Does Obesity Explain the Effect of the Metabolic Syndrome on Complications Following Elective Lumbar Fusion? A Propensity Score Matched Analysis

Postoperative Complications in Patients With Metabolic Syndrome Following Unicompartmental Knee Arthroplasty

INTRODUCTION

Metabolic syndrome is associated with increased risk of postoperative complications following various orthopedic surgeries. This study looked to identify specific postoperative complications in these patients following unicompartmental knee arthroplasty (UKA).

METHODS

Adult patients undergoing primary UKA were queried in the National Surgical Quality Improvement Program database from 2006-2019. Metabolic syndrome was defined by the simultaneous presence of hypertension, diabetes, and body mass index >30 kg/m2. Two patient groups were categorized in this study: patients with metabolic syndrome and patients without metabolic syndrome. Baseline characteristics and postoperative outcomes were compared between the two cohorts with the use of bivariate and multivariate analyses.

RESULTS

In total, 10,557 patients underwent UKA. Of these, 9,511 patients (90.1%) did not have metabolic syndrome whereas 1,046 (9.9%) had metabolic syndrome. Following adjustment for potential confounding variables on multivariate analysis, metabolic syndrome patients had an increased risk of an extended length of stay greater than four days (OR 1.66; p=0.016) compared to patients without metabolic syndrome.

CONCLUSION

Metabolic syndrome was associated with an increased risk of extended length of stay greater than four days following UKA. Physicians should be prepared for this complication as well as others when discussing treatment with metabolic syndrome patients.

Impact of Metabolic Syndrome on Early Postoperative Outcomes After Cervical Disk Replacement: A Propensity-matched Analysis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To compare the demographics, perioperative variables, and complication rates following cervical disk replacement (CDR) among patients with and without metabolic syndrome (MetS).

SUMMARY OF BACKGROUND DATA

The prevalence of MetS-involving concurrent obesity, insulin resistance, hypertension, and hyperlipidemia-has increased in the United States over the last 2 decades. Little is known about the impact of MetS on early postoperative outcomes and complications following CDR.

METHODS

The 2005-2020 National Surgical Quality Improvement Program was queried for patients who underwent primary 1- or 2-level CDR. Patients with and without MetS were divided into 2 cohorts. MetS was defined, according to other National Surgical Quality Improvement Program studies, as concurrent diabetes mellitus, hypertension requiring medication, and body mass index ≥30 kg/m 2 . Rates of 30-day readmission, reoperation, complications, length of hospital stay, and discharge disposition were compared using χ 2 and Fisher exact tests. One to 2 propensity-matching was performed, matching for demographics, comorbidities, and number of operative levels.

RESULTS

A total of 5395 patients were included for unmatched analysis. Two hundred thirty-six had MetS, and 5159 did not. The MetS cohort had greater rates of 30-day readmission (2.5% vs. 0.9%; P =0.023), morbidity (2.5% vs. 0.9%; P =0.032), nonhome discharges (3% vs. 0.6%; P =0.002), and longer hospital stays (1.35±4.04 vs. 1±1.48 days; P =0.029). After propensity-matching, 699 patients were included. All differences reported above lost significance ( P >0.05) except for 30-day morbidity (superficial wound infections), which remained higher for the MetS cohort (2.5% vs. 0.4%, P =0.02).

CONCLUSIONS

We identified MetS as an independent predictor of 30-day morbidity in the form of superficial wound infections following single-level CDR. Although MetS patients experienced greater rates of 30-day readmission, nonhome discharge, and longer lengths of stay, MetS did not independently predict these outcomes after controlling for baseline differences in patient characteristics.

LEVEL OF EVIDENCE

Level III.

A component-based analysis of metabolic syndrome's impact on 30-day outcomes after hip fracture: reduced mortality in obese patients

Introduction

Hip fractures are a common injury associated with significant morbidity and mortality. In the United States, there has been a rapid increase in the prevalence of metabolic syndrome (MetS), a condition comprised several common comorbidities, including obesity, diabetes mellitus, and hypertension, that may worsen perioperative outcomes. This article assesses the impact of MetS and its components on outcomes after hip fracture surgery.

