Morbid Obesity in Total Hip Arthroplasty: Redefining Outcomes for Operative Time, Length of Stay, and Readmission

Preoperative and Postoperative Weight Change has Minimal Influence on Health Care Utilization and Patient-Reported Outcomes Following Total Knee Arthroplasty

As obesity becomes more prevalent, more patients are at risk of lower extremity osteoarthritis and subsequent total knee arthroplasty (TKA). This study aimed to test (1) the association of preoperative weight change with health care utilization and (2) the association of pre- and postoperative weight changes with failure to achieve satisfaction and minimal clinically important difference (MCID) in Knee injury and Osteoarthritis Outcome Score for pain (KOOS-Pain) and function (KOOS-PS) 1 year after TKA. Prospectively collected monocentric data on patients who underwent primary TKA were retrospectively reviewed. Multivariable logistic regression assessed the influence of BMI and weight change on outcomes while controlling for confounding variables. Outcomes included prolonged length of stay (LOS >3 days), nonhome discharge, 90-day readmission rate, satisfaction, and achievement of MCID for KOOS-Pain and KOOS-PS. Preoperative weight change had no impact on prolonged LOS (gain, p = 0.173; loss, p = 0.599). Preoperative weight loss was associated with increased risk of nonhome discharge (odds ratio [OR]: 1.47, p = 0.003). There was also increased risk of 90-day readmission with preoperative weight gain (OR: 1.27, p = 0.047) and decreased risk with weight loss (OR: 0.73, p = 0.033). There was increased risk of nonhome discharge with obesity class II (OR: 1.6, p = 0.016) and III (OR: 2.21, p < 0.001). Weight change was not associated with failure to achieve satisfaction, MCID in KOOS-Pain, or MCID in KOOS-PS. Obesity class III patients had decreased risk of failure to reach MCID in KOOS-Pain (OR: 0.43, p = 0.005) and KOOS-PS (OR: 0.7, p = 0.007). Overall, pre- and postoperative weight change has little impact on the achievement of satisfaction and clinically relevant differences in pain and function at 1 year. However, preoperative weight gain was associated with a higher risk of 90-day readmissions after TKA. Furthermore, patients categorized in Class III obesity were at increased risk of nonhome discharge but experienced a greater likelihood of achieving MCID in KOOS-Pain and KOOS-PS. Our results raise awareness of the dangers of using weight changes and BMI alone as a measure of TKA eligibility.

Increasing Body Mass Index Not Associated With Worse Patient-Reported Outcomes After Primary THA or TKA

INTRODUCTION

As the US obesity epidemic continues to grow, so too does comorbid hip and knee arthritis. Strict body mass index (BMI) cutoffs for total hip and knee arthroplasty (THA and TKA) in the morbidly obese have been proposed and remain controversial, although current American Academy of Orthopaedic Surgeons guidelines recommend a BMI of less than 40 m/kg2 before surgery. This study sought to compare patient-reported outcomes and 30-day complication, readmission, and revision surgery rates after THA or TKA between morbidly obese patients and nonmorbidly obese control subjects.

METHODS

All patients undergoing primary THA and TKA at our institution from May 2020 to July 2022 were identified. Patient demographics, surgical time, length of stay and 30-day readmission, revision surgery, and complication rates were prospectively collected. Preoperative and postoperative Hip and Knee Society (Hip Osteoarthritis Outcome Score [HOOS] and Knee Osteoarthritis Outcome Score [KOOS]) were collected. Patients were stratified by BMI as ideal weight (20 to 24.9), overweight (25 to 29.9), class I obese (30 to 34.9), class II obese (35 to 39.9), and morbidly obese (>40 m/kg2).

RESULTS

A total of 1,423 patients were included for final analysis. No difference was observed in 30-day unplanned return to emergency department, readmission, or revision surgery in the morbidly obese cohort. Morbidly obese patients undergoing THA had lower preoperative HOOS (49.5 versus 54.5, P = 0.004); however, there was no difference in postoperative HOOS or KOOS at 12 months across all cohorts.

DISCUSSION

No difference was observed in 30-day return to emergency department, readmission, or revision surgery in the morbidly obese cohort. Despite a lower preoperative HOOS, there was no difference in 12-month HOOS or KOOS when stratified by BMI. These findings suggest that such patients may achieve similar benefit from arthroplasty as their ideal weight counterparts.

