions of the lower extremity for the busy orthopaedic surgeon.

Ultrasonography for the Busy Orthopaedic Surgeon: The Upper Extremity

Ultrasonography is increasingly used in the diagnosis and treatment of musculoskeletal conditions and injuries. Ultrasonography possesses multiple advantages compared with other methods of imaging, including low cost, lack of radiation exposure, speed, and means for dynamic examination. Because of these advantages, many orthopaedic surgeons are routinely using ultrasonography to diagnose musculoskeletal conditions of the upper extremity. Musculoskeletal ultrasonography is technically challenging, but with proper guidance and practice, every orthopaedic surgeon can confidently integrate ultrasonography into their clinical practice.

Femoral Stem Cementation in Primary Total Hip Arthroplasty

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Femoral stem cementation has undergone considerable investigation since bone cement was first used in arthroplasty, leading to the evolution of modern femoral stem cementation techniques.

➢

Although there is a worldwide trend toward the use of cementless components, cemented femoral stems have shown superiority in some studies and have clear indications in specific populations.

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There is a large evidence base regarding cement properties, preparation, and application techniques that underlie current beliefs and practice, but considerable controversy still exists.

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Although the cementing process adds technical complexity to total hip arthroplasty, growing evidence supports its use in certain cohorts. As such, it is critical that orthopaedic surgeons and investigators have a thorough understanding of the fundamentals and evidence underlying modern cementation techniques.

The Impact of Month on Joint Arthroplasty In-Hospital Outcomes: The December Effect

Background

The purpose of this study was to assess the impact of month of the year on postsurgical outcomes after primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) and to specifically analyze for a December effect.

Material and methods

The National Inpatient Sample was used to identify all patients older than 40 years undergoing primary TKA and THA between 2006 and 2015. Patients were stratified based on the month of the year of surgery. In-hospital complication, disposition, and economic outcomes were comparatively analyzed.

Results

There were statistically significant differences in outcomes based on month of the year. When comparing December to the other months, both TKA and THA patients had significantly lower rates of any complication, postoperative anemia, and genitourinary complications, while there were significantly higher rates of home than rehab discharge and shorter average length of stay in December. THA patients additionally had significantly lower rates of cardiac and respiratory complications during December.

Conclusion

Postoperative outcomes are significantly associated with the month in which arthroplasty is performed. This study provides evidence of a positive "December effect" of improved in-hospital complications and economic outcomes for surgeries performed in December. Future research should direct attention to the impact that social factors may have on outcomes after elective surgical procedures and how these factors may be translated to other months.

Predictive capacity of four machine learning models for in-hospital postoperative outcomes following total knee arthroplasty

Background

Machine learning (ML) methods have shown promise in the development of patient-specific predictive models prior to surgical interventions. The purpose of this study was to develop, test, and compare four distinct ML models to predict postoperative parameters following primary total knee arthroplasty (TKA).

Methods

Data from the Nationwide Inpatient Sample was used to identify patients undergoing TKA during 2016-2017. Four distinct ML models predictive of mortality, length of stay (LOS), and discharge disposition were developed and validated using 15 predictive patient and hospital-specific factors. Area under the curve of the receiver operating characteristic curve (AUCROC) and accuracy were used as validity metrics, and the strongest predictive variables under each model were assessed.

Results

A total of 305,577 patients were included. For mortality, the XGBoost, neural network (NN), and LSVM models all had excellent responsiveness during validation, while random forest (RF) had fair responsiveness. For predicting LOS, all four models had poor responsiveness. For the discharge disposition outcome, the LSVM, NN, and XGBoost models had good responsiveness, while the RF model had poor responsiveness. LSVM and XGBoost had the highest responsiveness for predicting discharge disposition with an AUCROC of 0.747.

Discussion

The ML models tested demonstrated a range of poor to excellent responsiveness and accuracy in the prediction of the assessed metrics, with considerable variability noted in the predictive precision between the models. The continued development of ML models should be encouraged, with eventual integration into clinical practice in order to inform patient discussions, management decision making, and health policy.

Epidemiology of Obese Patients Undergoing Revision Total Knee Arthroplasty: Understanding Demographics, Comorbidities, and Propensity Weighted Analysis of Inpatient Outcomes

INTRODUCTION

Obesity is a public health epidemic that is projected to grow in coming years. Observational data on the epidemiologic profile and immediate postoperative outcomes of obesity and morbid obesity after revision total knee arthroplasty (rTKA) are limited.

