Risk factors for surgical site infection following lumbar spinal surgery: a meta-analysis

Primary Cervical Disc Arthroplasty Among Medicare Beneficiaries Versus Alternative Payers: Is It Time to Consider Nationwide Coverage?

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

As of 2022, the Centers for Medicare and Medicaid Services does not provide nationwide coverage for cervical disc arthroplasty (CDA). The aim was to determine whether Medicare beneficiaries have differences in: (1) lengths of stay (LOS); (2) complications; (3) readmissions; and (4) costs of care.

METHODS

Using the 2010 to 2020 PearlDiver database, we queried patients undergoing primary CDA for degenerative disc pathology. Study groups patients were those undergoing CDA with Medicare coverage (n = 1467); patients without Medicare coverage were the comparison cohort (n = 15,389). Endpoints were to compare demographics and comorbidities within the Elixhauser comorbidity index (ECI), LOS, 90-day complications, 90-day readmissions, and 90-day reimbursements. A multivariate logistic regression was used to calculate odds (OR) of medical complications and readmissions within 90-days. A P-value less than .003 was significant.

RESULTS

Patients with Medicare coverage undergoing CDA had higher mean ECI compared to alternative payers (5.24 vs 3.26; P < .0001). Mean LOS was significantly higher for Medicare beneficiaries (2.20 vs 1.76 days; P < .010). There was no significant differences in odds of all medical complications (OR: 1.19, 95% CI: .98-1.44; P = .069) or readmission rates (1.77% vs 1.33%, OR:0.82, 95% CI: .50-1.29; P = .417) within 90-days following the index procedure among Medicare beneficiaries vs alternative payers. Non-Medicare beneficiaries had higher 90-day reimbursements compared to Medicare beneficiaries ($6,700 vs $7,086,P < .001).

CONCLUSIONS

Medicare beneficiaries despite having slightly longer lengths of stay did not have higher rates of medical complications or readmissions. Surgeons and policy makers may use this data to consider alternative treatments in Medicare patients.

Risk Factors for Surgical Site Infections After Single-Level Anterior Lumbar Interbody Fusion

Abstract Background: Anterior lumbar interbody fusion (ALIF) has become an increasingly popular and effective treatment modality for various conditions of the lumbar spine. However, complications after this procedure can be costly. Surgical site infections (SSIs) are one of these types of complications. The present study identifies independent risk factors for SSI after single-level ALIF to identify high-risk patients better. Patients and Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was queried to identify single-level ALIF patients from 2005 to 2016. Multilevel fusions and non-anterior approach procedures were excluded. Mann-Pearson χ² tests analyzed categorical variables, whereas one-way analysis of variance (ANOVA) and independent t-tests analyzed differences in mean values of continuous variables. Risk factors for SSI were identified via a multivariable logistic regression model. A receiver operating characteristic (ROC) curve was generated utilizing the predicted probabilities. Results: A total of 10,017 patients met inclusion criteria; 80 (0.80%) had developed SSI and 9,937 (99.20%) had not. On multivariable logistic regression models, class 3 obesity (p = 0.014), dialysis (p = 0.025), long-term steroid use (p = 0.010), and wound classification 4 (dirty/infected) (p = 0.002) all independently increased the risk for SSI in single-level ALIF. The area under the receiver operating characteristic curve (AUROC; C-statistic) was 0.728 (p < 0.001), indicating relatively strong reliability of the final model. Conclusions: Several independent risk factors including obesity, dialysis, long-term steroid use, and dirty wound classification all increased risk for SSI after single-level ALIF. By identifying these high-risk patients, surgeons and patients can have more informed pre-operative discussions. In addition, identifying and optimizing these patients prior to operative intervention may help to minimize infection risk.

A meta-analysis of risk factors for non-superficial surgical site infection following spinal surgery

BACKGROUND

Surgical site infection (SSI) is the most common complications in spinal surgery. In SSI, non-superficial surgical site infections are more likely to result in poor clinical outcomes. It has been reported that there are multiple factors contributing to postoperative non-superficial SSI, but still remains controversial. Therefore, the aim of this meta-analysis is to investigate the potential risk factors for non-superficial SSI following spinal surgery.