Does Your Patient Need to Lose Weight? Weight Change Before and After Total Hip Arthroplasty Does Not Affect Health Care Utilization and Achievement of the Minimal Clinically Important Difference

BACKGROUND

Despite the potential negative impact of preoperative obesity on total hip arthroplasty (THA) outcomes, the association between preoperative and postoperative weight change and outcomes is much less understood. Therefore, this study aimed to determine the impact of preoperative and postoperative weight change and preoperative body mass index (BMI) on health care utilization, satisfaction, and achievement of minimal clinically important difference (MCID) for Hip Disability and Osteoarthritis Outcome Score Physical Function Short-Form (HOOS PS) and HOOS Pain.

METHODS

Patients who underwent primary elective unilateral THA between January 2016 and December 2019 were included (N = 2,868). Multivariable logistic regression assessed the association between BMI and preoperative and postoperative weight change on outcomes while controlling for demographic characteristics.

RESULTS

There was no association between preoperative weight change and prolonged length of stay (> 3 days), 90-day readmission, nonhome discharge, patient dissatisfaction at 1 year, or achievement of HOOS Pain or HOOS PS MCID. Postoperative weight loss was an independent risk factor for patient dissatisfaction at 1 year but was not associated with achievement of either HOOS Pain or HOOS PS MCID at 1-year postoperative. Preoperative obesity classes I to III were independent risk factors for nonhome discharge. Nevertheless, preoperative obesity class I and class II were associated with an increased probability of reaching HOOS Pain MCID. Preoperative BMI was not associated with an increased risk of patient dissatisfaction.

CONCLUSIONS

Preoperative weight change does not appear to influence health care utilization, satisfaction, or achievement of MCID in pain and function following THA. Postoperative weight loss may play a role as a risk factor for dissatisfaction following THA. Additionally, patients who had a higher baseline BMI may be more likely to see improvement in pain following THA. Therefore, when counseling obese patients for THA, surgeons must balance the risk of perioperative complications with the expectation of greater improvements in pain.

Weight Is a Predictor of Delayed Operation Time in Primary Isolated Anterior Cruciate Ligament Reconstruction

BACKGROUND

Few studies have evaluated the impact of obesity on operation time in patients with ACL reconstruction. The purpose of this study was to understand the effect of obesity on operation time in patients with arthroscopic anterior cruciate ligament (ACL) reconstruction.

METHODS

A total of 103 patients were included. The mean pure operation time was 45.9 ± 13.4 min. Considering that 15 min incremental increases in operation time are an independent risk factor for complications, all patients were classified into two groups according to operation time: more or less than 61 min. Demographic data were compared between both groups. Pure operation time was defined as operative time without suture time (pure operation time = suture start time - operation start time). Correlation analysis between demographic data and pure operation time was performed, and multiple linear regression analysis was used to identify the predictors of pure operation time.

RESULTS

The pure operation time ≥61 min group (n = 34) had a 14.7 kg higher weight and 4.5 kg/m2 higher body mass index (BMI) than those with pure operation time < 61 min (n = 69). Weight (r = 0.635, p < 0.001) and BMI (r = 0.584, p < 0.001) were positively correlated with operation time. Multiple linear regression analysis showed that weight (β = 0.635, p < 0.001) was the only predictor of operation time. A weight of 74.25 kg was a cut-off value for a pure operation time of >61 min.

CONCLUSIONS

The weight and BMI of the group with pure operation time of ≥61 min were 14.7 kg and 4.5 kg/m2 higher, respectively. The weight of patients with ACL tears was a factor affecting delay in the operation time. Patients weighing over 74.25 kg were more likely to delay ACL reconstruction.