METHODS

Discharge data from the National Inpatient Sample was used to identify patients who underwent rTKA from 2006 to 2015. Patients were stratified into morbidly obese, obese, and not obese control cohorts. An analysis was performed to compare etiology of revision, demographic and medical comorbidity profiles, and immediate in-hospital economic and complication outcomes after rTKA.

RESULTS

An estimated 605,603 rTKAs were included in this analysis. Morbidly obese and obese patients were at significantly higher risk for any complication than not obese patients. Patients with obesity were associated with an increased risk of postoperative anemia but a lower risk of peripheral vascular disease and gastrointestinal, and hematoma/seroma complications compared with not obese patients. Patients with morbid obesity were associated with an increased risk of any, hematoma/seroma, wound dehiscence, postoperative infection, pulmonary embolism, and postoperative anemia complications and a lower risk of gastrointestinal complications when compared with not obese patients. Morbidly obese patients had a significantly longer length of stay than both obese and not obese patients, while no significant difference in length of stay was observed between obese and not obese patients.

DISCUSSION

Morbidly obese patients are at higher odds for worse postoperative medical and economic outcomes compared with those with obesity after rTKA. As the number of patients with obesity and morbid obesity continues to rise, these risk factors should be considered in preoperative discussions and perioperative protocol optimization.

Hospital-Acquired Conditions: A Review of Classical and Novel Risk Factors Following Total Hip and Knee Arthroplasties

»

In 2016, a total of 48,771 hospital-acquired conditions (HACs) were reported in U.S. hospitals. These incidents resulted in an excess cost of >$2 billion, which translates to roughly $41,000 per patient per HAC.

»

In the settings of total hip arthroplasty (THA) and total knee arthroplasty (TKA), increased age, a body mass index of >35 kg/m2, male sex, diabetes mellitus, electrolyte disturbances, and a history of anemia increase the likelihood of surgical site infections.

»

Institution-specific (surgical) risk factors such as increased tourniquet time, an operative time of >130 minutes, bilateral procedures, a femoral nerve block, and general anesthesia increase the risk of HACs in the settings of THA and TKA.

Chronic kidney disease impact on total joint arthroplasty outcomes: A National Inpatient Sample-based study

INTRODUCTION

In the United States, chronic kidney disease (CKD) affects roughly 11% of the population or 19.2 million people. As the prevalence of CKD and demand for total joint arthroplasty (TJA) continue to rise, it is critical to assess the impact of CKD on postoperative clinical and economic outcomes.

METHODS

Discharge data from 2006 to 2011 National Inpatient Sample were used for this study. A total of 851,150 TJA patients were divided into three cohorts: group 1 included no CKD, CKD stage I, and CKD stage II; group 2 included CKD stage III and stage IV; group 3 included CKD stage V. Inverse probability of treatment weighting/propensity score weighting was used to predict outcome variables as a function of age, sex, and Elixhauser comorbidities. Patients were compared against group I for in-hospital postoperative outcomes.

RESULTS

Stage III/IV CKD patients undergoing primary TJA had higher odds of any complication (odds ratio (OR), 2.63; p < 0.0001), longer length of stay (LOS), and higher total charge (LOS, 4.34 vs. 3.48 days; total charge, US$56,003 vs. US$46,115; p < 0.0001) when compared to patients with no CKD/stage I or II. Similarly, stage V CKD patients undergoing primary TJA had higher odds of any complication (OR, 1.64; p < 0.0001), longer LOS, and higher total charges (LOS, 5.81 vs. 3.48 days; total charge, US$59,869 vs. US$46,115) than their counterparts with no CKD/stage I or II CKD.

DISCUSSION

Our results indicate that stage III, IV, or V CKD, compared with those with no CKD, stage I or II patients are at a greater risk for postoperative complications and consume more resources following TJA.

Interventions for Obesity and Nutritional Status in Arthroplasty Patients

Nutritional risk in patients undergoing total joint arthroplasty has been well-studied with regard to diagnostic criteria; however, therapeutic management of abnormal body mass index (BMI) values and serum markers remains to be studied in patients undergoing joint replacement surgery. Patients with a BMI value of >40 kg/m2 are at increased risk for postoperative complications; weight loss programs and bariatric surgery are therapeutic modalities that can be used in the prehabilitation and long-term rehabilitation of patients undergoing total joint arthroplasty. Management of patients with abnormal nutritional status should be multidisciplinary and allow for the incorporation of dietitians and nutritionists in therapeutic planning. Hypoalbuminemia correction can be completed intravenously or orally; however, arthroplasty studies remain lacking with regard to the preferred modalities of correction.

