Obesity increases length of stay and direct medical costs in total hip arthroplasty

Early adverse outcomes remain challenging to prevent in morbidly obese patients undergoing total hip arthroplasty

Aims

The prevalence of obesity is increasing substantially around the world. Elevated BMI increases the risk of complications following total hip arthroplasty (THA). We sought to evaluate trends in BMI and complication rates of obese patients undergoing primary THA over the last 30 years.

Methods

Through our institutional total joint registry, we identified 15,455 primary THAs performed for osteoarthritis from 1990 to 2019. Patients were categorized according to the World Health Organization (WHO) obesity classification and groups were trended over time. Cox proportional hazards regression analysis controlling for confounders was used to investigate the association between year of surgery and two-year risk of any reoperation, any revision, dislocation, periprosthetic joint infection (PJI), venous thromboembolism (VTE), and periprosthetic fracture. Regression was stratified by three separate groups: non-obese; WHO Class I and Class II (BMI 30 to 39 kg/m2); and WHO Class III patients (BMI ≥ 40 kg/m2).

Results

There was a significant increase in the proportion of all obesity classes from 1990 to 2019, and the BMI values within each WHO class significantly increased over time. Risk of any reoperation did not change over time among non-obese or WHO Class I/II patients, but increased for WHO Class III patients (hazard ratio (HR) 1.04; p = 0.044). Risk of dislocation decreased over time for non-obese (HR 0.96; p < 0.001) and WHO Class I/II (HR 0.96; p = 0.002) patients, but did not change over time for WHO Class III (HR 0.94; p = 0.073) patients. Risks of any revision and PJI did not change over time for any group.

Conclusion

The proportion of patients undergoing THA who are obese has increased dramatically at our institution between 1990 and 2019. Despite BMI values increasing within all WHO classes over time, two-year complication risks have remained stable or decreased in WHO Class I/II patients. However, continued efforts will be required to mitigate risks in the heaviest WHO Class III patients.

Inpatient Hospital Costs, Emergency Department Visits, and Readmissions for Revision Hip and Knee Arthroplasty

BACKGROUND

Revision total hip arthroplasty (THA) and total knee arthroplasty (TKA) tremendously burden hospital resources. This study evaluated factors influencing perioperative costs, including emergency department (ED) visits, readmissions, and total costs-of-care within 90 days following revision surgery.

METHODS

A retrospective analysis of 772 revision TKAs and THAs performed on 630 subjects at a single center between January 2007 and December 2019 was conducted. Cost data were available from January 2015 to December 2019 for 277 patients. Factors examined included comorbidities, demographic information, preoperative Anesthesia Society of Anesthesiologists score, implant selection, and operative indication using mixed-effects linear regression models.

RESULTS

Among 772 revisions (425 THAs and 347 TKAs), 213 patients required an ED visit, and 90 required hospital readmission within 90 days. There were 22.6% of patients who underwent a second procedure after their initial revision. Liver disease was a significant predictor of ED readmission for THA patients (multivariable odds ratio [OR]: 3.473, P = .001), while aseptic loosening, osteolysis, or instability significantly reduced the odds of readmission for TKA patients (OR: 0.368, P = .014). In terms of ED visits, liver disease increased the odds for THA patients (OR: 1.845, P = .100), and aseptic loosening, osteolysis, or instability decreased the odds for TKA patients (OR: 0.223, P < .001). Increased age was associated with increased costs in both THA and TKA patients, with significant cost factors including congestive heart failure for TKA patients (OR: $7,308.17, P = .004) and kidney disease for THA patients. Revision surgeries took longer than primary ones, with TKA averaging 3.0 hours (1.6 times longer) and THA 2.8 hours (1.5 times longer).

CONCLUSIONS

Liver disease increases ED readmission risk in revision THA, while aseptic loosening, osteolysis, or instability decreases it in revision TKA. Increased age and congestive heart failure are associated with increased costs. These findings inform postoperative care and resource allocation in revision arthroplasty.

LEVEL OF EVIDENCE

Economic and Decision Analysis, Level IV.

The classification algorithms to support the management of the patient with femur fracture

Effectiveness in health care is a specific characteristic of each intervention and outcome evaluated. Especially with regard to surgical interventions, organization, structure and processes play a key role in determining this parameter. In addition, health care services by definition operate in a context of limited resources, so rationalization of service organization becomes the primary goal for health care management. This aspect becomes even more relevant for those surgical services for which there are high volumes. Therefore, in order to support and optimize the management of patients undergoing surgical procedures, the data analysis could play a significant role. To this end, in this study used different classification algorithms for characterizing the process of patients undergoing surgery for a femoral neck fracture. The models showed significant accuracy with values of 81%, and parameters such as Anaemia and Gender proved to be determined risk factors for the patient's length of stay. The predictive power of the implemented model is assessed and discussed in view of its capability to support the management and optimisation of the hospitalisation process for femoral neck fracture, and is compared with different model in order to identify the most promising algorithms. In the end, the support of artificial intelligence algorithms laying the basis for building more accurate decision-support tools for healthcare practitioners.

Weighing the Impact: The Influence of Body Mass Index on Facility Costs in Total Joint Arthroplasty

BACKGROUND

Using time-driven activity-based costing (TDABC), a novel cost calculation method that more accurately reflects true resource utilization in health care, we sought to compare the total facility costs across different body mass index (BMI) groups following total joint arthroplasty (TJA).

METHODS

The study consisted of 13,806 TJAs (7,340 total knee arthroplasties [TKAs] and 6,466 total hip arthroplasties [THAs]) performed between 2019 and 2023. The TDABC data from an analytics platform was employed to depict total facility costs, comprising personnel and supply costs. For the analysis, patients were stratified into four BMI categories: <30, 30 to <35, 35 to <40, and ≥40. Multivariable regression was used to determine the independent effect of BMI on facility costs.

RESULTS

When indexed to patients who had BMI <30, elevated BMI categories (30 to <35, 35 to <40, and ≥40) were associated with higher total personnel costs (TKA 1.03x versus 1.07x versus 1.13x, P < .001; THA 1.00x versus 1.08x versus 1.08x, P < .001), and total supply costs (TKA 1.01x versus 1.04x versus 1.04x, P < .001; THA 1.01x versus 1.02x versus 1.03x, P = .007). Total facility costs in TJAs were significantly greater in higher BMI categories (TKA 1.02x versus 1.05x versus 1.08x, P < .001; THA 1.01x versus 1.05x versus 1.05x, P < .001). Notably, when incorporating adjustments for demographics and comorbidities, BMI values of 35, 40, and 45 relative to BMI of 25, exhibit a significant association with a 2, 3, and 5% increase in total facility cost for TKAs and a 3, 5, and 7% increase for THAs.

CONCLUSIONS

Using TDABC methodology, this study found that overall facility costs of TJAs increase with BMI. The present study provides patient-level cost insights, indicating the potential need for reassessment of physician compensation models in this population. Further studies may facilitate the development of risk-adjusted procedural codes and compensation models for public and private payors.

LEVEL OF EVIDENCE

Level IV, economic and decision analyses.

Remote Delivery of Partial Meal Replacement for Weight Loss in People Awaiting Arthroplasty

Background: Obesity is linked to higher rates of complications; lower absolute recovery of mobility, pain, and function; and increased costs of care following total knee or hip arthroplasty (TKA, THA). The aim of this prospective cohort study was to evaluate the effectiveness of a 12-week partial meal replacement (PMR) weight loss program for people awaiting TKA or THA and living with obesity (body mass index (BMI) ≥ 30 kg/m2). Methods: The intervention was delivered remotely and included a 12-week PMR plan of 1200 calories/day, incorporating two meal replacement shakes/soups and a third suitable simple meal option. The intervention support was provided through online group education sessions, one-to-one teleconsultation with a dietitian, and access to a structured PMR App with functions for goal setting and providing educational content on diet, physical activity, and behaviour changes. Results: Of the 182 patients approached, 29 provided consent to participate, 26 participants commenced the program, and 22 participants completed the 12-week PMR plan. Completers exhibited statistically significant weight loss from baseline to 12 weeks, with a paired difference of 6.3 kg (95% CI: 4.8, 7.7; p < 0.001), with 15 out of 22 (68.2%) participants achieving at least 5% weight loss. Statistically significant reductions in HbA1c and low density lipoprotein (LDL) were observed at 12 weeks compared to baseline. Moreover, a significant increase in the proportion of participants in the action and maintenance phases of the readiness to change diet, physical activity, and weight were observed at 12 weeks. The majority of program completers (18 out of 22) expressed willingness to pay for the service if offered on a long-term basis following the arthroplasty. Conclusions: This study's findings demonstrated that significant weight loss is achievable for people living with obesity awaiting arthroplasty following a 12-week PMR weight loss program. The remote delivery of the intervention was feasible and well accepted by people awaiting TKA or THA.

Preoperative weight loss interventions before total hip and knee arthroplasty: a systematic review of randomized controlled trials

BACKGROUND

The high co-prevalence of obesity and end-stage osteoarthritis requiring arthroplasty, with the former being a risk factor for complications during arthroplasty, has led to increasing interest in employing preoperative weight loss interventions such as bariatric surgery and diet modification. However, the current evidence is conflicting, and this study aimed to investigate the effect of weight loss intervention before arthroplasty in prospective randomized controlled trials.

METHODS

Four electronic databases (MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials) were searched for prospective randomized controlled trials that compared weight loss interventions with usual care from inception to October 2023 by following the PRISMA guidelines. The Cochrane risk of bias tool and GRADE framework were used to assess the quality of the studies. Meta-analyses were performed when sufficient data were available from 2 or more studies.

RESULTS

Three randomized controlled trials involving 198 patients were identified. Two studies employed diet modification, and one study utilized bariatric surgery. All three studies reported significant reductions in body weight and body mass index (BMI), and intervention groups had fewer postoperative complications. There was no difference in the length of stay between the intervention group and the control group. Variable patient-reported outcome measures were used by different research groups.

CONCLUSION

Weight loss intervention can achieve significant reductions in body weight and body mass index before arthroplasty, with fewer postoperative complications reported. Further studies with different populations could confirm the effect of these interventions among populations with different obesity characteristics.

Association of medical comorbidities in obese subjects diagnosed with heparin-induced thrombocytopenia

Objectives

Heparin-induced thrombocytopenia can occur in obese subjects. The medical comorbidities associated with obesity may contribute to the pathogenesis of this disease. It is unknown, however, which specific medical comorbidities and if higher odds of thrombosis are present in obese heparin-induced thrombocytopenia patients. We sought to determine whether obese heparin-induced thrombocytopenia subjects had higher odds of both comorbidities and thrombosis, hypothesizing that this patient population would have higher odds of both these conditions.