Anaesthetic nurse specialist role in perioperative anaesthetic management of patients who are morbidly obese

This integrative literature review examined the role of an anaesthetic nurse specialist (ANS) in the perioperative anaesthetic nursing management of morbidly obese patients associated with elective orthopaedic surgery. The responsibility of the ANS is to provide high-quality perioperative anaesthetic care to ensure patient safety. Morbid obesity is increasing globally, with significant implications for healthcare delivery, care and treatment, including perioperative care. The Association of Anaesthetists of Great Britain and Ireland emphasises that the perioperative management of these patients presents significant organisational and practical issues. However, there are limited data or guidelines on whether surgeons, anaesthetists and nurses routinely take special precautions in managing morbidly obesity patients undergoing elective orthopaedic operative procedures. The authors carried out a search of databases, followed by an integrated literature review and synthesis of 11 studies. The main findings revealed significant clinical challenges and resource requirements for perioperative anaesthetic management of this patient group. Recommendations are made to prepare for and manage these surgical patients, from preoperative assessment to postoperative care.

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.

Obesity is a predictor of increased morbidity after tracheostomy

OBJECTIVE

The purpose of this study was to analyze the relationship between body mass index (BMI) and 30-day morbidity and mortality risk in patients undergoing tracheostomy using the American College of Surgeons National Quality Improvement Program (ACS-NSQIP).

STUDY DESIGN

This is a retrospective, cross-sectional, cohort study.

SETTING

Patients were identified with Current Procedural Terminology codes in the ACS-NSQIP database.

SUBJECTS AND METHODS

Patients who underwent tracheostomy from 2005 to 2018 were queried. They were stratified into four BMI classes and matched to normal BMI cohorts. Multivariate logistic regression was used to identify independent predictors for complications, readmissions, and unplanned reoperations within 30 days.

RESULTS

Among 3784 patients meeting inclusion and exclusion criteria, obesity was shown to be a significant independent risk factor for overall complications (OR 1.439, 95% CI 1.226-1.689, p < 0.001), postoperative acute renal failure (OR 10.715, 95% CI 1.213-94.646, p = 0.033), and unplanned readmissions (OR 1.702, 95% CI 1.095-2.647, p = 0.018). A significantly lower rate of postoperative transfusions was observed for obese patients (OR 0.581, 95% CI 0.432-0.781, p < 0.001).

CONCLUSIONS

Obesity was found to be independently associated with an increased risk of overall complication, developing acute renal failure, and having an unplanned 30-day readmission following tracheostomy. The risk of postoperative transfusion appears to be lower in obese patients.

LEVEL OF EVIDENCE

4.

The Effect of Obesity on Operating Room Utilization in Breast Surgery

BACKGROUND

The current obesity epidemic is associated with increased health care costs associated with comorbidities such as diabetes and heart disease as well as postoperative complications. However, the effect of obesity on operating room (OR) utilization, especially in common breast procedures, has not been completely evaluated. Our study is the first to examine the effect of patient obesity on operative time (OPT) for common breast procedures.

METHODS

The American College of Surgeons National Surgical Quality Improvement Project databases for 2010-2018 were searched for this retrospective review. Patients undergoing common breast operations (lumpectomy, lumpectomy with sentinel lymph node biopsy (SLNB) (+/- injection), lumpectomy and axillary lymph node dissection (ALND), simple mastectomy, mastectomy with SLNB (+/- injection), and mastectomy with ALND) were filtered out by Current Procedural Terminology code and divided into three groups based on their body mass index (BMI) and weight. Using the two-sample t-test, OPT for the procedures was compared among the lowest and highest BMI and weight categories. We also used a linear regression t-test to demonstrate that for every unit increase in BMI, there was a corresponding increase in OPT for each procedure.

RESULTS

When the lowest and highest BMI and weight groups were compared, significant differences in OPT (P < 0.0001) were seen for each of the procedures. Numerous factors that could affect the complexity of surgery and thus OR time were identified. The correlation between BMI and weight and OPT remained significant after controlling for these variables. The differences between the highest and lowest BMI groups were most pronounced for higher complexity procedures, such as lumpectomy with ALND and mastectomy with ALND, with average operating times increasing by 18.2 min and 18.6 min, respectively, for patients with a higher BMI.

CONCLUSIONS

Patient BMI and weight significantly affect OPT for common breast procedures. Therefore, patient BMI should be taken into account to improve OR scheduling.

Diverticulitis in Morbidly Obese Adults: A Rise in Hospitalizations with Worse Outcomes According to National US Data

BACKGROUND AND AIMS

Obesity is a known risk factor for diverticulitis. Our objective was to examine the less investigated impact of morbid obesity (MO) on admissions and clinical course of diverticulitis in a US representative database.

