Lumbar decompression in the elderly: increased age as a risk factor for complications and nonhome discharge

Factors associated with poorer outcomes for posterior lumbar decompression and or/or discectomy: an exploratory analysis of administrative data

PURPOSE

This study aimed to identify factors associated with poorer patient outcomes for lumbar decompression and/or discectomy (PLDD).

METHODS

We extracted data from the Hospital Episodes Statistics database for the 5 years from 1st April 2014 to 31st March 2019. Patients undergoing an elective one- or two-level PLDD aged ≥ 17 years and without evidence of revision surgery during the index stay were included. The primary patient outcome measure was readmission within 90 days post-discharge.

RESULTS

Data for 93,813 PLDDs across 111 hospital trusts were analysed. For the primary outcome, greater age [< 40 years vs 70-79 years odds ratio (OR) 1.28 (95% confidence interval (CI) 1.14 to 1.42), < 40 years vs ≥ 80 years OR 2.01 (95% CI 1.76-2.30)], female sex [OR 1.09 (95% CI 1.02-1.16)], surgery over two spinal levels [OR 1.16 (95% CI 1.06-1.26)] and the comorbidities chronic pulmonary disease, connective tissue disease, liver disease, diabetes, hemi/paraplegia, renal disease and cancer were all associated with emergency readmission within 90 days. Other outcomes studied had a similar pattern of associations.

CONCLUSIONS

A high-throughput PLDD pathway will not be suitable for all patients. Extra care should be taken for patients aged ≥ 70 years, females, patients undergoing surgery over two spinal levels and those with specific comorbidities or generalised frailty.

Patient-specific Risk Factors Increase Episode of Care Costs After Lumbar Decompression

STUDY DESIGN

Retrospective cohort analysis.

OBJECTIVE

To determine, which patient-specific risk factors increase total episode of care (EOC) costs in a population of Centers for Medicare and Medicaid Services beneficiaries undergoing lumbar decompression.

SUMMARY OF BACKGROUND DATA

Lumbar decompression is an effective option for the treatment of central canal stenosis or radiculopathy in patients unresponsive to nonoperative management. Given that elderly Americans are more likely to have one or more chronic medical conditions, there is a need to determine, which, if any, patient-specific risk factors increase health care costs after lumbar decompression.

METHODS

Care episodes limited to lumbar decompression surgeries were retrospectively reviewed on a Centers for Medicare and Medicaid Service reimbursement database at our academic institution between 2014 and 2019. The 90-day total EOC reimbursement payments were collected. Patient electronic medical records were then matched to the selected care episodes for the collection of patient demographics, medical comorbidities, surgical characteristics, and clinical outcomes. A stepwise multivariate linear regression model was developed to predict patient-specific risk factors that increased total EOC costs after lumbar decompression. Significance was set at P <0.05.

RESULTS

A total of 226 patients were included for analysis. Risk factors associated with increased total EOC cost included increased age (per year) (β = $324.70, P < 0.001), comorbid depression (β = $4368.30, P = 0.037), revision procedures (β = $6538.43, P =0.012), increased hospital length of stay (per day) (β = $2995.43, P < 0.001), discharge to an inpatient rehabilitation facility (β = $14,417.42, P = 0.001), incidence of a complication (β = $8178.07, P < 0.001), and readmission (β = $18,734.24, P < 0.001) within 90 days.

CONCLUSIONS

Increased age, comorbid depression, revision decompression procedures, increased hospital length of stay, discharge to an inpatient rehabilitation facility, and incidence of a complication and readmission within 90 days were all associated with increased total episodes of care costs.

Rates, Predictive Factors, and Adverse Outcomes of Fusion Surgery for Lumbar Degenerative Disorders in Ontario, Canada, Between 2006 and 2015: A Retrospective Cohort Study

BACKGROUND

The addition of fusion surgery to the decompression for lumbar degenerative disorders remains controversial. The purpose of this study is to compare the rate and outcome of decompression and fusion versus decompression alone.

METHODS

This population-based retrospective cohort study used several linked administrative databases to identify patients who underwent spinal decompression surgery in Ontario, Canada, from 2006 to 2015. Patients who had previous spine surgery, concurrent lumbar disc replacement, or a diagnosis other than degenerative disc disease were excluded. Adjusted logistic regression was used to assess our outcomes.

RESULTS

We identified 33,912 patients, of whom 9748 (28.74%) underwent fusion. Overall, fusion rates increased from 27.66% to 31.33% over the study period (P = 0.025). Factors associated with fusion included: older age, female sex, American Society of Anesthesiologists score ≥3, previous total joint replacement, and surgery by an orthopedic surgeon. Fusion surgery was associated with increased odds of 30-day mortality (odds ratio [OR] 1.77, 95% confidence interval [CI] 1.01-3.09; P = 0.046), 30-day (OR 1.94, 95% CI 1.53-2.46; P < 0.0001) and 90-day reoperation (OR 1.66, 95% CI 1.35-2.05; P < 0.0001), and 30-day readmission (OR 1.23, 95% CI 1.02-1.49; P = 0.027) when adjusting for confounding variables. The odds of suffering a complication after fusion and decompression surgery vs. decompression surgery alone were 4.3-fold greater (95% CI 3.78-5.09; P < 0.0001).

CONCLUSIONS

As compared with decompression alone, spinal fusion for degenerative lumbar disorders is associated with increased odds of adverse outcomes. These findings highlight the need for spine surgeons to consider carefully their indications for fusion procedures in the setting of degenerative spinal disorders.

Improvement following minimally invasive lumbar decompression in patients 80 years or older compared with younger age groups

OBJECTIVE

The objective of this study was to assess the outcomes of minimally invasive lumbar decompression in patients ≥ 80 years of age and compare them with those of younger age groups.

METHODS

This was a retrospective cohort study. Patients who underwent primary unilateral laminotomy for bilateral decompression (ULBD) (any number of levels) and had a minimum of 1 year of follow-up were included and divided into three groups by age: < 60 years, 60-79 years, and ≥ 80 years. The outcome measures were 1) patient-reported outcome measures (PROMs) (visual analog scale [VAS] back and leg, Oswestry Disability Index [ODI], 12-Item Short-Form Health Survey [SF-12] Physical Component Summary [PCS] and Mental Component Summary [MCS] scores, and Patient-Reported Outcomes Measurement Information System Physical Function [PROMIS PF]); 2) percentage of patients achieving the minimal clinically important difference (MCID) and the time taken to do so; and 3) complications and reoperations. Two postoperative time points were defined: early (< 6 months) and late (≥ 6 months).

RESULTS

A total of 345 patients (< 60 years: n = 94; 60-79 years: n = 208; ≥ 80 years: n = 43) were included in this study. The groups had significantly different average BMIs (least in patients aged ≥ 80 years), age-adjusted Charlson Comorbidity Indices (greatest in the ≥ 80-year age group), and operative times (greatest in 60- to 79-year age group). There was no difference in sex, number of operated levels, and estimated blood loss between groups. Compared with the preoperative values, the < 60-year and 60- to 79-year age groups showed a significant improvement in most PROMs at both the early and late time points. In contrast, the ≥ 80-year age group only showed significant improvement in PROMs at the late time point. Although there were significant differences between the groups in the magnitude of improvement (least improvement in ≥ 80-year age group) at the early time point in VAS back and leg, ODI, and SF-12 MCS, no significant difference was seen at the late time point except in ODI (least improvement in ≥ 80-year group). The overall MCID achievement rate decreased, moving from the < 60-year age group toward the ≥ 80-year age group at both the early (64% vs 51% vs 41% ) and late (72% vs 58% vs 52%) time points. The average time needed to achieve the MCID in pain and disability increased, moving from the < 60-year age group toward the ≥ 80-year age group (2 vs 3 vs 4 months). There was no significant difference seen between the groups in terms of complications and reoperations except in immediate postoperative complications (5.3% vs 4.8% vs 14%).