Methods

Patients who underwent nonelective operative treatment for traumatic hip fractures were identified in the 2015-2020 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Baseline characteristics between groups were compared, and significant differences were included as covariates. Multivariate regression was performed to assess the impact of characteristics of interest on postoperative outcomes. Patients with MetS, or a single one of its constitutive components-hypertension, diabetes, and obesity-were compared with metabolically healthy cohorts.

Results

In total 95,338 patients were included. Patients with MetS had increased complications (OR 1.509; P < 0.001), but reduced mortality (OR 0.71; P < 0.001). Obesity alone was also associated with increased complications (OR 1.14; P < 0.001) and reduced mortality (OR 0.736; P < 0.001). Both hypertension and diabetes alone increased complications (P < 0.001) but had no impact on mortality. Patients with MetS did, however, have greater odds of adverse discharge (OR 1.516; P < 0.001), extended hospital stays (OR 1.18; P < 0.001), and reoperation (OR 1.297; P = 0.003), but no significant difference in readmission rate.

Conclusion

Patients with MetS had increased complications but decreased mortality. Our component-based analysis showed had obesity had a similar effect: increased complications but lower mortality. These results may help surgeons preoperatively counsel patients with hip fracture about their postoperative risks.

Metabolic syndrome and surgical complications: a systematic review and meta-analysis of 13 million individuals

BACKGROUND

Metabolic syndrome (MetS) is characterised by the presence of at least three of the five following components: insulin resistance, obesity, chronic hypertension, elevated serum triglycerides, and decreased high-density lipoprotein cholesterol concentrations. It is estimated to affect 1 in 3 people around the globe and is reported to affect 46% of surgical patients. For people with MetS who undergo surgery, an emerging body of literature points to significantly poorer postoperative outcomes compared with nonaffected populations. The aim of this study is to review the current evidence on the risks of surgical complications in patients with MetS compared to those without MetS.

METHODS

Systematic review and meta-analysis using PRISMA and AMSTAR reporting guidelines.

RESULTS

The meta-analysis included 63 studies involving 1 919 347 patients with MetS and 11 248 114 patients without MetS. Compared to individuals without the condition, individuals with MetS were at an increased risk of mortality (OR 1.75 95% CI: 1.36-2.24; P <0.01); all surgical site infection types as well as dehiscence (OR 1.64 95% CI: 1.52-1.77; P <0.01); cardiovascular complications (OR 1.56 95% CI: 1.41-1.73; P <0.01) including myocardial infarction, stroke, cardiac arrest, cardiac arrythmias and deep vein thrombosis; increased length of hospital stay (MD 0.65 95% CI: 0.39-0.9; P <0.01); and hospital readmission (OR 1.55 95% CI: 1.41-1.71; P <0.01).

CONCLUSION

MetS is associated with a significantly increased risk of surgical complications including mortality, surgical site infection, cardiovascular complications, increased length of stay, and hospital readmission. Despite these risks and the high prevalence of MetS in surgical populations there is a lack of evidence on interventions for reducing surgical complications in patients with MetS. The authors suggest prioritising interventions across the surgical continuum that include (1) preoperative screening for MetS; (2) surgical prehabilitation; (3) intraoperative monitoring and management; and (4) postoperative rehabilitation and follow-up.

Impact of metabolic syndrome on morbidity and mortality following transforaminal interbody fusion (TLIF)

Study design

Retrospective Multi-Institutional Database Study.

Objective

Investigate the effect of metabolic syndrome (MetS) on the outcomes of Transforaminal Lumbar Interbody Fusion (TLIF).

Summary of background data

TLIF procedures in lumbar spine pathology are common. MetS is a combination of conditions, including medication required hypertension, diabetes mellitus (DM), and body mass index (BMI) of 30 kg/m2s or more. The prevalence of MetS has increased drastically over the past two decades. Our study aimed to understand the effect of MetS on morbidity and mortality of TLIF postoperatively.