The Joint Utilization Management Program-Implementation of a Bundle Payment Model and Comparison Between Year 1 and 2 Results

BACKGROUND

Health care spending is projected to increase throughout the next decade alongside the number of total joint arthroplasties (TJAs) performed. Such growth places significant financial burden on the economic system. To address these concerns, Bundled Payments for Care Improvement (BPCI) is becoming a favorable reimbursement model. The aim of this study is to present the outcomes with BPCI model focused on the post-acute care (PAC) phase and compare the outcomes between years 1 and 2 of implementation.

METHODS

The Joint Utilization Management Program (JUMP) was implemented in January 2014. Inclusion criteria were Medicare patients undergoing primary unilateral in-patient TJA procedures, outpatient procedures that resulted in an in-hospital admission, and trauma episodes that required TJA. Scorecards monitoring surgeons' performance and tracking length of stay (LOS) in the PAC setting were established. The data generated from these scorecards guided percentage sum-allocation from the total gain-shared sum among the participating providers.

RESULTS

A total of 683 JUMP patients were assessed over two years. PAC utilization decreased between 2014 and 2015. The average LOS was longer in year 1 than year 2 (4.50 vs 3.19 days). In-patient rehabilitation (IPR) decreased from 6.45% to 3.22%, with a decrease in IPR average LOS of 1.47 days. The rate of 30-day readmission was lower for JUMP patients in 2015 than 2014 (8.77% vs 10.56%), with day of readmission being earlier (11.91 days vs 13.71 days) in 2014.

CONCLUSION

Under the BPCI program, our experience with the JUMP model demonstrates higher efficiency of care in the PAC setting through reduced LOS, IPR admission rates, and 30-day readmission rate.

Rheumatoid Arthritis vs Osteoarthritis: Comparison of Demographics and Trends of Joint Replacement Data from the Nationwide Inpatient Sample

Current literature regarding complications following total joint arthroplasty have primarily focused on patients with osteoarthritis (OA), with less emphasis on the trends and in-hospital outcomes of rheumatoid arthritis (RA) patients undergoing these procedures. The purpose of this study is to analyze the outcomes and trends of RA patients undergoing total knee arthroplasty (TKA) or total hip arthroplasty (THA) compared to OA patients. Data from the Nationwide Inpatient Sample from 2006 to 2011 was extracted using the International Classification of Diseases, Ninth Revision codes for patients that received a TKA or THA. Outcome measures included cardiovascular complications, cerebrovascular complications, pulmonary complications, wound dehiscence, and infection. Inpatient and hospital demographics including primary diagnosis, age, gender, primary payer, hospital teaching status, Charlson Comorbidity Index score, hospital bed size, location, and median household income were analyzed. Logistic regression analysis of OA vs RA patients with patient outcomes revealed that osteoarthritic THA candidates had lower risk for cardiovascular complications, pulmonary complications, wound dehiscence, infections, and systemic complications, compared to rheumatoid patients. There was a significantly elevated risk of cerebrovascular complication in osteoarthritic THA compared to RA THA. OA patients undergoing TKA had significantly higher risk for cardiovascular and cerebrovascular complications. There were significant decreases in mechanical wounds, infection, and systemic complications in the OA TKA patients. RA patients are at higher risk for postoperative infection, wound dehiscence, and systemic complications after TKA and THA compared to OA patients. These findings highlight the importance of preoperative medical clearance and management to optimize RA patients and improve the postoperative outcomes.

Osteolysis Complicating Total Knee Arthroplasty

Osteolysis is a process mounted by the host immune system that relies on several variables, including patient-related factors, type of insert material, modes of wear, and implant design. Imaging techniques such as radiography, computed tomography (CT) scans, magnetic resonance imaging (MRI), and tomosynthesis aid in diagnosing osteolysis. Surgical options for the treatment of osteolysis include the insertion of bone grafts, bone cement, and prosthetic augmentation. Although no approved pharmacological therapies for the specific treatment of osteolysis exist, the use of bisphosphonates and statins decreases the risk of osteolysis.