CONCLUSIONS

Although in this study minimally invasive decompression led to less and slower improvement in patients ≥ 80 years of age compared with their younger counterparts, there was significant improvement compared with the preoperative baseline.

Machine Learning Approaches to Define Candidates for Ambulatory Single Level Laminectomy Surgery

STUDY DESIGN

retrospective cohort study.

OBJECTIVES

To test and compare 2 machine learning algorithms to define characteristics associated with candidates for ambulatory same day laminectomy surgery.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was queried for patients who underwent single level laminectomy in 2017 and 2018. The main outcome was ambulatory same day discharge. Study variables of interest included demographic information, comorbidities, preoperative laboratory values, and intra-operative information. Two machine learning predictive modeling algorithms, artificial neural network (ANN) and random forest, were trained to predict same day discharge. The quality of models was evaluated with area under the curve (AUC), accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) measures.

RESULTS

Among 35,644 patients, 13,230 (37.1%) were discharged on the day of surgery. Both ANN and RF demonstrated a satisfactory model quality in terms of AUC (0.77 and 0.77), accuracy (0.69 and 0.70), sensitivity (0.83 and 0.58), specificity (0.55 and 0.80), PPV (0.77 and 0.69), and NPV (0.64 and 0.70). Both models highlighted several important predictive variables, including age, duration of operation, body mass index and preoperative laboratory values including, hematocrit, platelets, white blood cells, and alkaline phosphatase.

CONCLUSION

Machine learning approaches provide a promising tool to identify candidates for ambulatory laminectomy surgery. Both machine learning algorithms highlighted the as yet unrecognized importance of preoperative laboratory testing on patient pathway design.

Perioperative Complications of Open Spine Surgery in Older Adults over 90 Years of Age

Introduction

Despite perioperative risks in nonagenarian patients who undergo open spine surgery for degeneration disorder or spinal trauma being of great interest, the prevalence of complications in this group remains unclear. This study aims to examine the perioperative complications of open spine surgery in the elderly over 90 years of age.

Methods

Preoperative and intraoperative characteristics including the American Society of Anesthesiologists Physical Status (ASA-PS) class, type of surgery, and complications within 30 postoperative days were retrospectively collected from the medical records of nonagenarians who underwent open spine surgery between April 2004 and July 2019 at our spine centers.

Results

A total of 48 patients met the inclusion criteria of this study. All belong to ASA-PS class 2 (69%) or 3. Preoperative American Spinal Injury Association Impairment Scale grades in trauma group were grade A in 4 cases, B in 1 case, C in 5 cases, D in 11 cases, and E in 1 case. Major complications (deep surgical site infection, cardiac event, respiratory disorder, gastrointestinal hemorrhage, and renal failure) occurred in 13 cases, and the rate of overall perioperative complications was 45.8%. One patient who underwent cervical stabilization for cervical fracture dislocation died at postoperative 13 days due to respiratory disorder. The rates of major complications and overall perioperative complications were 3.6% and 14.3% in the degenerative group and 45.5% and 81.8% in the trauma group, respectively. Especially in the trauma group, respiratory disorder occurred in 7 cases, delirium in 11 cases, and urinary tract infection in 5 cases.

Conclusions

Although the perioperative complication rate reached 81.8% in spinal trauma cases, the complication rate in degenerative disorders was relatively low as 14.3%. Open spine surgery for degenerative disorders can be relatively safe even in nonagenarians, whereas the risks of perioperative complications, including respiratory disorder and delirium, were high in spinal trauma cases.

Risk Factors for 30-day and 90-day Readmission After Lumbar Decompression

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To assess readmission rates and risk factors for 30-day and 90-day readmission after elective lumbar decompression at a single institution.

SUMMARY OF BACKGROUND DATA

Hospital readmission is an undesirable aspect of interventional treatment. Studies evaluating readmissions after elective lumbar decompression typically analyze national databases, and therefore have several drawbacks inherent to their macroscopic nature that limit their clinical utility.

METHODS

Patients undergoing primary one- to four-level lumbar decompression surgery were retrospectively identified. Demographic, surgical, and readmission data within "30-days" (0-30 days) and "90-days" (31-90 days) postoperatively were extracted from electronic medical records. Patients were categorized into four groups: (1) no readmission, (2) readmission during the 30-day or 90-day postoperative period, (3) complication related to surgery, and (4) Emergency Department (ED)/Observational (OBs)/Urgent (UC) care.

RESULTS

A total of 2635 patients were included. Seventy-six (2.9%) were readmitted at some point within the 30- (2.3%) or 90-day (0.3%) postoperative periods. Patients in the pooled readmitted group were older (63.1 yr, P  < 0.001), had a higher American Society of Anesthesiologists (ASA) grade (31.2% with ASA of 3, P = 0.03), and more often had liver disease (8.1%, P = 0.004) or rheumatoid arthritis (12.0%, P = 0.02) than other cohorts. A greater proportion of 90-day readmissions and complications had surgical-related diagnoses or a diagnosis of recurrent disc herniation than 30-day readmissions and complications (66.7% vs. 44.5%, P = 0.04 and 33.3% vs. 5.5%, P < 0.001, respectively). Age (Odds ratio [OR]: 1.02, P = 0.01), current smoking status (OR: 2.38, P < 0.001), longer length of stay (OR: 1.14, P < 0.001), and a history of renal failure (OR: 2.59, P = 0.03) were independently associated with readmission or complication.

CONCLUSION

Increased age, current smoking status, hospital length of stay, and a history of renal failure were found to be significant independent predictors of inpatient readmission or complication after lumbar decompression.

Rates and risk factors associated with 30- and 90-day readmissions and reoperations after spinal fusions for adult lumbar degenerative pathology and spinal deformity

PURPOSE

Analyze state databases to determine variables associated with of short-term readmissions and reoperations following thoracolumbar spine fusions for degenerative pathology and spinal deformity.

METHODS

Retrospective study of State Inpatient Database (2005-13, CA, NE, NY, FL, NC, UT).

INCLUSION CRITERIA

age > 45 years, diagnosis of degenerative spinal deformity, ≥ 3 level posterolateral lumbar spine fusion.

EXCLUSION CRITERIA

revision surgery, cervical fusions, trauma, and cancer. Univariate and step-wise multivariate logistic regression analyses were performed to identify independent variables associated with of 30- and 90-day readmissions and reoperations.

RESULTS

12,641 patients were included. All-cause 30- and 90-day readmission rates were 14.6% and 21.1%, respectively. 90-day readmissions were associated with: age > 80 (OR: 1.42), 8 + level fusions (OR: 1.19), hospital length of stay (LOS) > 7 days (OR: 1.43), obesity (OR: 1.29), morbid obesity (OR: 1.66), academic hospital (OR: 1.13), cancer history (OR:1.21), drug abuse (OR: 1.31), increased Charlson Comorbidity index (OR: 1.12), and depression (OR: 1.20). Private insurance (OR: 0.64) and lumbar-only fusions (OR: 0.87) were not associated with 90-day readmissions. All-cause 30- and 90-day reoperation rates were 1.8% and 4.2%, respectively. Variables associated with 90-day reoperations were 8 + level fusions (OR: 1.28), LOS > 7 days (OR: 1.43), drug abuse (OR: 1.68), osteoporosis (OR: 1.26), and depression (OR: 1.23). Circumferential fusion (OR: 0.58) and lumbar-only fusions (OR: 0.68) were not associated with 90-day reoperations.