METHODS

A systematic database search of PubMed, Embase, Web of Science, Cochrane Library and Clinical Trials was performed for relevant articles published until September 2022. According to the inclusion and exclusion criteria, two evaluators independently conducted literature screening, data extraction and quality evaluation of the obtained literature. The Newcastle-Ottawa Scale (NOS) score was used for quality evaluation, and meta-analysis was performed by STATA 14.0 software.

RESULTS

A total of 3660 relevant articles were initially identified and 11 articles were finally included in this study for data extraction and meta-analysis. The results of meta-analysis showed that the diabetes mellitus, obesity, using steroids, drainage time and operative time were related to the non-superficial SSI. The OR values (95%CI) of these five factors were 1.527 (1.196, 1.949); 1.314 (1.128, 1.532); 1.687(1.317, 2.162); 1.531(1.313, 1.786) and 4.255(2.612, 6.932) respectively.

CONCLUSIONS

Diabetes mellitus, obesity, using steroids, drainage time and operative time are the current risk factors for non-superficial SSI following spinal surgery. In this study, operative time is the most important risk factor resulting in postoperative SSI.

Health Care Utilization and Associated Economic Burden of Postoperative Surgical Site Infection after Spinal Surgery with Follow-Up of 24 Months

BACKGROUND

 Surgical site infection (SSI) may lead to vertebral osteomyelitis, diskitis, paraspinal musculoskeletal infection, and abscess, and remains a significant concern in postoperative management of spinal surgery. SSI is associated with greater postoperative morbidity and increased health care payments.

METHODS

 We conducted a retrospective analysis using MarketScan to identify health care utilization payments and risk factors associated with SSI that occurs postoperatively. Known patient- or procedure-related risk factors were searched across those receiving spine surgery who developed postoperative infection.

RESULTS

 A total of 33,061 patients who developed infection after spinal surgery were identified in Marketscan. Overall payments at 6 months, including index hospitalization for those with infection, were $53,573 and $46,985 for the cohort with no infection. At 24 months, the infection group had overall payments of $83,280 and $66,221 for no infection. Risk factors with largest effect size most likely to contribute to infection versus no infection were depression (4.6%), diabetes (3.7), anemia (3.3%), two or more levels (2.8%), tobacco use (2.2%), trauma (2.1%), neoplasm (1.8%), congestive heart failure (1.3%), instrumentation (1.1%), renal failure (0.9%), intravenous drug use (0.8%), and malnutrition (0.5%).

CONCLUSIONS

 SSIs were associated with significant health care utilization payments at 24 months of follow-up. The following clinical and procedural risk factors appear to be predictive of postoperative SSI: depression, diabetes, anemia, two or more levels, tobacco use, trauma, neoplasm, congestive heart failure, instrumentation, renal failure, intravenous drug use, and malnutrition. Interpretation of modifiable and nonmodifiable risk factors for infection informs surgeons of expected postoperative course and preoperative risk for this most common and deleterious postoperative complication to spinal surgery.

Development and validation of a point-of-care clinical risk score to predict surgical site infection following open spinal fusion

Background

Surgical site infection (SSI) after open spine surgery increases healthcare costs and patient morbidity. Predictive analytics using large databases can be used to develop prediction tools to aid surgeons in identifying high-risk patients and strategies for optimization. The purpose of this study was to develop and validate an SSI risk-assessment score for patients undergoing open spine surgery.

Methods

The Premier Healthcare Database of adult open spine surgery patients (n = 157,664; 2,650 SSIs) was used to create an SSI risk scoring system using mixed effects logistic regression modeling. Full and reduced multilevel logistic regression models were developed using patient, surgery or facility predictors. The full model used 38 predictors and the reduced used 16 predictors. The resulting risk score was the sum of points assigned to 16 predictors.

Results

The reduced model showed good discriminatory capability (C-statistic = 0.75) and good fit of the model ([Pearson Chi-square/DF] = 0.90, CAIC=25,517) compared to the full model (C-statistic = 0.75, [Pearson Chi-square/DF] =0.90, CAIC=25,578). The risk scoring system, based on the reduced model, included the following: female (5 points), hypertension (4), blood disorder (8), peripheral vascular disease (9), chronic pulmonary disease (6), rheumatic disease (16), obesity (12), nicotine dependence (5), Charlson Comorbidity Index (2 per point), revision surgery (14), number of ICD-10 procedures (1 per procedure), operative time (1 per hour), and emergency/urgent surgery (12). A final risk score as the sum of the points for each surgery was validated using a 1,000-surgery random hold-out (independent from the study cohort) sample (C-statistic = 0.77).