Methods

Our study used American College of Surgeons National Surgical Quality Improvement (ACS-NSQIP) data from 2006 to 2019 to find all patients who underwent TLIF. Patients with MetS were compared to those without MetS. Fisher's test identified univariate relationships between MetS and preoperative/postoperative variables. Multivariable logistic regression models were utilized to analyze the association between MetS and postoperative morbidity and mortality.

Results

54,980 patients were identified who received TLIF. 10.7 % had MetS preoperatively. Patients with and without MetS showed statistically significant univariate differences in most preoperative and postoperative variables. After adjusting for preoperative comorbidities, patients with MetS had greater multivariate-adjusted odds of wound infections (aOR = 1.5889, CI 1.1952-2.112, p = 0.00144), pulmonary events (aOR = 1.5517, CI 1.1207-2.1485, p = 0.00813), renal events (aOR = 2.8685, CI 1.5511-5.3045, p = 0.00078), sepsis (aOR = 1.6773, CI 1.1647-2.4155, p = 5.44E-03), and return to OR (aOR = 1.4764, CI 1.2201-1.7866, p = 6.19E-05).

Conclusions

Patients with MetS are at elevated risk for various morbidity and mortality markers after TLIF. Surgeons performing TLIFs on these patients should be aware of the increased potential for postoperative events that may complicate the patient's recovery.

Level of evidence

Level III.

The Effect of Modifiable Risk Factors on Postoperative Complications in Lumbar Spine Fusions

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The impact of modifiable risk factors (MRFs) on complications, costs, and readmission rates at 30, 90, and 180-days following lumbar spine fusion.

METHODS

Patients with lumbar spine fusions within the 2016-2017 Nationwide Readmissions Database (NRD). Patients were stratified by the following MRFs: Alcohol use, tobacco/nicotine use, nutritional malnourishment, dyslipidemia, and primary hypertension. Differences in complications, non-elective readmission rates, costs, and length of stay were compared between MRFs and the non-MRF group. Statistical analysis was conducted using Tukey multiple comparisons of means, 1-way ANOVA, Wald testing, unpaired Welch 2-sample t-tests, multivariate analysis, and predictive modeling.

RESULTS

The final analysis included 297,579 lumbar fusion patients. At 30 and 90 days, patients with nutritional malnutrition, dyslipidemia, and primary hypertension had significantly greater readmission rates than patients without MRFs (all P<0.01). At 180-days, all MRFs had significantly greater readmission rates than the non-MRF group (all P<0.001). Dyslipidemia demonstrated significantly greater rates of myocardial infarction at 90 days compared to all groups (all P<0.02). Nutritional malnutrition was associated with a significantly greater mortality rate than primary hypertension, non-MRF, and tobacco/nicotine use at 90 days (P<0.001) and only tobacco/nicotine use at 180 days (P=0.007). Predictive modeling showed increases of 0.77%, 1.70%, and 2.44% risk of readmission at 30, 90, and 180-days respectively per additional MRF (all P<0.001).

CONCLUSIONS

These findings highlight the negative impact each MRF has on patients following lumbar spinal fusion. Further longitudinal research is necessary to comprehensively characterize the effects of various MRFs on spine surgery outcomes.

Metabolic Syndrome: Is Arthroscopic Rotator Cuff Repair Safe in This Patient Population?

Purpose Metabolic syndrome is associated with postoperative morbidity and mortality in surgical patients. With the increased use of arthroscopic techniques for rotator cuff repair (RCR), it is important to identify the impact this disorder has on surgical patients. The purpose of this study is to evaluate the clinical impact of metabolic syndrome on outcomes following arthroscopic RCR. Methods The 2006-2019 National Surgical Quality Improvement Program database was queried for adult patients who underwent arthroscopic RCR. Two patient groups were categorized: patients with metabolic syndrome and patients without metabolic syndrome. Demographics, comorbidities, and 30-day postoperative outcomes were compared using bivariate and multivariate analyses. Results Of 40,156 patients undergoing arthroscopic RCR, 36,391 did not have metabolic syndrome and 3,765 had metabolic syndrome. After adjusting for differences in baseline characteristics between the two groups, those with metabolic syndrome had an increased risk of developing renal complications and cardiac complications, as well as requiring hospital admission postoperatively and hospital readmission. Conclusion Metabolic syndrome is an independent risk factor for developing renal and cardiac complications, as well as requiring overnight hospital admission and hospital readmission. Providers should understand the need for preoperative evaluation and surveillance of these patients following their surgery to minimize the risk of poor outcomes.

