Obesity is associated with inferior results after surgery for lumbar spinal stenosis: a study of 2633 patients from the Swedish spine register

The impact of obesity on postoperative and perioperative outcomes in lumbar spine surgery: a systematic review and meta-analysis

BACKGROUND CONTEXT

Obesity is increasingly prevalent globally and is associated with various health issues, including spine-related disorders. Previous studies have shown mixed results regarding the impact of obesity on spine surgery outcomes.

PURPOSE

This meta-analysis aims to evaluate the effects of obesity on perioperative and postoperative outcomes in spine surgery patients.

STUDY DESIGN/SETTING

We performed a systematic review and meta-analysis of prospective and retrospective studies comparing outcomes between obese and nonobese spine surgery patients.

PATIENT SAMPLE

The meta-analysis included 35,639 patients, of which 9,369 were obese (BMI≥30 kg/m²) and 26,270 were nonobese (BMI<30 kg/m²).

OUTCOME MEASURES

Primary outcomes included patient-reported outcome measures (PROMs) such as the Oswestry Disability Index (ODI) and the Visual Analog Scale (VAS) for leg and back pain. Secondary outcomes involved perioperative measures like estimated blood loss (EBL), operative time, and length of stay (LOS), as well as complication and reoperation rates.

METHODS

Following PRISMA guidelines, four databases were searched for relevant studies. The quality of included studies was assessed using the Cochrane Risk of Bias tool. Mean differences were used to quantify the differences in PROMs and perioperative outcomes. Odds ratios were used to analyze differences in complication rates.

RESULTS

Obese patients had similar PROMs compared to nonobese patients, with differences not exceeding the minimal clinically important difference (MCID). However, obese patients experienced longer operative times, greater EBL, and extended hospital stays. They also had higher rates of postoperative complications such as Dural tears, infections, and reoperations.

CONCLUSIONS

While obesity is associated with certain perioperative challenges, the postoperative recovery in terms of pain and disability appears comparable between obese and nonobese patients. Spine surgeons should be aware of the increased perioperative risks but can reassure obese patients of similar long-term outcomes postsurgery.

A retrospective cohort review of BMI on SI joint fusion outcomes: examining the evidence to improve insurance guidelines

PURPOSE

The demand for SIJ fusion among obese patients has grown substantially. However, the clinical relevance of obesity in the context of SI joint fusion has not been well investigated specifically, whether there is a BMI cutoff above which the benefit-risk ratio is low.

METHODS

Adult patients ≥ 21 years of age who underwent minimally invasive SIJ fusion between 2020 and 2023. Participants were classified using the National Institutes for Health body mass index (BMI). Patients with a BMI of 30 to 39 with no significant comorbidity are considered obese, patients with a BMI of 35 to 39 with a significant comorbidity or a BMI of 40 or greater are considered morbidly obese. All subjects completed the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) at baseline and 12 months. One-way analysis of variance was used to examine the impact of BMI category on score changes.

RESULTS

Overall, mean VAS improved at 12 months by 2.5 points (p < .006). Over the 12-month follow-up period, BMI category did not impact mean improvement in VAS (ANOVA p = .08). Mean ODI at 12 months improved by 23.2 points (p < .001). BMI category did impact mean improvement in ODI (ANOVA p = .03).

CONCLUSION

This study demonstrates similar benefits across all BMI categories. This data suggests that obese patients do benefit from minimally invasive SIJ fusion, specifically the 35-40 BMI cohort of patients, and should not be denied this procedure based on arbitrary healthcare organizations BMI criteria.

Comprehensive guidelines for prehabilitation in spine surgery

Study Design

Literature review.

Objectives

Review prehabilitation techniques used for elective spine surgery to create a comprehensive list of recommendations.

Methods

A systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines by searching three electronic databases from 1997 to 2021. Pertinent literature reporting information on prehabilitation, applicable to spine surgery, was identified. Seventy studies were selected for further analysis. Findings from the literature were reinforced by practices employed by the authors.

Results

Preoperative smoking cessation should be achieved 3-4 weeks before elective spine surgery. Preoperative weight loss programs to reach a goal BMI <35 kg/m2 may be a viable solution to minimize wound complications and surgical site infections. To minimize the negative impact of cardiopulmonary comorbidities, patients can enroll in an exercise program prior to surgery. Patients should abstain from alcohol before elective spine surgery. Patients with osteoporosis may benefit from supplementation with Vitamin D, calcium, and parathyroid hormone. Opioids should be weaned to complete cessation 6-8 weeks before surgery. Preoperative cognitive behavioral therapy (CBT) and education seem to be the most beneficial in reducing complications associated with psychiatric comorbidities. Patients should engage in a comprehensive prehabilitation regimen.

Conclusion

Targeting patient risk factors with personalized interventions can improve postoperative outcomes in patients undergoing elective spine surgery.

Patient Comorbidities, Their Influence on Lumbar Spinal Fusion Surgery, and Recommendations to Reduce Unfavorable Outcomes

Improvements in healthcare management have led to a decrease in perioperative and postoperative complications. However, perioperative medical complications and mortality rates continue to increase in patients undergoing elective spinal surgeries. This trend is driven by the increase in the older population and the rise in the number of patients with more than two comorbidities. Managing patients with multiple comorbidities requires additional resources, augmenting the financial and societal burden. Despite the high risk of complications and mortality, patients with multiple comorbidities undergo spinal surgery for degenerative spinal conditions daily. These findings highlight the need for heightened awareness, patient education, and management of comorbidities before elective spinal surgeries. This article comprehensively reviews literature on the effects of medical comorbidities on spinal fusion surgery outcomes to increase awareness of the surgical complications associated with comorbidities. In addition, suggested preoperative and postoperative comorbidity management strategies are outlined.

Comparison of functional outcomes and patient satisfaction in patients with lumbar canal stenosis with and without concomitant obesity following lumbar decompression surgery and their correlation with BMI

BACKGROUND

Obesity is an important predictor of development of Lumbar canal stenosis (LCS) and its symptoms. LCS further restricts the mobility of the patient and a vicious cycle develops. The operative decision on patients with LCS and obesity is a matter of debate. Hence, we attempted to compare changes in body mass index and patient satisfaction in patients with LCS with and without concomitant obesity, undergoing spinal decompression surgery.

METHODS

Patients undergoing decompression for LCS between 1st June 2019 to 31st May 2020 were included. Baseline characteristics including age, sex, co-morbidities, BMI, self-recorded maximal walking distance (SR-MWD) and Oswestry disability index score (ODI) were recorded. All patients were followed up prospectively at 1 year post surgery. Satisfaction was recorded on a five-point Likert scale. Participants were classified into non obesity (group 1) and obesity (group 2) groups according to JAPI and WHO classification and compared.

RESULTS

55 patients met the inclusion criteria, 23 in group 1 and 32 in group 2. Group 2 showed a mean decrease in BMI of 0.95 ± 1.32 kg/m2 while other group had an increase of 0.14 ± 1.31 kg/m2 (p = 0.021). Significant weight change was seen in 31.3 % group 2 vs 8.7 % group 1 patients which was significant (p = 0.046). Pre operative BMI positively correlated with change in BMI after surgery (r = 0.406, p = 0.001) and with percentage weight reduction (r = 0.321, p = 0.017). Both the groups were comparable in improvement in ODI and SR-MWD scores and patient satisfaction.

CONCLUSION

Patients with obesity achieve significant reduction in weight and BMI following decompression surgery for LCS. It will further prevent other health conditions attributed to obesity. Both the groups were comparable in ODI, SR-MWD and satisfactory outcome following surgery. Hence obesity should not be a deterring factor for surgical consideration for patients with lumbar canal stenosis.

The 3-Steps Approach for Lumbar Stenosis with Anatomical Insights, Tailored for Young Spine Surgeons

Background/Objectives: Lumbar decompression surgery for degenerative lumbar stenosis is an intervention which addresses a degenerative condition affecting many patients. This article presents a meticulous three-phase surgical approach, derived from our clinical experiences and intertwining anatomical insights, offering a nuanced perspective tailored for the educational needs of young spinal surgeons. Methods: Six hundred and eighty-seven patients who underwent lumbar decompression surgery at a single institution were included in the present study. A retrospective analysis of patient demographics and surgical techniques was performed. All surgeries were performed by a consistent surgical team, emphasizing uniformity in approach. The surgical technique involves a meticulous three-phase process comprising exposure and skeletal visualization; microscopic identification and decompression; and undermining of the spinous process base and contralateral decompression. Results: Presenting results from 530 patients, the study examines demographic characteristics, health profiles, operative details, complications, and clinical assessments. The three-phase approach demonstrates low complication rates, absence of recurrences, and improved clinical outcomes, emphasizing its efficacy. Conclusions: The three-phase surgical approach emerges as a valuable educational tool for both novice and seasoned spinal surgeons. Rooted in anatomical insights, the structured methodology not only caters to the educational needs of young surgeons, but also ensures a standardized and safe procedure. The emphasis on tissue preservation and anatomical points aligns with current trends toward minimally invasive techniques, promising enhanced patient outcomes and satisfaction.

Predictors of Patient Dissatisfaction after Lumbar Spinal Canal Stenosis Surgery: A Multicenter Retrospective Study

Introduction

Recently, patient satisfaction has gained prominence as a crucial measure for ensuring patient-centered care. Furthermore, patient satisfaction after lumbar spinal canal stenosis (LCS) surgery is an important metric for physician's decision of surgical indication and informed consent to patient. This study aimed to elucidate how patient satisfaction changed after LCS surgery to identify factors that predict patient dissatisfaction.