Conclusions

The resulting SSI risk score composed of readily obtainable clinical information could serve as a strong prediction tool for SSI in preoperative settings when open spine surgery is considered.

The Temporality of Deep Surgical Site Infection Rates Following Spinal Laminectomy and Fusion

BACKGROUND

Deep surgical site infections (dSSI) following spinal laminectomy and fusion are serious complications associated with poor patient outcomes. The objective of this study is to investigate the monthly and seasonal variability of dSSI rates following common spinal surgeries to investigate the "July effect," which refers to the alleged increase in adverse health outcomes due to new hospital trainees at the beginning of the academic year.

METHODS

We performed a retrospective analysis of patients who had a dSSI following laminectomy (without fusion) or spinal fusion (with or without laminectomy) at a single large urban academic medical center between January 2009 and August 2018. The change in dSSI rate over the entire study period was calculated. The monthly and seasonal variability of dSSI were assessed using a Poisson regression model to assess for the presence of the July effect.

RESULTS

A total of 7931 laminectomies and 14,637 spinal fusions were reviewed. The average dSSI rates following laminectomy and spinal fusion were 0.46 (SD, 0.47) and 1.26 (SD, 0.86) per 100 patients, respectively. The rate of dSSI following spinal fusion significantly decreased over the study period (rate ratio [RR] = 0.89, 95% CI 0.84-0.94, P < 0.01). With summer as the reference season, there were significantly lower dSSI rates following spinal fusions performed in the fall (RR = 0.62, 95% CI 0.39-0.98, P = 0.04 ). With July as the reference month, there was a significantly higher dSSI rate in April following spinal fusions.

CONCLUSION

The overall decrease in dSSI rate over the study period is consistent with previous reports. The monthly analysis revealed no significant differences in either procedure, calling into question the July effect.

CLINICAL RELEVANCE

This study is relevant to practicing spinal surgeons and can inform surgeons about seasonal data regarding dSSIs.

LEVEL OF EVIDENCE: 3

Vancomycin Use in Posterior Lumbar Interbody Fusion of Deep Surgical Site Infection

Objective

To retrospectively analyze if the use of topical intraoperative vancomycin powder reduces deep surgical site infection (DSSI) after posterior lumbar interbody fusion.

Methods

All spinal surgeries for lumbar degenerative disease and underwent posterior fixation interbody fusion between January 2013 and December 2018 were reviewed. A total of 891 patients were included, of which 527 patients (treatment group) received intraoperatively topical vancomycin powder; the others were served as control group. The primary outcomes were the overall incidence of DSSI and the effect of vancomycin on its development. The secondary outcome was risk factors for DSSI. Data on the baseline characteristics, postoperative complications, perioperative risk factors, and one-year postoperative prognoses were extracted from the medical records.

Results

A total of 20 patients met the diagnostic criteria for DSSI (2.24%), of which 7 patients (1.33%) in the treatment group and 13 patients (3.57%) in the control group. There was a significant difference in the incidence of DSSI between the groups (P = 0.026). Multivariate logistic regression analysis with stepwise backward elimination showed that the local use of vancomycin powder was an independent protective factor for DSSI (odds ratio (OR): 0.25, P = 0.01), whereas high body mass index (BMI) (OR: 1.21, P = 0.005), drinking (OR: 5.19, P = 0.005), urinary tract infections (OR: 4.49, P = 0.021), diabetes mellitus (OR: 4.32, P = 0.03), and blood transfusions (OR: 3.67, P = 0.03) were independent risk factors for DSSI.

Conclusion

The intraoperative usage of vancomycin powder could reduce effectively decreases the incidence of DSSI after posterior lumbar interbody fusion for degenerative lumbar diseases. High BMI, diabetes mellitus, drinking, and urinary tract infections were independent risk factors for DSSI, whereas the local use of vancomycin protected against these factors.