Methods

This was a multi-center retrospective study utilizing TriNetX©, an electronic health record database, in subjects aged 18-99 years diagnosed with heparin-induced thrombocytopenia. The cohort was divided into two groups (1) non-obese (body mass index < 30 kg/m2) and (2) obese (body mass index ⩾ 30 kg/m2). We evaluated patient characteristics, diagnostic, laboratory, medication, and procedure codes.

Results

A total of 1583 subjects (696 (44.0%) non-obese and 887 (56.0%) obese) were included. Obese subjects had higher odds of diabetes with complications (OR = 1.73, 95% CI = 1.35-2.22, p < 0.001) and without complications (OR = 1.81, 95% CI = 1.47-2.22, p < 0.001). This association was still present after correcting for demographic and clinical factors. There were no increased odds of thrombosis observed in the obesity group.

Conclusions

Our study found that obese heparin-induced thrombocytopenia subjects had higher odds of having a diabetes mellitus comorbidity, but did not have higher odds of thrombosis. Given obesity is considered a hypercoagulable state, further study may be needed to understand why obese subjects diagnosed with heparin-induced thrombocytopenia do not have higher rates of thrombosis.

The Impact of Preoperative Medical Evaluation in an Orthopaedic Perioperative Medical Clinic on Total Joint Arthroplasty Outcomes: An Observational Study

BACKGROUND

A preoperative medical evaluation (PME) in total joint arthroplasty (TJA) is routine despite considerable variation and uncertainty regarding its benefits. The orthopaedic department in our academic health system established a perioperative medical clinic (PMC) to standardize perioperative management and to study the effect of this intervention on total hip arthroplasty (THA) and total knee arthroplasty (TKA) outcomes. This observational study compared the impact of a PME within 30 days prior to surgery at the PMC (Periop30) versus elsewhere ("Usual Care") on postoperative length of stay (LOS), extended LOS (i.e., a stay of >3 days), and Patient-Reported Outcomes Measurement Information System-10 (PROMIS-10) Global Physical Health (GPH) score improvement in TJA.

METHODS

We stratified adult patients (≥18 years of age) who underwent primary TJA between January 2015 and December 2020 into Periop30 or Usual Care. We utilized univariate tests (a chi-square test for categorical variables and a t test for continuous variables) to assess for differences in patient characteristics. For both TKA and THA, LOS was assessed with use of multivariable negative binomial regression models; extended LOS, with use of binary logistic regression; and PROMIS-10 GPH score, with use of mixed-effects models with random intercept and slope. Interaction terms between the focal predictor (Periop30, yes or no) and year of surgery were included in all models.

RESULTS

Periop30 comprised 82.3% of TKAs (1,911 of 2,322 ) and 73.8% of THAs (1,876 of 2,541). For THA, the Periop30 group tended to be male (p = 0.005) and had a higher body mass index (p = 0.001) than the Usual Care group. The Periop30 group had a higher rate of staged bilateral THA (10.6% versus 7.5%; p = 0.028) and a lower rate of simultaneous bilateral TKA (5.1% versus 12.2%; p < 0.001) than the Usual Care group. Periop30 was associated with a lower mean LOS for both TKA (43.46 versus 54.15 hours; p < 0.001) and THA (41.07 versus 57.94 hours; p < 0.001). The rate of extended LOS was lower in the Periop30 group than in the Usual Care group for both TKA (15% versus 26.5%; p < 0.001) and THA (13.3% versus 27.4%; p < 0.001). There was no significant difference in GPH score improvement between Periop30 and Usual Care for either TKA or THA.

CONCLUSIONS

Periop30 decreased mean LOS and the rate of extended LOS for TJA without an adverse effect on PROMIS-10 GPH scores.

LEVEL OF EVIDENCE

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

Short stem hip arthroplasty with the optimys prosthesis is a safe and effective option for obese patients: a mid-term follow-up multicenter study

INTRODUCTION

Short stems are a valuable option in young patients undergoing total hip arthroplasty (THA) because of their bone stock preserving properties facilitating revision hip arthroplasty. Although the effect of obesity on conventional THA is well studied, data about short stem THA in obese patients are lacking. Therefore, this study aimed to investigate the influence of obesity on complications, revisions, and outcome after short stem THA.

MATERIALS AND METHODS

This multicenter, observational cohort study included patients undergoing short stem THA with the optimys prosthesis. Follow-up examinations were performed at specific intervals up to 7 years postoperatively. Operation characteristics, general and specific complications, revisions, VAS rest pain, VAS load pain, VAS patient satisfaction, and Harris Hip Score (HHS) were recorded and statistically compared between obese (BMI ≥ 30 kg/m2) and non-obese (BMI < 30 kg/m2) patients.

RESULTS

Of the 224 patients included with a mean follow-up of 87.2 months (range 81.9-104.0), 69 were assigned to the OB group and 155 to the non-OB group. A minimally invasive approach was significantly less often selected in obese patients (p = 0.049), whereas operating time and length of hospital stay were not significantly different. The rate of general and specific complications did not significantly differ between both groups. Survival of the optimys prosthesis was 99.1% at 7-year follow-up and one patient per group had to undergo revision surgery. VAS rest pain, load pain, and satisfaction improved from preoperatively to postoperatively in both groups without a significant difference between both groups. While the HHS was improved from preoperatively to postoperatively, obese patients showed a significantly lower HHS at the 7-year follow-up (p = 0.01) but still exhibited an excellent scoring above the PASS threshold.

CONCLUSION

Short stem THA with the optimys prosthesis is a safe and effective option also in obese patients with an excellent clinical outcome and a low complication rate.

Multiplicative effect of frailty and obesity on postoperative mortality following spine surgery: a deep dive into the frailty, obesity, and Clavien-Dindo dynamic

BACKGROUND/OBJECTIVES

Obesity is a global health challenge that affects a large proportion of adults worldwide. Obesity and frailty pose considerable health risks due to their potential to interact and amplify one another's negative effects. Therefore, we sought to compare the discriminatory thresholds of the risk analysis index (RAI), 5-factor modified frailty index (m-FI-5) and patient age for the primary endpoint of postoperative mortality.

SUBJECTS/METHODS

We included spine surgery patients ≥18 years old, from the American College of Surgeons National Quality Improvement program database from 2012-2020, that were classified as obese. We performed receiver operating characteristic curve analysis to compare the discrimination threshold of RAI, mFI-5, and patient age for postoperative mortality. Proportional hazards risk-adjusted regressions were performed, and Hazard ratios and corresponding 95% Confidence intervals (CI) are reported.

RESULTS

Overall, there were 149 163 patients evaluated, and in the ROC analysis for postoperative mortality, RAI showed superior discrimination C-statistic 0.793 (95%CI: 0.773-0.813), compared to mFI-5 C-statistic 0.671 (95%CI 0.650-0.691), and patient age C-statistic 0.686 (95%CI 0.666-0.707). Risk-adjusted analyses were performed, and the RAI had a stepwise increasing effect size across frailty strata: typical patients HR 2.55 (95%CI 2.03-3.19), frail patients HR 3.48 (95%CI 2.49-4.86), and very frail patients HR 4.90 (95%CI 2.87-8.37). We found increasing postoperative mortality effect sizes within Clavein-Dindo complication strata, consistent across obesity categories, exponentially increasing with frailty, and multiplicatively enhanced within CD, frailty and obesity strata.

CONCLUSION

In this study of 149 163 patients classified as obese and undergoing spine procedures in an international prospective surgical database, the RAI demonstrated superior discrimination compared to the mFI-5 and patient age in predicting postoperative mortality risk. The deleterious effects of frailty and obesity were synergistic as their combined effect predicted worse outcomes.

Is Morbid Obesity a Modifiable Risk Factor in Patients Who Have Severe Knee Osteoarthritis and do Not Have a Formal Perioperative Optimization Program?

BACKGROUND

Obesity is considered a modifiable risk factor prior to total knee arthroplasty (TKA); however, little data support this hypothesis. Our purpose was to evaluate patients who have a body mass index (BMI) >40 presenting for TKA to determine the incidence of: (1) patients who achieved successful weight loss through nutritional modification or bariatric surgery and (2) patients who underwent TKA over the study period without the presence of a formal optimization program.

METHODS

This was a retrospective, single-center analysis. Inclusion criteria included: Kellgren and Lawrence grade 3 or 4 knee osteoarthritis, BMI >40 at presentation, and minimum 1-year follow-up (mean 45 months) (N = 624 patients). Demographics, weight loss interventions, pursuit of TKA, maximum BMI change, and Patient-Reported Outcomes Measurement Information System scores were collected. Multivariable logistic and linear regressions evaluated associations of underlying demographic and treatment characteristics with outcomes.

RESULTS

There were 11% of patients who ended up pursuing TKA over the study period. Bariatric surgery was 3.7 times more likely to decrease BMI by minimum 10 compared to nonsurgical intervention (95% confidence interval [CI] [1.7, 8.1]; P = .001). Bariatric surgery resulted in mean BMI change of -3.3 (range, 0 to 22) compared to nonsurgical interventions (-2.6 [range, 0 to 12]) and no intervention (0.4 [range, 0 to 15]; P < .0001). Bariatric surgery patients were 3.1 times more likely to undergo TKA (95% CI [1.3, 7.1]; P = .008), and nonsurgical interventions were 2.4 times more likely to undergo TKA (95% CI [1.3, 4.5]; P = .006) compared to no intervention. Non-White patients across all interventions were less likely to experience loss >5 BMI compared to White patients (95% CI [0.2, 0.9]; P = .018).

CONCLUSIONS

Most patients were unable to reduce BMI more than 5 to 10 over a mean 4-year period without a formal weight optimization program. Utilization of bariatric surgery was most successful compared to nonsurgical interventions, although ultimate pursuit of TKA remained low in all cohorts.

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.

A Longitudinal analysis of weight changes before and after total hip arthroplasty: Weight trends, patterns, and predictors

BACKGROUND

It is crucial to understand weight trends in patients undergoing total hip arthroplasty (THA).

OBJECTIVE

To evaluate preoperative and postoperative weight trends for patients undergoing primary THA and factors associated with clinically significant weight change.

METHODS

A prospective cohort who underwent primary unilateral THA (n= 3,011) at a tertiary healthcare system (January 2016 to December 2019) were included in the study. The primary outcomes were clinically significant weight change (> 5% change in body mass index [BMI]) during the one-year preoperative and one-year postoperative periods.