Methods

We retrospectively reviewed time-course data of patients aged ≥40 years who underwent LCS surgery at multiple hospitals. The participants completed the Zurich Claudication Questionnaire (ZCQ) and the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) before surgery and then 6 months and 1 year postsurgery. Patient satisfaction was categorized according to the postoperative score of the satisfaction domain of the ZCQ: satisfied, score ≤2.0; moderately satisfied, 2.0< score ≤2.5; and dissatisfied, score >2.5.

Results

The study enrolled 241 patients. Our data indicated a satisfaction rate of around 70% at 6 months and then again 1 year after LCS surgery. Among those who were dissatisfied 6 months after LCS surgery, 47.6% were more satisfied 1 year postsurgery. Furthermore, 86.2% of those who were satisfied 6 months after LCS surgery remained satisfied at 1 year. Multivariable analysis revealed that age (relative risk, 0.5; 95% confidence interval, 0.2-0.8) and preoperative score of psychological disorders on the JOABPEQ (relative risk, 0.2; 95% confidence interval, 0.03-0.08) were significantly associated with LCS surgery dissatisfaction. In addition, the receiver operating characteristic curve analysis revealed that the cutoff value for the preoperative score of psychological disorder of the JOABPEQ was estimated at 40 for LCS surgery dissatisfaction.

Conclusions

Age and psychological disorders were identified as significant predictors of dissatisfaction, with a JOABPEQ cutoff value providing potential clinical applicability.

Effects of BMI on SI joint fusion outcomes: examining the evidence to improve insurance guidelines

BACKGROUND CONTEXT

Obesity is increasing. Previous studies have demonstrated an association between obesity and adverse events after lumbar fusion. There is limited evidence on the effect of obesity on minimally invasive SI joint fusion (SIJF) outcomes.

PURPOSE

The purpose of this study was to investigate the impact of obesity on patient-reported outcomes in patients undergoing SIJF surgery using triangular titanium implants (TTI).

STUDY DESIGN

Retrospective cohort study based on four prospective clinical trials (INSITE [NCT01681004], SIFI [NCT01640353], iMIA [NCT01741025], and SALLY [NCT03122899]).

PATIENT SAMPLE

Adult patients ≥18 years of age who underwent minimally invasive surgery (MIS) sacroiliac joint (SIJ) fusion between 2012 and 2021.

OUTCOME MEASURES

Visual analog scale (VAS Pain), Oswestry Disability Index (ODI).

METHODS

Participants were classified using the National Institutes of Health body mass index (BMI). Patients with a BMI of 30 to 39 with no significant comorbidity are considered obese, patients with a BMI of 35 to 39 with a significant comorbidity or a BMI of 40 or greater are considered morbidly obese. All subjects underwent either minimally invasive SIJ fusion with TTI or nonsurgical management (INSITE and iMIA studies only). All subjects completed SIJ pain scale scores (measured with a 100-point VAS) and disability scores (measured with ODI) at baseline and at scheduled visits to 24 months. Repeated measures analysis of variance was used to examine the impact of BMI category on score changes.

RESULTS

In the SIJF group, mean SIJ pain improved at 24 months by 53.3 points (p<.0001). Over the 24-month follow-up period, BMI category did not impact mean improvement in SIJ pain scale score (repeated measures analysis of variance (ANOVA) p=.44). In the SIJF group, mean ODI at 24 months improved by 25.8 points (p<.0001). BMI category did not impact mean improvement in ODI (ANOVA p=.60). In the nonsurgical management (NSM) group, mean improvements in SIJ pain scale and ODI were clinically small (8.7 and 5.2 points, respectively) and not affected by BMI category (ANOVA p=.49 and .40).

CONCLUSION

This study demonstrates similar benefits and risks of minimally invasive SIJ fusion with TTI across all BMI categories. This analysis suggests that obese patients benefit from minimally invasive SIJ fusion and should not be denied this procedure based solely on elevated BMI.

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

BACKGROUND/OBJECTIVES

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

SUBJECTS/METHODS

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

RESULTS

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

CONCLUSION

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

Preoperative Motor Function Associated with Short-Term Gain of Health-Related Quality of Life after Surgery for Lumbar Degenerative Disease: A Pilot Prospective Cohort Study in Japan

This study aimed to estimate the relationship between preoperative motor function and short-term recovery of health-related quality of life after lumbar surgery in patients with lumbar degenerative disease. This prospective cohort study involved 50 patients with lumbar degenerative disease at a general hospital in Japan. The primary outcome was the achievement of minimal clinically important difference (MCID) for EuroQOL 5 dimensions (EQ-5D) at discharge. Preoperative demographic, medication, surgical, and physical function data were collected. Logistic regression analysis was performed using the achievement of MCID for EQ-5D as the dependent variable and preoperative characteristics, including the Five Times Sit to Stand test (FTSTS), Oswestry Disability Index (ODI), and Self-rating Depression Scale (SDS), as the independent variables. The logistic regression analysis showed that Model 1 had a moderate predictive accuracy (Nagelkerke R2: 0.20; Hosmer-Lemeshow test: p = 0.19; predictive accuracy: 70.0%). Among the independent variables in the logistic regression model, the FTSTS was the only independent variable related to the achievement of MCID for EQ-5D at discharge (odds ratio: 0.03; 95% CI: 1.79 × 10-3, 0.18). Our results highlighted the importance of baseline motor function in the postoperative recovery of health-related quality of life in individuals with lumbar degenerative disease.

Does paraspinal muscle morphometry predict functional status and re-operation after lumbar spinal surgery? A systematic review and meta-analysis

OBJECTIVES

Whether paraspinal muscle degeneration is related to poor clinical outcomes after lumbar surgery is still indistinct, which limits its clinical application. This study aimed to evaluate the predictive value of paraspinal muscle morphology on functional status and re-operation after lumbar spinal surgery.

METHODS

A review of the literature was conducted using a total of 6917 articles identified from a search of PubMed, EMBASE, and Web of Science databases through September 2022. A full-text review of 140 studies was conducted based on criteria including an objective assessment of preoperative paraspinal muscle morphology including multifidus (MF), erector spinae (ES), and psoas major (PS) in addition to measuring its relationship to clinical outcomes including Oswestry disability index (ODI), pain and revision surgery. Meta-analysis was performed when required metrics could be calculated in ≥ three studies, otherwise vote counting model was a good alternative to show the effect direction of evidence. The standardized mean difference (SMD) and 95% confidence interval (CI) were calculated.

RESULTS

A total of 10 studies were included in this review. Of them, five studies with required metrics were included in the meta-analysis. The meta-analysis suggested that higher preoperative fat infiltration (FI) of MF could predict higher postoperative ODI scores (SMD = 0.33, 95% CI 0.16-0.50, p = 0.0001). For postoperative pain, MF FI could also be an effective predictor for persistent low back pain after surgery (SMD = 0.17, 95% CI 0.02-0.31, p = 0.03). However, in the vote count model, limited evidence was presented for the prognostic effects of ES and PS on postoperative functional status and symptoms. In terms of revision surgery, there was conflicting evidence that FI of MF and ES could predict the incidence of revision surgery in the vote count model.

CONCLUSION

The assessment of MF FI could be a viable method to stratify patients with lumbar surgery by the risk of severe functional disability and low back pain.

KEY POINTS

• The fat infiltration of multifidus can predict postoperative functional status and low back pain after lumbar spinal surgery. • The preoperative evaluation of paraspinal muscle morphology is conducive for surgeons.

Predictors of poor outcome following lumbar spinal fusion surgery: a prospective observational study to derive two clinical prediction rules using British Spine Registry data

PURPOSE

Lumbar spinal fusion surgery (LSFS) is common for lumbar degenerative disorders. The objective was to develop clinical prediction rules to identify which patients are likely to have a favourable outcome to inform decisions regarding surgery and rehabilitation.

METHODS

A prospective observational study recruited 600 (derivation) and 600 (internal validation) consecutive adult patients undergoing LSFS for degenerative lumbar disorder through the British Spine Registry. Definition of good outcome (6 weeks, 12 months) was reduction in pain intensity (Numerical Rating Scale, 0-10) and disability (Oswestry Disability Index, ODI 0-50) > 1.7 and 14.3, respectively. Linear and logistic regression models were fitted and regression coefficients, Odds ratios and 95% CIs reported.

RESULTS

Lower BMI, higher ODI and higher leg pain pre-operatively were predictive of good disability outcome, higher back pain was predictive of good back pain outcome, and no previous surgery and higher leg pain were predictive of good leg pain outcome; all at 6 weeks. Working and higher leg pain were predictive of good ODI and leg pain outcomes, higher back pain was predictive of good back pain outcome, and higher leg pain was predictive of good leg pain outcome at 12 months. Model performance demonstrated reasonable to good calibration and adequate/very good discrimination.

CONCLUSIONS

BMI, ODI, leg and back pain and previous surgery are important considerations pre-operatively to inform decisions for surgery. Pre-operative leg and back pain and work status are important considerations to inform decisions for management following surgery. Findings may inform clinical decision making regarding LSFS and associated rehabilitation.

Perioperative Management of Comorbidities in Spine Surgery

The number of spinal operations performed in the United States has significantly increased in recent years. Along with these rising numbers, there has been a corresponding increase in the number of patient comorbidities. The focus of this article is to review comorbidities in Spine surgery patients and outline strategies to optimize patients and avoid complications.