Sweat contamination induced surgical site infections after spine surgery: Three case reports and literature review

Introduction and importance

Surgical site infection (SSI) is one of the most intractable complications following spine surgery during the early postoperative stage. Elderly (age > 70 years), body mass index > 30, smoking, diabetes mellitus, coronary artery disease, chronic obstructive pulmonary disease, anemia, low serum albumin, operation time > 3 h, and perioperative blood loss > 500 mL are the common risk factors of SSI after spine surgery. However, there are few published reports about sweat contamination induced surgical site infections with Staphylococcus epidermidis up to date. Staphylococcus epidermidis is a permanent member of the normal human microbiota and has emerged as an important opportunistic pathogen in SSI. We aim to detect the influence of sweat infiltration on SSI with Staphylococcus epidermidis and effective management.

Case presentation

A 73-year-old male, a 54-year-old male and a 73-year-old female were admitted to our hospital. All of them underwent posterior compression and fusion surgery with internal fixation and got surgical site infection after primary surgery. Two of them suffered moderate surgical site infection while the third patient with comorbidities suffered severe surgical site infection. Antibiotic therapy and debridement with internal fixation retained were utilized during which microbiological culture were taken. The moderate infection patients got fully recovered after debridement and primary suture while the serious one had recurrence after the first debridement, and then the second operation was performed. SSI, however, relapsed after three days. Vacuum-assisted closure (VAC) system was placed in the third debridement. The severe patient got well recovered and discharged after displacement of VAC system.

Clinical discussion

This report serves to explore a normal but overlooked factor for SSI. SSI is one of the most intractable complications after spine surgery and the report introduce some uncomplicated but effective methods to moderate and severe SSI.

Conclusion

Sweat-contaminated is an inducement of SSI with Staphylococcus epidermidis that should attract surgeons' attention. For mild infection, changing dressing and infrared treatment can achieve good results. For moderate infection, one debridement and primary suture are enough. For severe infection, early application of VAC system can reduce the number of debridement and achieve good clinical outcome.

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The article introduces a factor that can cause early postoperative stage infection which is intractable complications.

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Three patients with fixation retained were shown to discuss whether instrumentation should be removed in deep infection.

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The report generalized effective therapeutics for mild, moderate and severe infection in early stage.

Surgical management of lumbar spinal stenosis in patients over 80: is there an increased risk?

Management of lumbar spinal stenosis (LSS) represents the first cause of spinal surgery for the elderly and will increase with the aging population. Although the surgery improves quality of life, the procedure involves anaesthetic and operative risks. The aim of this study was to assess whether the postoperative complication rate was higher for elderly patients and to find confounding factors. We conducted a retrospective study including all LSS surgeries between 2012 and 2020 at the University Hospital of Caen. We compared two populations opposing patients aged over 80 with others. The primary endpoint was the occurrence of a severe complication (SC). Minor complications were the secondary endpoint. Comorbidities, history of lumbar spine surgery and surgical characteristics were recorded. Nine hundred ninety-six patients undergoing surgery for degenerative LSS were identified. Patients over 80 were significantly affected by additional comorbidities: hypertension, heart diseases, higher age-adjusted comorbidity Charlson score, ASA score and use of anticoagulants. Knee-chest position was preferred for younger patients. Older patients underwent a more extensive decompression and had more incidental durotomies. Of the patients, 5.2% presented SC. Age over 80 did not appear to be a significant risk factor for SC, but minor complications increased. Multivariate analysis showed that heart diseases, history of laminectomy, AA-CCI and accidental durotomies were independent risk factors for SC. Surgical management for lumbar spinal stenosis is not associated to a higher rate of severe complications for patients over 80 years of age. However, preoperative risk factors should be investigated to warn the elderly patients that the complication risk is increased although an optimal preparation is the way to avoid them.

The Interplay of Obesity, Dyslipidemia and Immune Dysfunction: A Brief Overview on Pathophysiology, Animal Models, and Nutritional Modulation

Obesity has emerged as a leading global health concern. It is characterized by chronic low-grade inflammation, which impairs insulin signaling, lipid metabolism and immune function. Recent findings from animal and clinical studies have begun to elucidate the underlying mechanisms of immune dysfunction seen in the context of obesity. Here, we provide a brief review on the current understanding of the interplay between obesity, dyslipidemia and immunity. We also emphasize the advantages and shortcomings of numerous applicable research models including rodents and large animal swine that aim at unraveling the molecular basis of disease and clinical manifestations. Although there is no perfect model to answer all questions at once, they are often used to complement each other. Finally, we highlight some emerging nutritional strategies to improve immune function in the context of obesity with a particular focus on choline and foods that contains high amounts of choline.