RESULTS

Preoperatively, 66.6% maintained a stable weight, 16.0% gained and 17.4% lost weight, respectively. Postoperatively, 64.0% maintained a stable weight, while 22.6% gained and 13.4% lost weight, respectively. Female sex, Black race, obesity, higher Charlson Comorbidity Index (CCI) scores, and older age were associated with preoperative weight loss. Female sex, obesity, higher CCI scores, and Medicare insurance were associated with postoperative weight loss. Preoperative weight loss was associated with postoperative weight gain (OR = 3.37 [CI: 2.67 to 4.25]; p< 0.001), and preoperative weight gain was associated with postoperative weight loss (OR = 1.74 [CI: 1.30 to 2.3]; p< 0.001).

CONCLUSION

Most patients maintained a stable BMI one-year before and one-year after THA. Several factors are associated with weight loss before and after THA. Preoperative weight changes were associated with a reciprocal rebound in BMI post-operatively.

Understanding factors that impact the length of stay after total hip arthroplasty - A national in-patient sample-based study

Background

Total hip arthroplasty (THA) is increasingly used every year; however, there is currently limited information on factors that impact the length of stay (LOS) following the procedure. Longer LOS following THA is met with an increase in the cost of care, necessitating studies to identify factors that may impact LOS.

Methods

In this retrospective study, we used the Nationwide Inpatient Sample (NIS) database from 2016 to 2019 to analyze the preoperative comorbidities and postoperative complications that impact the LOS following THA. We divided our cohort into patients with a LOS greater than two days, and patients with a LOS less than two days.

Results

A total of 367,890 patients were identified in the NIS database who underwent THA during the study period. Of this cohort, 112,288 (30.52%) patients were identified as having a LOS greater than two days, while the remaining 255,602 (69.48%) patients were patients who had a LOS less than two days. Multivariate analysis demonstrated several pre-operative factors, such as diabetes, systemic lupus erythematosus, organ transplant, dialysis, the human immunodeficiency virus, chronic kidney disease, and Parkinson's disease, were independently associated with a higher risk of a LOS greater than two days. The subsequent multivariate analysis for post-operative variables demonstrated that acute renal failure, myocardial infarction, blood loss anemia, blood transfusion, pulmonary embolism, deep vein thrombosis, periprosthetic fracture, periprosthetic mechanical complications, periprosthetic infections, and wound dehiscence were all independently associated with a higher risk of a LOS greater than two days.

Conclusions

Several pre-operative comorbidities and postoperative complications were found to increase the likelihood of a LOS greater than two days. In addition, the group with a LOS greater than two days incurred a higher cost of care. This information is useful for providers to make informed decisions regarding patient care and resource utilization for patients undergoing THA, potentially reducing LOS.

Obesity negatively affects outcomes following arthroscopic rotator cuff repair at four-year follow-up

Introduction

The purpose is to evaluate the influence of obesity (BMI 30 to 39.9 kg/m2) on surgical outcomes following arthroscopic rotator cuff repair surgery.

Materials and Methods

A retrospective review was performed examining the outcomes of arthroscopic rotator cuff repair in both a normal weight (BMI 18.5 to 24.9 kg/m2) and an obese (BMI 30 to 39.9 kg/m2) patient population, specifically looking at functional outcomes and range of motion. Secondary variables analyzed were surgical time, complications, and medical comorbidities.

Results

52 normal weight patients (mean BMI 23.7 ± 2.1) and 59 obese patients (mean BMI 34.0 ± 2.4) were included. Both groups demonstrated statistically significant improvements in VAS, SANE and ASES scores (P < 0.0001), however there were significantly better outcomes in the normal weight group in VAS (0.56 ± 0.96 vs 1.42 ± 2.22; P = 0.0108), ASES (96.1 ± 5.8 vs 90.6 ± 15.6; P = 0.0192), and internal rotation (9.2 ± 3.0 vs 10.9 ± 2.3; P = 0.0010). Additionally, the obese cohort had more complications, longer surgical times, and a greater comorbid background.

Conclusions

Obesity is associated with significantly more comorbid conditions, surgical complications, longer surgical time, and worse patient reported outcomes than normal weight patients undergoing arthroscopic rotator cuff repair.

Hip arthroscopy versus total hip arthroplasty-A study on patients with obesity above 40 years of age

Patients older than 40 years with a body-mass-index (BMI) >30 kg/m2 , a femoroacetabular-impingement (FAI) and little cartilage damage are a challenge for hip surgeons. Hip-arthroscopy (HAS) or conservative therapy until a total hip arthroplasty (THA) is needed are possible treatments. Our research purpose was to compare the clinical results and complication/reoperation rate after HAS and THA in patients with obesity over 40 years. This retrospective study includes a consecutive series of patients with obesity (BMI >30 kg/m2 ) who underwent HAS (19 hips) and THA (37 hips) over 40 years of age between 2007 and 2013 at our institution with a minimum of 12-months follow-up. Outcome measures were WOMAC (Western Ontario und McMaster Universities Arthritis Index), subjective-hip-value (SHV), residual complaints and the reoperation rate. Patient data and scores were collected pre-operative, 12 months post-operatively and at the last follow-up. Both groups showed a comparable age (mean 48 years). Regarding SHV-Scores the THA-group shows continuous significant improvements. Reaching 87% (range 50%-100%), the HAS-group showed in case of the SHV no significant change after 1 year and an improvement from preoperative to the last follow-up reaching 72% (range 30%-100%) at the last follow-up. Residual groin pain was significant higher in the HAS-group. Two deep infections (5.4%) requiring reoperations were reported in the THA-group. The conversion rate to THA after a mean time of 60 months was 26% (5 of 19). Patients with obesity over 40 years demonstrated inferior SHV, more often residual pain and revision surgery after HAS, when compared to THA at short-term, with conversions rate of one fourth. However, THA in this patient group showed high infection rate of 5%. This information is relevant for counselling above-mentioned patients.

The Effectiveness of Nutritional Strategies in the Treatment and Management of Obesity: A Systematic Review

Obesity, a condition primarily resulting from positive energy balance, has become a significant global health concern. Numerous studies have demonstrated that obesity is a major risk factor for various illnesses, including different types of cancer, coronary heart disease, sleep apnea, CV stroke, type II diabetes mellitus, etc. To effectively address this issue, prevention and treatment approaches to manage body weight are crucial. There are several evidence-based approaches available for the treatment and management of obesity, taking into account factors such as body mass index classification, individual weight history, and existing comorbidities. To facilitate successful obesity treatment and management, there are pragmatic approaches and tools available, including the reduction of energy density, portion control, and diet quality enhancement. These approaches encompass the use of medications, lifestyle interventions, bariatric surgery, and formula diets. Regardless of the specific method employed, behavior change, reduction of energy intake, and increased energy expenditure are integral components for successful treatment and management of obesity. These measures allow patients to personalize and customize their dietary patterns, leading to effective and sustainable weight reduction. Incorporating physical activities and self-monitoring of individual diets are effective techniques for promoting behavior change in obesity and weight management. The main objective of this systematic review is to evaluate the effectiveness of dietary/nutritional interventions in the treatment and management of obesity through provision of valuable insights into the effectiveness of such nutritional strategies. To attain this, a comprehensive analysis of various dietary approaches and their impacts on weight will be conducted.

Postoperative Day 1 Discharge in Deep Inferior Epigastric Artery Perforator Flap Breast Reconstruction

With high success rates of autologous breast reconstruction, the focus has shifted from flap survival to improved patient outcomes. Historically, a criticism of autologous breast reconstruction has been the length of hospital stay. Our institution has progressively shortened the length of stay after deep inferior epigastric artery perforator (DIEP) flap reconstruction and began discharging select patients on postoperative day 1 (POD1). The purpose of this study was to document our experience with POD1 discharges and to identify preoperative and intraoperative factors that may identify patients as candidates for earlier discharge.

Methods

An institutional review board-approved, retrospective chart review of patients undergoing DIEP flap breast reconstruction from January 2019 to March 2022 at Atrium Health was completed, consisting of 510 patients and 846 DIEP flaps. Patient demographics, medical history, operative course, and postoperative complications were collected.

Results

Twenty-three patients totaling 33 DIEP flaps were discharged on POD1. The POD1 group and the group of all other patients (POD2+) had no difference in age, ASA score, or comorbidities. BMI was significantly lower in the POD1 group (P = 0.039). Overall operative time was significantly lower in the POD1 group, and this remained true when differentiating into unilateral operations (P = 0.023) and bilateral operations (P = 0.01). No major complications occurred in those discharged on POD1.

Conclusions

POD1 discharge after DIEP flap breast reconstruction is safe for select patients. Lower BMI and shorter operative times may be predictive in identifying patients as candidates for earlier discharge.

Episode-of-care costs of total hip arthroplasty: day surgery versus same-day admission

BACKGROUND

Although day surgery (DS) total hip arthroplasty (THA) has good patient satisfaction and a good safety profile, accurate episode-of-care cost (EOCC) calculations for this procedure compared to standard same-day admission (SDA) THA are not well known. We determined the EOCCs for patients who underwent THA, comparing DS and SDA pathways.

METHODS

We evaluated the EOCCs for consecutive patients who underwent DS or SDA THA for osteoarthritis or osteonecrosis performed by a single surgeon at 1 academic centre from July 2018 to January 2020. Patient demographic and clinical data were recorded, as were preoperative diagnosis, type of anesthesia, type of implant used, surgical time and estimated blood loss. We determined direct and indirect costs from time of arrival at the presurgical unit to hospital discharge. We determined the EOCCs using an ABC method.

RESULTS

The study included 50 patients who underwent THA (25 DS, 25 SDA). The mean length of stay in the SDA group was 45.1 (standard deviation [SD] 21.4) hours. Differences were observed between the 2 groups in mean age, mean Charlson Comorbidity Index score, surgical technique and mean surgical time (p ≤ 0.001). The mean total EOCC for SDA THA was $10 911 (SD $706.12, range $9944.07-$12 871.95), compared to $9672 (SD $546.55, range $8838.30-$11 058.07) for DS THA, a difference of 11.4%, mostly attributable to hospital resources such as laboratory tests, radiologic studies and cost of the surgical admission.

CONCLUSION

Day surgery THA is cost-effective in selected patient populations. With the savings identified in this study, every 10 additional DS THA procedures would save sufficient resources to perform an additional THA operation.