The Effect of Diabetes and Metabolic Syndrome on Spine Surgery Outcomes

PURPOSE OF REVIEW

Diabetes and metabolic syndrome are highly prevalent in patients undergoing spine surgery. This review aims to capture both the findings of recently published literature investigating the effects of diabetes and metabolic syndrome on spine surgery outcomes and the current best practices in patient management.

RECENT FINDINGS

Diabetes and metabolic syndrome both contribute to worse outcomes in patients undergoing spine surgery. Although patients with diabetes are at greater risk of complications, those with uncontrolled diabetes experience increased healthcare costs and greater odds of postoperative complications. Furthermore, metabolic syndrome is repeatedly shown to have an adverse effect on spine surgery outcomes, including healthcare costs and medical complications. Spine surgeons should coordinate care with primary care physicians to optimize the preoperative profile of patients with comorbidities like diabetes and metabolic syndrome to minimize operative risk. With the shift to value-based care, understanding the patient factors that lead to complications is becoming increasingly important. Future studies should build upon the current literature and design preoperative interventions for at-risk patients. Additionally, further research is needed to analyze the modulatory effects of the social determinants of health in patients with diabetes and metabolic syndrome.

Obesity and Spine Surgery: A Qualitative Review About Outcomes and Complications. Is It Time for New Perspectives on Future Researches?

STUDY DESIGN

Literature review.

OBJECTIVES

An increasing number of obese patients requires operative care for degenerative spinal disorders. The aim of this review is to analyze the available evidence regarding the role of obesity on outcomes after spine surgery. Peri-operative complications and clinical results are evaluated for both cervical and lumbar surgery. Furthermore, the contribution of MIS techniques for lumbar surgery to play a role in reducing risks has been analyzed.

METHODS

Only articles published in English in the last 10 years were reviewed. Inclusion criteria of the references were based on the scope of this review, according to PRISMA guidelines. Moreover, only paper analyzing obesity-related complications in spine surgery have been selected and thoroughly reviewed. Each article was classified according to its rating of evidence using the Sacket Grading System.

RESULTS

A total number of 1636 articles were found, but only 130 of them were considered to be relevant after thorough evaluation and according to PRISMA checklist. The majority of the included papers were classified according to the Sacket Grading System as Level 2 (Retrospective Studies).

CONCLUSION

Evidence suggest that obese patients could benefit from spine surgery and outcomes be satisfactory. A higher rate of peri-operative complications is reported among obese patients, especially in posterior approaches. The use of MIS techniques plays a key role in order to reduce surgical risks. Further studies should evaluate the role of multidisciplinary counseling between spine surgeons, nutritionists and bariatric surgeons, in order to plan proper weight loss before elective spine surgery.

The Impact of Metabolic Syndrome on Reoperations and Complications After Primary Total Hip Arthroplasty

BACKGROUND

Metabolic syndrome (MetS) represents a constellation of interrelated conditions including insulin resistance, abdominal obesity, hypertension, and dyslipidemia. The goals of this study are to determine the impact of MetS on implant survivorship, complications, and clinical outcomes after primary total hip arthroplasty (THA).

METHODS

Utilizing our institutional total joint registry, 1,268 patients undergoing primary THA were identified with MetS based on the World Health Organization definition and matched 1:1 to those without MetS based on age, gender, and surgical year. MetS patients were further stratified according to the World Health Organization body mass index (BMI) classification to contextualize obesity. Kaplan-Meier analyses were utilized to compare survivorship free of any reoperation, revision, and complications. Clinical outcomes were assessed with Harris hip scores. Mean follow-up after THA was 5 years.