CONCLUSIONS

30- and 90-day readmission and reoperation rates in thoracolumbar fusions for adult degenerative pathology and spinal deformity may have been underreported in previously published smaller studies. Identification of modifiable risk factors is important for improving quality of care through preoperative optimization.

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.

Biomechanical Comparison of Fixation Stability among Various Pedicle Screw Geometries: Effects of Screw Outer/Inner Projection Shape and Thread Profile

The proper screw geometry and pilot-hole size remain controversial in current biomechanical studies. Variable results arise from differences in specimen anatomy and density, uncontrolled screw properties and mixed screw brands, in addition to the use of different tapping methods. The purpose of this study was to evaluate the effect of bone density and pilot-hole size on the biomechanical performance of various pedicle screw geometries. Six screw designs, involving three different outer/inner projections of screws (cylindrical/conical, conical/conical and cylindrical/cylindrical), together with two different thread profiles (square and V), were examined. The insertional torque and pullout strength of each screw were measured following insertion of the screw into test blocks, with densities of 20 and 30 pcf, predrilled with 2.7-mm/3.2-mm/3.7-mm pilot holes. The correlation between the bone volume embedded in the screw threads and the pullout strength was statistically analyzed. Our study demonstrates that V-shaped screw threads showed a higher pullout strength than S-shaped threads in materials of different densities and among different pilot-hole sizes. The configuration, consisting of an outer cylindrical shape, an inner conical shape and V-shaped screw threads, showed the highest insertional torque and pullout strength at a normal and higher-than-normal bone density. Even with increasing pilot-hole size, this configuration maintained superiority.

Application of Cooperative Game Theory Principles to Interpret Machine Learning Models of Nonhome Discharge Following Spine Surgery

STUDY DESIGN

Retrospective analysis of prospectively acquired data.

OBJECTIVE

The aim of this study was to identify interaction effects that modulate nonhome discharge (NHD) risk by applying coalitional game theory principles to interpret machine learning models and understand variable interaction effects underlying NHD risk.

SUMMARY OF BACKGROUND DATA

NHD may predispose patients to adverse outcomes during their care. Previous studies identified potential factors implicated in NHD; however, it is unclear how interaction effects between these factors contribute to overall NHD risk.

METHODS

Of the 11,150 reviewed cases involving procedures for degenerative spine conditions, 1764 cases (15.8%) involved NHD. Gradient boosting classifiers were used to construct predictive models for NHD for each patient. Shapley values, which assign a unique distribution of the total NHD risk to each model variable using an optimal cost-sharing rule, quantified feature importance and examined interaction effects between variables.

RESULTS

Models constructed from features identified by Shapley values were highly predictive of patient-level NHD risk (mean C-statistic = 0.91). Supervised clustering identified distinct patient subgroups with variable NHD risk and their shared characteristics. Focused interaction analysis of surgical invasiveness, age, and comorbidity burden suggested age as a worse risk factor than comorbidity burden due to stronger positive interaction effects. Additionally, negative interaction effects were found between age and low blood loss, indicating that intraoperative hemostasis may be critical for reducing NHD risk in the elderly.

CONCLUSION

This strategy provides novel insights into feature interactions that contribute to NHD risk after spine surgery. Patients with positively interacting risk factors may require special attention during their hospitalization to control NHD risk.Level of Evidence: 3.

Cost and Complications of Single-Level Lumbar Decompression in Those Over and Under 75: A Matched Comparison

STUDY DESIGN

Retrospective database analysis.

OBJECTIVE

This study aimed to compare costs and complication rates following single-level lumbar decompression in patients under age 75 versus patients aged 75 and older.

SUMMARY OF BACKGROUND DATA

Lumbar decompression is a common surgical treatment for lumbar pathology; however, its effectiveness can be debated in elderly patients because complication rates and costs by age group are not well-defined.

METHODS

The Medicare database was queried through the PearlDiver server for patients who underwent single-level lumbar decompression without fusion as an index procedure. The 90-day complication and reoperation rates were compared between age groups after matching for sex and comorbidity burden. Same day and 90-day costs are compared.

RESULTS

The matched cohort included 89,388 total patients (n = 44,694 for each study arm). Compared to the under 75 age group, the 75 and older age group had greater rates of deep venous thrombosis (odds ratio [OR] 1.443, P = 0.042) and dural tear (OR 1.560, P = 0.043), and a lower rate of seroma complicating the procedure (OR 0.419, P = 0.009). There was no difference in overall 90-day reoperation rate in patients under age 75 versus patients aged 75 and older (9.66% vs. 9.28%, P = 0.051), although the 75 and older age group had a greater rate of laminectomy without discectomy (CPT-63047; OR 1.175, P < 0.001), while having a lower rate of laminotomy with discectomy (CPT-63042 and CPT-63030; OR 0.727 and 0.867, respectively, P = 0.013 and <0.001, respectively). The 75 and older age group had greater same day ($3329.24 vs. $3138.05, P < 0.001) and 90-day ($5014.82 vs. $4749.44, P < 0.001) mean reimbursement.

CONCLUSION

Elderly patients experience greater rates of select perioperative complications, with mildly increased costs. There is no significant difference in overall 90-day reoperation rates.

LEVEL OF EVIDENCE

3.

Adult spinal deformity surgery: the effect of surgical start time on patient outcomes and cost of care

PURPOSE

There are reports investigating the effect of surgical start time (SST) on outcomes, length of stay (LOS) and cost in various surgical disciplines. However, this has not been studied in spine deformity surgery to date. This study compares outcomes for patients undergoing spinal deformity surgery based on SST.

METHODS

Patients at a single academic institution from 2008 to 2016 undergoing elective spinal deformity surgery (defined as fusing ≥ 7 segments) were divided by SST before or after 2 PM. Co-primary outcomes were LOS and direct costs. Secondary outcomes included delayed extubation, ICU stay, complications, reoperation, non-home discharge, and readmission rates.

RESULTS

There were 373 surgeries starting before 2 PM and 79 after 2 PM. The cohorts had similar demographics including age, sex, comorbidity burden, and levels fused. The late SST cohort had shorter operation durations (p = 0.0007). Multivariable linear regression showed no differences in LOS (estimate 0.4 days, CI - 1.2 to 2.0, p = 0.64) or direct cost (estimate $3652, 95% CI - $1449 to $8755, p = 0.16). Multivariable logistic regression revealed the late SST cohort was more likely to have delayed extubation (OR 2.6, 95% CI 1.4-4.9, p = 0.004) and non-home discharge (OR 2.2, 95% CI 1.1-4.2, p = 0.03). All other secondary outcomes were non-significant.

CONCLUSION

Patients undergoing spinal deformity surgery before and after 2 PM have similar LOS and cost of care. However, the late SST cohort had increased likelihood of delayed extubation and non-home discharges, which increase cost in bundled payment models. These findings can be utilized in OR scheduling to optimize outcomes and minimize cost.

Chronic opioid use is associated with increased postoperative urinary retention, length of stay and non-routine discharge following lumbar fusion surgery

BACKGROUND

The incidence of chronic opioid use (COU) is increasing with health related complications impacting both patients and healthcare services.

OBJECTIVE

The aim of this study was to identify the impact of COU on postoperative urinary retention (PUR) in patients following lumbar fusion surgery as well as its impact on length of stay (LOS) and non-routine discharges (NRD).