Impact of body mass index on outcomes after lumbar spine surgery

The impact of body mass index (BMI) on outcomes after lumbar spine surgery is currently unknown. Previous studies have reported conflicting evidence for patients with high BMI, while little research has been conducted on outcomes for underweight patients. This study aims to examine the impact of BMI on outcomes after lumbar spine surgery. This prospective cohort study enrolled 5622 patients; of which, 194, 5027, and 401 were in the low (< 18.5 kg/m²), normal (18.5-30), and high (≥ 30) BMI groups, respectively. Pain was assessed via the numerical pain rating scale (NPRS) for the lower back, buttock, leg, and plantar area. Quality of life was assessed via the EuroQol 5 Dimension (EQ-5D) and Oswestry Disability Index (ODI). Inverse probability weighting with propensity scores was used to adjust patient demographics and clinical characteristics between the groups. After adjustment, the 1-year postoperative scores differed significantly between groups in terms of leg pain. The proportion of patients who achieved a 50% decrease in postoperative NPRS score for leg pain was also significantly different. Obese patients reported less improvement in leg pain after lumbar spine surgery. The outcomes of patients with low BMI were not inferior to those of patients with normal BMI.

Morbid Obesity Increases Length of Surgery in Elective Anterior Cervical Discectomy and Fusion Procedures but Not Readmission or Reoperation Rates: A Cohort Study

BACKGROUND

As the obesity epidemic grows, the number of morbidly obese patients undergoing anterior cervical discectomy and fusion (ACDF) continues to increase. Despite the association of obesity with perioperative complications in anterior cervical surgery, the impact of morbid obesity on ACDF complications remains controversial, and studies examining morbidly obese cohorts are limited.

METHODS

A single-institution, retrospective analysis of patients undergoing ACDF from September 2010 to February 2022 was performed. Demographic, intraoperative, and postoperative data were collected via review of the electronic medical record. Patients were categorized as nonobese (body mass index [BMI] <30), obese (BMI 30-39.9), or morbidly obese (BMI ≥40). Associations of BMI class with discharge disposition, length of surgery, and length of stay were assessed using multivariable logistic regression, multivariable linear regression, and negative binomial regression, respectively.

RESULTS

The study included 670 patients undergoing single-level or multilevel ACDF: 413 (61.6%) nonobese, 226 (33.7%) obese, and 31 (4.6%) morbidly obese patients. BMI class was associated with prior history of deep venous thrombosis (P < 0.01), pulmonary thromboembolism (P < 0.05), and diabetes mellitus (P < 0.001). In bivariate analysis, there was no significant association between BMI class and reoperation or readmission rates at 30, 60, or 365 days postoperatively. In multivariable analysis, greater BMI class was associated with increased length of surgery (P = 0.03), but not length of stay or discharge disposition.

CONCLUSIONS

For patients undergoing ACDF, greater BMI class was associated with increased length of surgery, but not reoperation rate, readmission rate, length of stay, or discharge disposition.

High Failure Rates in Prisoners Undergoing Spine Fusion Surgery

OBJECTIVE

The medical literature on prisoner health care is limited, despite data showing that prisoners experience high rates of physical and mental health challenges. We compared clinical outcomes for prisoners undergoing spine fusion with comparable nonincarcerated patients and determined what factors were implicated in differences in outcomes.

METHODS

Prisoners who underwent spinal fusion in 2011-2021 were retrospectively compared with an age-, sex-, and procedure-matched 3:1 control group of nonincarcerated spinal fusion patients. Fusion failure was confirmed by lack of bridging bone between vertebrae on CT or radiographic images >1 year postoperatively or evidence of instrumentation failure with resultant >2 mm of translation on flexion/extension radiographs.

RESULTS

Twenty-seven identified prisoners were compared with 81 nonincarcerated controls. Ten prisoners and 6 controls experienced nonunion (37% vs. 7%, P < 0.01). Rates of risk factors for nonunion, such as smoking history, elevated body mass index, chronic steroid use, diabetes mellitus, previous spine surgery, and levels fused, were not significantly different between prisoners and controls. Among prisoners, those with nonunion were younger (45 vs. 53 years, P = 0.03), had greater body mass index (34 vs. 29, P = 0.02), and were more likely to undergo reoperation (30% vs. 0%, P = 0.02). Multivariate analysis revealed that prisoners carry a 9.62 increased odds of nonunion compared with controls.

CONCLUSIONS

This is one of few studies investigating health care outcomes in prisoners. We found they had a significantly higher rate of nonunion than matched control patients from the general population treated at the same hospital, suggesting additional measures may be necessary postoperatively to support fusion in prisoners.

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of lumbar spinal stenosis, 2021 - Secondary publication

BACKGROUND

The Japanese Orthopaedic Association (JOA) guideline for the management of lumbar spinal stenosis (LSS) was first published in 2011. Since then, the medical care system for LSS has changed and many new articles regarding the epidemiology and diagnostics of LSS, conservative treatments such as new pharmacotherapy and physical therapy, and surgical treatments including minimally invasive surgery have been published. In addition, various issues need to be examined, such as verification of patient-reported outcome measures, and the economic effect of revised medical management of patients with lumbar spinal disorders. Accordingly, in 2019 the JOA clinical guidelines committee decided to update the guideline and consequently established a formulation committee. The purpose of this study was to describe the formulation we implemented for the revision of the guideline, incorporating the recent advances of evidence-based medicine.

METHODS

The JOA LSS guideline formulation committee revised the previous guideline based on the method for preparing clinical guidelines in Japan proposed by the Medical Information Network Distribution Service in 2017. Background and clinical questions were determined followed by a literature search related to each question. Appropriate articles based on keywords were selected from all the searched literature. Using prepared structured abstracts, systematic reviews and meta-analyses were performed. The strength of evidence and recommendations for each clinical question was decided by the committee members.

RESULTS

Eight background and 15 clinical questions were determined. Answers and explanations were described for the background questions. For each clinical question, the strength of evidence and the recommendation were both decided, and an explanation was provided.

CONCLUSIONS

The 2021 clinical practice guideline for the management of LSS was completed according to the latest evidence-based medicine. We expect that this guideline will be useful for all medical providers as an index in daily medical care, as well as for patients with LSS.

The association between preoperative MRI findings and clinical improvement in patients included in the NORDSTEN spinal stenosis trial

PURPOSE

To investigate potential associations between preoperative MRI findings and patient reported outcome measures (PROMs) after surgery for lumbar spinal stenosis (LSS).

METHODS

The NORDSTEN trial included 437 patients. We investigated the association between preoperative MRI findings such as morphological grade of stenosis (Schizas grade), quantitative grade of stenosis (dural sac cross-sectional area), disc degeneration (Pfirrmann score), facet joint tropism and fatty infiltration of the multifidus muscle, and improvement in patient reported outcome measures (PROMs) 2 years after surgery. We dichotomized each radiological parameter into a moderate or severe category. PROMs i.e., Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ) and Numeric rating scale (NRS) for back and leg pain were collected before surgery and at 2 year follow-up. In the primary analysis, we investigated the association between MRI findings and ODI score (dichotomized to ≥ 30% improvement or not). In the secondary analysis, we investigated the association between MRI findings and the mean improvement on the ODI-, ZCQ- and NRS scores. We used multivariable regression models adjusted for patients' gender, age, smoking status and BMI.

RESULTS

The primary analysis showed that severe disc degeneration (Pfirrmann score 4-5) was significantly associated with less chance of achieving a 30% improvement on the ODI score (OR 0.54, 95% CI 0.34, 0.88). In the secondary analysis, we detected no clinical relevant associations.

CONCLUSION

Severe disc degeneration preoperatively suggest lesser chance of achieving 30% improvement in ODI score after surgery for LSS. Other preoperative MRI findings were not associated with patient reported outcome.

Usefulness of preoperative Short Form-36 Mental Component Score as a prognostic factor in patients who underwent decompression surgery for degenerative lumbar spinal stenosis

Physical factors such as frequency of low back pain, sensory abnormalities in the lower extremities, smoking history before surgery, and preoperative mental health status as predictors of operative outcomes have been growing as areas of interest in the field of degenerative lumbar spinal stenosis (DLSS). This study aimed to investigate the correlation between the preoperative Short Form-36 Mental Component Score (SF-36 MCS) and long-term prognosis after decompression surgery for DLSS. In total, 198 patients were enrolled in this study. The Oswestry Disability Index (ODI) and Rolland Morris Disability Questionnaire (RMDQ) were used to evaluate spinal functional outcomes. The SF-36 questionnaire was used and analyzed by classifying it into physical component score (PCS) and mental component score (MCS). The SF-36 MCS was divided into role limitations caused by emotional problems, social functioning, vitality, and emotional well-being. In the correlation between preoperative MCS and ODI improvement, the r value was -0.595 (P < .05) at 12 months postoperatively. ODI improvement at 12 months after decompression surgery showed a statistically significant and strong negative correlation with preoperative MCS. In the correlation between preoperative MCS and RMDQ improvement, the r value was -0.544 (P < .05) at 12 months postoperatively. Therefore, RMDQ improvement 12 months after decompression surgery showed a strong negative correlation with preoperative MCS. Regarding the correlation between preoperative MCS and SF-36 PCS improvement, the r values were 0.321 (P < .05) at 6 months postoperatively and 0.343 (P < .05) at 12 months postoperatively. Therefore, SF-36 PCS improvement at 6 and 12 months after decompression surgery showed a strong positive correlation with preoperative SF-36 MCS scores. Preoperative SF-36 MCS is a factor that can predict the prognosis of patients who underwent decompression surgery for lumbar spinal stenosis for at least 1 year postoperatively.