Applications of Tissue Engineering in Joint Arthroplasty: Current Concepts Update

Research in tissue engineering has undoubtedly achieved significant milestones in recent years. Although it is being applied in several disciplines, tissue engineering's application is particularly advanced in orthopedic surgery and in degenerative joint diseases. The literature is full of remarkable findings and trials using tissue engineering in articular cartilage disease. With the vast and expanding knowledge, and with the variety of techniques available at hand, the authors aimed to review the current concepts and advances in the use of cell sources in articular cartilage tissue engineering.

Deep Vein Thrombosis and Pulmonary Embolism Considerations in Orthopedic Surgery

Patients undergoing orthopedic surgery have an increased risk for deep venous thrombosis (DVT) and pulmonary embolism (PE). These complications are considered detrimental, as they cause major postoperative morbidity and mortality and lead to a substantial health care burden. Because of the high incidence and serious nature of these complications, it is essential for orthopedic surgeons to have a comprehensive knowledge of the risk factors, diagnosis, and treatment of acute DVT and PE. Perioperative management of orthopedic patients to prevent postoperative DVT and PE and optimize postoperative outcomes is also discussed in this review.

Two-Stage Revision Total Knee Arthroplasty in the Setting of Periprosthetic Knee Infection

Two-stage revision total knee arthroplasty (TKA) is the standard of care for patients who require a revision procedure for the mangement of a late or chronic periprosthetic knee infection. A careful examination of two-stage revision TKA is warranted as the number of patients who require revision TKA in the United States continues to rise. Surgeons should understand the intricacies involved in two-stage revision TKA, including the indications, procedural variations, and current deliberations on two-stage revision TKA in the literature. Surgeons also should understand the alternative treatments for periprosthetic knee infections.

Single-Stage Revision Total Knee Arthroplasty in the Setting of Periprosthetic Knee Infection: Indications, Contraindications, and Postoperative Outcomes

Single-stage revision total knee arthroplasty has become an increasingly common treatment option for patients with failed knee prostheses. Periprosthetic knee infection is the leading and most devastating cause of revision total knee arthroplasty. Although periprosthetic knee infection has been extensively studied in the orthopaedic literature, the role of single-stage revision total knee arthroplasty for the treatment of periprosthetic knee infection warrants further research. As healthcare reform shifts from a volume-based to a value-based system, it is imperative that orthopaedic surgeons understand the procedural indications, risks, and benefits of single-stage revision total knee arthroplasty.

Prevention and Diagnosis of Periprosthetic Knee Infection

Total knee arthroplasty (TKA) has become an increasingly common treatment option for patients who have debilitating knee arthritis. TKA is a relatively safe and efficient procedure that results in promising outcomes and has a positive effect on a patient's quality of life. More TKAs are being performed annually because the procedure substantially reduces pain and improves functionality; however, as the number of TKAs continues to rise, there is concern for potential complications that may result in prosthetic joint failure. Primary TKA failure may result in revision procedures that have high costs and an increased risk for additional complications. Infection is the second most common cause of primary TKA failure and the single most common cause of revision TKA failure. Surgeons who have a better understanding of the epidemiology, risk factors, and diagnostic modalities associated with periprosthetic knee infection will be able to implement preventive measures and treat patients in whom such a complication occurs.

Reimbursement Based on Value in Knee Surgery: What You Need to Know about the Medicare Access and Children's Health Insurance Program Reauthorization Act of 2015

Health care cost is consuming a large portion of the nation's gross domestic product while placing added economic burdens on physicians and their patients. With total joint replacement being one of the early-targeted procedures in the evolving health care environment, knee surgeons will benefit from developing a critical knowledge on health care reforms and their financial implications. The Medicare Access and Children's Health Insurance Program Reauthorization Act represents a cohesive movement toward value-based payment reform and contains several unchartered rulings that require detailed attention by knee surgeons. In this article, we provide a contextual framework of health care legislation that has led to the formation of the current health policy, and present a comprehensive summary and update on the Merit-Based Incentive Payment Systems and Alternative Payment Models reimbursement models.

A Meta-Analysis Comparing All-Polyethylene Tibial Component to Metal-Backed Tibial Component in Total Knee Arthroplasty: Assessing Survivorship and Functional Outcomes

BACKGROUND

This meta-analysis compares the clinical performance of all-polyethylene tibial (APT) to the metal-backed tibial (MBT) components.