MATERIALS & METHODS

The State Inpatient Databases were utilised to identify patients undergoing elective lumbar fusion procedures. Patients with and without COU were separated into groups and matched using 3:1 propensity score matching. PUR, LOS in the upper quartile and discharge to a location other than home were the outcomes of interest. Multivariable logistic regression was used to examine the impact of COU on the above outcomes and Wald chi-square tests were used to determine the factors with the most significant associations.

RESULTS

COU was significant for PUR (p = 0.037), prolonged LOS (p < 0.001), and NRD (p < 0.001). Factors most significantly associated with PUR were Elixhauser Mortality Index and COU both with p < 0.05. Factors associated with prolonged LOS and NRD were Elixhauser Mortality Index, COU, and insurance status.

CONCLUSION

COU has a notable impact on PUR, LOS, and NRD. The Elixhauser Mortality Index and insurance status of patients also showed predictive utility for these outcomes. This knowledge enables us to identify sources of pressure for health services and approach them strategically through increased awareness.

Outcomes and Complications With Age in Spondylolisthesis: An Evaluation of the Elderly From the Quality Outcomes Database

STUDY DESIGN

Prospective database analysis.

OBJECTIVE

To assess the effect of age on patient-reported outcomes (PROs) and complication rates after surgical treatment for spondylolisthesis SUMMARY OF BACKGROUND DATA.: Degenerative lumbar spondylolisthesis affects 3% to 20% of the population and up to 30% of the elderly. There is not yet consensus on whether age is a contraindication for surgical treatment of elderly patients.

METHODS

The Quality Outcomes Database lumbar registry was used to evaluate patients from 12 US academic and private centers who underwent surgical treatment for grade 1 lumbar spondylolisthesis between July 2014 and June 2016.

RESULTS

A total of 608 patients who fit the inclusion criteria were categorized by age into the following groups: less than 60 (n = 239), 60 to 70 (n = 209), 71 to 80 (n = 128), and more than 80 (n = 32) years. Older patients showed lower mean body mass index (P < 0.001) and higher rates of diabetes (P = 0.007), coronary artery disease (P = 0.0001), and osteoporosis (P = 0.005). A lower likelihood for home disposition was seen with higher age (89.1% in <60-year-old vs. 75% in >80-year-old patients; P = 0.002). There were no baseline differences in PROs (Oswestry Disability Index, EuroQol health survey [EQ-5D], Numeric Rating Scale for leg pain and back pain) among age categories. A significant improvement for all PROs was seen regardless of age (P < 0.05), and most patients met minimal clinically important differences (MCIDs) for improvement in postoperative PROs. No differences in hospital readmissions or reoperations were seen among age groups (P < 0.05). Multivariate analysis demonstrated that, after controlling other variables, a higher age did not decrease the odds of achieving MCID at 12 months for the PROs.

CONCLUSION

Our results indicate that well-selected elderly patients undergoing surgical treatment of grade 1 spondylolisthesis can achieve meaningful outcomes. This modern, multicenter US study reflects the current use and limitations of spondylolisthesis treatment in the elderly, which may be informative to patients and providers.

LEVEL OF EVIDENCE

4.

Large Rises in Thoracolumbar Fusions by 2040: A Cause for Concern with an Increasingly Elderly Surgical Population

BACKGROUND

With a growing aging population in the United States, the number of operative lumbar spine pathologies continues to grow. Therefore, our objective was to estimate the future demand for lumbar spine surgery volumes for the United States to the year 2040.

METHODS

The National/Nationwide Inpatient Sample was queried for years 2003-2015 for anterior interbody and posterior lumbar fusions (ALIF, PLF) to create national estimates of procedural volumes for those years. The average age and comorbidity burden was characterized, and Poisson modeling controlling for age and sex allowed for surgical volume prediction to 2040 in 10-year increments. Age was grouped into categories (<25, 25-34, 35-44, 45-54, 55-64, 65-74, 75-84, and >85 years), and estimates of surgical volumes for each age subgroup were created.

RESULTS

ALIF volume is expected to increase from 46,903 to 55,528, and PLF volume is expected to increase from 248,416 to 297,994 from 2020 to 2040. For ALIF, the largest increases are expected in the 45-54 years (10,316 to 12,216) and 75-84 years (2,898 to 5,340) age groups. Similarly the largest increases in PLF will be seen in the 65-74 years (71,087 to 77,786) and 75-84 years (28,253 to 52,062) age groups.

CONCLUSIONS

The large increases in expected volumes of ALIF and PLF could necessitate training of more spinal surgeons and an examination of projected costs. Further analyses are needed to characterize the needs of this increasingly large population of surgical patients.

A sliding scale to predict postoperative complications undergoing posterior spine surgery

BACKGROUND

There is a lack of consensus of operative time (OT) and estimated blood loss (EBL) for elderly patients based on the predicted risk of complications after posterior spine surgery. The purpose of this study was to evaluate the effect of age, OT, and EBL on the postoperative complication risk and to develop a simple sliding scale.

METHODS

We explored prospectively collected data of consecutive patients who underwent posterior spine surgery in seven tertiary referral hospitals from November 2013 to May 2016. Age (<70, 70-74, 75-79, 80-84, ≥85 years), OT (<2, 2-<3, 3-<4, 4-<5, ≥5 h), and EBL (<500, 500-<1000, 1000-<1500, 1500-<2000, ≥2000 ml) were categorized ranging from 1 (lowest) to 5 (highest). The association between the crude cumulative categories' number and the incidence of complications was analyzed. We further evaluated the association by re-categorizing the cumulative number into three groups (3-4, 5-10, ≥11).

RESULTS

Total of 2416 patients (median age: 70 years old) were enrolled and major complications were observed in 75 (3.1%) patients. Age, OT, and EBL showed similar odds ratio (1.18-1.19) as each category increased. The cumulative categories' number fitted the estimate complication risk (Hosmer-Lemeshow P = 0.87), and statistically significant trend was observed between predicted and actual complication rates (Cochran-Armitage test, P < 0.001). When cumulative categories' numbers were stratified into three groups, significant increasing trend of risk were observed (Mantel-Haenszel P < 0.001). Based on the categorical numbers, we proposed a simple sliding scale.

CONCLUSION

Our data indicated that the risk of postoperative complication was associated with cumulative score based on increased age, OT, and EBL. A simple sliding scale was developed based on these factors, which may be useful to predict complication risk after posterior spine surgery.

[The joint management of Geriatrics-Neurosurgery of patients older than 75 years reduces the average stay, morbidity, hospital readmissions and mortality per year]

OBJECTIVE

Population ageing is a reality for which national health systems are not adapted. The World Health Organisation has already raised awareness about the implementation of specific measures, from undergraduate training to dedicated elderly care units, to tackle this situation. In this article, the aim is to analyse the potential benefits of geriatric monitoring on elderly neurosurgical patients.

MATERIAL AND METHODS

A descriptive analysis was performed in this medical centre, comparing the information collected from elderly patients (over 75 years of age) admitted into the neurosurgical department during 2periods: June 2015 to February 2017, in which a shared geriatric monitoring was implemented, and between October 2013 and May 2015, equivalent period, in which only the geriatrician performed the evaluation of the patients' general condition, before referring them to other social-healthcare units. A number of factors were considered, including mean age, gender, the neurosurgical condition that led to admission, mean stay, infectious complications, acute confusional syndrome, admission into an intensive care unit, need for support from other medical departments, reoperations, mortality during hospitalisation, referral to social-health units, readmission within a month, and mortality within a year.