Obesity and perioperative adverse events in patients undergoing complex revision surgery for the thoracolumbar spine

Background

There are no previous studies that evaluate the effect of obesity on patients undergoing complex revision thoracolumbar spine surgery. The primary objective was to determine the relationship between obesity and perioperative adverse events (AEs) with patients undergoing complex revision thoracolumbar spine surgery while controlling for psoas muscle index (PMI) as a confounding variable. The secondary objective was to determine the relationship between obesity and 30-day readmission rates, 30-day re-operation rates, rate of discharge to a facility, and post-operative length of stay (LOS).

Methods

Between May 2016 and February 2020, a retrospective analysis of individuals undergoing complex revision surgery of the thoracolumbar spine was performed at a single institution. Obesity was defined as BMI ≥ 30.0 kg/m². PMI < 500 mm²/m² for males and < 412 mm²/m² for females were used to define low muscle mass. A Spine Surgical Invasiveness Index (SSII) > 10 was used to define complex revision surgery. A multivariable logistic regression model was used to ascertain the effects of low muscle mass, obesity, age, and gender on the likelihood of the occurrence of any AE.

Results

A total of 114 consecutive patients were included in the study. Fifty-four patients were in the obese cohort and 60 patients in the non-obese cohort. There was not a significant difference in perioperative outcomes of both the obese and non-obese patients. There were 22 obese patients (40.7%) and 33 non-obese patients (55.0%) that experienced any AE (p = 0.130).

Multivariable analysis demonstrated that individuals with low muscle mass had a significantly higher likelihood for an AE than individuals with normal or high muscle mass (OR: 7.53, 95% CI: 3.05-18.60). Obesity did not have a significant effect in predicting AEs.

Conclusions

Obesity is not associated with perioperative AEs, 30-day readmission rates, 30-day re-operation rates, rate of discharge to a facility, or post-operative length of stay (LOS) among patients undergoing complex revision thoracolumbar spine surgery.

Level of evidence

III

Factors Associated with Pain Intensity and Walking Disability After Lumbar Fusion: A Longitudinal Study

STUDY DESIGN

Retrospective longitudinal study.

OBJECTIVE

To identify the preoperative factors associated with postoperative lumbar fusion recovery in back or leg pain, self-reported walking time, and gait speed over a 6-month period.

SUMMARY OF BACKGROUND DATA

The demand for lumbar fusion surgeries has significantly increased over the years. Yet, some patients report persistent postsurgical pain and poor functional outcomes. Unfortunately, the associated risk factors are not well understood.

METHODS

The study analyzed 232 subjects with mono- or bisegmental lumbar fusion surgery who underwent standardized assessment preoperatively and at 4, 12, and 24weeks postoperatively. Preoperative variables collected were demographic, clinical, and psychological variables. Back or leg pain was measured by the Numeric Pain Rating Scale. Walking disability was measured by self-reported walking time and performance-based fast gait speed. Risk factors of pain and walking disability over time were identified using ordinal and linear mixed-effects modeling.

RESULTS

At 6 months post-surgery, 17% of patients reported having moderate or severe back/leg pain and 24% were unable to walk longer than 30 minutes. Greater preoperative self-reported leg weakness frequency and body-mass-index (BMI) were strongly associated with greater pain and walking disability. Additionally, greater preoperative depression symptoms were associated with greater back/leg pain (adjusted odds ratio = 4.0) and shorter walking time (adjusted odds ratio = 2.7)-but not with slower gait speed (difference = 0.01 m/s). Old age and female gender were strongly associated with gait speed but not with self-reported walking time.

CONCLUSION

A sizable proportion of patients had poor pain and walking outcomes even at 6 months post-surgery. Preoperative leg weakness and BMI were consistent risk factors and patients with greater depression symptoms may have poorer self-reported outcomes. Although requiring validation, our study has identified potentially modifiable risk factors which may give clinicians an opportunity to provide early (preoperative) and targeted intervention strategies to optimize postoperative outcomes.

Level of Evidence: NA.

Impact of Obesity on Complications and Surgical Outcomes of Adult Degenerative Scoliosis with Long- Segment Spinal Fusion

INTRODUCTION

The relationship between obesity and outcome of spine surgery has been controversial. The impact of obesity on surgical outcomes of patients undergoing long- segment (6 vertebrae or more) spinal fusion have not been studied. This study was designed to define the influence of obesity on the outcomes of patients undergoing long-segment spinal fusion.

METHODS AND MATERIALS

A retrospective study of patients undergoing long-segment (6 vertebrae or more) spinal fusion was realized. Patients were divided into non-obese group and obese group. Variables such as blood loss, operative time, length of stay, complications, reoperation rates, and clinical outcome were compared between the two groups.

RESULTS

Thirty-four non-obese patients (BMI: 26.43 ± 0.87) and 27 obese ones (BMI: 35.35 ± 1.81) were recruited. Number of fused levels in non-obese group was not significantly different from obese group (9.06±0.57 vertebrae vs 8.85±0.68 vertebrae, p=0.65). There was no significant difference between non-obese group and obese group in the blood loss during surgery (p= 0.12), the operating time (p=0.46) and the length of hospitalization (p=0.64). Similarly, no significant difference was found in surgical complications (p= 0.76) and medical complications (p=0.82) between the two groups. The rate of ambulatory improvement is similar between non-obese group and obese group (p=0.64).

CONCLUSION

Our study showed that there was no relationship between obesity and adverse surgical outcomes in ADS surgery with long-segment (6 vertebrae or more) spinal fusion.

Reducing Postoperative Opioid-prescribing Following Posterior Lumbar Fusion Does Not Significantly Change Patient Satisfaction

STUDY DESIGN

Retrospective comparative; LOE-3.

OBJECTIVE

The purpose of this study was to investigate what effect, if any, an institutional opioid reduction prescribing policy following one- or two-level lumbar fusion has on Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey results.

SUMMARY OF BACKGROUND DATA

Previous research has demonstrated that high levels of opioid-prescribing may be related, in part, to a desire to produce superior patient satisfaction.

METHODS

A retrospective review of prospectively collected data was conducted on patients who underwent one- or two-level lumbar fusions L3-S1 between October 2014 and October 2019 at a single institution. Patients with complete survey information were included in the analysis. Patients with a history of trauma, fracture, spinal deformity, fusions more than two levels, or prior lumbar fusion surgery L3-S1 were excluded. Cohorts were based on date of surgery relative to implementation of an institutional opioid reduction policy, which commenced in October 1, 2018. To better compare groups, opioid prescriptions were converted into milligram morphine equivalents (MME).

RESULTS

A total of 330 patients met inclusion criteria: 259 pre-protocol, 71 post-protocol. There were 256 one-level fusions and 74 two-level fusions included. There were few statistically significant differences between groups with respect to patient demographics (P > 0.05) with the exception of number of patients who saw the pain management service, which increased from 36.7% (95) pre-protocol to 59.2% (42) post-protocol; P < 0.001. Estimated blood loss (EBL) decreased from 533 ± 571 mL to 346 ± 328 mL (P = 0.003). Percentage of patients who underwent concomitant laminectomy decreased from 71.8% to 49.3% (P < 0.001). Average opioids prescribed on discharge in the pre-protocol period was 534 ± 425 MME, compared to after initiation of the protocol, that is 320 ± 174 MME (P < 0.001). There was no statistically significant difference with respect to satisfaction with pain control, 4.49 ± 0.85 pre-protocol versus 4.51 ± 0.82 post-protocol (P = 0.986).

CONCLUSION

A reduction in opioids prescribed at discharge after one- or two-level lumbar fusion is not associated with any statistically significant change in patient satisfaction with pain management, as measured by the HCAHPS survey.Level of Evidence: 3.

The predictive value of preoperative paraspinal muscle morphometry on complications after lumbar surgery: a systematic review

PURPOSE

The effect of paraspinal muscles atrophy and fat infiltration (FI) on the complications of spinal surgery has not been established.

METHODS

A review of the literature was conducted from a search of the PubMed, EMBASE, and Web of Science databases from inception through January 2021. The literature was searched and assessed by independent reviewers based on criteria that included an assessment of preoperative paraspinal muscle morphology in addition to measuring its relationship to surgical complications. All relevant papers were assessed for risk of bias according to the modified Newcastle Ottawa Scale and the Joanna Briggs Institute Critical Appraisal Tools. A narrative synthesis was conducted.

RESULTS

The initial search yielded 5632 studies, of which 16 studies were included in the analysis. All included studies were at a low risk of bias. There existed strong evidence that the atrophy and FI of paraspinal muscles had an association with the development of bone nonunion (two high quality studies), pedicle screw loosening (two high quality studies), adjacent segment degeneration (three high quality studies) and proximal junctional kyphosis (five high quality studies) after lumbar surgery. Besides, there is also limited evidence for association between atrophy and FI of paraspinal extensor muscles and less local and global curve improvement.

CONCLUSIONS

Strong evidence was found for an association between preoperative paraspinal muscle degeneration and multiple postoperative complications after lumbar surgery. However, the findings should be interpreted with caution due to the small quantity of the available literature and high heterogeneity among studies.

Patient-Related Risk Factors for the Development of Lumbar Spine Adjacent Segment Pathology

Objectives

Individual risk factors for the development of adjacent segment pathology (ASP) need to be investigated and identified to address possible modifiable factors in advance and improve outcomes and reduce medical costs. This study aimed to review the literature regarding patient-related risk factors and sagittal alignment parameters associated with ASP development.