METHODS

We retrospectively queried the 2010-2014 Nationwide Readmission Database to compare diverticulitis hospitalizations in 48,651 MO and 841,381 non-obese patients. Outcomes of mortality, clinical course, surgical events, and readmissions were compared using multivariable and propensity-score-matched analyses.

RESULTS

The number of MO patients admitted with diverticulitis increased annually from 7570 in 2010 to 11,935 in 2014, while the total number of patients admitted with diverticulitis decreased (p = 0.003). Multivariable analysis demonstrates that MO was associated with increased mortality (adjusted odds ratio [aOR] 1.54; 95% confidence internal [CI]: 1.16, 2.05), intensive care admissions (aOR = 1.92; 95% CI: 1.61, 2.31), emergent surgery (aOR = 1.20; 95% CI: 1.11, 1.30), colectomy (aOR = 1.13; 95% CI: 1.08, 1.18), open laparotomy (aOR = 1.28; 95% CI: 1.21, 1.34), and colostomy (aOR = 1.34; 95% CI: 1.25, 1.43). Additionally, MO was associated with higher risk for multiple readmissions for diverticulitis within 30 days (aOR = 1.45; 95% CI: 1.08, 1.96) and 6 months (aOR = 1.21; 95% CI: 1.03, 1.42). A one-to-one matched propensity-score analysis confirmed our multivariable analysis findings.

CONCLUSIONS

Analysis of national data demonstrates an increasing trend of MO patients' admissions for diverticulitis, with a presentation at a younger age. Furthermore, MO is associated with an increased risk of adverse outcomes and readmissions of diverticulitis. Future strategies are needed to ameliorate these outcomes.

Published Operative Times Do Not Reflect Surgeon Effort: A Novel Approach for Calculating Operative Times in Total Hip Arthroplasty to Better Quantify Surgeon Work

BACKGROUND

Current estimates of operative time (OT) for total hip arthroplasty (THA) are reported as the mean OT across all procedures. This method does not reflect variability among surgeons and surgical settings and should not be used to infer individual surgeon work. We hypothesized that this method would underestimate the time it takes individual surgeons to perform THA. Therefore, we compared the mean OT for all THA cases ("overall OT") with the mean OT for individual surgeons ("individual surgeon OT") and examined which factors were associated with each.

METHODS

Mean OT was calculated for 3972 primary THA cases ("overall OT") by 41 surgeons from 2015 to 2018 in a single health system. The mean OT for each surgeon was determined ("individual surgeon OT"), averaged across surgeons, and compared with overall OT. Overall OT and individual surgeon OT were assessed for associations with surgeon-related (adult reconstruction fellowship training, THA volume, years' experience), hospital-related (hospital type, trainee presence), and patient-related (age, body mass index category, American Society of Anesthesiologists physical status classification) factors (alpha = 0.05).

RESULTS

Mean individual surgeon OT was significantly longer (106 ± 21 minutes) than overall OT (96 ± 28 minutes) (P = .03), with 73% of individual surgeon OTs being greater than overall OT. Although all surgeon-, hospital-, and patient-related factors were associated with significant differences in overall OT, only hospital type was associated with differences in individual surgeon OT.

CONCLUSION

Individual surgeon OT was longer than overall OT for most surgeons and provides a better estimate of surgeon work.

Greater risks of complications, infections, and revisions in the obese versus non-obese total hip arthroplasty population of 2,190,824 patients: a meta-analysis and systematic review

BACKGROUND

Obesity is an epidemic, especially in developed countries. This affects the general health of these patients, especially when they are having a major surgical procedure such as total hip arthroplasty (THA). Several articles have described the effects of obesity on THA with varying conclusions. This meta-analysis aims to compare the outcomes, complications, and peri-operative parameters of THA in the obese (BMI≥30 kg/m²) vs non-obese (BMI<30 kg/m²) population as well as a subgroup analysis of morbidly obese (BMI≥40 kg/m²) vs non-obese population.

METHODS

A multi-database search was performed according to PRISMA guidelines. Data from studies assessing the outcomes and complications of THA in the obese and non-obese population were extracted and analyzed.