RESULTS

A total of 173 patients on shared monitoring were compared to 189 patients from the previous period. Both groups had similar demographic characteristics. During the analysis, a significant reduction was observed in shared monitoring as regards, mean hospitalisation, infectious complications, admissions into an intensive care unit, the need for support from other medical departments, readmissions within a month, and mortality within a year.

CONCLUSIONS

On patients of over 75 years of age, shared geriatric-neurosurgical monitoring reduces mean hospitalisation, morbidity, the need for support from other medical departments, early readmission, and mortality within a year. This strategy prioritises patient care, reduces costs, and rationalises resources.

Risk Factors Associated With 90-Day Readmissions After Degenerative Lumbar Fusion: An Examination of the Michigan Spine Surgery Improvement Collaborative (MSSIC) Registry

BACKGROUND

Most studies have evaluated 30-d readmissions after lumbar fusion surgery. Evaluation of the 90-d period, however, allows a more comprehensive assessment of factors associated with readmission.

OBJECTIVE

To assess the reasons and risk factors for 90-d readmissions after lumbar fusion surgery.

METHODS

The Michigan Spine Surgery Improvement Collaborative (MSSIC) registry is a prospective, multicenter, and spine-specific database of patients surgically treated for degenerative disease. MSSIC data were retrospectively analyzed for causes of readmission, and independent risk factors impacting readmission were found by multivariate logistic regression.

RESULTS

Of 10 204 patients who underwent lumbar fusion, 915 (9.0%) were readmitted within 90 d, most commonly for pain (17%), surgical site infection (16%), and radicular symptoms (10%). Risk factors associated with increased likelihood of readmission were other race (odds ratio [OR] 1.81, confidence interval [CI] 1.22-2.69), coronary artery disease (OR 1.57, CI 1.25-1.96), ≥4 fused levels (OR 1.41, CI 1.06-1.88), diabetes (OR 1.34, CI 1.10-1.63), and surgery length (OR 1.09, CI 1.03-1.16). Factors associated with decreased risk were discharge to home (OR 0.63, CI 0.51-0.78), private insurance (OR 0.79, CI 0.65-0.97), ambulation same day of surgery (OR 0.81, CI 0.67-0.97), and spondylolisthesis diagnosis (OR 0.82, CI 0.68-0.97). Of those readmitted, 385 (42.1%) patients underwent another surgery.

CONCLUSION

Ninety-day readmission occurred in 9.0% of patients, mainly for pain, wound infection, and radicular symptoms. Increased focus on postoperative pain may decrease readmissions. Among factors impacting the likelihood of 90-d readmission, early postoperative ambulation may be most easily modifiable. Optimization of preexisting medical conditions could also potentially decrease readmission risk.

Minimally Invasive Lumbar Decompression and Interspinous Process Device for the Management of Symptomatic Lumbar Spinal Stenosis: a Literature Review

PURPOSE OF REVIEW

Symptomatic lumbar spinal stenosis (LSS) is a condition affecting a growing number of individuals resulting in significant disability and pain. Traditionally, treatment options have consisted of conservative measures such as physical therapy, medication management, epidural injections and percutaneous adhesiolysis, or surgery. There exists a treatment gap for patients failing conservative measures who are not candidates for surgery. Minimally invasive lumbar decompression (MILD®) and interspinous process device (IPD) with Superion® represent minimally invasive novel treatment options that may help fill this gap in management. We performed a literature review to separately evaluate these procedures and assess the effectiveness and safety.

RECENT FINDINGS

The available evidence for MILD and Superion has been continuously debated. Overall, it is considered that while the procedures are safe, there is only modest evidence for effectiveness. For both procedures, we have reviewed 13 studies. Based on the available evidence, MILD and Superion are safe and modestly effective minimally invasive procedures for patients with symptomatic LSS. It is our recommendation that these procedures may be incorporated as part of the continuum of treatment options for patients meeting clinical criteria.

Trends in Ambulatory Laminectomy in the USA and Key Factors Associated with Successful Same-Day Discharge: A Retrospective Cohort Study

BACKGROUND

Laminectomy is commonly used in the treatment of lumbar spine pathology. Laminectomies are increasingly being performed in outpatient settings, but patient safety concerns remain.

QUESTIONS/PURPOSES

We aimed to describe trends in outpatient lumbar laminectomy between 2008 and 2016 and to identify factors associated with successful same-day discharge.

METHODS

We identified patients who underwent single-level lumbar laminectomy between 2008 and 2016 in the American College of Surgeons' National Surgical Quality Improvement Program database and divided them into two groups according to their admission status, either inpatient or outpatient. Inpatient and outpatient groups were further divided according to actual length of stay (LOS): did not remain in the hospital overnight (LOS = 0) or stayed in the hospital overnight or longer (LOS ≥ 1). We then analyzed patient characteristics and complications for significance and to identify factors associated with successful same-day discharge.

RESULTS

We identified 85,769 patients, 41,149 classified as outpatient status and 44,620 as inpatient status. Between 2008 and 2016, the proportion of procedures performed on an outpatient basis increased from 24.1 to 56.74%. Overall, 27.3% of all patients were discharged on the day of surgery, representing 52.8% of outpatients and 3.8% of inpatients. Older age and longer duration of surgery predicted that patients were less likely to have same-day discharge. Patients with a primary diagnosis other than intervertebral disk disorder, Hispanic ethnic background, or an American Society of Anesthesiologists physical status classification of III were less likely to achieve same-day discharge. Patients under the care of orthopedic surgeons (as opposed to neurosurgeons) were more likely to be discharged on the day of surgery. We also found an association between sex and day of discharge, with female patients being less likely to be discharged on the day of surgery.

CONCLUSIONS

Laminectomy is increasingly being performed in the outpatient setting. Younger, healthier non-Hispanic male patients undergoing uncomplicated surgery have a higher likelihood of successful same-day discharge.

Clinical outcomes of lumbar spinal surgery in patients 80 years or older with lumbar stenosis or spondylolisthesis: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis of all available evidence was performed to assess the safety and efficacy of surgery for lumbar stenosis and spondylolisthesis in patients 80 years or older versus those younger than 80 years.

METHODS

A search of the literature was conducted in PubMed/MEDLINE, EMBASE and the Cochrane Collaboration Library. Relevant studies comparing the clinical outcomes of lumbar surgery in octogenarians and younger patients were selected according to the eligibility criteria. The predefined endpoints were extracted and meta-analysed from the identified studies.

RESULTS

Data from 16 observational studies including 374,197 patients were included in the final analysis. The pooled data revealed that patients 80 years or older had a significantly higher incidence of overall complication, mortality, readmission and longer length of hospital stay than younger patients. There was a similar improvement in the clinical symptoms (Oswestry Disability Index and pain) of patients in the two groups. No significant differences in overall wound complication, reoperation rate, operative time and intraoperative blood loss were found between the groups.

CONCLUSIONS

Our results revealed that the clinical improvement in pain and disability did not significantly differ according to age, although the patients aged 80 years or older had increased incidences of mortality and complication than younger patients. Age alone is not a contraindication for lumbar surgery in very old patients. A careful preoperative evaluation, proper patient selection and appropriate surgical approach are important to achieve successful surgical outcomes. These slides can be retrieved under Electronic Supplementary Material.

Complications of Spine Surgery in Elderly Japanese Patients: Implications for Future of World Population Aging

Objective

To analyze the relationship between age and perioperative complications of spine surgery in a Japanese cohort with the longest average life expectancy in the world.