Methods

The authors performed an extensive review of the literature addressing the objectives mentioned earlier.

Results

Certain patient factors such as age, gender, obesity, preexisting degeneration, osteoporosis, postmenopausal state, rheumatoid arthritis, and facet tropism may contribute to adjacent segment degeneration. Genetic influences, such as polymorphisms of the vitamin D receptor and collagen IX genes, can also be a potential cause for disc degeneration with consequent deterioration of the motion segment.The influence of sagittal imbalances, particularly after lumbar fusion, is a significant parameter to be taken into account as an independent risk factor for ASP development.

Conclusions

Patient-specific risk factors, such as age, gender, obesity, preexisting degeneration, and genetic features increase the likelihood of developing ASP. On the other hand, sagittal alignment plays a significant role in the development of this condition.

The Effect of Morbid Obesity on Complications, Readmission, and Patient-Reported Outcomes Following Minimally Invasive Transforaminal Lumbar Interbody Fusion: An Inverse Propensity Score Weighted Analysis

STUDY DESIGN

Retrospective review of prospectively collected data at a single institution.

OBJECTIVE

To compare perioperative and clinical outcomes in morbidly obese patients who underwent minimally invasive transforaminal lumbar interbody fusion (MiTLIF).

SUMMARY OF BACKGROUND DATA

Obesity remains a serious public health concern. Obese patients who undergo lumbar fusion have historically thought to be at higher risk for complications and fare worse regarding quality-of-life outcomes. However, recent literature may demonstrate comparable risk and outcomes in obese patients. An increasing number of patients are categorized as morbidly obese (body mass index [BMI] ≥ 40 kg/m2). Perioperative and patient-reported outcomes (PROs) are lacking in this patient population.

METHODS

The authors retrospectively reviewed a prospectively collected database of all morbidly obese and non-obese patients that underwent MiTLIF between 2015 and 2018 for degenerative conditions who had minimum 1-year follow-up for outcome assessment. An inverse propensity/probability of treatment weighting was utilized to create a synthetic weighted sample in which covariates were independent of obesity designation to adjust for imbalance between groups. Generalized estimating equations (GEE) was used to estimate the association of morbid obesity and complications and 1-year PROs.

RESULTS

A total of 292 patients were analyzed with 234 non-obese patients and 58 morbidly obese patients. Multivariate analysis failed to demonstrate any association between morbid obesity and achieving minimal clinically important difference (MCID) for Oswestry disability index (ODI), visual analog scale (VAS), or short form-12 (SF-12) physical component score. However, morbid obesity was associated with significant decrease in odds of achieving MCID for SF-12 mental component score (P = 0.001). Increased surgery duration was significantly associated with morbid obesity (P = 0.001). Morbid obesity exhibited no statistically significant association with postoperative complications, readmission, pseudarthrosis, or adjacent segment disease (ASD).

CONCLUSION

Morbidly obese patients who undergo MiTLIF can achieve meaningful clinical improvement comparable to nonobese patients. Morbid obesity was associated with longer surgical times but was not associated with postoperative complications, readmission, or ASD.Level of Evidence: 3.

Pre-operative prognostic factors for walking capacity after surgery for lumbar spinal stenosis: a systematic review

BACKGROUND

Lumbar spinal stenosis (LSS) reduces walking and quality of life. It is the main indication for spinal surgery in older people yet 40% report walking disability post-operatively. Identifying the prognostic factors of post-operative walking capacity could aid clinical decision-making, guide rehabilitation and optimise health outcomes.

OBJECTIVE

To synthesise the evidence for pre-operative mutable and immutable prognostic factors for post-operative walking in adults with LSS.

DESIGN

Systematic review with narrative synthesis.

METHODS

Electronic databases (CENTRAL, MEDLINE, EMBASE, CINAHL, PsycINFO, Web of Science, OpenGrey) were searched for observational studies, evaluating factors associated with walking after surgery in adults receiving surgery for LSS from database inception to January 2020. Two reviewers independently evaluated studies for eligibility, extracted data and assessed risk of bias (Quality in Prognosis Studies). The Grading of Recommendations Assessment, Development and Evaluation method was used to determine level of evidence for each factor.

RESULTS

5526 studies were screened for eligibility. Thirty-four studies (20 cohorts, 9,973 participants, 26 high, 2 moderate, 6 low risk of bias) were included. Forty variables (12 mutable) were identified. There was moderate quality of evidence that pre-operative walking capacity was positively associated with post-operative walking capacity. The presence of spondylolisthesis and the severity of stenosis were not associated with post-operative walking capacity. All other factors investigated had low/very low level of evidence.

CONCLUSION

Greater pre-operative walking is associated with greater post-operative walking capacity but not spondylolisthesis or severity of stenosis. Few studies have investigated mutable prognostic factors that could be potentially targeted to optimise surgical outcomes.

Obese people benefit from lumbar spinal stenosis surgery as much as people of normal weight

Background

Lumbar spinal stenosis (LSS) is a common degenerative condition of the spine that causes back pain radiating to the lower extremity. Surgical treatment is indicated to treat progressive radical symptoms. Obesity has been associated with inferior results in the domains of quality of life (QoL) following an LSS operation, but the research findings have been limited. This paper aims to identify whether obesity affects QoL due to back pain among patients who underwent an operation for LSS.

Methods

This study is based on a series of patients operated on for LSS between 2012 and 2018. Operated patients who returned for follow-up forms within the first or second years were included. A total of 359 patients were selected, 163 males (45%) and 196 females (55%). The mean age was 68.9 years. The EuroQol five-dimension scale (EQ-5D) questionnaire was chosen to measure QoL and the Oswestry Disability Index (ODI) for functional disability.

Results

QoL, as measured by EQ-5D, was preoperatively lower in those patients with a BMI ≥ 30. One year after the operation, all groups had a similar trend of improved QoL. At the second year, the results in all groups levelled off even though there was no statistical difference in clinical outcomes (p = 0.92).

The ODI was preoperatively statistically higher in patients with a BMI ≥ 30 (p < 0.001). Two years after the surgery, all groups had improved ODI scores, but there was no statistical difference in ODI between the BMI groups (p = 0.54).

Conclusion

Surgical intervention for debilitating or longstanding symptoms of LSS should be considered as a treatment option for suitable patients in spite of an elevated BMI.

Obesity in Patients Undergoing Lumbar Degenerative Surgery-A Retrospective Cohort Study of Postoperative Outcomes

STUDY DESIGN

Retrospective cohort studying using a national, administrative database.

OBJECTIVE

The aim of this study was to determine the postoperative complications and quality outcomes of patients with and without obesity undergoing surgical management for lumbar degenerative disease (LDD).

SUMMARY OF BACKGROUND DATA

Obesity is a global epidemic that negatively impacts health outcomes. Characterizing the effect of obesity on LDD surgery is important given the growing elderly obese population.

METHODS

This study identified patients with who underwent surgery for LDD between 2007 and 2016. Patients were stratified based on whether the patient had a concurrent diagnosis of obesity at time of surgery. Propensity score matching (PSM) was then utilized to mitigate intergroup differences between patients with and without obesity. Patients who underwent three or more levels surgical correction, were under the age of 18 years, or those with any previous history of trauma or tumor were excluded from this study. Baseline comorbidities, postoperative complication rates, and reoperation rates were determined.

RESULTS

A total of 67,215 patients underwent primary lumbar degenerative surgery, of which 22,405 (33%) were obese. After propensity score matching, baseline covariates of the two cohorts were similar. The complication rate was 8.3% in the nonobese cohort and 10.4% in the obese cohort (P < 0.0001). Patients with obesity also had longer lengths of stay (2.7 days vs. 2.4 days, P < 0.05), and higher rates of reoperation and readmission at all time-points through the study follow-up period to their nonobese counterparts (P < 0.05). Including payments after discharge, lumbar degenerative surgery in patients with obesity was associated with higher payments throughout the 2-year follow-up period ($68,061 vs. $59,068 P < 0.05).

CONCLUSION

Patients with a diagnosis of obesity at time of LDD surgery are at a higher risk for postoperative complications, reoperation, and readmission.Level of Evidence: 4.

The Influence of Body Mass Index in Obese and Morbidly Obese Patients on Complications and 30- and 90-day Readmissions Following Lumbar Spine Fusion

STUDY DESIGN

Retrospective cohort study using the 2013-2017 National Readmission Database.

OBJECTIVE

The aim of this study was to quantify the influence of body mass index (BMI) on complication and readmission rates following lumbar spine fusion.

SUMMARY OF BACKGROUND DATA

Compared to controls, patients with BMI ≥35 had greater odds of readmission, infection, and wound complications following lumbar spine fusion.

METHODS

Patients who underwent elective lumbar spine fusion within the population-based sample were considered for inclusion. Exclusion criteria included nonelective lumbar spine fusions, malnourished, anorexic, or underweight patients, and surgical indications of trauma or neoplasm. Patients were grouped by BMI: 18.5 to 29.9 (controls), 30 to 34.9 (obesity I), 35 to 39.9 (obesity II), and ≥40 (obesity III). Multivariate regression was performed to analyze differences in complications and readmissions between groups. Predictive modeling was conducted to estimate the impact of BMI on 30- and 90-day infection, wound complication, and readmissions rates.