METHODS

We included comparative studies in primary total knee arthroplasty involving APT and MBT implant components. The primary outcomes were function, durability, and reports of adverse events.

RESULTS

Twenty-eight articles with 95 847 knees were available for synthesis. The meta-analysis showed an association of APT with lower revision rates (incidence rate ratio, 0.709; P = .002) and adverse events (incidence rate ratio, 0.785; P = .204). Moderator analyses were performed to determine the effect of posterior cruciate ligament status on outcome, and no statistically significant effect was found for revision risk or adverse events incidence.

CONCLUSION

All-polyethylene tibial components seem to be an equal option, with less financial burden than the MBT.

Approach to Decrease Infection Following Total Joint Arthroplasty

Surgical site infection in total joint arthroplasty is a challenging complication that warrants discussion with regard to prevention and management. Limiting postoperative infection rate is a paramount quest in the orthopedic community. Several preoperative risk factors have been identified in orthopedic literature with regards to likelihood of developing postoperative infection. This article evaluates several factors that predispose total joint arthroplasty patients to infection. Methods of patient surgical preparation designed to decrease postoperative infection, decreasing intraoperative traffic during procedural settings, and elaborate intraoperative prophylactic advancements are assessed. Approaches to decrease postoperative infection by discussing means of lowering rates of postoperative transfusion, wound drainage, and hematoma formation are analyzed.

Patient Centeredness in Total Joint Replacement: Beyond the Slogan

Patient-centered care (PCC) is gaining considerable momentum among health care professionals and policy-making authorities. The need for PCC stems from the innumerable benefits of adopting such a system. The practice of PCC in orthopedic surgery in general, and in total joint replacement in particular, is still in its youth. However, present literature already establishes the need for applying PCC in total joint replacement. Extensive research and effort should be invested to better grasp and define the dimensions of PCC as they relate to total joint replacement.

Health Care Reform: Impact on Total Joint Replacement

The US health care system has been fragmented for more than 40 years; this model created a need for modification. Sociopoliticomedical system-related factors led to the Affordable Care Act (ACA) and a restructuring of health care provision/delivery. The ACA increases access to high-quality "affordable care" under cost-effective measures. This article provides a comprehensive review of health reform and the motivating factors that drive policy to empower arthroplasty providers to effectively advocate for the field of orthopedics as a whole, and the patients served.

Planning, Building, and Maintaining a Successful Musculoskeletal Service Line

Within the past 3 decades, a recent trend in the growth of musculoskeletal service lines has been seen nationally. Orthopedics offers an appealing concourse for implementation of service-line care. Within this review, the authors address the components involved in planning and building a musculoskeletal service line. The authors also address methods by which orthopedic surgeons can maintain the efficacy of their service lines by examining how orthopedic surgeons can navigate their service line through recent advents in health care reform. Finally, the authors review successful examples of musculoskeletal service lines currently in practice within the orthopedic community.

Big Data, Big Problems: Incorporating Mission, Values, and Culture in Provider Affiliations

This article explores how integration of data from clinical registries and electronic health records produces a quality impact within orthopedic practices. Data are differentiated from information, and several types of data that are collected and used in orthopedic outcome measurement are defined. Furthermore, the concept of comparative effectiveness and its impact on orthopedic clinical research are assessed. This article places emphasis on how the concept of big data produces health care challenges balanced with benefits that may be faced by patients and orthopedic surgeons. Finally, essential characteristics of an electronic health record that interlinks musculoskeletal care and big data initiatives are reviewed.

Comparing In-Hospital Total Joint Arthroplasty Outcomes and Resource Consumption Among Underweight and Morbidly Obese Patients

BACKGROUND

As orthopedic surgeons search for objective measures that predict total joint arthroplasty (TJA) outcomes, body mass index may aid in risk stratification. The purpose of this study was to compare in-hospital TJA outcomes and resource consumption amongst underweight (body mass index ≤19 kg/m(2)) and morbidly obese patients (≥40 kg/m(2)).

METHODS

Discharge data from 2006 to 2012 National Inpatient Sample were used for this study. A total of 1503 total hip arthroplasty (THA) and 956 total knee arthroplasty (TKA) patients were divided into 2 cohorts, underweight (≤19 kg/m(2)) and morbidly obese (≥40 kg/m(2)). Patients were matched by gender and 27 comorbidities by use of Elixhauser Comorbidity Index. Patients were compared for 13 in-hospital postoperative complications, length of stay, total hospital charge, and disposition. Multivariate analyses were generated by SAS software. Significance was assigned at P value <.05.