Association between eating behavior and the immediate neural activity caused by viewing food images presented in and out of awareness: A magnetoencephalography study

Obesity is a serious health problem in modern society. Considering the fact that the outcomes of treatments targeting appetitive behavior are suboptimal, one potential reason proposed for these poor outcomes is that appetitive behavior is driven more by unconscious decision-making processes than by the conscious ones targeted by traditional behavioral treatments. In this study, we aimed to investigate both the conscious and unconscious decision-making processes related to eating behavior, and to examine whether an interaction related to eating behavior exists between conscious and unconscious neural processes. The study was conducted on healthy male volunteers who viewed pictures of food and non-food items presented both above and below the awareness threshold. The oscillatory brain activity affected by viewing the pictures was assessed by magnetoencephalography. A visual backward masking procedure was used to present the pictures out of awareness. Neural activity corresponding to the interactions between sessions (i.e., food or non-food) and conditions (i.e., visible or invisible) was observed in left Brodmann's areas 45 and 47 in the high-gamma (60-200 Hz) frequency range. The interactions were associated with eating behavior indices such as emotional eating and cognitive restraint, suggesting that conscious and unconscious neural processes are differently involved in eating behavior. These findings provide valuable clues for devising methods to assess conscious and unconscious appetite regulation in individuals with normal or abnormal eating behavior.

The Impact of Obesity on Total Hip Arthroplasty Outcomes: A Retrospective Matched Cohort Study

Aim

Previous research has shown that obesity is associated with worse postoperative outcomes. We aim to determine how rates of specific complications after total hip arthroplasty (THA) align with obesity status. We hypothesize that obese patients would have higher rates of complications and cost and thus have worse outcomes than non-obese patients.

Methods

Data were collected from a large commercial insurance database between 2011 and 2020. Patients underwent a hip replacement under current procedural terminology (CPT) and International Statistical Classification of Diseases (ICD-9/ICD-10) codes. Obese (defined as having a BMI of 30 kg/m² or higher) and non-obese patients were matched on age, gender, Charlson Comorbidity Index (CCI), and Elixhauser Comorbidity Index (ECI). Standardized complications and costs in one year were compared using unequal variance t-tests.

Results

Under CPT codes, 61,462 obese (45% male) and 61,462 non-obese patients (45% male) underwent a hip replacement. Obese patients had significantly higher rates of surgical site infection (SSI) (OR=1.193, p=0.0001), deep vein thrombosis (DVT) (OR=1.275, p=0.001), wound complication (OR=1.736, p<0.0001), hematoma (OR=1.242, p=0.0001), pulmonary embolism (OR=1.141, p=0.0355), UTI (OR=1.065, p=0.0016), and opioid prescriptions (OR=1.17, p<0.0001), and significantly lower rates of arrhythmia (OR=0.907, p<0.0001), congestive heart failure (CHF) (OR=0.863, p<0.0001), cardiac arrest (OR=0.637 p<0.0001), pneumonia (OR=0.795, p<0.0001), and transfusion (OR=0.777, p<0.0001). Furthermore, obese patients were significantly more likely to undergo revision within 10 years (OR=1.172, p<0.0001). Under ICD codes, 31,922 obese (45% male) and 31,922 non-obese patients (45% male) were included. Obese patients did not have a significant difference in total cost or drug cost.

Conclusions

Obese patients had significantly higher rates of infection, venous thromboembolic event, wound complication, hematoma, and opioid prescriptions but significantly lower rates of cardiac issues, pneumonia, and transfusion, after hip replacement. Additionally, there was no significant difference in total or drug cost. Therefore, this study did not support our hypothesis that obese patients have worse outcomes than non-obese patients, as there neither was a clear significant increase in complication rates nor a significant increase in costs. However, further research should be done to better understand the complex relationship between obesity and postoperative outcomes.

Obesity trends over 10 years in primary hip and knee arthroplasty-a study of 12,000 patients

OBJECTIVES/AIMS

Obesity and its increasing prevalence are global public health concerns. Following joint replacement, there is evidence to support that obese patients are more likely to suffer complications. We examined 10-year trends in BMI of the primary total hip and total knee replacement cohorts in our institution to discern whether the BMI of these patients has changed over time.

METHODS

We examined BMI data of patients who underwent primary hip and knee arthroplasty from our institutional database from January 1, 2010 to December 31, 2019 (n = 12,169). We analysed trends in BMI over this period with respect to (i) surgical procedure, (ii) gender, and (iii) age categories.

RESULTS

The overall number of surgical procedures increased over the study period which meant more obese patients underwent surgery over time. Average BMI did not change significantly over time; however, there was a statistically significant increase in BMI in females aged < 45 in both arthroplasty groups.

CONCLUSION

The average BMI of patients undergoing primary hip and knee arthroplasty in our high-volume tertiary orthopaedic centre has remained relatively unchanged over the past 10 years; however, our local service is caring for a greater number of overweight/obese patients due to the increase in overall volume. This will have significant implications on health care expenditure and infrastructure going forward which further emphasises the importance of ongoing national obesity prevention strategies. The increase in BMI seen in females aged < 45 may mark an impending era of obese younger patients with end-stage osteoarthritis.

Predictive factors for discharge destination after total hip arthroplasty

BACKGROUND

This study aimed to investigate factors affecting discharge to an inpatient rehabilitation facility or home following total hip arthroplasty, using a clinical pathway in Japan.

METHODS

Five hundred hips with osteoarthritis who underwent unilateral total hip arthroplasty at our institution, with no deviation from the pathway, were included in this retrospective study. The variables were examined by univariate analysis. Multivariate logistic regression analysis was used to identify the independent factors that influenced the discharge outcome.

RESULTS

Four hundred and thirty-four hips were discharged home directly, and 66 were discharged to an inpatient rehabilitation facility. Patients discharged to an inpatient rehabilitation facility were significantly older, shorter, lighter, and more likely to live alone. Additionally, the preoperative clinical score was significantly lower in the inpatient rehabilitation facility Group for all items. Logistic regression analysis showed a significant association between being discharged to an inpatient rehabilitation facility and higher age [odds ratio 3.87, 95% confidence interval 2.03-7.38, P < 0.001], lower total score in the preoperative Japanese Orthopaedic Association hip score [odds ratio 2.42, 95% confidence interval 1.38-4.23, P = 0.002] and living alone [odds ratio 1.84, 95% confidence interval 1.01-3.35, P = 0.046].

CONCLUSIONS

In this study, age, the preoperative Japanese Orthopaedic Association hip score, and living arrangement impacted the discharge destination after THA.

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.

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.

Patterns and Predictors of Weight Change Before and After Total Hip Arthroplasty in Class 2 and 3 Obese Patients

BACKGROUND

This study aimed to better understand body mass index (BMI) change patterns and factors associated with BMI change before and after total hip arthroplasty (THA) in Class 2 and 3 obese patients, and assess if preoperative or postoperative BMI change affects postoperative clinical outcomes.

METHODS

We retrospectively reviewed World Health Organization Class 2 and 3 obese patients (BMI > 35.0 at surgery) who underwent THA at a tertiary medical center from 2010 to 2020. BMI was recorded at 1 year preoperatively (mean 11.6 months), and at most recent postoperative visit (mean 29.0 months). Baseline demographics and postoperative clinical outcomes were recorded.

RESULTS

We reviewed 436 THAs with a mean age of 59.9 (11.5) years. Leading up to surgery 55.5% had unchanged BMI, and postoperatively 48.2% had unchanged BMI. Multivariate logistic regression revealed that those who lost BMI preoperatively were more likely to gain BMI postoperatively (odds ratio [OR] 3.28, confidence interval [CI] 1.83-5.97, P = .005), but those who gained >5% BMI preoperatively had no association with BMI change postoperatively. Those in a higher BMI class preoperatively were less likely to gain BMI preoperatively (Class 3 obese patients: OR 0.001, CI 0.0002-0.004, P < .001). African American patients were more likely to gain BMI preoperatively (OR 2.32, CI 1.16-4.66, P = .017). We did not detect an association between BMI change and postoperative clinical outcomes.

CONCLUSION

In World Health Organization Class 2 or 3 obese patients, most maintained BMI between their first preoperative and final postoperative visit. Preoperatively, Class 3 obese patients were less likely to gain weight than Class 2 obese patients. The primary predictor of postoperative weight gain was preoperative weight loss. Weight change preoperatively and postoperatively were not associated with worse clinical outcomes.

Do TKAs in Patients with Higher BMI Take Longer, and is the Difference Associated with Surgeon Volume? A Large-database Study from a National Arthroplasty Registry

BACKGROUND

Increased surgical time in TKA may impact economic costs and clinical outcomes. Prior work has found that TKAs in patients with high BMI take longer, and these patients may be at greater risk for postoperative complications like infection. However, these studies included small numbers of patients and surgeons from single institutions and they did not consider surgeon volume.

QUESTIONS/PURPOSES

Using the New Zealand Joint Registry (NZJR), we asked: (1) Is there a relationship between increasing patient BMI and TKA operative time? (2) Is the effect of BMI on surgical time less pronounced among surgeons who perform more TKAs per year than those who perform fewer?

METHODS

Data were collected from the NZJR between January 2010 and December 2018 as it is the only national registry that records both BMI and surgical time. Primary TKA performed for osteoarthritis by surgeons with more than 50 TKAs over the period of the study were identified. BMI and operative time (skin incision to closure in minutes) were recorded. Patients with the following were excluded: lateral parapatellar or minimally invasive approaches; navigated, patient-specific instrumentation, or robot-assisted TKA; uncemented or hybrid fixation; those with procedures performed by a trainee (all or part); or a nonosteoarthritic indication. Of 64,108 TKAs performed during the study period, a total of 42% (27,057) met our inclusion criteria. The primary outcome was the effect of BMI on operative time. Operative time is expressed in minutes as a mean for each single-unit BMI increase across all surgeons, controlled for other variables that might influence operative time such as patella resurfacing and cruciate-retaining versus posterior-stabilized designs. Overall, the mean operative time (skin incision to closure) was 79 ± 22 minutes. Surgical experience was assessed by subdividing surgeons into six groups according to the number of TKAs performed annually (< 10, 10 to 24, 25 to 49, 50 to 74, 75 to 99, and > 100). Statistical analyses were performed including a general linear model to assess the independent association between BMI and operative time, allowing for the effects of other patient and surgical features. In addition, linear regression analyses explored the associations between BMI and operative time in the whole group and within surgical volume groups.

RESULTS

There was an association between increasing BMI and increasing surgical duration. The mean operative time increased from 75 ± 22 minutes in patients with a normal BMI of 25 kg/m2 to 87 ± 24 minutes in patients with a BMI of 40 kg/m2 to 94 ± 28 minutes in patients with a BMI > 50 kg/m2 (p < 0.001). Surgeons performing fewer than 25 TKAs per year took 14% longer to perform a TKA on a patient with a BMI of 40 kg/m2 than on a patient with a normal BMI of 25 kg/m2. However, surgeons performing greater than 25 TKAs per year took 10% longer.