RESULTS

Sixty-seven studies were included in this meta-analysis, consisting of 581,012 obese and 1,609,812 non-obese patients. Meta-analysis could not be performed on patient reported outcome measures due to heterogeneous reporting methods. Obese patients had a higher risk of all complications (OR = 1.53, 95%CI: 1.30-1.80, P < 0.001), deep infections (OR = 2.71, 95%CI: 2.08-3.53, P < 0.001), superficial infections (OR = 1.99, 95%CI: 1.55-2.55, P < 0.001), dislocations (OR = 1.72, 95%CI: 1.66-1.79, P < 0.001), reoperations (OR = 1.61, 95%CI: 1.40-1.85, P < 0.001), revisions (OR = 1.44, 95%CI: 1.32-1.57, P < 0.001), and readmissions (OR = 1.37, 95%CI: 1.15-1.63, P < 0.001). When sub-group analysis of morbidly obese (BMI≥40 kg/m²) patients was performed, the risks of all these parameters were even greater.

CONCLUSION

Obese and morbidly obese patients are at higher risks of complications post THA than non-obese patients. Surgeons should be aware of these risks in order to counsel patients and adopt prophylactic strategies to reduce these risks where applicable.

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.

Effect of morbid obesity on patient-reported outcomes in total joint arthroplasty: a minimum of 1-year follow-up

The objective of this study is to explore the effect of morbid obesity on patient-reported outcomes in primary total joint arthroplasty. We retrospectively reviewed 755 primary total joint arthroplasty cases with a minimum of 1-year follow-up. Two groups were compared: (1) patients with BMI < 40 and (2) those with BMI ≥ 40. The primary outcome was the difference in Short Form-12 physical component summary, Short Form-12 mental component summary, Western Ontario and McMaster Universities Osteoarthritis Index, and patient satisfaction. Multivariate analyses were performed to control for potential confounding factors. 37 patients (5%) were morbidly obese. Morbidly obese patients undergoing total knee arthroplasty had significantly lower net gains in their Short Form-12 physical component summary (P = .008), Short Form-12 mental component summary (P = .049), and Western Ontario and McMaster Universities Osteoarthritis Index (P = .009) in the first 6 months only. For total hip arthroplasty, morbid obesity did not affect any of the outcomes measured (P > .05). There was also no difference in patient satisfaction rates between the two groups (P = .401 and .143 for total hip arthroplasty and total knee arthroplasty, respectively). The impact of morbid obesity on patient-reported outcomes appears to be limited to total knee arthroplasty only in the initial 6 months after surgery.

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

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

The Effect of Obesity on Operative Times and 30-Day Readmissions After Anterior Cruciate Ligament Reconstruction

PURPOSE

To understand the effect of obesity on operative times and 30-day readmission rates after arthroscopic anterior cruciate ligament reconstruction (ACLR).

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was queried using Current Procedural Terminology billing codes to identify all patients aged 18 years and older who underwent ACLR between 2007 and 2014. The Student t test was used for continuous variables, and the χ-square or Fisher exact test was used for categorical variables. Multivariate analysis was conducted to identify factors associated with 30-day readmission.

RESULTS

We identified 9,000 patients who underwent ACLR. In the readmission analysis, the total readmission rate was 0.70%. After multivariate analysis, a body mass index (BMI) of 40 or greater was associated with a significantly increased risk of 30-day readmission (odds ratio, 3.06; 95% confidence interval, 1.09-8.57). An operative time of less than 80 minutes was associated with a decreased risk of readmission (odds ratio, 0.40, 95% confidence interval, 0.18-0.92). In the operative-time analysis, the mean operative time was 100.7 minutes. Older age was predictive of decreasing operative time, with the operative time being 32.75 minutes shorter in patients aged 65 years or older than in those younger than 25 years. After multivariate analysis, class II obesity (BMI of 35-39.9) predicted an increase of 7.11 minutes and class III obesity (BMI ≥ 40) predicted an increase of 8.70 minutes compared with normal weight (BMI of 18.5-24.9).

CONCLUSIONS

Obesity is associated with longer operative times and increased 30-day readmissions after ACLR, with patients with a BMI of 40 or greater having over 3 times the risk of readmission compared with patients with a normal weight. Male sex, black race, and younger age are all also associated with increased operative times.

LEVEL OF EVIDENCE

Level III, observational, retrospective cohort study.