RESULTS

MetS patients had significantly worse 5-year survivorship free from any reoperation compared to those without MetS (93.5% vs 96.1%, respectively; hazard ratio [HR] 1.4, P = .04). When stratifying MetS and BMI classification, the BMI >40 kg/m² had significantly decreased 5-year implant survivorship free from any reoperation (85.9% vs 96.1%, HR 3.4, P < .001), any revision (91.7% vs 97.3%, HR 2.7, P < .001), and reoperation for periprosthetic joint infection (95% vs 99%, HR 5.1, P < .001). Both groups experienced significant and similar improvement in final Harris hip scores (P < .001).

CONCLUSION

Patients with MetS had a 1.4-fold increased risk of reoperation after primary THA compared to a matched cohort without the condition. MetS patients with a BMI >40 kg/m² had the highest risk of reoperation, and had a significantly higher revision and periprosthetic joint infection rates, suggesting that morbid obesity remains a critical, independent risk factor beyond MetS.

LEVEL OF EVIDENCE

Level 3, Case-control study.

Preoperative Opioid Weaning Before Major Spinal Fusion: Simulated Data, Real-World Insights

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To identify gaps in opioid prescription immediately prior to spinal fusion and to study the effect of such simulated "opioid weaning/elimination" on risk of long-term postoperative opioid use.

SUMMARY OF BACKGROUND DATA

Numerous studies have described preoperative opioid duration and dose thresholds associated with sustained postoperative opioid use. However, the benefit and duration of preoperative opioid weaning before spinal fusion has not been elaborated.

METHODS

Humana commercial insurance data (2007-Q1 2017) was used to study primary cervical and lumbar/thoracolumbar fusions. More than 5000 total morphine equivalents in the year before spinal fusion were classified as chronic preoperative opioid use. Based on time between last opioid prescription (<14-days' supply) and spinal fusion, chronic opioid users were divided as; no gap, >2-months gap (2G) and >3-months gap (3G). Primary outcome measure was long-term postoperative opioid use (>5000 total morphine equivalents between 3 and 12-mo postoperatively). The effect of "opioid gap" on risk of long-term postoperative opioid use was studied using multiple-variable logistic regression analyses.

RESULTS

17,643 patients were included, of whom 3590 (20.3%) had chronic preoperative opioid use. Of these patients, 41 (1.1%) were in the 3G group and 106 (3.0%) were in the 2G group. In the 2G group, 53.8% patients ceased to have long-term postoperative use as compared with 27.8% in NG group. This association was significant on logistic regression analysis (OR 0.30, 95% CI: 0.20-0.46, P < 0.001).

CONCLUSIONS

Chronic opioid users whose last opioid prescription was >2-months prior to spinal fusion and less than 14-days' supply had significantly lower risk of long-term postoperative opioid use. We have simulated "opioid weaning" in chronic opioid users undergoing major spinal fusion and our analysis provides an initial reference point for current clinical practice and future clinical studies.Level of Evidence: 3.

Metabolic syndrome increases risk for perioperative outcomes following posterior lumbar interbody fusion

The present study is a retrospective cohort study. Metabolic syndrome (MetS) is a clustering of clinical findings that has been shown to increase the risk of the surgical outcomes. Our study aimed to evaluate whether MetS was a risk factor for increased perioperative outcomes in patients undergoing posterior lumbar interbody fusion (PLIF).We retrospectively analyzed patients over 18 years following elective posterior lumbar spine fusion from January 2014 to December 2018. Emergency procedures, infections, tumor, fracture, and revision surgeries were excluded. Patients were divided into 2 groups with and without MetS. The MetS was defined by having 3 of the following 4 criteria: obesity (body mass index ≥30 kg/m), dyslipidemia, hypertension, and diabetes. The follow-up period lasted up to 30 days after surgery. The outcomes of demographics, comorbidities, perioperative complications, and length of stay were compared between the 2 groups. Multivariate logistic regression analysis was used to identify perioperative outcomes that were independently associated with MetS.The overall prevalence of MetS was 12.5% (360/2880). Patients with MetS was a significantly higher risk factor for perioperative complications, and longer length of stay cmpared with patients without MetS (P < .05). The MetS group had a higher rate of cardiac complications (P = .019), pulmonary complication (P = .035), pneumonia (P = .026), cerebrovascular event (P = .023), urinary tract infection (P = .018), postoperative ICU admission (P = .02), and deep vein thrombosis (P = .029) than non-MetS group. The patients with MetS had longer hospital stays than the patients without MetS (22.16 vs 19.99 days, P < .001). Logistic regression analysis revealed that patients with MetS were more likely to experience perioperative complications (odds ratio [OR] 1.31; 95% confidence interval [CI]: 1.06-2.07; P < .001), and extend the length of stay (OR: 1.69; 95% CI: 1.25-2028; P = .001).The MetS is a significant risk factor for increased perioperative complications, and extend length of stay after PLIF. Strategies to minimize the adverse effect of MetS should be considered for these patients.