CONCLUSION

In this study, an increase BMI was associated with increased surgical time in TKA. Surgical duration for high-volume surgeons appears less influenced by increases in BMI than lower volume surgeons. Although the absolute increase in duration was small, prolonged surgical time may reduce theater productivity. Even though the issues around managing patients with high BMI are multifactorial and complex, considerations from these findings include ensuring appropriate theater scheduling and possibly referring patients with high BMI to specialist centers. Further studies should focus on assessing the effectiveness of such measures in reducing complications and improving outcomes in patients with elevated BMI.

LEVEL OF EVIDENCE

Level III, therapeutic study.

The Metabolic Syndrome Paradox: Increased Morbidity and Decreased Mortality in Operative Orthopedic Trauma

We examined the impact of metabolic syndrome (MetS) on operative outcomes with orthopedic trauma, particularly among patients with pelvic, acetabular, and lower extremity fractures. This retrospective cohort study used the American College of Surgeons National Surgical Quality Improvement Program database to identify patients who had operative pelvic, acetabular, and lower extremity trauma from 2006 through 2014. We defined MetS as type 2 diabetes, a history of hypertension requiring medication, and body mass index of 30 kg/m² or greater. Patients with MetS were compared with unaffected patients and assessed for association with in-hospital complications and mortality. The study population included 37,495 patients; 5.7% (n=2154) had MetS. On multivariable logistic regression, MetS was associated with increased odds of any hospital complication (odds ratio [OR], 1.30; 95% CI, 1.13-1.51; P<.001), Clavien-Dindo grade IV complications (OR, 1.51; 95% CI, 1.23-1.87; P<.001), readmission (OR, 1.39; 95% CI, 1.18-1.63; P<.001), and reoperation (OR, 1.40; 95% CI, 1.11-1.76; P=.004). Conversely, MetS significantly decreased the odds of mortality (OR, 0.67; 95% CI, 0.49-0.92; P=.01). Although MetS is a risk factor for postoperative complications, longer length of stay, and increased readmission after surgical intervention for orthopedic lower extremity trauma, MetS appears to decrease the odds of mortality in this specific patient population, which merits further investigation. [Orthopedics. 2022;45(2):103-108.].

Obesity, preoperative weight loss, and telemedicine before total joint arthroplasty: a review

The preoperative period prior to elective total joint arthroplasty (TJA) is a critical time for lifestyle interventions since a scheduled surgery may help motivate patients to lose weight. Weight loss may reduce complications associated with obesity following TJA and enable patients with severe obesity (body mass index [BMI] > 40 kg/m²) to become eligible for TJA, as many institutions use a 40 kg/m² cut-off for offering surgery. A comprehensive review was conducted to (1) provide background on complications associated with obesity following TJA, (2) synthesize prior research on the success rate of patients losing weight after being denied TJA for severe obesity, (3) discuss bariatric surgery before TJA, and (4) propose mobile health telemedicine weight loss interventions as potential weight loss methods for patients preoperatively. It is well established that obesity increases complications associated with TJA. In total knee arthroplasty (TKA), obesity increases operative time, length of stay, and hospitalization costs as well as the risk of deep infection, revision, and component malpositioning. Obesity may have an even larger impact on complications associated with total hip arthroplasty (THA), including wound complications and deep infection. Obesity also increases the risk of hip dislocation, aseptic loosening, and venous thromboembolism after THA. Synthesis of the only two studies (n = 417), to our knowledge, that followed patients denied TJA for severe obesity demonstrated that only 7% successfully reduced their BMI below 40 kg/m² via lifestyle modifications and ultimately underwent TJA. Unfortunately, bariatric surgery may only increase certain post-TKA complications including death, pneumonia, and implant failure, and there is limited research on preoperative weight loss via lifestyle modification. A review of short-term mobile health weight loss interventions that combined personalized counseling with self-monitoring via a smartphone app found about 5 kg of weight loss over 3-6 months. Patients with severe obesity have more weight to lose and may have additional motivation to do so before TJA, so weight loss results may differ by patient population. Research is needed to determine whether preoperative mobile health interventions can help patients become eligible for TJA and produce clinically significant weight loss sufficient to improve postoperative outcomes.

The Association of Body Mass Index with Surgical Time Is Mediated by Comorbidity in Patients Undergoing Total Hip Arthroplasty

Overweight represents a major issue in contemporary orthopaedic practice. A higher body mass index (BMI) is associated with an increase of perioperative complications following several orthopaedic procedures, in particular total hip arthroplasty (THA). However, the influence of overweight on THA surgical time is controversial. In this study, we investigated the association between BMI and surgical time analyzing the role of patients’ comorbidities. We conducted a retrospective study on 748 patients undergoing THA at our institutions between 2017 and 2018. Information regarding medical diseases was investigated and the burden of comorbidity was quantified using the Charlson score (CCI). Surgical time and blood loss were also recorded. Median surgical time was 76.5 min. Patients with surgical time above the median had both a higher BMI (28.3 vs. 27.1 kg/m²; p = 0.002); and CCI (1 vs. 0; p = 0.016). According to linear regression, surgical time was associated with BMI in the unadjusted model (p < 0.0001), after adjusting for age and sex (p < 0.0001), and in the multivariable model (p = 0.005). Furthermore, BMI was associated with increased surgical time only in patients with a Charlson score above the median, but not in others. Obesity is associated with increased surgical time during THA, especially in pluricomorbid patients, with a higher risk of perioperative complications.

Morbid obesity is not a contraindication to lower limb arthroplasty

There are concerns that increased BMI is associated with a greater length of stay (LOS) and perioperative complications following total knee (TKR) and total hip replacements (THR). We analysed data from a six-month period to see if there was a correlation between BMI and LOS. We performed a subgroup analysis for patients with morbid obesity (BMI >40) looking at perioperative complications. 285 TKRs and 195 THRs were analysed. For TKRs, the average length of stay was 2.7 days. The average BMI was 32.4. There was no significant correlation between BMI and LOS (r=-0.0447, p=0.2267). The morbidly obese category (n=33) had the shortest LOS (2.5 days) compared to other BMI categories. 30- day readmission rate was 6%. 90-day re-admission rate was 12%. Six patients had minor wound issues requiring no intervention or antibiotics only. The was one prosthetic joint infection, one stitch abscess, one DVT and one patellar tendon injury. For THRs, the average LOS was 2.9 days. The average BMI was 29.9. There was no significant correlation between BMI and LOS (r=0.007, p=0.4613). The morbid obese category (n=9) had the shortest LOS (1.9 days) compared to other BMI categories. No patients were readmitted within 90 days or had documented complications. We have shown that for TKRs and THRs, increased BMI is not associated with increased LOS. The morbidly obese were found to have the shortest LOS. Re-admission rates and complications were commendable for patients with morbid obesity. BMI >40 is not a contraindication to TKR or THR.

Preoperative Nonsurgical Weight Loss Interventions Before Total Hip and Knee Arthroplasty: A Systematic Review

BACKGROUND

An upcoming total joint arthroplasty (TJA) may motivate patients with severe obesity (body mass index [BMI] > 40 kg/m²) to lose weight. Weight loss can optimize outcomes following TJA, and many surgeons use a 40 kg/m² cut-off for undergoing TJA to reduce the risk of complications. However, few patients who are denied TJA for severe obesity successfully lose weight. This is the first systematic review of nonsurgical weight loss interventions before TJA.

METHODS

Five electronic databases were searched for articles on January 11, 2021. Studies that utilized preoperative nonsurgical weight loss interventions for patients with obesity (BMI ≥ 30 kg/m²) scheduled for or awaiting TJA of the hip or knee were included. Two reviewers independently screened articles, assessed methodological quality, and extracted data.

RESULTS

We retrieved 1943 unique records, of which 7 met inclusion criteria including 2 randomized clinical trials and 5 single-arm case series. Overall, weight loss ranged from 5.0 to 32.5 kg. Four interventions reduced BMI by 3 kg/m² at 3-5 months, while 1 reduced BMI by 12.7 kg/m². Other weight outcomes and those related to pain, function, complications, and adverse events were inconsistently reported.

CONCLUSION

Although larger trials are needed, particularly randomized controlled trials that measure preoperative weight loss in a control group, nutritional status, and postoperative complications, the available evidence indicates that short-term, nonsurgical, preoperative weight loss interventions before TJA produce both statistically significant weight loss and reduced BMI before surgery. It remains unknown if the amount of weight loss from these interventions is clinically significant and sufficient to improve outcomes after TJA.

Cost analysis of primary single-level lumbar discectomies using the Value Driven Outcomes database in a large academic center

BACKGROUND CONTEXT

Improving value is an established point of emphasis to reduce the rapidly rising health care costs in the United States. Back pain is a major driver of costs with a substantial fraction caused by lumbar radiculopathy. The most common surgical treatment for lumbar radiculopathy is microdiscectomy. Research is sparse regarding variables driving cost in microdiscectomies and often limited by cost data derived from payer-based Medicare data.

PURPOSE

To identify targets for cost reduction by determining variables associated with significant cost variation in microdiscectomies, using cost data derived from the Value Driven Outcomes tool and actual system costs.

STUDY DESIGN

Single-center, retrospective study of prospectively collected registry data.

PATIENT SAMPLE

Six hundred twenty-two patients identified by CPT code and manually screened for initial, unilateral, single-level lumbar discectomy performed between 2014 and 2018 at a single institution.

OUTCOME MEASURES

Primary outcome measures include total direct cost, clinical length of stay, and OR minutes. Total Direct Cost was further differentiated into facility and nonfacility costs.

METHODS

Univariate and multivariate generalized linear models (GLM) were used to identify variables associated with variation in primary outcome measures. Costs were normalized by mean cost for patients with normal body mass index (BMI) and a healthy American Society of Anesthesiologists (ASA) classification. Average marginal effects were reported as percentage of normalized costs.

RESULTS

Advanced age, male gender, Hispanic, black, unemployment, obesity, higher ASA class, insurance status, and being retired were positively associated with costs in univariate analysis. Asian, Native American, outpatient procedures, and being a student were associated with decreases in costs. In multivariate analysis, we found that obesity led to higher average marginal total direct (9%), total facility (15%), and facility OR costs (22%), as well as 24 more OR minutes per surgery. While being overweight was not associated with greater total direct costs, it was associated with higher total facility (8%), and facility OR costs (12%), with 11 more OR minutes per surgery. Age was associated with a longer LOS but not with OR costs. As expected, outpatient surgical costs, LOS, and OR time were significantly lower than inpatient procedures. Severe systematic disease was associated with greater total and nonfacility costs. In addition, Medicare patients had higher facility costs (14%) compared to privately insured patients.