Effectiveness of topical vancomycin in the prevention of spinal surgical site infections: a retrospective cohort study

BACKGROUND

The risk of surgical site infections (SSIs), particularly methicillin-resistant Staphylococcus aureus (MRSA) SSIs, after spinal surgeries is one of the most daunting experiences to patients and surgeons. Some authors suggest applying vancomycin powder on the wound before skin closure to minimize the risk of SSIs; however, this practice is not supported by well-established evidence. This study sought to assess the effectiveness of topical (i.e. intra-wound) vancomycin in minimizing the risk of SSIs in patients who underwent spinal surgeries at a Saudi hospital.

METHODS

A retrospective cohort study was conducted using the hospital database. Patients who underwent spinal surgeries from the period of 09/2013 to 09/2019 were included and followed up (observed from the time of the surgery) to 30 days (surgeries without implants) or 90 days (with implants). The odds ratio (OR) of the primary outcome between vancomycin treated versus non-treated patients was estimated using a logistic regression model adjusting for the measured confounders. A sensitivity analysis was conducted using propensity score analysis (inverse probability of treatment weighting [IPTW] with stabilized weights) to control for confounding by indication. All study analyses were completed using RStudio Version 1.2.5033.

RESULTS

We included 81 vancomycin treated vs. 375 untreated patients with 28 infections (8/81 vs. 20/375; respectively). The adjusted OR of SSIs between the two groups was 0.40 (95% confidence interval [CI] 0.11 to 1.34). The result of the propensity score analysis was consistent (OR: 0.97 [95% CI 0.35 to 2.68]).

CONCLUSIONS

We could not find a lower association of SSIs with intra-wound vancomycin in patients who underwent spinal surgeries. Further studies are needed to assess benefits of using topical vancomycin for this indication vs. the risk of antimicrobial resistance.

Risk of Postoperative Complications and Revision Surgery Following Robot-assisted Posterior Lumbar Spinal Fusion

STUDY DESIGN

Retrospective Study.

OBJECTIVE

This investigation examined matched cohorts of lumbar spinal fusion (LSF) patients undergoing robot-assisted and conventional LSF to compare risk of revision, 30-day readmission, 30-day complications, and postoperative opioid utilization.

SUMMARY OF BACKGROUND DATA

Patient outcomes and complication rates associated with robot-assisted LSF compared to conventional fusion techniques are incompletely understood.

METHODS

The PearlDiver Research Program (www.pearldiverinc.com) was used to identify patients undergoing primary LSF between 2011 and 2017. Patients receiving robot-assisted or conventional LSF were matched using key demographic and comorbidity variables. Indication for revision was also studied. Risk of revision, 30-day readmission, 30-day complications, and postoperative opioid utilization at 1 and 6 months was compared between the cohorts using multivariable logistic regression additionally controlling for age, sex, and Charlson Comorbidity Index.

RESULTS

The percent of LSFs that were robot-assisted rose by 169% from 2011 to 2017, increasing linearly each year (p = 0.0007). Matching resulted in 2528 patients in each cohort for analysis. Robot-assisted LSF patients experienced higher risk of revision (adjusted odds ratio [aOR] = 2.35, P ≤ 0.0001), 30-day readmission (aOR = 1.39, P = 0.0002), and total 30-day complications (aOR = 1.50, P < 0.0001), specifically respiratory (aOR = 1.56, P = 0.0006), surgical site infection (aOR = 1.56, P = 0.0061), and implant-related complications (aOR = 1.74, P = 0.0038). The risk of revision due to infection after robot-assisted LSF was an estimated 4.5-fold higher (aOR = 4.46, 95% confidence interval [CI] 1.95-12.04, P = 0.0011). Furthermore, robot-assisted LSF had increased risk of revision due to instrument failure (aOR = 1.64, 95% CI 1.05-2.58, P = 0.0300), and pseudarthrosis (aOR = 2.24, 95%CI = 1.32-3.95, P = 0.0037). A higher percentage of revisions were due to infection in robot-assisted LSF (19.0%) than in conventional LSF (9.2%) (P = 0.0408).