RESULTS

Underweight patients undergoing primary TJA had higher risk for developing postoperative anemia compared with morbidly obese patients (TKA: odds ratio [OR], 3.1; 95% CI, 2.3-4.1; THA: OR, 1.8; 95% CI, 1.5-2.3). Underweight THA candidates displayed greater risk for deep venous thrombosis (75.36% vs 24.64%; OR, 3.1; 95% CI, 1.1-8.4). Underweight TJA patients were charged more (TKA: USD 51,368.90 vs USD 40,128.80, P = .001, THA: USD 57,451.8 vs USD 42,776.9, P < .001) compared to the morbidly obese patients. Length of stay was significantly longer for underweight THA patients (4.6 days vs 3.5 days, P = .008) compared to morbidly obese counterparts.

CONCLUSION

Our results indicate underweight, compared to morbidly obese, TJA patients are at a greater risk for postoperative anemia and consume more resources.

High Reliability of Care in Orthopedic Surgery: Are We There Yet?

As health care reimbursement models shift from volume-based to value-based models, orthopedic surgeons must provide patients with highly reliable care, while consciously minimizing cost, maintaining quality, and providing timely interventions. An established means of achieving these goals is by implementing a highly reliable care model; however, before such a model can be initiated, a safety culture, robust improvement strategies, and committed leadership are needed. This article discusses interdependent and critical changes required to implement a highly reliable care system. Specific operative protocols now mandated are discussed as they pertain to high reliability of orthopedic care and elimination of wrong-site procedures.

Reducing Length of Stay in Total Joint Arthroplasty Care

As health care reforms continue to improve quality of care, significant emphasis will be placed on evaluation of orthopedic patient outcomes. Total joint arthroplasty (TJA) has a proven track record of enhancing patient quality of life and are easily replicable. The outcomes of these procedures serve as a measure of health care initiative success. Specifically, length of stay, will be targeted as a marker of quality of surgical care delivered to TJA patients. Within this review, we will discuss preoperative and postoperative methods by which orthopedic surgeons may enhance TJA outcomes and effectively reduce length of stay.

Assessing In-Hospital Outcomes and Resource Utilization After Primary Total Joint Arthroplasty Among Underweight Patients

BACKGROUND

Poor nutritional status is a preventable condition frequently associated with low body mass index (BMI). The purpose of this study is to comparatively analyze low (≤19 kg/m(2)) and normal (19-24.9 kg/m(2)) BMI cohorts, examining if a correlation between BMI, postoperative outcomes, and resource utilization exists.

METHODS

Discharge data from the 2006-2012 National Inpatient Sample were used for this study. A total of 3550 total hip arthroplasty (THA) and 1315 total knee arthroplasty (TKA) patient samples were divided into 2 cohorts, underweight (≤19 kg/m(2)) and normal BMI (19-24.9 kg/m(2)). Using the Elixhauser Comorbidity Index, all cohorts were matched for 27 comorbidities. In-hospital postoperative outcomes and resource utilization among the cohorts was then comparatively analyzed. Multivariate analyses and chi-squared tests were generated using SAS software. Significance was assigned at P < .05.

RESULTS

Underweight patients undergoing THA were at higher risk of developing postoperative anemia and sustaining cardiac complications. In addition, underweight patients had a decreased risk of developing postoperative infection. Resource utilization in terms of length of stay and hospital charge were all higher in the underweight THA cohort. Similarly, in the underweight TKA cohort, a greater risk for the development of hematoma/seroma and postoperative anemia was observed. Underweight TKA patients incurred higher hospital charge and were more likely to be discharged to skilled nursing facilities.

CONCLUSION

Our results indicate that low-BMI patients were more likely to have postoperative complications and greater resource utilization. This serves a purpose in allowing orthopedic surgeons to better predict patient outcomes and improve treatment pathways designed toward helping various patient demographics.