CONCLUSIONS

Significant drivers of total direct cost in multivariate GLM analysis were obesity, severe systemic disease and inpatient surgery. Average LOS was increased due to age and inpatient status, conversely it was decreased by unemployment and retirement. Significant variables in OR time were male sex, Hispanic race and both obese and overweight BMIs.

Increasing Reoperations and Failures With Increasing BMI in Patients Undergoing 2-Stage Exchange for Infected Total Hip Arthroplasty

BACKGROUND

While morbid obesity is associated with increased infection after total hip arthroplasty, little is known on the outcomes after 2-stage reimplantation for prosthetic joint infection (PJI) in this population. The purpose of this study is to evaluate the impact of morbid obesity (body mass index>40 kg/m2) on reinfection, postoperative complications, readmissions, and reoperations.

METHODS

We conducted a retrospective review of 107 patients undergoing first time 2-stage reimplantation for PJI from 2013 to 2019. 18 patients (50% women) with body mass index>40 kg/m2 were identified. To minimize confounders, three propensity score matched cohorts were created, yielding 16 nonobese (<30 kg/m2), 16 obese (30-39.9 kg/m2), and 18 morbidly obese (>40 kg/m2) patients. Outcomes were compared using chi-square or Fisher's exact tests. All patients had minimum 12-month follow-up, with mean follow-up of 36.3, 30.1, and 40.0 months in the nonobese, obese, and morbidly obese cohorts, respectively.

RESULTS

Compared with nonobese patients, morbidly obese patients had a higher rate of reinfection (0% vs 33%, P = .020 and higher likelihood of length of stay>4 days (19% vs 61%, P = .012). In addition, compared with nonobese and obese patients, morbidly obese patients had higher rate of return to the operating room for any reason (13% vs 19% vs 50%, respectively, P = .020). No differences between cohorts were found regarding complications, death, or revision surgery.

CONCLUSION

Morbidly obese patients have significantly increased risk of reinfection and reoperation after 2-stage reimplantation for PJI when compared with obese and nonobese patients. These data can be used to counsel morbidly obese patients contemplating total hip arthroplasty and supports the notion of deferring arthroplasty in this population pending optimization.

Body Mass Index Is Associated with the Severity and All-Cause Mortality of Acute Kidney Injury in Critically Ill Patients: An Analysis of a Large Critical Care Database

Background

Acute kidney injury (AKI) is a common clinical syndrome carrying high morbidity and mortality. Body mass index (BMI) is a common health indicator, and a high BMI value-obesity has been shown to be associated with the outcomes of several diseases. However, the relationship between different BMI categories and mortality in all critically ill patients with AKI is unclear and needs further investigation. Therefore, we evaluated the ability of BMI to predict the severity and all-cause mortality of AKI in critically ill patients.

Methods

We extracted clinical data from the MIMIC-III v1.4 database. All adult patients with AKI were initially screened. The baseline data extracted within 24 hours after ICU admission were presented according to WHO BMI categories. Logistic regression models and the Cox proportional hazards models were, respectively, constructed to assess the relationship between BMI and the severity and all-cause mortality of AKI. The generalized additive model (GAM) was used to identify nonlinear relationships as BMI was a continuous variable. The subgroup analyses were performed to further analyze the stability of the association between BMI category and 365-day all-cause mortality of AKI.

Result

A total of 15,174 patients were extracted and were divided into four groups according to BMI. Obese patients were more likely to be young and male. In the fully adjusted logistic regression model, we found that overweight and obesity were significant predictors of AKI stage III (OR, 95 CI: 1.17, 1.05-1.30; 1.32, 1.18-1.47). In the fully adjusted Cox proportional hazards model, overweight and obesity were associated with significantly lower 30-day, 90-day, and 365-day all-cause mortality. The corresponding adjusted HRs (95 CIs) for overweight patients were 0.87 (0.77, 0.99), 0.84 (0.76, 0.93), and 0.80 (0.74, 0.88), and for obese patients, they were 0.87 (0.77, 0.98), 0.79 (0.71, 0.88), and 0.73 (0.66, 0.80), respectively. The subgroup analyses further presented a stable relationship between BMI category and 365-day all-cause mortality.

Conclusions

BMI was independently associated with the severity and all-cause mortality of AKI in critical illness. Overweight and obesity were associated with increased risk of AKI stage III; however, they were predictive of a relatively lower mortality risk in these patients.

Higher Patient Complexities are Associated with Increased Length of Stay, Complications, and Readmissions After Total Hip Arthroplasty

INTRODUCTION

There is an increased incidence of complex patients undergoing total hip arthroplasty (THA), which demands a rigorous preoperative, intraoperative, and postoperative assessment. It is important how increases in patient complexity impact a variety of patient outcomes. Therefore, the purpose of our study is to determine if a higher Elixhauser Comorbidity Index (ECI), a measure of patient complexity, is correlated with: 1) longer hospital length of stay; 2) increased 90-day medical complications; 3) higher 90-day readmissions; and 4) greater two-year implant-related complications following primary THA.

MATERIALS AND METHODS

Patients undergoing primary THA from January 1, 2004 to December 31, 2015 were queried from the Medicare Standard Analytical Files using the International Classification of Disease, ninth revision (ICD-9) procedure code 81.51. The queried patients (387,831) were filtered by ECI scores of 1 to 5. Patients who have ECI scores of 2 to 5 represented the study cohorts and were matched according to age and sex to patients who have the lowest ECI score (ECI of 1). All cohorts were longitudinally followed to assess and compare hospital length of stay, 90-day medical complications, 90-day readmissions, and two-year implant-related complications. We compared odds-ratios (OR), 95% confidence intervals (95% CI), and p-values using logistic regression analyses and Welch's t-tests.

RESULTS

Patients who have ECI scores greater than 1 had higher hospital length of stay (p<0.001), 90-day medical complications (p<0.001), 90-day readmissions (p<0.001), and two-year implant-related complications (p<0.001). Patients who have an ECI score of 2 (1.26, 95% CI: 1.20-1.32), ECI of 3 (1.61, 95% CI: 1.53-1.69), ECI of 4 (2.05, 95% CI: 1.95-2.14), and ECI of 5 (2.32, 95% CI: 2.21-2.43) had an increasing trend for readmissions, with higher ECI scores correlating with greater odds of readmission following primary THA. Two-year implant-related complications also showed a similar increasing trend with greater patient complexity. Patients who had an ECI score of 5 (2.54, 95% CI: 2.39-2.69) had more implant-related complications compared to patients who had an ECI score of 2 (1.39, 95% CI:1.31-1.48).

CONCLUSION

The results of this study illustrate that a higher Elixhauser-Comorbidity Index is an independent risk factor for longer hospital length of stay, higher 90-day medical complications, greater 90-day readmissions, and increased two-year implant-related complications following primary THA. This study is important as it further defines and heightens awareness of adverse events for complex patients undergoing this procedure. Future studies can examine if these events can potentially be mitigated through reductions in ECI scores prior to surgery and increased incentives for the healthcare team.

Projected Economic Burden of Periprosthetic Joint Infection of the Hip and Knee in the United States

BACKGROUND

In addition to the significant morbidity and mortality associated with periprosthetic joint infection (PJI), the cost of treating PJI is substantial. Prior high-quality national estimates of the economic burden of PJI utilize data up to 2009 to project PJI growth in the United States through 2020. Now in the year 2020, it is appropriate to evaluate these past projections and incorporate the latest available data to better understand the current scale and burden of PJI in the United States.

METHODS

The Nationwide Inpatient Sample (2002-2017) was used to identify rates and associated inpatient costs for primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) and PJI-related revision TKA and THA. Poisson regression was utilized to model past growth and project future rates and cost of PJI of the hip and knee.

RESULTS

Using the most recent data, the combined annual hospital costs related to PJI of the hip and knee were estimated to be $1.85 billion by 2030. This includes $753.4 million for THA PJI and $1.1 billion for TKA PJI, in that year. Increases in PJI costs are mainly attributable to increases in volume. Although the growth in incidence of primary THA and TKA has slowed in recent years, the incidence of PJI and the cost per case of PJI remained relatively constant from 2002 to 2017.

DISCUSSION

Understanding the current and potential future financial burden of PJI for surgeons, patients, and healthcare systems is essential. There is an urgent need for efficacious preventive strategies in reducing rates of PJI after THA and TKA.

Understanding the Main Predictors of Length of Stay After Total Hip Arthroplasty: Patient-Related or Procedure-Related Risk Factors?

BACKGROUND

Removing total hip arthroplasty (THA) from the Centers for Medicare & Medicaid Services (CMS) inpatient-only list allows Medicare to cover outpatient THA, driving hospitals to recommend outpatient surgery for appropriate patients and raising safety concerns over which patients' admissions should remain inpatient. Thus, we aimed to determine the influence of patient-related and procedure-related risk factors as predictors of >1-day Length of Stay (LOS) after THA.

METHODS

A prospective cohort of 5281 patients underwent primary THA from 2016 to 2019. Risk factors were categorized as patient-related or procedure-related. Multivariable cumulative link models identified significant predictors for 1-day, 2-day, and ≥3-day LOS. Discriminating 1-day LOS from >1-day LOS, we compared performance between two regression models.

RESULTS

A>1-day LOS was significantly associated with age, female gender, higher body mass index, higher Charlson Comorbidity Index, Medicare status, and higher Hip disability and Osteoarthritis Outcome Physical Function Shortform(HOOS-PS) and lower Veterans RAND12 Mental Component (VR-12 MCS) scores via the initial regression model that contained patient factors only. A second regression model included procedure-related risk factors and indicated that procedure-related risk factors explain LOS more effectively than patient-related risk factors alone, as Akaike information criterion (AIC) increased by approximately 1100 units upon removal from the model.

CONCLUSION

Although patient-related risk factors alone provide predictive value for LOS following THA, procedure-related risk factors remain the main drivers of predicting LOS. These findings encourage examination of which specific procedural risk factors should be targeted to optimize LOS when choosing between inpatient and outpatient THA, especially within a Medicare population.

Discriminative Ability for Adverse Outcomes After Hip Fracture Surgery: A Comparison of Three Commonly Used Comorbidity-Based Indices

INTRODUCTION

Preoperative risk assessment can predict adverse outcomes following hip fracture surgery, helping with decision-making and management strategies. Several risk adjustment models based on coded comorbidities such as Charlson Comorbidity Index (CCI), modified Elixhauser's Comorbidity Measure (mECM), and modified frailty index (mFI-5) are currently prevalent for orthopedic patients, but there is no consensus regarding which is optimal. The primary purpose was to identify the risk factors of CCI, mECM, and mFI-5, as well as patient characteristics for predicting (1) 1-month, 3-month, 1-year, and 2-year mortality, (2) perioperative complications, and (3) extended length of stay (LOS) following hip fractured surgery. The secondary aim was to compare the best-performing comorbidity index combined with characteristics identified in terms of their discriminative ability for adverse outcomes.