Patients with metabolic syndrome have a greater rate of complications after arthroplasty: A systematic review and meta-analysis

Aims

Patients with metabolic syndrome (MetS) are known to be at increased risk of postoperative complications, but it is unclear whether MetS is also associated with complications after total hip arthroplasty (THA) or total knee arthroplasty (TKA). Here, we perform a systematic review and meta-analysis linking MetS to postoperative complications in THA and TKA.

Methods

The PubMed, OVID, and ScienceDirect databases were comprehensively searched and studies were selected and analyzed according to the guidelines of the Meta-analysis of Observational Studies in Epidemiology (MOOSE). We assessed the methodological quality of each study using the Newcastle-Ottawa Scale (NOS), and we evaluated the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Data were extracted and meta-analyzed or qualitatively synthesized for several outcomes.

Results

Ten cohort studies involving 1,352,685 patients were included. Qualitative analysis suggested that MetS was associated with a higher incidence of cardiovascular events, and meta-analysis showed that MetS increased the risk of all-cause complications (risk ratio (RR) 1.55, 95% confidence interval (CI) 1.28 to 1.89), surgical site infection (SSI; RR 2.99, 95% CI 1.30 to 6.90), urinary tract infection (UTI; RR 2.58, 95% CI 1.03 to 6.43), and 30-day readmission (RR 1.45, 95% CI 1.33 to 1.59). There was insufficient evidence for assessing an association between MetS and venous thromboembolism events, pulmonary or gastrointestinal complications, or mortality.

Conclusion

Patients with MetS undergoing THA and TKA are at increased risk of all-cause complications, cardiovascular complications, SSI, UTI, and 30-day readmission. Surgeons should be aware of the increased risk of these complications in MetS, and presurgical protocols for these complications should give special consideration to MetS patients.

Cite this article:Bone Joint Res. 2020;9(3):120–129.

The Impact of Metabolic Syndrome on 30-Day Outcomes Following ORIF for Ankle Fractures

Introduction: Metabolic syndrome (MetS) is associated with significant postoperative morbidity. Despite an increasing prevalence of MetS in the US population, its impact on postoperative outcomes following ankle fractures remains limited. Materials and Methods: The 2012-2016 American College of Surgeons-National Surgical Quality Improvement Program database was queried for patients undergoing open reduction with internal fixation (ORIF) for ankle fractures using Current Procedural Terminology codes: 27766, 27769, 27792, 27814, 27822, and 27823. The study cohort was divided into 2 groups: MetS versus No MetS. MetS was identified using a predefined criteria as the coexistence of (1) diabetes mellitus, (2) hypertension, and (3) body mass index ≥30 kg/m2. Results: A total of 1013 (6.7%) MetS underwent ORIF for ankle fractures. Following adjustment for baseline differences, MetS was an independent predictor of experiencing any 30-day complication (odds ratio [OR] = 1.35; P = .020), wound complications (OR = 1.67; P = .024), renal complications (OR = 3.54; P = .022), 30-day readmissions (OR = 1.66; P = .001), 30-day unplanned reoperations (OR = 1.69; P = .009) and decreased odds of home discharge (OR = 0.66; P < .001). Conclusion: Patients with MetS undergoing ORIF for ankle fractures are at an increased risk of experiencing adverse 30-day complications, readmissions, and reoperations. Providers should understand the need of appropriate postoperative surveillance in this high-risk group to minimize the risk of poor outcomes. Level of Evidence: Level III.