Methods

Patients with spinal stenosis who underwent standard spine surgery without instrumented fusion were divided into 4 groups: adults (20–64 years), the young-old (65–74), the middle old (75–84), and the oldest-old (≥85). Data on medical complications, surgical complications, and deaths within 30 days of index surgery were compared across the groups. Risk factors for complications were identified through multivariate analysis.

Results

A total of 584 patients underwent 673 operations: 35% were performed on adult patients, 33% on the young-old, 27% on the middle old, and 5% on the oldest-old. The rates of total or [major] medical complications significantly increased with age (8% [0.8%], 11% [0.9%], 27% [3.9%], 45% [9.1%], respectively; p<0.001 [p=0.003]), whereas those of surgical complications did not differ (11%, 8.1%, 14%, 9.1%, respectively; p=0.25). Independent risk factors for medical complications were an age of 75 years or older (75–84: odds ratio [OR], 5.1; ≥85: OR, 6.2) and American Society of Anesthesiologists (ASA) physical status classification III (OR, 5.4). Two patients older than 85 years died from medical complications.

Conclusion

The complications of spine surgery increased in the middle and oldest-old patients because of medical complications; however, most were minor and treatable. Major complications were associated with preoperative medical comorbidities and their severities; therefore, most elderly patients with low ASA physical status classification (≤II) may benefit from spine surgery.

Reporting Methodology of Neurosurgical Studies Utilizing the American College of Surgeons-National Surgical Quality Improvement Program Database: A Systematic Review and Critical Appraisal

BACKGROUND

Use of large databases such as the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) has become increasingly common in neurosurgical research.

OBJECTIVE

To perform a critical appraisal and evaluation of the methodological reporting for studies in neurosurgical literature that utilize the ACS-NSQIP database.

METHODS

We queried Ovid MEDLINE, EMBASE, and PubMed databases for all neurosurgical studies utilizing the ACS-NSQIP. We assessed each study according to number of criteria fulfilled with respect to Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement, REporting of studies Conducted using Observational Routinely-collected Health Data (RECORD) Statement, and Journal of American Medical Association–Surgical Section (JAMA-Surgery) Checklist. A separate analysis was conducted among papers published in core and noncore journals in neurosurgery according to Bradford's law.

RESULTS

A total of 117 studies were included. Median (interquartile range [IQR]) scores for number of fulfilled criteria for STROBE Statement, RECORD Statement, and JAMA-Surgery Checklist were 20 (IQR:19-21), 9 (IQR:8-9), and 6 (IQR:5-6), respectively. For STROBE Statement, RECORD Statement, and JAMA-Surgery Checklist, item 9 (potential sources of bias), item 13 (supplemental information), and item 9 (missing data/sensitivity analysis) had the highest number of studies with no fulfillment among all studies (56, 68, 50%), respectively. When comparing core journals vs noncore journals, no significant difference was found (STROBE, P = .94; RECORD, P = .24; JAMA-Surgery checklist, P = .60).

CONCLUSION

While we observed an overall satisfactory reporting of methodology, most studies lacked mention of potential sources of bias, data cleaning methods, supplemental information, and external validity. Given the pervasive role of national databases and registries for research and health care policy, the surgical community needs to ensure the credibility and quality of such studies that ultimately aim to improve the value of surgical care delivery to patients.

Adjacent Intervertebral Disk Height Decrease Phenomenon After Single-Level Transforaminal Lumbar Interbody Fusion of the Lumbar Spine

BACKGROUND

The increase of intradiskal pressure on the upper segment resulting from intervertebral distraction after lumbar intervertebral fusion decreases intervertebral height and aggravates degeneration. However, the incidence rate and risk factors of the adjacent intervertebral disk height decrease phenomenon have not been studied. The purpose of this study was to identify the incidence rate and risk factors of the adjacent intervertebral disk height decrease phenomenon after single-level transforaminal lumbar interbody fusion (TLIF) of the lumbar spine.

METHODS

A retrospection of 68 patients who underwent L4-5 TLIF. Patient age, sex, and body mass index were collected. Lumbar lordosis, facet sagittalization, Pfirrmann classification, L4-5 distraction height, and L3-4 reduction height were evaluated by radiologic image. The patients were divided into 2 groups based on whether their L3-4 intervertebral height decreased.

RESULTS

Forty of 68 patients (58.8%) had L3-4 intervertebral height decrease. The patients' mean age was 62.05 ± 10.90 years in the L3-4 intervertebral height decrease positive (IHDP) group, significantly higher than the 56.14 ± 12.06 years in the L3-4 intervertebral height decrease negative (IHDN) group (P = 0.039). The mean facet sagittalization angle in the IHDP group was 67.5° ± 20.36°, significantly larger than the 55.43° ± 14.97° in the IHDN group (P = 0.010). The preoperative lumbar lordosis was significantly higher in the IHDP group (P = 0.049). No significant effects of other factors on L3-4 height decrease were observed (P > 0.05).

CONCLUSIONS

Distraction of the L4-5 intervertebral space by cage insertion leads to a reduced height on the adjacent L3-4 segment in some patients. In addition, the decrease in L3-4 intervertebral height resulting from L4-5 distraction was correlated with age, preoperative lumbar lordosis, and facet joint sagittalization.

Predicting discharge placement after elective surgery for lumbar spinal stenosis using machine learning methods

PURPOSE

An excessive amount of total hospitalization is caused by delays due to patients waiting to be placed in a rehabilitation facility or skilled nursing facility (RF/SNF). An accurate preoperative prediction of who would need a RF/SNF place after surgery could reduce costs and allow more efficient organizational planning. We aimed to develop a machine learning algorithm that predicts non-home discharge after elective surgery for lumbar spinal stenosis.

METHODS

We used the American College of Surgeons National Surgical Quality Improvement Program to select patient that underwent elective surgery for lumbar spinal stenosis between 2009 and 2016. The primary outcome measure for the algorithm was non-home discharge. Four machine learning algorithms were developed to predict non-home discharge. Performance of the algorithms was measured with discrimination, calibration, and an overall performance score.

RESULTS

We included 28,600 patients with a median age of 67 (interquartile range 58-74). The non-home discharge rate was 18.2%. Our final model consisted of the following variables: age, sex, body mass index, diabetes, functional status, ASA class, level, fusion, preoperative hematocrit, and preoperative serum creatinine. The neural network was the best model based on discrimination (c-statistic = 0.751), calibration (slope = 0.933; intercept = 0.037), and overall performance (Brier score = 0.131).

CONCLUSIONS

A machine learning algorithm is able to predict discharge placement after surgery for lumbar spinal stenosis with both good discrimination and calibration. Implementing this type of algorithm in clinical practice could avert risks associated with delayed discharge and lower costs. These slides can be retrieved under Electronic Supplementary Material.

Improving Complex Pediatric and Adult Spine Care While Embracing the Value Equation

INTRODUCTION

Value in health care is defined as the quotient of outcomes to cost. Both pediatric and adult spinal deformity surgeries are among the most expensive procedures offered today. With high variability in both outcomes and costs in spine surgery today, surgeons will be expected to consider long-term cost effectiveness when comparing treatment options.

METHODS

We summarize various methods by which value can be increased in complex spine surgery, both through the improvement of outcomes and the reduction of cost. These methods center around standardization, team-based and collaborative approaches, rigorous outcomes tracking through dashboards and registries, and continuous process improvement.

RESULTS

This manuscript reviews the expert opinion of leading spine specialists on the improvement of safety, quality and improvement of value of pediatric and adult spinal surgery.