METHODS

We retrospectively reviewed 3,379 consecutive patients presenting with intertrochanteric fractures at our Level I trauma center from 2013 to 2018. After eliminated by exclusion criteria, 2,241 patients undergoing hip fracture surgery by PFNA, with age ≥65 years, were included. Three main multivariate logistic regression models were constructed. Cox proportional hazards models were used to calculate hazard ratios for mortality. A base model included age, BMI, surgical delay, anesthesia type, hemoglobin record at admission, and American Society of Anesthesiologists grade (ASA) also was constructed and assessed.

RESULTS

Base model + mECM outperformed other models for the occurrence of major complications including severe complications, cardiac complications, and pulmonary complications [the area under the receiver operating characteristic curve (AUC), 0.647; 95% CI, 0.616-0.677; AUC, 0.637; 95% CI, 0.610-0.664; AUC, 0.679; 95% CI, 0.642-0.715, respectively], while base model + CCI provided better prediction of minor complications of neurological complications and hematological complications (AUC, 0.659; 95% CI, 0.609, 0.709; AUC, 0.658; 95% CI, 0.635, 0.680). In addition, BMI, surgical delay, anesthesia type, and ASA were found highly relevant to extended LOS. Age-group (with a 10-year interval) was indicated to be mostly associated with all-cause mortality with fully adjusted hazard ratio of 1.35 and 95% CI range 1.20-1.51.

CONCLUSIONS

In comparison with mFI-5 and CCI, mECM so far may be the best comorbidity index combined with the base model for predicting major complications following hip fracture. The base model already achieved good discrimination for all-cause mortality and extended LOS, further addition of risk adjustment indices led to only 1% increase in the amount of variation explained.

Impact of Value-Based Reimbursement on Health-Care Disparities for Total Joint Arthroplasty Candidates

As the U.S. Centers for Medicare & Medicaid Services (CMS) implements value-based reimbursement models based on predetermined outcome measures, access to total joint arthroplasty (TJA) is jeopardized for patients who are disproportionately affected by conditions that predispose them to higher odds of complications. Obesity, depression, and chronic illness, each of which occur at disproportionately higher rates in minorities or individuals in lower socioeconomic brackets, are individually associated with worse TJA postoperative outcomes, including longer hospital lengths of stay and higher rates of readmission within 90 days. Medicaid may even be considered an independent risk factor for worse outcome measures with TJA as enrollees have higher rates of postoperative mortality and complications and longer lengths of stay than patients on Medicare or with private insurance. As same-day discharge for TJA becomes more common, eligibility requirements for the procedure tighten, and existing disparities in access to the procedure will be further exacerbated. The current CMS uniform quality metrics endanger access to TJA for patients in certain racial and socioeconomic groups and oblige physicians who treat more complex patients to jeopardize their reimbursement.

Revision Rates and Functional Outcomes Among Severely, Morbidly, and Super-Obese Patients Following Primary Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Obesity has been associated with a greater burden of symptomatic knee osteoarthritis. There is some evidence that patients with a very high body mass index (BMI) may have a higher risk of complications and poor outcomes following total knee replacement compared with non-obese patients or obese patients with a lower BMI. We hypothesized that increasing degrees of obesity would be associated with deteriorating outcomes for patients following total knee replacement.

METHODS

We performed a comprehensive systematic review of 4 medical databases (MEDLINE, AMED, Ovid Healthstar, and Embase) from inception to August 2016. We extracted data to determine revision risk (all-cause, septic, and aseptic) and functional outcome scores (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], Knee Society Score, Oxford Knee Score, EuroQol-5D, and Short Form [SF]-12 Physical Component Summary) in patients with severe obesity (BMI ≥35 kg/m), morbid obesity (BMI ≥40 kg/m), and super-obesity (BMI ≥50 kg/m) in comparison with patients with a normal BMI (<25 kg/m). Meta-analysis was performed using a random effects model.

RESULTS

We screened 3,142 titles and abstracts and 454 full-text articles to identify 40 eligible studies, of which 37 were included in the meta-analysis. Compared with patients with a normal BMI, the risk ratio for an all-cause revision surgical procedure was 1.19 (95% confidence interval [CI], 1.03 to 1.37; p = 0.02) in patients with severe obesity, 1.93 (95% CI, 1.27 to 2.95; p < 0.001) in patients with morbid obesity, and 4.75 (95% CI, 2.12 to 10.66; p < 0.001) in patients with super-obesity. The risk ratio for septic revision was 1.49 (95% CI, 1.28 to 1.72; p < 0.001) in patients with severe obesity, 3.69 (95% CI, 1.90 to 7.17; p < 0.001) in patients with morbid obesity, and 4.58 (95% CI, 1.11 to 18.91; p = 0.04) in patients with super-obesity. There were no significant differences (p > 0.05) in risk of aseptic revision. Based on the Knee Society Scores reported in a single study, patients with super-obesity had outcome scores, expressed as the standardized mean difference, that were 0.52 lower (95% CI, 0.80 lower to 0.24 lower; p < 0.001) than non-obese controls; however, no difference was observed for severe or morbidly obese patients.

CONCLUSIONS

The risk of septic revision is greater in patients with severe obesity, morbid obesity, and super-obesity, with progressively higher BMI categories associated with a higher risk. However, the risk of aseptic revision was similar between all obese and non-obese patients. Functional outcome improvements are also similar, except for super-obese patients, in whom data from a single study suggested slightly lower scores. These findings may serve to better inform evidence-based clinical, research, and policy decision-making.

LEVEL OF EVIDENCE

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

Increased fat depth is not associated with increased risk of surgical complications following total hip arthroplasty

AIMS

Previous research has demonstrated increased early complication rates following total hip arthroplasty (THA) in obese patients, as defined by body mass index (BMI). Subcutaneous fat depth (FD) has been shown to be an independent risk factor for wound infection in cervical and lumbar spine surgery, as well as after abdominal laparotomy. The aim of this study was to investigate whether increased peritrochanteric FD was associated with an increased risk of complications in the first year following THA.

METHODS

We analyzed prospectively collected data on a consecutive series of 1,220 primary THAs from June 2013 until May 2018. The vertical soft tissue depth from the most prominent part of the greater trochanter to the skin was measured intraoperatively using a sterile ruler and recorded to the nearest millimetre. BMI was calculated at the patient's preoperative assessment. All surgical complications occuring within the initial 12 months of follow-up were identified.

RESULTS

Females had a significantly greater FD at the greater trochanter in comparison to males (median 3.0 cm (interquartile range (IQR) 2.3 to 4.0) vs 2.0 cm (IQR 1.7 to 3.0); p < 0.001) despite equivalent BMI between sexes (male median BMI 30.0 kg/m² (IQR 27.0 to 33.0); female median 29.0 kg/m² (IQR 25.0 to 33.0)). FD showed a weak correlation with BMI (R² 0.41 males and R² 0.43 females). Patients with the greatest FD (upper quartile) were at no greater risk of complications compared with patients with the lowest FD (lower quartile); 7/311 (2.3%) vs 9/439 (2.1%); p = 0.820 . Conversely, patients with the highest BMI (≥ 40 kg/m²) had a significantly increased risk of complications compared with patients with lower BMI (< 40 kg/m²); 5/60 (8.3% vs 18/1,160 (1.6%), odds ratio (OR) 5.77 (95% confidence interval (CI) 2.1 to 16.1; p = 0.001)).

CONCLUSION

We found no relationship between peritrochanteric FD and the risk of surgical complications following primary THA. Cite this article: Bone Joint J 2020;102-B(9):1146-1150.

Differences in patient characteristics and external validity of randomized clinical trials on pain management following total hip and knee arthroplasty: a systematic review

Background

The external validity of randomized controlled trials (RCTs) is critical for the relevance of trial results in a clinical setting. We aimed to assess the external validity of RCTs investigating postoperative pain treatment after total hip and knee arthroplasty (THA and TKA) by comparing patient characteristics in these trials with a clinical cohort. Further, we assessed the use of exclusion criteria of the included RCTs.

Methods

We searched PubMed, Embase, and Cochrane Central Register of Controlled Trials for relevant RCTs up to June 2019. Data on patient characteristics from this research population were compared with an unselected clinical cohort from the Danish Hip and Knee Arthroplasty Registries in the period 2005–2019. Trends in patient characteristics and the use of exclusion criteria were assessed with control charts.

Results

In total, 550 RCTs with 48 962 participants were included in the research cohort. The clinical cohort included 101 439 THA patients and 90 505 TKA patients. Patient characteristics (age, body mass index (BMI), American Society of Anesthesiologists (ASA) score and sex distribution) in the research cohort resembled those of the clinical cohort. Age, BMI and ASA scores did not change over time in the research cohort. In the clinical cohort, age increased among both THA and TKA patients, and BMI and ASA scores increased among TKA patients. Most commonly used exclusion criteria in the RCTs were high ASA score (62%), older age (45%), obesity (32%) and chronic opioid use (41%). Exclusion of chronic opioid users and individuals with obesity increased over time.

Conclusion

Patient characteristics in research trials investigating postoperative pain management after THA and TKA currently resemble those of a clinical cohort. However, individuals in the clinical cohort are getting older, and TKA patients more obese with increasing ASA scores. Concomitantly, RCTs increase the tendency to exclude patients with older age, obesity, chronic pain and/or opioid use. This trending discrepancy can hinder the generalizability of future research results, and therefore increased focus on pragmatic trials resembling real-world conditions are needed.

PROSPERO registration number

CRD42019125691

Bariatric Surgery Prior to Total Hip Arthroplasty Is Cost-Effective in Morbidly Obese Patients

BACKGROUND

The cost-effectiveness of bariatric surgery to achieve weight loss prior to total hip arthroplasty (THA), and decrease the complications and costs associated with THA in the morbidly obese, is unknown. This study evaluated the cost-effectiveness of bariatric surgery prior to THA for morbidly obese patients with end-stage hip osteoarthritis (OA).

METHODS

A state-transition Markov model was constructed to compare the cost-utility of 2 treatment protocols for patients with morbid obesity and end-stage hip OA: (1) immediate THA and (2) bariatric surgery 2 years prior to THA (combined protocol). The analysis was performed from both a payer and a societal perspective using direct and indirect costs over a 40-year time horizon. Utilities, associated costs, and probabilities for health state transitions were derived from the literature. One-way, 2-way and probabilistic sensitivity analyses were performed to validate the robustness of the base case results, using the standard willingness-to-pay threshold of $100,000/quality-adjusted life years.