Obesity Increases the Risk of Postoperative Complications and Revision Rates Following Primary Total Hip Arthroplasty: An Analysis of 131,576 Total Hip Arthroplasty Cases

BACKGROUND

The aim of our study is to evaluate the association of body mass index (BMI) and the risk of postoperative complications, mortality, and revision rates following primary total hip arthroplasty given other potentially confounding patient characteristics in a large cohort study.

METHODS

Using nationwide billing data for inpatient hospital treatment of the biggest German healthcare insurance, 131,576 total hip arthroplasties in 124,368 patients between January 2012 and December 2014 were included. Outcomes were 90-day mortality, 1-year revision procedures (with and without removal or exchange of implants), 90-day surgical complications, 90-day femoral fractures, and overall complications. The effect of BMI on outcome was analyzed using multivariable logistic regression. Risk-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.

RESULTS

BMI had a significant effect on overall complications (30-34 in kg/m²: OR 1.1, CI 1.0-1.2, P = .014; 35-39: OR 1.5, CI 1.3-1.6, P < .001; ≥40: OR 2.1, CI 1.9-2.3, P < .001; <30: reference). The OR for 1-year revision procedures (30-34: OR 1.2, CI 1.1-1.4, P = .001; 35-39: OR 1.6, CI 1.4-1.8, P < .001; ≥40: OR 2.4, CI 2.1-2.7, P < .001; <30: reference) and 90-day surgical complications increased with every BMI category. For mortality and periprosthetic fractures there was a higher risk only for patients with BMI ≥40.

CONCLUSION

BMI increases the risk of revision rates in a liner trend. Therefore, the authors believe that patients with a BMI >40 kg/m² should be sent to obesity medicine physicians in order to decrease the body weight prior elective surgery.

The Influence of Obesity on Total Elbow Arthroplasty

Total elbow arthroplasty (TEA) has undergone a significant evolution in indications and outcomes in the past decade. Although rheumatoid patients once had the overwhelming number of TEAs, now TEAs for the sequelae of trauma predominate. Furthermore, as obesity has mirrored the increase in the posttraumatic population, TEA complications have increased whereas the durability of implants under these loads has decreased. Solutions are urgently needed to address the complications and revision burden related to posttraumatic deformity and obesity.

Reducing cost drivers in total joint arthroplasty: understanding patient readmission risk and supply cost

Introduction: Understanding and planning for the factors that impact supply cost and unplanned readmission risk for total joint arthroplasty (TJA) patients is helpful for hospitals at financial risk under bundled payments. Readmission and operating room supply costs are two of the biggest expenses. Methods: Logistic and linear regressions are used to measure the impacts of TJA patient attributes on readmission risk and supply costs, respectively. Results: Patients' health market segment and the number/type of comorbidity impacts 30/90-day readmission rates. Surgeon implant preference and type of surgery impact supply costs. Discharge location and two of the five health market segments increase the odds of 30-day readmission. Arrhythmia and lymphoma are the primary comorbidities that impact the odds of readmission at 90 days. Conclusions: Preoperatively identifying TJA patients likely to have large supply costs and higher readmission risk allows hospitals to invest in low-cost interventions to reduce risk and improve healthcare value.

Fluoroscopically Guided Acetabular Component Positioning: Does It Reduce the Risk of Malpositioning in Obese Patients?

BACKGROUND

Obesity has been described as an independent risk factor for acetabular component malpositioning. The purpose of this study was to determine if this could be overcome by use of fluoroscopic navigation in total hip arthroplasty (THA).

METHODS

The first, postoperative, standing, anteroposterior pelvis radiographs from 1599 consecutive patients who underwent fluoroscopic-guided THAs via anterior approach during a six-year period were obtained. We retrospectively reviewed this prospectively collected data. Inclination and anteversion were measured as described by Barrack et al. Intraoperative target ranges for inclination and anteversion angles were 30°-50° and 5°-25°. Patients were divided into 3 cohorts by body mass index, nonobese (<30 kg/m²) obese (between 30 and 40 kg/m²) and morbidly obese (>40 kg/m²), looking for significant differences in acetabular component positioning.