CONCLUSION

Robotic-assisted posterior LSF is independently associated with increased risk of revision surgery, infection, instrumentation complications, and postoperative opioid utilization compared to conventional fusion techniques. Further research is needed to investigate long-term postoperative outcomes following robot-assisted LSF. Spine surgeons should be cautious when considering immediate adoption of this emerging surgical technology.

LEVEL OF EVIDENCE

3.

Hypoalbuminemia Increased the Length of Stay in the Treatment of Postoperative Acute Surgical Site Infection in Spinal Surgery

STUDY DESIGN

Multicenter retrospective study.

OBJECTIVE

The aim of this study was to identify specific risk factors for increased length of stay (LOS) in the management of acute surgical site infection (SSI) following spinal surgery.

SUMMARY OF BACKGROUND DATA

Postoperative SSI is a serious complication of spinal surgery and is known to be associated with increased LOS and additional cost. Although many risk factors contribute to the development of SSI following spinal surgery, little is known about risk factors associated with the treatment of SSI that contribute to increased LOS.

METHODS

Patients at two institutions experiencing deep SSI following spinal surgery between January 2009 and December 2016 were identified. The patients were divided into two groups depending upon the median LOS attributable to SSI. The effects of patient characteristics, comorbidities, disease history, and invasiveness of the elective surgery on the risk of increased LOS were determined using univariate analyses and multivariate logistic regression.

RESULTS

Of the 1656 spinal surgery cases, 40 (2.4%) experienced deep SSI. The median LOS was 67 days. Multivariate logistic regression analysis revealed that hypoalbuminemia during hospitalization was associated with increased LOS (odds ratio 0.042, confidence interval 0.005-0.342; P = 0.003). We determined the appropriate diagnostic cutoff of hypoalbuminemia during hospitalization using receiver-operating characteristic curves. A serum albumin level <3.1 g/dL (sensitivity, 86.4%; specificity, 75.0%; area under the curve, 0.84) was indicative of a longer hospital stay.

CONCLUSION

Low serum albumin level during hospitalization was an independent risk factor for increased LOS in the treatment of SSI following spinal surgery. When the serum albumin level is <3.1 g/dL in patients with SSI, we should consider interventions aimed at correcting this hypoalbuminemia.

LEVEL OF EVIDENCE

4.

How Does Body Mass Index Influence Outcomes in Patients After Lumbar Fusion?

STUDY DESIGN

Retrospective study.

OBJECTIVE

The purpose of the present study is to determine how body mass index (BMI) affects patient-reported outcome measurements (PROMs) after lumbar fusions.

SUMMARY OF BACKGROUND DATA

Although greater preoperative BMI is known to increase the rates of adverse events after surgery, there is a paucity of literature assessing the influence of BMI on PROMs after lumbar fusion.

METHODS

Patients undergoing lumbar fusion surgery between 1 and 3 levels were retrospectively identified. PROMs analyzed were the Short Form-12 Physical Component Score, Mental Component Score, Oswestry Disability Index (ODI), and Visual Analog Scale Back and Leg pain scores. Patients were divided into groups based on preoperative BMI: class 1, BMI <25.0; class 2, BMI 25.0 to 29.9; class 3, BMI 30.0 to 34.9; and class 4, BMI ≥35.0. Absolute PROM scores, the recovery ratio, and the percentage of patients achieving minimum clinically important difference between groups were compared.

RESULTS

A total of 54 (14.8%) patients in class 1, 140 (38.2%) in class 2, 109 (29.8%) in class 3, and 63 (17.2%) in class 4 were included. All patients improved after surgery across all outcome measures (P < 0.001) except for class 4 patients, who did not improve in terms of Short Form-12 Mental Component Score scores after surgery (P = 0.276). Preoperative Short Form-12 Physical Component Score (P = 0.002) and Oswestry Disability Index (P < 0.0001) scores were significantly different between BMI groups-with class 4 having worse disability than class 1 and 2. BMI was not a significant predictor for any outcome domain. Overall 30- and 90-day readmission rates were similar between groups, with a higher revision rate in the class 4 group (P = 0.036), due to a higher incidence of postoperative surgical site infections (P = 0.014).

CONCLUSION

All patients undergoing short-segment lumbar fusion for degenerative disease improved to a similar degree with respect to PROMs. Those in the highest class of obesity (BMI ≥35.0) were, however, at a greater risk for postoperative surgical site infection.

LEVEL OF EVIDENCE

3.