RESULTS

From the societal perspective, the combined protocol was more effective (13.16 vs 12.26) with less cost ($91,717 vs $92,684) and thus was the dominant strategy over immediate THA. These results were stable across broad ranges for independent model variables. Monte Carlo simulation with 100,000 samples demonstrated that bariatric surgery prior to THA was the preferred cost-effective strategy over 95% of the time from both a societal and payer perspective.

CONCLUSION

In the morbidly obese patient with end-stage hip OA, bariatric surgery prior to THA is a cost-effective strategy for improving quality of life and decreasing societal and payer costs.

LEVEL OF EVIDENCE

II.

Total Hip Arthroplasty in the Obese Patient: Tips and Tricks and Review of the Literature

AIM

There is a lack of consensus on the optimal method of performing primary hip arthroplasty in obese patients and limited evidence. This article presents a series of considerations based on the authors' experiences as well as a review of the literature.

PREOPERATIVE CARE

In the preoperative phase, an informed consent process is recommended. Weight loss is recommended according to NHS England guidelines, and body habitus should be taken into account. When templating, steps are taken to avoid overestimating the implant size.

SURGICAL PROCEDURE

During the surgical procedure, specialist bariatric equipment is utilised: bariatric beds, extra supports, hover mattresses, longer scalpels, diathermy, cell saver and minimally invasive surgery equipment. Communication with the anaesthetist and surgical team to anticipate is vital. Intraoperative sizing and imaging, if required, should be considered. Pneumatic foot pumps are preferable for VTE prophylaxis. Regional anaesthesia is preferred due to technical difficulty. IV antibiotics and tranexamic acid are recommended. The anterior and posterior surgical approaches are most frequently used; we advocate posterior. Incisions are extensile and a higher offset is considered intraoperatively, as well as dual mobility and constrained liners to reduce dislocation risk. When closing the wound, Charnely button and sponge should be considered as well as negative pressure wound dressings (iNPWTd) and drains.

POST-OPERATIVE CONSIDERATIONS

Postoperatively, difficult extubation should be anticipated with ITU/HDU beds available. Epidural anaesthetics for postoperative pain management require higher nursing vigilance. Chemical prophylaxis is recommended.

CONCLUSION

Despite being technically more difficult with higher risks, functional outcomes are comparable with patients with a normal BMI.

Determinants of Cost Variation in Total Hip and Knee Arthroplasty: Implications for Alternative Payment Models

BACKGROUND

Alternative payment models have been proposed to deliver high-quality, cost-effective care. Under these models, payments may be shared between the hospital and the post-acute care services. Post-acute care services may account for one-third of the episode costs for total hip or knee arthroplasty (THA/TKA). Because hospitals or episode initiators bear notable financial risks in these payment models with minimal risk adjustment for complexity, it has been suggested these models may lead to prospective selection of healthier and younger patients. Studies evaluating the effect of patient demographics, medical complexity, and surgical characteristics on the cost of index hospitalization have been limited. We aimed to (1) quantify the impact of patient demographics, medical complexity, and surgical characteristics (type of anesthesia and operating time) on variation in direct cost of index hospitalization and (2) examine the association of these characteristics with discharge with home health services or to rehabilitation facility.

METHODS

Retrospective study of 3,542 patients admitted to our hospital for elective THA/TKA between 2012 and 2017. Multivariable generalized estimating equations were used for analysis.

RESULTS

Patient demographics and medical complexity accounted for 6.2% (THA) and 5.6% (TKA) of variation in direct cost of index hospitalization. Surgical characteristics accounted for 37.1% (THA) and 35.3% (TKA) of the cost variation. One thousand one hundred eighty-three (53.4%) patients were discharged with home health services, and 1,237 (29.4%) were discharged to rehabilitation facility. Patient demographics and higher medical complexity were markedly associated with discharge with home health services or to rehabilitation facility after THA/TKA.

DISCUSSION

Patient demographics and medical complexity had minimal impact on variation in direct cost of index hospitalization for elective THA/TKA compared with surgical characteristics but were markedly associated with discharge with home health services or to rehabilitation facility. Having additional risk adjustment in these payment models could mitigate concerns about access to care for higher risk, higher cost patients.

Limited Influence of Comorbidities on Length of Stay after Total Hip Arthroplasty: Experience of Enhanced Recovery after Surgery

Objectives

To identify predictors of length of stay (LOS) after total hip arthroplasty (THA) in an enhanced recovery after surgery (ERAS) program and evaluate the safety and cost‐efficiency of the ERAS program with reduced LOS for unselected patients in a Chinese population.

Methods

A total of 311 consecutive, unselected patients undergoing primary THA at a single institution were retrospectively reviewed and divided into two groups: LOS ≤ 3 and LOS > 3 group. All patients were managed with the same ERAS protocol and went back home after discharge. Multivariate logistic regression analysis was used to determine independent risk factors for LOS > 3. Harris Hip Score at 90‐day follow‐up, 90‐day readmission rate, and hospitalization costs were compared between two groups.

Results

Multivariate regression analysis identified female gender (odds ratio [OR] = 2.623), living alone (OR = 4.127), and primary osteoarthritis of hip (OR = 3.565) to be correlated with LOS > 3. Preoperative hemoglobin (HB), postoperative HB, drain use, blood transfusion, diabetes, respiratory disease, osteoporosis, number of comorbidities, and CCI score showed no significant influence on LOS after adjusting for other risk factors in the multivariate model. Harris Hip Score and readmission rate at 90‐day follow‐up showed no significant differences between two groups. Patients in LOS > 3 group had approximately 3948.6 Chinese yuan higher hospital costs.

Conclusion

Female gender, living alone, and primary osteoarthritis of hip were identified as independent risk factors for prolonged LOS. The experience from our institution suggested aggressive management of comorbidities in the ERAS program can minimize the influence of comorbidities on LOS. The safety, efficiency, and costs‐saving benefits of the ERAS program with reduced LOS for unselected patients was confirmed in this study.

Length of Hospital Stay for Osteoarthritic Primary Hip and Knee Replacement Surgeries in New Zealand

This study aims to explore the length of stay (LOS) of publicly funded osteoarthritic primary hip and knee replacement surgeries in New Zealand. Patients with osteoarthritis who underwent publicly funded primary hip and knee replacement surgery in 2005-2017 were included. We have identified 53,439 osteoarthritic primary hip replacements and 50,072 osteoarthritic primary knee replacements. LOS has been reduced by almost 40% over the last 13 years. Logistic regression showed that women, Māori, Pacific and Asian patients, older patients, people with more comorbidities and those having opiates on discharge and patients in earlier years were more likely to have extended LOS following hip replacements and knee replacements. Regional differences were noted in LOS between the Waitemata District Health Board (DHB) compared to Tairāwhiti DHB where patients were the most likely to have a LOS of more than 5 days after hip and knee replacements. LOS after hip and knee replacements has been reduced dramatically. Women, Māori, Pacific and Asian patients, older patients and people with more comorbidities are more likely to have extended LOS. Patients dispensed opiates on discharge had a longer LOS. There are great geographical variations in LOS for primary hip and knee surgeries in New Zealand.

Predictors for Unfavorable Early Outcomes in Elective Total Hip Arthroplasty: Does Extreme Body Mass Index Matter?

Background

Studies of previous cohorts have demonstrated a controversial association between extreme body mass index (BMI) and complication rates following total hip arthroplasty (THA). The purpose of this study was to compare 30-day perioperative complications in underweight (BMI <18.50 kg/m²), normal-weight (BMI 18.50–24.99 kg/m²), overweight (BMI 25.00–29.99 kg/m²), class I obesity (BMI 30.00–34.99 kg/m²), and morbidly obese (BMI ≥35.00 kg/m²) groups.

Methods

We performed a cohort study including patients who underwent unilateral primary THA by a single surgeon between January 2010 and December 2015 at our institution. We assessed 30-day complications, operation time, operative blood loss, and length of hospital stay.

Results

We identified 1565 primary THAs that were performed in patients with varying BMI levels. Compared with the normal-weight patients, the morbidly obese group had a higher 30-day complication rate (8.9% vs. 2.4%), longer operative time (79 minutes vs. 70 minutes), and more blood loss (376 mL vs. 302 mL). Underweight patients did not present any 30-day complications, and there were no differences among underweight and normal-weight patients regarding complication rates, operative time, or blood loss. The mean length of hospital stay was comparable among the different BMI groups. In the multivariate regression model, higher BMI was not associated with a higher risk of 30-day complications. Independent risk factors for 30-day complications were advanced age, prolonged operative time, and cardiovascular comorbidities.

Conclusion

Although increased operative time, blood loss, and perioperative complications were seen in the morbidly obese patients, BMI alone was not an independent risk factor for a higher 30-day complication rate. Therefore, our data suggest clinicians should make elderly patients aware of increased 30-day complications before the procedure, particularly those with cardiovascular comorbidities. Withholding THA solely on the basis of BMI is not justified.

Weight changes after total knee arthroplasty in Chinese patients: a matched cohort study regarding predictors and outcomes

BACKGROUND

The purpose of this study was to compare 2-year BMI changes between patients undergoing simultaneous bilateral total knee arthroplasty (TKA), staged bilateral TKA, and unilateral TKA. We also sought to determine the predictors of weight change and whether clinically meaningful weight changes affected outcomes.

PATIENTS AND METHODS

This retrospective, single-institution study included 202 Chinese patients who received simultaneously bilateral TKA, staged bilateral TKA, or unilateral TKA from 2008 to 2015. There were 49 simultaneous bilateral TKAs, 52 staged bilateral TKAs, and a matched 101 unilateral TKAs.

RESULTS

66.8% (135/202) of patients lost weight after TKA surgery. However, 20.7% (42/202) of patients experienced clinically meaningful weight loss (a BMI decrease of more than 5%). Paired t test showed that 2-year BMI was significantly lower than preoperative BMI (p < 0.001). Weight loss was significantly different between the surgical strategy (p < 0.001). Preoperative BMI and age were predictive of clinically significant weight loss or gain (p < 0.05). Multiple linear regression showed that post-operative weight loss was associated with better Western Ontario and McMaster Universities Osteoarthritis Index and SF-36 scores (p < 0.001).

CONCLUSION

Patients after TKA experience weight loss. Age and preoperative BMI predict clinically meaningful weight change. Simultaneous bilateral TKA is associated with higher likelihood of weight loss. Clinically meaningful weight loss experiences better patient-reported outcomes.