CONCLUSION

Without surgeon leadership in this arena, suboptimal solutions may result from the isolated intervention of regulatory bodies or payer groups. The cooperative development of standardized, team-based approaches in complex spine surgery will lead to the high-quality, high-value care for patients.

Can Elective Spine Surgery Be Performed Safely Among Nonagenarians?: Analysis of a National Inpatient Database in Japan

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To compare morbidity and mortality between nonagenarians and other older adult patients who underwent elective spine surgery.

SUMMARY OF BACKGROUND DATA

There is a lack of information of the perioperative risks of nonagenarians undergoing spine surgery.

METHODS

Data of patients aged ≥65 years who underwent elective spine surgery from July 2010 to March 2013 were extracted from the Diagnosis Procedure Combination database, a nationwide administrative inpatient database in Japan. Clinical outcomes included mortality, occurrence of major complications (cardiac events, respiratory complications, pulmonary embolism, stroke, and acute renal failure), urinary tract infection, and postoperative delirium. These clinical outcomes in nonagenarians were compared with those in patients aged 65 to 79 years and octogenarians. A multivariate logistic regression model fitted with a generalized estimation equation was used to evaluate the influence of advanced age on 90-day mortality and postoperative major complications.

RESULTS

Of 88,370 patients identified in the database, 418 were nonagenarians. Compared with patients aged 65 to 79 years and octogenarians, nonagenarians had the highest rates of 90-day mortality (0.2%, 0.3%, and 1.7%, respectively; P < 0.001) and at least one major complication (3.7%, 5.0%, and 7.4%, respectively; P < 0.001). Nonagenarians had the highest proportions of cardiac events, respiratory complications, urinary tract infections, and delirium. The multivariable logistic regression analyses revealed that nonagenarians had increased risks of both 90-day mortality (odds ratio, 8.65; 95% confidence interval, 3.62-20.6) and postoperative major complications (odds ratio, 2.32; 95% confidence interval, 1.61-3.36) compared with patients aged 65 to 79 years.

CONCLUSION

Nonagenarians had increased morbidity and mortality following elective spine surgery compared with other older adult patients. Among the complications, cardiac events, respiratory complications, urinary tract infection, and delirium were more likely to occur in nonagenarians.

LEVEL OF EVIDENCE

3.

Revised Cardiac Risk Index as a Predictor for Myocardial Infarction and Cardiac Arrest Following Posterior Lumbar Decompression

STUDY DESIGN

A retrospective analysis of prospectively collected data.

OBJECTIVE

The aim of this study was to determine the ability of Revised Cardiac Risk Index (RCRI) to predict adverse cardiac events following posterior lumbar decompression (PLD).

SUMMARY OF BACKGROUND DATA

PLD is an increasingly common procedure used to treat a variety of degenerative spinal conditions. The RCRI is used to predict risk for cardiac events following noncardiac surgery. There is a paucity of literature that directly addresses the relationship between RCRI and outcomes following PLD, specifically, the discriminative ability of the RCRI to predict adverse postoperative cardiac events.

METHODS

ACS-NSQIP was utilized to identify patients undergoing PLD from 2006 to 2014. Fifty-two thousand sixty-six patients met inclusion criteria. Multivariate and ROC analysis was utilized to identify associations between RCRI and postoperative complications.

RESULTS

Membership in the RCRI=1 cohort was a predictor for myocardial infarction (MI) [odds ratio (OR) = 3.3, P = 0.002] and cardiac arrest requiring cardiopulmonary resuscitation (CPR) (OR = 3.4, P = 0.013). Membership in the RCRI = 2 cohort was a predictor for MI (OR = 5.9, P = 0.001) and cardiac arrest requiring CPR (OR = 12.5), Membership in the RCRI = 3 cohort was a predictor for MI (OR = 24.9) and cardiac arrest requiring CPR (OR = 26.9, P = 0.006). RCRI had a good discriminative ability to predict both MI [area under the curve (AUC) = 0.876] and cardiac arrest requiring CPR (AUC = 0.855). The RCRI had a better discriminative ability to predict these outcomes that did ASA status, which had discriminative abilities of "fair" (AUC = 0.799) and "poor" (AUC = 0.674), respectively. P < 0.001 unless otherwise specified.

CONCLUSION

RCRI was predictive of cardiac events following PLD, and RCRI had a better discriminative ability to predict MI and cardiac arrest requiring CPR than did ASA status. Consideration of the RCRI as a component of preoperative surgical risk stratification can minimize patient morbidity and mortality. Studies such as this can allow for implementation of guidelines that better estimate the preoperative risk profile of surgical patients.

LEVEL OF EVIDENCE

3.

Surgical Site Infection in Spine Surgery: Who Is at Risk?

STUDY DESIGN

Retrospective literature review of spine surgical site infection (SSI).

OBJECTIVE

To perform a review of SSI risk factors and more specifically, categorize them into patient and surgical factors.

METHODS

A review of published literature on SSI risk factors in adult spine surgery was performed. We included studies that reported risk factors for SSI in adult spinal surgery. Excluded are pediatric patient populations, systematic reviews, and meta-analyses. Overall, we identified 72 cohort studies, 1 controlled-cohort study, 1 matched-cohort study, 1 matched-paired cohort study, 12 case-controlled studies (CCS), 6 case series, and 1 cross-sectional study.

RESULTS

Patient-associated risk factors-diabetes mellitus, obesity (body mass index >35 kg/m²), subcutaneous fat thickness, multiple medical comorbidities, current smoker, and malnutrition were associated with SSI. Surgical associated factors-preoperative radiation/postoperative blood transfusion, combined anterior/posterior approach, surgical invasiveness, or levels of instrumentation were associated with increased SSI. There is mixed evidence of age, duration of surgery, surgical team, intraoperative blood loss, dural tear, and urinary tract infection/urinary catheter in association with SSI.

CONCLUSION

SSIs are associated with many risk factors that can be patient or surgically related. Our review was able to identify important modifiable and nonmodifiable risk factors that can be essential in surgical planning and discussion with patients.

Continued Inpatient Care After Elective 1- to 2-level Posterior Lumbar Fusions Increases 30-day Postdischarge Readmissions and Complications

STUDY DESIGN

This was a retrospective cohort study.

OBJECTIVE

The main objective of this article was to investigate the impact of discharge destination on postdischarge outcomes following an elective 1- to 2-level posterior lumbar fusion (PLF) for degenerative pathology.

BACKGROUND DATA

Discharge to an inpatient care facility may be associated with adverse outcomes as compared with home discharge.

MATERIALS AND METHODS

The 2012-2016 American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database was used to query for patients undergoing PLFs using Current Procedural Terminology (CPT) codes (22612, 22630, and 22633). Additional levels were identified using CPT-22614, CPT-22632, and CPT-22634. Records were filtered to include patients undergoing surgery for degenerative spine pathologies. Only patients undergoing a single-level or 2-level PLF were included in the study. A total of 23,481 patients were included in the final cohort.

RESULTS

A total of 3938 (16.8%) patients were discharged to a skilled care or rehabilitation facility following the primary procedure. Following adjustment for preoperative, intraoperative, and predischarge clinical characteristics, discharge to a skilled care or rehabilitation facility was associated with higher odds of any complication [odds ratio (OR), 1.70; 95% confidence interval (CI), 1.43-2.02], wound complications (OR, 1.73; 95% CI, 1.36-2.20), sepsis-related complications (OR, 1.64; 95% CI, 1.08-2.48), deep venous thrombosis/pulmonary embolism complications (OR, 1.72; 95% CI, 1.10-2.69), urinary tract infections (OR, 1.96; 95% CI, 1.45-2.64), unplanned reoperations (OR, 1.49; 95% CI, 1.23-1.80), and readmissions (OR, 1.29; 95% CI, 1.10-1.49) following discharge.