RESULTS

A total of 86,697 patients were included for analysis, with an average age of 58.9 years and 58.9% being female. The obesity II group had significantly higher odds of infection (odds ratio [OR]: 1.82, 95% confidence interval [CI]: 1.28-2.62, P = 0.001), wound dehiscence (OR: 3.08, 95% CI: 1.70-6.18, P = 0.0006), and 30-day readmission (OR: 1.32, 95% CI: 1.11-1.58, P = 0.002), whereas the obesity III group had significantly higher odds of acute renal failure (OR: 2.14, 95% CI: 1.20-4.06, P = 0.014), infection (OR: 2.43, 95% CI: 1.72-3.48, P < 0.0001), wound dehiscence (OR: 3.76, 95% CI: 2.08-7.51, P < 0.0001), 30-day readmission (OR: 1.62, 95% CI: 1.36-1.93, P < 0.0001), and 90-day readmission (OR: 1.53, 95% CI: 1.31-1.79, P < 0.0001) compared with controls. Predictive modeling showed cumulative increases of 6.44% in infection, 3.69% in wound dehiscence, and 1.35% in readmission within 90-days for each successive BMI cohort.

CONCLUSION

Progressively higher risks for infection, wound complications, and hospital readmission were found with each progressive BMI level.Level of Evidence: 3.

Does a high BMI affect the outcome of minimally invasive TLIF? A retrospective study of 207 patients

PURPOSE

We investigated whether a high Body Mass Index (BMI) affects the outcomes following Minimally Invasive TLIF (MI-TLIF) for degenerative lumbar pathologies.

METHODS

A retrospective study was undertaken to include patients operated between January 2016 and January 2020 with at least one-year follow-up. Various preoperative and demographic parameters were recorded and the patients were classified into normal, overweight and obese based on the BMI. The operative and outcome measures used for assessment were surgical time, blood loss, number of levels operated upon, skin incision length, day of independent mobilisation, total hospital stay including ICU stay, return to work and Visual Analogue Score (VAS) for back pain (VAS-BP) and leg pain (VAS-LP) and Oswestry Disability Index (ODI). Attainment of Minimal Clinically Important Difference (MCID) for the scores was calculated. Multivariate analyses were done to assess the effect of BMI on different parameters.

RESULTS

Blood loss and postoperative ICU stay were found to be higher in the obese patients. However, the other variables were comparable. VAS-BP, VAS-LP and ODI scores were significantly improved in all the patients with no inter-group variability. The MCID attainment was also similar. The satisfaction rating at 1-year and willingness for surgery again for similar disease was also similar. The overall complication rate was 14.9% and was comparable among the groups. Multivariate analyses revealed no significant association between BMI and various parameters.

CONCLUSION

In patients treated by MI-TLIF for degenerative lumbar spine pathology, BMI is not a factor that negatively affects the functional and clinical outcomes.

The influence of comorbidities on the treatment outcome in symptomatic lumbar spinal stenosis: A systematic review and meta-analysis

BACKGROUND

Lumbar spinal stenosis (LSS) affects mainly elderly patients. To this day, it is unclear whether comorbidities influence treatment success. The aim of this systematic review and meta-analysis was to assess the impact of comorbidities on the treatment effectiveness in symptomatic LSS.

METHODS

We conducted a systematic review and meta-analysis and reviewed prospective or retrospective studies from Medline, Embase, Cochrane Library and CINAHL from inception to May 2020, including adult patients with LSS undergoing surgical or conservative treatment. Main outcomes were satisfaction, functional and symptoms improvement, and adverse events (AE). Proportions of outcomes within two subgroups of a comorbidity were compared with risk ratio (RR) as summary measure. Availability of ≥3 studies for the same subgroup and outcome was required for meta-analysis.

RESULTS

Of 72 publications, 51 studies, mostly assessing surgery, there was no evidence reported that patients with comorbidities were less satisfied compared to patients without comorbidities (RR 1.06, 95% confidence interval (CI) 0.77 to 1.45, I 2 94%), but they had an increased risk for AE (RR 1.46, 95% CI 1.06 to 2.01, I 2 72%). A limited number of studies found no influence of comorbidities on functional and symptoms improvement. Older age did not affect satisfaction, symptoms and functional improvement, and AE (age >80 years RR 1.22, 95% CI 0.98 to 1.52, I 2 60%). Diabetes was associated with more AE (RR 1.72, 95% CI 1.19 to 2.47, I 2 58%).

CONCLUSION

In patients with LSS and comorbidities (in particular diabetes), a higher risk for AE should be considered in the treatment decision. Older age alone was not associated with an increased risk for AE, less functional and symptoms improvement, and less treatment satisfaction.

Independent Association of Obesity and Nonroutine Discharge Disposition After Elective Anterior Cervical Discectomy and Fusion for Cervical Spondylotic Myelopathy

OBJECTIVE

The prevalence of obesity continues to rise in the United States at a disparaging rate. Although previous studies have attempted to identify the influence obesity has on short-term outcomes following elective spine surgery, few studies have assessed the impact on discharge disposition following anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy (CSM). The aim of this study was to determine whether obesity impacts the hospital management, cost, and discharge disposition after elective ACDF for adult CSM.

METHODS

The National Inpatient Sample database was queried using the International Classification of Diseases, 10th revision, Clinical Modification, coding system to identify all (≥18 years) patients with a primary diagnosis of CSM undergoing an elective ACDF for the years 2016 and 2017. Discharge weights were used to estimate national demographics, Elixhauser comorbidities, complications, length of stay, total cost of admission, and discharge disposition.

RESULTS

There were 17,385 patients included in the study, of whom 3035 (17.4%) had obesity (no obesity: 14,350; obesity: 3035). The cohort with obesity had a significantly greater proportion of patients with 3 or more comorbidities compared with the cohort with no obesity (no obesity: 28.1% vs. obesity: 43.5%, P < 0.001). The overall complication rates were greater in the cohort with obesity (no obesity: 10.3% vs. obesity: 14.3%, P = 0.003). On average, the cohort with obesity incurred a total cost of admission $1154 greater than the cost of the cohort with no obesity (no obesity: $19,732 ± 11,605 vs. obesity: $20,886 ± 10,883, P = 0.034) and a significantly greater proportion of nonroutine discharges (no obesity: 16.6% vs. obesity: 24.2%, P < 0.001). In multivariate regression analysis, obesity, age, race, health care coverage, hospital bed size, region, comorbidity, and complication rates all were independently associated with nonroutine discharge disposition.

CONCLUSIONS

Our study demonstrates that obesity is an independent predictor for nonroutine discharge disposition following elective anterior cervical discectomy and fusion for cervical spondylotic myelopathy.

Outcome of non-instrumented lumbar spinal surgery in obese patients: a systematic review

INTRODUCTION

Lumbar spinal decompression procedures are well known in their techniques and outcomes. However, outcomes of lumbar spinal surgery in patients with obesity are relatively unknown. The aim of this review is to assess the effect of obesity on post-operative outcomes of lumbar non-instrumented decompressive spinal surgery.

METHODS AND MATERIALS

A literature search through PubMed, Embase, Web of Science and Cochrane was performed. Articles were included if they reported outcomes of obese patients after non-instrumented lumbar decompression surgery, if these outcomes were described using patient-reported outcome measures and if there was at least two months of follow-up. Risk of bias was assessed using an adjusted version of the Cowley score.

RESULTS

From the 222 unique articles, 14 articles, comprising 13,653 patients, met the inclusion criteria. Eight out of 14 studies had a low risk of bias, while the remaining six had an intermediate risk of bias. Thirteen studies evaluated leg and back pain, and the vast majority demonstrated less decrease in pain in the obese group. Six studies evaluated disability and all but one showed less improvement in obese patients. Five studies evaluated functionality and wellbeing and all but one showed less satisfactory outcome in obese patients.

CONCLUSIONS

Literature does not reveal a difference in clinical outcome nor in complications in patients undergoing non-instrumented lumbar surgery with a BMI lower than 30 or equal to or higher than 30. This may be used by physicians to inform patients prior to lumbar decompression surgery.

[Research progress in effect of obesity on the effectiveness of posterior lumbar fusion]

Objective

To review the effect of obesity on the effectiveness of posterior lumbar fusion in patients with lumbar degenerative diseases (LDD).

Methods

The related literature at home and abroad was extensively reviewed. And the difficulty of operation, risk of complications, and long-term effectiveness of posterior lumbar fusion for obese patients with LDD were summarized.

Results

Although some relevant literature suggest that the posterior lumbar fusion for obese patients is difficult and the risk of postoperative complications is high, the overall research results do not suggest that obesity is a risk factor for the implementation of posterior lumbar fusion. By assessing the physical condition of patients and strictly grasping the surgical indications, obese patients can obtain good surgical efficacy.

Conclusion

Posterior lumbar fusion is an effective method for the treatment of LDD in obese patients. However, relevant studies need to be completed to further evaluate the safety and efficacy of posterior lumbar fusion for obese patients.

Long-term impact of obesity on patient-reported outcomes and patient satisfaction after lumbar spine surgery: an observational study

OBJECTIVE

Obese body habitus is a challenging issue to address in lumbar spine surgery. There is a lack of consensus on the long-term influence of BMI on patient-reported outcomes and satisfaction. This study aimed to examine the differences in patient-reported outcomes over the course of 12 and 24 months among BMI classifications of patients who underwent lumbar surgery.