Assessing Tibial Tray Rotation in TKA: A Cadaveric Study

Tibial anatomical landmarks for transverse plane rotation of the tibial tray have not been validated. The current authors propose aligning the tibial tray with both the anterior tibial center point of rotation (ATCPR) and the femoral trochlear groove (FTG) to establish the ideal tibial tray rotation in total knee arthroplasty (TKA). When the tibial tray centerline was aligned with ATCPR and FTG lines, the mean range of motion (ROM) was 144.3° (preoperatively 145°) and tibial rotation range was 22.8 mm (preoperatively, 24.9 mm). When the tibial component was rotated 5 mm medially to the ATCPR, the knee ROM decreased in flexion with patellar subluxation, while it decreased in extension when rotated 5 mm laterally. This method identifies the ideal tibial tray rotation in TKA, at which maximal range of tibial rotation and knee ROM are achieved without obvious overriding of components. [Orthopedics, 2016; 39(3):S67-S71.].

Postoperative Radiographic Assessment of the Vega Posterior-Stabilized TKA

Different biomechanical designs are incorporated into various total knee arthroplasty (TKA) implants. The posterior-stabilized prosthesis design utilizes a polyethylene post and femoral cam in place of the posterior cruciate ligament. This produces a more stable component interface, increased range of motion, and potentially a less technical procedure. This study aimed to assess the short-term (>2 year) outcomes associated with the Vega System posterior-stabilized knee prosthesis (Aesculap Implant Systems, Center Valley, Pennsylvania) based on postoperative radiographs using the Knee Society Roentgenographic Evaluation and Scoring System (KSRESS). Thirty-seven TKA patients who had received the Vega posterior-stabilized knee prosthesis and had postoperative radiographs at each follow-up for a minimum of 2 years were enrolled, retrospectively. Two independent observers evaluated the radiographs using KSRESS. Descriptive statistics were used to analyze the data. The average age and body mass index of patients enrolled was 67 years (range, 51-89 years) and 38.5 kg/m(2) (range, 21.2-54 kg/m(2)), respectively. Patients had radiographic follow-up for an average of 36 months (range, 24-58 months). Comparison between first and last available postoperative radiographs revealed a stable femoral and tibial interface with no significant change in prosthesis alignment over the follow-up period. Assessment of the short-term survivorship of the Vega posterior-stabilized prosthesis using KSRESS revealed no significant change in alignment after 2 years of follow-up; however, mid- to long-term studies assessing this junction are needed. A future prospective study using KSRESS in combination with clinical follow-up is recommended to allow comparison of the Vega posterior-stabilized to other prostheses. [Orthopedics. 2016; 39(3):S56-S60.].

Economics of All-Polyethylene Versus Metal-Backed Tibial Prosthesis Designs

With the large number of total knee arthroplasties being performed and expectations that these numbers will be on the rise over the coming decades, efforts to provide cost-efficient care are of greater interest. The preferred design of knee arthroplasty implants has changed over time, with the original all-polyethylene tibial (APT) design being replaced by metal-backed tibial (MBT) components, as well as more recent considerations of newer APT designs. Modern APT components have been shown to have similar or superior outcomes than MBT components. Despite their limitations, APT components can be used to reduce the economic burden to the provider, medical institution, and health care system as a whole. There is a paucity of evidence-based literature directly comparing the cost associated with APT and MBT components. The purpose of this report is to review the literature to assess the available data regarding direct and indirect costs of both designs so that orthopedic surgeons can account for economic differences in everyday practice. [Orthopedics. 2016; 39(3):S61-S66.].

Cardiovascular Considerations for Joint Replacement Surgery

Heart disease is the leading cause of death in the United States. Cardiovascular complications are associated with higher morbidity and mortality rates for patients who undergo orthopaedic surgery. Therefore, the clinical importance of a comprehensive preoperative evaluation and medical clearance is crucial and may substantially improve postoperative outcomes. A thorough knowledge of cardiovascular perioperative planning and management can enable healthcare professionals to identify patients who are potentially at risk for cardiovascular complications, and eventually improve both short- and long-term patient outcomes and satisfaction.

Perioperative Treatment of Patients with Rheumatoid Arthritis

Rheumatoid arthritis is an autoimmune disease mediated by a widespread, chronic, and systematic inflammatory process that causes joint deterioration, which leads to pain, disability, and poor quality of life. The increased use of disease-modifying antirheumatic drugs has been shown to markedly slow disease progression, which has translated into a decrease in the need for orthopaedic intervention in this population. However, in a substantial percentage of patients with the disease, optimal pharmacologic treatment fails and surgical intervention is required. A thorough understanding of medical considerations in these patients and improved knowledge of the medical complications caused by the disease process and the pharmacologic therapy used to treat it may lead to improved preoperative planning and medical clearance, which may ultimately improve the overall postoperative outcome.