CONCLUSIONS

After controlling for predischarge characteristics, discharge to skilled care or rehabilitation facilities versus home following 1- to 2-level PLF is associated with higher odds of complications, reoperations, and readmissions. These results stress the importance of careful patient selection before discharge to inpatient care facilities to minimize the risk of complications. Furthermore, the results further support the need for uniform and standardized care pathways to promote home discharge following hospitalization for elective PLFs.

LEVEL OF EVIDENCE

Level III.

Development of machine learning algorithms for prediction of discharge disposition after elective inpatient surgery for lumbar degenerative disc disorders

OBJECTIVE

If not anticipated and prearranged, hospital stay can be prolonged while the patient awaits placement in a rehabilitation unit or skilled nursing facility following elective spine surgery. Preoperative prediction of the likelihood of postoperative discharge to any setting other than home (i.e., nonroutine discharge) after elective inpatient spine surgery would be helpful in terms of decreasing hospital length of stay. The purpose of this study was to use machine learning algorithms to develop an open-access web application for preoperative prediction of nonroutine discharges in surgery for elective inpatient lumbar degenerative disc disorders.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program was queried to identify patients who underwent elective inpatient spine surgery for lumbar disc herniation or lumbar disc degeneration between 2011 and 2016. Four machine learning algorithms were developed to predict nonroutine discharge and the best algorithm was incorporated into an open-access web application.

RESULTS

The rate of nonroutine discharge for 26,364 patients who underwent elective inpatient surgery for lumbar degenerative disc disorders was 9.28%. Predictive factors selected by random forest algorithms were age, sex, body mass index, fusion, level, functional status, extent and severity of comorbid disease (American Society of Anesthesiologists classification), diabetes, and preoperative hematocrit level. On evaluation in the testing set (n = 5273), the neural network had a c-statistic of 0.823, calibration slope of 0.935, calibration intercept of 0.026, and Brier score of 0.0713. On decision curve analysis, the algorithm showed greater net benefit for changing management over all threshold probabilities than changing management on the basis of the American Society of Anesthesiologists classification alone or for all patients or for no patients. The model can be found here: https://sorg-apps.shinyapps.io/discdisposition/.

CONCLUSIONS

Machine learning algorithms show promising results on internal validation for preoperative prediction of nonroutine discharges. If found to be externally valid, widespread use of these algorithms via the open-access web application by healthcare professionals may help preoperative risk stratification of patients undergoing elective surgery for lumbar degenerative disc disorders.

Revised Cardiac Risk Index versus ASA Status as a Predictor for Noncardiac Events After Posterior Lumbar Decompression

BACKGROUND

The Revised Cardiac Risk Index (RCRI) was designed to predict risk for cardiac events after noncardiac surgery. However, there is a paucity of literature that directly addresses the relationship between RCRI and noncardiac outcomes after posterior lumbar decompression (PLD). The objective of this study is to determine the ability of RCRI to predict noncardiac adverse events after PLD.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program was used to identify patients undergoing PLD from 2006 to 2014. Multivariate and receiver operating characteristic analysis was used to identify associations between RCRI and postoperative complications.

RESULTS

A total of 52,066 patients met the inclusion criteria. Membership in the RCRI=1 cohort independently predicted unplanned intubation, ventilation >48 hours, progressive renal insufficiency, acute renal failure, urinary tract infection (UTI), sepsis, septic shock, and readmission. Membership in the RCRI=2 cohort independently predicted for superficial surgical site infection, pneumonia, unplanned intubation, ventilation >48 hours, bleeding transfusion, progressive renal insufficiency, acute renal failure, UTI, sepsis, septic shock, and readmission. Membership in the RCRI=3 cohort independently predicted unplanned intubation (odds ratio [OR], 11.8), ventilation >48 hours (OR, 23.0), acute renal failure (OR, 84.5), and UTI (OR, 3.6). RCRI had a poor discriminative ability (DA) (area under the curve = 0.623), and American Society of Anesthesiologists status had a fair DA (area under the curve = 0.770) to predict a composite of noncardiac complications.

CONCLUSIONS

RCRI was predictive of a wide range of noncardiac complications after PLD but had a diminished DA to predict a composite of any noncardiac complication than did American Society of Anesthesiologists score. Consideration of the RCRI as a component of preoperative surgical risk stratification can minimize patient morbidity and mortality after lumbar decompression.

Risk Factors for Lower Limb Deep Vein Thrombosis in Patients With Single-Level Lumbar Fusion: A Prospective Study of 710 Cases

Lower limb deep vein thrombosis (DVT) is not an uncommon postoperative complication of spinal fusion surgery. However, the related risk factors identified in previous studies remain controversial. This study aimed to investigate risk factors for lower limb DVT in patients with single-level lumbar fusion surgery. Between January 2010 and December 2016, a total of 710 patients undergoing lumbar fusion were recruited for this study, including 172 males and 538 females (aged 18-75 years). Deep vein thrombosis was detected by ultrasonography. Accordingly, patients were divided into the DVT group and the non-DVT group and compared in terms of operative data, underlying diseases, and biochemical data. Additionally, logistic regression analysis was performed to identify risk factors for lower limb DVT. The incidence of lower limb DVT was 11.8% (84 of 710 cases). Five patients were symptomatic, with lower limb pain and swelling. Two patients developed pulmonary embolism and 1 died. Binary logistic regression indicated that advanced age (P = .001, odds ratio [OR] = 2.86, 95% CI: 1.85-5.12), hypertension (P = .006, OR = 4.10, 95% CI: 1.09-2.30), and increased d-dimer (P < .001, OR = 3.49, 95% CI: 2.05-6.36) were risk factors for postoperative DVT. In conclusion, for patients with single-level lumbar fusion, advanced age, increased d-dimer, and hypertension may contribute to DVT development after spinal fusion surgery. Therefore, patients with these risk factors should be protected during the perioperative period.

Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Comparison Study Based on End Plate Subsidence and Cystic Change in Individuals Older and Younger than 65 Years

OBJECTIVE

To compare the outcomes between patients older and younger than 65 years who underwent single-level minimally invasive transforaminal interbody fusion (MI-TLIF) surgery.

METHODS

This study is a retrospective analysis of 76 patients who underwent MI-TLIF between April 2012 and June 2016. Group A consisted of 35 patients (<65 years) and group B consisted of 41 patients (≥65 years). Intraoperative data were recorded. The evaluation of clinical outcomes was based on the visual analog scale for back and leg pain and the Oswestry Disability Index. Radiologic outcomes including cage subsidence, end plate cyst formation, and fusion rate were assessed.

RESULTS

The mean age of the study subjects was 65.3 years, and the mean duration of follow-up was 18.98 months. Group B had a higher rate of comorbidities compared with group A (90.24% vs. 57.14%, respectively; P < 0.05). There was no statistically significant difference in the rate of complications between the groups (group A, 14.29%; group B, 17.07%). Clinical outcomes significantly improved in both groups postoperatively (P < 0.05). Although bony fusion in group A was slightly higher than that in group B, the fusion rate was not statistically different according to age. There were no statistically significant differences in the rates of cage subsidence or positive cyst sign between the groups.

CONCLUSIONS

MI-TLIF presented similar safeness and acceptable outcomes and complication rate in both groups. Cyst formation may be aggravated by cage subsidence, because cage subsidence was a useful potential predictor of cyst formation.