RESULTS

Of the 1599 patients, 1065 were nonobese, 506 obese, and 28 morbidly obese. Overall, average inclination was 37.7° and anteversion was 16.3°. Regarding inclination, 95.0% of cups were positioned in the safe zone, 95.7% for anteversion, and 91.2% for both inclination and anteversion. Analysis of each cohort individually revealed an average inclination of 37.5° in the nonobese, 37.9° in the obese, and 39.9° in the morbidly obese patients. For anteversion, each group's averages were 16.1°, 16.5°, and 16.0°, respectively. There was no significant relationship between a patient's body mass index and cup position for inclination (P = .867), anteversion (P = .673), or both inclination and anteversion (P = .624).

CONCLUSION

Fluoroscopy is a useful tool for achieving a targeted acetabular component orientation in direct anterior THA, irrespective of patient BMI.

Morbid Obesity in Total Knee Arthroplasty: Joint-Specific Variance in Outcomes for Operative Time, Length of Stay, and Readmission

BACKGROUND

It is increasingly apparent that the effect of obesity in arthroplasty is joint-specific. This study evaluates the effects of morbid obesity on primary total knee arthroplasty by comparing short-term outcomes between a morbidly obese (body mass index ≥40 kg/m²) and a normal weight (body mass index 18.5-<25 kg/m²) cohort at our institution between January 2003 and December 2010.

METHODS

One hundred seventeen morbidly obese patients were compared with 94 normal weight patients. Operative time, length of stay, complications, 30-day readmission, and readmission length were compared.

RESULTS

Morbid obesity conveyed no significant increase in 30-day readmission. Operative time was increased at 100 minutes in the morbidly obese group, compared with 90.5 minutes (P = .026).

CONCLUSION

Morbid obesity conveyed no increased risk of length of stay or readmission in this cohort.

An analysis of surgical and nonsurgical operating room times in high-volume shoulder arthroplasty

BACKGROUND

A significant portion of operating room time in shoulder arthroplasty is devoted to nonsurgical tasks. To maximize efficiency and to increase access to care, it is important to accurately quantify surgical and nonsurgical time for shoulder arthroplasty. This study aimed to evaluate surgical vs. nonsurgical time and to assess the viability of using a 1-surgeon, 2-operating room model.

METHODS

An institutional database was used to identify all primary and revision shoulder arthroplasty cases from February 2011 through December 2013. Time intervals were analyzed, including anesthesia and positioning time, surgical time, conclusion time, and turnover time.

RESULTS

We identified 1062 shoulder arthroplasties. The average anesthesia and positioning time was 48.2 ± 11.7 minutes, surgical time was 122.7 ± 36.4  minutes, and conclusion time was 10.5 ± 7.0  minutes. Average turnover time at our institution was 40 minutes. An average of 58.8 ± 13.8 minutes (33.2%) of the patient's time in the operating room was not surgical. A 1-room surgical model, with each case following the next, would allow 3 arthroplasties to be performed in a 10-hour surgical day. A 2-room model would allow 4 cases to be performed in a 9-hour surgical day or 5 in an 11-hour day. In this 2-room model, there would be no time in which the surgeon is absent for any surgical portion of the case.

CONCLUSION

For a high-volume shoulder arthroplasty practice, a 2-room model leads to greater efficiency and patient access to care without sacrificing the surgeon's presence during surgical portions of the case.

Super Obesity Is an Independent Risk Factor for Complications After Primary Total Hip Arthroplasty

BACKGROUND

Recent studies have reported higher postoperative complication rates in obese and morbidly obese patients undergoing total hip arthroplasty (THA). Less data are available regarding super-obese (body mass index [BMI] >50 kg/m²) patients. This study aims to quantify the risk of complications after THA in super-obese patients on a national scale and to put these risks in context by comparing them to patients of other BMI classes as well as those undergoing revision THA.

METHODS

Utilizing a national insurance database, complication rates after THA in super-obese patients (n = 3244) were compared to nonobese, obese, and morbidly obese patients undergoing primary THA and all patients undergoing revision THA. A logistic regression analysis controlling for demographic and comorbidity variables was utilized to determine the independent effect of super obesity on complication rates after THA.

RESULTS

Super-obese patients had significantly higher rates of most complications than nonobese, obese, morbidly obese, and revision THA patients, including venous thromboembolism, infection, blood transfusion, medical complications, dislocation, readmission, and revision THA.