METHODS

A search was performed using the Quality Outcomes Database (QOD) Spine Registry from 2012 to 2018 to identify patients who underwent lumbar surgery and had either a 12- or 24-month follow-up. Patients were categorized based on their BMI as normal weight (≤ 25 kg/m2), overweight (25-30 kg/m2), obese (30-40 kg/m2), and morbidly obese (> 40 kg/m2). Outcomes included the Oswestry Disability Index (ODI) and the visual analog scale (VAS) for back pain (BP) and leg pain (LP), and patient satisfaction was measured at 12 and 24 months postoperatively.

RESULTS

A total of 31,765 patients were included. At both the 12- and 24-month follow-ups, those who were obese and morbidly obese had worse ODI, VAS-BP, and VAS-LP scores (all p < 0.01) and more frequently rated their satisfaction as "I am the same or worse than before treatment" (all p < 0.01) compared with those who were normal weight. Receiver operating characteristic curve analysis revealed that the BMI cutoffs for predicting worsening disability and surgery dissatisfaction were 30.1 kg/m2 and 29.9 kg/m2 for the 12- and 24-month follow-ups, respectively.

CONCLUSIONS

Higher BMI was associated with poorer patient-reported outcomes and satisfaction at both the 12- and 24-month follow-ups. BMI of 30 kg/m2 is the cutoff for predicting worse patient outcomes after lumbar surgery.

Complications and outcomes of open posterior lumbar spinal fusion surgery in obese patients: a meta-analysis

OBJECTIVE

The aim of this study was to determine whether obesity affects the operation, complications and outcomes after open posterior lumbar spinal fusion surgery for the treatment of low back pain and leg pain.

METHODS

A meta-analysis of studies that compared the outcome of posterior lumbar spinal fusion in obese and non-obese patients. A total of 16 studies were included.

RESULTS

There was no difference in pain and functional outcomes. Posterior lumbar spinal fusion in obese patients resulted in a statistically significant increase in intra-operative blood loss (weighted mean difference 40.93, 95% confidence interval (CI) 15.97-65.90, n = 243, and p=.001), longer duration of surgery (weighted mean difference -1.64, 95% CI -4.12 to 0.84, n = 1460, and p=.19), more complications (odds ratio: 1.59, 95% CI 1.24-2.05, n = 339, and p<.001) and extend length of stay (weighted mean difference 0.31, 95% CI 0.07-0.55, n = 1408, and p=.01).

CONCLUSIONS

Obese patients experience more blood loss, longer duration of surgery, more complications and extended length of stay, but their back and leg pain and functional outcomes are similar to non-obese patients. Based on these results, obesity is not a contraindication to open posterior lumbar spinal fusion surgery.

Degenerative Lumbar Stenosis Surgery: Predictive Factors of Clinical Outcome-Experience with 1001 Patients

BACKGROUND

Degenerative lumbar spinal stenosis (DLSS) carries a high risk of morbidity and represents a financial burden to society. A late diagnosis can lead to severe disability. Although lumbar decompressive surgery has been widely used worldwide, the proper preoperative factors to define the ideal candidates for decompression are missing.

METHODS

A total of 1001 patients who had undergone decompressive surgery from 2012 to 2019 for DLSS were screened for the presence of 9 clinical and radiological parameters. For all cases, the differences between the baseline and postoperative Oswestry disability index were calculated and the results categorized as 5 different classes (ranging from very poor outcomes to excellent outcomes) according to the specific scores. Generalized ordinal logistic regression was then used to analyze the significance of the 9 parameters (coded as dummy variables) in predicting the outcome as measured by Oswestry disability index improvement after surgery.

RESULTS

Of the 9 parameters, 8 were found to be significant predictors. The radiological grade of compression was the strongest, followed by polyneuropathy, obesity, symptom duration, gait autonomy, radicular deficits, American Society of Anesthesiologists score, and level of surgery. In contrast, previous back surgery was not predictive of the outcome.

CONCLUSIONS

Our findings have indicated that the ideal candidate for surgery will have the following preoperative characteristics: Schizas grade D, no signs of peripheral polyneuropathy, body mass index <30 kg/m², symptom duration of <2 years, gait autonomy <100 m, no radicular deficits, 1 level of stenosis, and an American Society of Anesthesiologists score of 1, 2, or 3.

Influence of dynamic preoperative body mass index changes on patient-reported outcomes after surgery for degenerative lumbar spine disease

Psychological factors demonstrably and often massively influence outcomes of degenerative spine surgery, and one could hypothesize that preoperative weight loss may correlate with motivation and lifestyle adjustment, thus leading to potentially enhanced outcomes. We aimed to evaluate the effect of preoperative weight loss or gain, respectively, on patient-reported outcomes after lumbar spine surgery. Weight loss was defined as a BMI decrease of ≤ − 0.5 kg/m² over a period of at least 1 month, and weight gain as a BMI increase of ≥ 0.5 kg/m² in the same time period, respectively. The primary endpoint was set as the achievement of the minimum clinically important difference (MCID) in the ODI at 1 or 2 years postoperatively. A total of 154 patients were included. Weight loss (odds ratio (OR): 1.18, 95% confidence interval (CI): 0.52 to 2.80) and weight gain (OR: 1.03, 95% CI: 0.43 to 2.55) showed no significant influence on MCID achievement for ODI compared to a stable BMI. The same results were observed when analysing long-term NRS-BP and NRS-LP. Regression analysis showed no correlation between BMI change and PROM change scores for any of the three PROMs. Adjustment for age and gender did not alter results. Our findings suggest that both preoperative weight loss and weight gain may have no measurable effect on long-term postoperative outcome compared to a stable BMI. Weight loss preoperatively—as a potential surrogate sign of patient motivation and lifestyle change—may thus not influence postoperative outcomes.

BMI Does Not Affect Complications or Patient Reported Outcomes After Lumbar Decompression Surgery

STUDY DESIGN

This is a retrospective comparative review.

OBJECTIVE

The objective of this study was to identify the influence of body mass index (BMI) on postsurgical complications and patient reported outcomes measures (PROMs) following lumbar decompression surgery.

SUMMARY OF BACKGROUND DATA

Current literature does not accurately identify the impact of BMI on postsurgical complications or outcomes.

MATERIALS AND METHODS

Records from a single-center, academic hospital were used to identify patients undergoing 1 to 3-level lumbar decompression surgery. Patients under 18 years of age, those undergoing surgery for infection, trauma, tumor, or revision, and those with <1-year follow-up were excluded. Patients were split into groups based on preoperative BMI: class I: BMI <25.0 kg/m; class II: BMI 25.0-29.9 kg/m; class III: BMI 30.0-34.9 kg/m; and class IV: BMI >35.0 kg/m. Absolute PROM scores, the recovery ratio and the percent of patients achieving minimum clinically important difference between groups were compared and a multiple linear regression analysis was performed.

RESULTS

A total of 195 patients were included with 34 (17.4%) patients in group I, 80 (41.0%) in group II, 49 (25.1%) in group III, and 32 (16.5%) in group IV. Average age was 60.0 (58.0, 62.0) years and average follow-up was 13.0 (12.6, 13.4) months. All patients improved significantly within each group, except for class III and class IV patients, who did not demonstrate significant improvements in terms of Mental Component Score (MCS-12) scores (P=0.546 and 0.702, respectively). There were no significant differences between BMI groups for baseline or postoperative PROM values, recovery ratio, or the percent of patients reaching minimum clinically important difference. Multiple linear regression analysis revealed that BMI was not a significant predictor for change in outcomes for any measure. The 30-day readmission rate was 6.2% and overall revision rate at final follow-up was 5.1%, with no significant differences between groups.

CONCLUSION

This study's results suggest that BMI may not significantly affect complications or patient outcomes at 1-year in those undergoing lumbar decompression surgery.

LEVEL OF EVIDENCE

Level III.

Does Obesity Affect Outcomes of Multilevel ACDF as a Treatment for Multilevel Cervical Spondylosis?: A Retrospective Study

STUDY DESIGN

This was a retrospective study of the clinical and radiologic outcomes of multilevel anterior cervical discectomy and fusion (ACDF) surgery for multilevel cervical spondylosis patients.

OBJECTIVE

In this retrospective study, we intended to determine the relationship of neck circumference, neck length, and body mass index (BMI) with the outcomes of multilevel ACDF surgeries for patients with multilevel cervical spondylosis.

SUMMARY OF BACKGROUND DATA

Obesity has become a worldwide epidemic problem since the beginning of the 21st century. However, no study has focused on how local or whole-body obesity indexes (neck circumference, length of neck, and BMI) are related to the outcome of anterior cervical surgery.

METHODS

A total of 156 consecutive patients with multilevel cervical spondylosis who underwent anterior cervical surgery in our department from 2010 to 2016 were enrolled in our study. Preoperative parameters of patients such as the neck circumference, length of neck, height and weight were measured, and the BMI was also calculated. Neck circumference and length of neck in neutral position ratio was determined as an index for evaluated the neck situation. Preoperative and postoperative neurological functions were evaluated using the neck disability index (NDI) and Japan Orthopedic Association (JOA) scores. Postoperative complications during the follow-up period were also recorded. Correlations between the obesity indexes and the various factors were analyzed.

RESULTS

The mean follow-up duration was 3.9±1.4 years (2.0-7.3 y). Compared with the preoperative score, the NDI and JOA score had significantly improved. There were 46 patients (29.49%) developed complications after surgery. Patients in the obese group had the highest rate of complications. Neck circumference and length of neck in neutral position ratio, BMI, and number of operation levels were significant risk factors for the occurrence of dysphagia after multilevel ACDF.

CONCLUSIONS

Patients with a higher BMI, larger neck circumference, and shorter neck length may have a longer operation duration, more blood loss, and more postoperative complications. The authors recommended that the presence of obesity and neck circumference and length should be carefully considered in the perioperative risk assessment for a multilevel ACDF surgery.