CONCLUSION

Super-obese patients (BMI >50 kg/m²) have higher rates of postoperative complications after THA than nonobese, obese, morbidly obese, and revision THA patients. Super obesity is an independent risk factor for increased rates of most postoperative complications including the need for early revision THA.

Surgical Risks and Costs of Care are Greater in Patients Who Are Super Obese and Undergoing THA

BACKGROUND

Patients with morbid obesity, defined as a BMI greater than 40 kg/m², and super obesity, defined as a BMI greater than 50 kg/m², increasingly present for total hip replacement. There is disagreement in the literature whether these individuals have greater surgical risks and costs for the episode of care, and the magnitude of those risks and costs. There also is no established threshold for obesity as defined by BMI in identifying increased complications, risks, and costs of care. Until recently, analysis of higher BMI data was limited to small cohorts from hospital-based data banks, based on BMI or height and weight only, often as part of a multivariate analysis. On October 1, 2010 the Centers for Medicare & Medicaid Services added a fifth digit to the BMI data, V85.xx, in the Medicare data bank, which allowed data mining of cases of patients with higher BMI. To our knowledge, our study is the first large retrospective Medicare data mining study, which allows us to examine BMI levels greater than 40 and 50 kg/m² to delineate risks, complications, and costs for these patients.

QUESTIONS/PURPOSES

We sought to quantify (1) the surgical risk, and (2) the costs associated with complications after THA in patients who were morbidly obesity (BMI ≥ 40 kg/m²) or super obese (BMI ≥ 50 kg/m²).

METHODS

This is a retrospective study of patients, using Medicare hospital claims data, who underwent THA. The ICD-9 Clinical Modification (CM) diagnosis code V85.4x was used to identify patients with morbid obesity and with super obesity from October 1, 2010 through December 31, 2014. Patients without any BMI-related diagnosis codes were used as the control group. Twelve complications occurring during the 90 days after THA were analyzed using multivariate Cox models adjusting for patient demographic, comorbidities, and institutional factors. In addition, hospital charges and payments were compared from primary surgery through the subsequent 90 days.

RESULTS

Patients with morbid obesity had increased postoperative complications including prosthetic joint infection (hazard ratio [HR], 3.71; 95% CI, 3.2-4.31; p < 0.001), revision (HR, 1.91; 95% CI, 1.69-2.16; p < 0.001), and wound dehiscence (HR, 3.91; 95% CI, 3.14-4.86; p < 0.001). In addition, patients with morbid obesity had increased risk of deep vein thrombosis (HR, 1.43; 95% CI, 1.14-1.79; p < 0.002), pulmonary embolism (HR, 1.57; 95% CI, 1.25-1.99; p < 0.001), implant failure (HR, 1.48; 95% CI, 1.3-1.68; p < 0.001), acute renal failure (HR, 1.68; 95% CI, 1.56-1.80; p < 0.001), and all-cause readmission (HR, 1.48; 95% CI, 1.40-1.56; p < 0.001). However, death (HR, 0.94 95% CI, 0.73-1.19 p < 0.592), acute myocardial infarction (HR, 0.94; 95% CI, 0.74-1.2 p < 0.631), and dislocation (HR 1.07; 95% CI, 0.85-1.34; p < 0.585) were not different between patients in the control and morbidly obese groups. Super obese patients had an increased risk of infection (HR, 6.48; 95% CI, 4.54-9.25; p < 0.001), wound dehiscence (HR, 9.81; 95% CI, 6.31-15.24; p < 0.001), and readmission (HR, 2.16; 95% CI, 1.84-2.54; p < 0.001) compared with patients with normal BMI. Controlling for patient and institutional factors, each THA had mean total hospital charges of USD 88,419 among patients who were super obese compared with USD 73,827 for the control group, a difference of USD 14,591. Medicare payment for the patients who were super obese also was higher, but only by USD 3631.

CONCLUSIONS

Patients who are super obese are at increased risk for serious complications compared with patients with morbid obesity, whose risks are elevated relative to patients whose BMI is less than 40 kg/m². Costs of care for patients who were super obese, likewise, were increased. We present BMI outcomes to allow an objective basis for patient counseling, risk stratification, maintaining access to orthopaedic surgical care, and maintaining hospital operating margins.

LEVEL OF EVIDENCE

Level III, therapeutic study.