Symptomatic Epidural Hematoma after Elective Posterior Lumbar Decompression: Incidence, Timing, Risk Factors, and Associated Complications

BACKGROUND

Symptomatic post-operative lumbar epidural hematoma (PLEH) is a complication of lumbar spine surgery that can cause permanent neurologic consequences through compression of the cauda equina and nerve roots.

QUESTIONS/PURPOSES

We sought to investigate the incidence, timing, and risk factors for symptomatic epidural hematomas following posterior lumbar decompression, as well as to identify additional post-operative complications associated with symptomatic lumbar epidural hematomas.

METHODS

Elective lumbar spine procedures were identified in the National Surgical Quality Improvement Program (NSQIP) database between 2012 and 2016. Analyzed predictors of reoperation or readmission within 30 days for symptomatic PLEH included demographics, comorbidities, pre-operative laboratory values, peri-operative characteristics, and post-operative complications.

RESULTS

There were 75,878 cases included in the analysis. The incidence rate of symptomatic PLEH was 0.27% (n = 206), 54.4% (n = 112) of which occurred within 5 days of the procedure. Increased age, obesity (body mass index of 35 or higher), peri-operative transfusion, multilevel surgery (two or more levels), dural tear repair, and microscope use were independently associated with PLEH. Post-operative complications associated with PLEH included surgical site infection and urinary tract infection.

CONCLUSIONS

Readmission or reoperation for symptomatic PLEH following elective lumbar spine surgery is rare and can occur many days or weeks after a procedure. There are modifiable risk factors for PLEH and associated additional post-operative complications that physicians should be suspicious of following posterior lumbar decompression.

Effects of Body Mass Index on Perioperative Outcomes in Patients Undergoing Anterior Cervical Discectomy and Fusion Surgery

Objective

Obesity has become a public health crisis and continues to be on the rise. An elevated body mass index has been linked to higher rates of spinal degenerative disease requiring surgical intervention. Limited studies exist that evaluate the effects of obesity on perioperative complications in patients undergoing anterior cervical discectomy and fusion (ACDF). Our study aims to determine the incidence of obesity in the ACDF population and the effects it may have on postoperative inpatient complications.

Methods

The National Inpatient Sample was evaluated from 2004 to 2014 and discharges with International Classification of Diseases procedure codes indicating ACDF were identified. This cohort was stratified into patients with diagnosis codes indicating obesity. Separate univariable followed by multivariable logistic regression analysis were performed for the likelihood of perioperative inpatient outcomes among the patients with obesity.

Results

From 2004 to 2014, estimated 1,212,475 ACDFs were identified in which 9.2% of the patients were obese. The incidence of obesity amongst ACDF patients has risen dramatically during those years from 5.8% to 13.4%. Obese ACDF patients had higher inpatient likelihood of dysphagia, neurological, respiratory, and hematologic complications as well as pulmonary emboli, and intraoperative durotomy.

Conclusion

Obesity is a well-established modifiable comorbidity that leads to increased perioperative complications in various surgical specialties. We present one of the largest retrospective analyses evaluating the effects of obesity on inpatient complications following ACDF. Our data suggest that the number of obese patients undergoing ACDF is steadily increasing and had a higher inpatient likelihood of developing perioperative complications.

Preoperative Factors Predict Postoperative Trajectories of Pain and Disability Following Surgery for Degenerative Lumbar Spinal Stenosis

STUDY DESIGN

Longitudinal analysis of prospectively collected data.

OBJECTIVE

Investigate potential predictors of poor outcome following surgery for degenerative lumbar spinal stenosis (LSS).

SUMMARY OF BACKGROUND DATA

LSS is the most common reason for an older person to undergo spinal surgery, yet little information is available to inform patient selection.

METHODS

We recruited LSS surgical candidates from 13 orthopedic and neurological surgery centers. Potential outcome predictors included demographic, health, clinical, and surgery-related variables. Outcome measures were leg and back numeric pain rating scales and Oswestry disability index scores obtained before surgery and after 3, 12, and 24 postoperative months. We classified surgical outcomes based on trajectories of leg pain and a composite measure of overall outcome (leg pain, back pain, and disability).

RESULTS

Data from 529 patients (mean [SD] age = 66.5 [9.1] yrs; 46% female) were included. In total, 36.1% and 27.6% of patients were classified as experiencing a poor leg pain outcome and overall outcome, respectively. For both outcomes, patients receiving compensation or with depression/depression risk were more likely, and patients participating in regular exercise were less likely to have poor outcomes. Lower health-related quality of life, previous spine surgery, and preoperative anticonvulsant medication use were associated with poor leg pain outcome. Patients with ASA scores more than two, greater preoperative disability, and longer pain duration or surgical waits were more likely to have a poor overall outcome. Patients who received preoperative chiropractic or physiotherapy treatment were less likely to report a poor overall outcome. Multivariable models demonstrated poor-to acceptable (leg pain) and excellent (overall outcome) discrimination.

CONCLUSION

Approximately one in three patients with LSS experience a poor clinical outcome consistent with surgical non-response. Demographic, health, and clinical factors were more predictive of clinical outcome than surgery-related factors. These predictors may assist surgeons with patient selection and inform shared decision-making for patients with symptomatic LSS.

LEVEL OF EVIDENCE

2.

Preoperative psychological factors affecting surgical satisfaction of elderly patients with lumbar spinal stenosis

OBJECTIVE

The objective of this observational study was to investigate the effects of preoperative psychological factors on short-term patient satisfaction with surgery in elderly patients with lumbar spinal stenosis (LSS).

METHODS

Surgery was performed on 90 elderly patients with clinically and radiologically defined LSS: mean age at surgery, 73 years; 46 men and 44 women. Patients completed questionnaires before surgery and 1 year postoperatively. They used a self-administered the Roland Morris Disability Questionnaire (RDQ), the Japanese Orthopaedic Association Back Pain Questionnaire (JOABPEQ), MOS 36-Item Short-Form Health Survey (SF-36), and satisfaction for surgery (VAS) were completed. At baseline, psychological factors were assessed using the Self-Rating Questionnaire for Depression (SRQ-D), Hospital Anxiety and Depression scale (HADS), Pain Catastrophizing Scale (PCS), Pain Anxiety Symptoms Scale-20, and Brief Scale for Psychiatric Problems in Orthopaedic Patients (BS-POP). At follow-up, patient satisfaction was evaluated using 2 items: (1) satisfaction with surgery and (2) Would you undergo the same surgery again?.

RESULTS

Satisfaction item 1 correlated negatively with the VAS for low back pain, leg pain, numbness, JOABPEQ social life disturbance score, SF-36 physical function score, and HADS anxiety score (p < 0.05). Satisfaction 2 correlated negatively with age at surgery, VAS of leg pain, PCS magnification score, and BS-POP score (p < 0.05). Multiple regression analysis showed significant associations between satisfaction 1 and SF-36 physical function and HADS anxiety scores, and between satisfaction 2 and PCS magnification score (p < 0.05).

STATISTICAL ANALYSIS

The preoperative factors independently associated with surgical satisfaction were analyzed utilizing Speaman's rank correlation coefficient and multiple regression analysis.

CONCLUSION

Physical function and anxiety were identified as preoperative factors that affected patient satisfaction with surgery. Preoperative assessment of psychological factors and interventions for anxiety may help improve patient satisfaction after surgery for LSS.

Pedicle Screw Fixation in Single-Level, Double-Level, or Multilevel Posterior Lumbar Fusion for Osteoporotic Spine: A Retrospective Study with a Minimum 2-Year Follow-Up

BACKGROUND

Pedicle screw loosening is a common postoperative complication for osteoporotic patients, and several studies have identified the important role of fusion length in internal fixation failure, but the relationship between the number of fusion segments and the potential risks remains unclear. This study aimed to investigate the rate and risk factors of screw loosening in osteoporotic patients with different levels of degenerative lumbar disease.

METHODS

The total cohort of 217 patients was divided into 3 groups according to the different fusion levels: single-level (group A; 100 cases), double-level (group B; 73 cases), and multilevel group (group C; 44 cases). Patient baseline demographic characteristics and assessments with a visual analog scale (VAS) and the Oswestry Disability Index (ODI) before operation and at the last follow-up were compared among the 3 groups.

RESULTS

Compared with preoperative values, VAS and ODI scores at the last follow-up were significantly improved in all 3 groups. Operative time, blood loss, length of hospital stay, screw loosening rate, fusion rate, and VAS and ODI scores at the last follow-up obviously increased with the increasing number of fusion segments (group C> group B> group A). Of note, all the screw loosening was observed in cranial and caudal vertebra. Furthermore, multivariate logistic regression analysis identified lumbosacral fixation, larger pelvic incidence (PI)-lumbar lordosis (LL) difference (PT-LL), and greater postoperative pelvic tilt (PT) as independent predictors of screw loosening. However, sex, bone mineral density, body mass index, LL, sacral slope, PI, the change in LL, and preoperative PT were not relevant to screw loosening (P > 0.05).

CONCLUSIONS

Owing to the high rate of screw loosening in cranial and caudal vertebra, osteoporotic patients with double-level or multilevel pedicle screw fixation benefited less than those with single-level pedicle screw fixation. Larger PI-LL, larger PT, and lumbosacral fixation are other risk factors for screw loosening. An instrument with stronger holding strength at cranial and caudal pedicle screws is recommended for those high-risk patients.