Increasing Rates of Surgical Management of Multilevel Spinal Curvature in Elderly Patients

Posterior Column Reconstruction of the Lumbar Spine Using En Bloc Resected Vertebral Arch in Spinal Tumor and Deformity Surgeries

Introduction

In high-grade spinal osteotomy involving large anterior column resection, restoration of the structural integrity of the posterior column at the osteotomy site can reduce postoperative instrumentation failure (IF). This study aimed to describe our technique of posterior strut bone grafting using an en bloc resected vertebral arch, which is useful for posterior column reconstruction after high-grade osteotomies during surgeries for spinal tumor and deformity in the lower lumbar spine.

Technical Note

Using a posterior approach, en bloc resection of the targeted vertebral arch was performed in accordance with the surgical technique for total en bloc spondylectomy (TES). The posterior elements in the upper and lower adjacent vertebrae were separated by a significant space after vertebral body resection followed by cage insertion in TES or anterior column osteotomy followed by correction in deformity surgery. To create a new posterior column, the en bloc resected vertebral arch was placed at 90° rotation to bridge the upper and lower vertebral arches. Using this technique, an abundant amount of bone chips made from the resected vertebral elements were placed over the en bloc resected posterior arch as an additional bone graft. The technique was used in three patients who underwent TES for spinal tumors and in one patient who underwent grade 4 osteotomy for adult spinal deformity in the lower lumbar spine. One year after surgery, computed tomography showed that the structural integrity of bony fusion was successfully achieved between the en bloc resected arch and the posterior elements of the adjacent vertebrae in all patients and showed no postoperative IFs.

Conclusions

This bone graft technique created new continuity of the posterior column after high-grade osteotomies in the lower lumbar spine. Bone fusion was achieved in the posterior elements to prevent IF after surgery.

5-Year Revision Rates After Elective Multilevel Lumbar/Thoracolumbar Instrumented Fusions in Older Patients: An Analysis of State Databases

OBJECTIVE

The purpose of this study wasto evaluate cause-specific 5-year revision rates and risk factors for revision after elective multilevel lumbar instrumented fusion in older patients.

METHODS

Older patients (>60 years) who underwent elective multilevel (3+) lumbar instrumented fusions were identified in Healthcare Cost and Utilization Project state inpatient databases and followed for 5 years for revision operations because of mechanical failure, degenerative disease (DD), infection, postlaminectomy syndrome, and stenosis. Cox proportional hazards multivariate analyses were conducted to determine risk factors associated with revision for each diagnostic cause.

RESULTS

The cohort included 5,636 patients (female-3,285; average age-71.6 years). Most of the operations were 3 to 7 levels (97.4%), and the mean length of stay was 5.4 days. The overall 5-year revision rate was 16.5% with predominant etiologies of DD (50.7%), mechanical failure (32.2%), and stenosis (8.0%). The revision procedure at the index operation was associated with an increased revision risk for DD (hazards ratio [HR] = 1.59, 95% confidence interval [CI], 1.29 to 1.98, P < 0.001) and mechanical failure (HR = 1.56, 95% CI, 1.19 to 2.04, P = 0.020). Male sex was associated with a significantly reduced revision risk for DD (HR = 0.75, 95% CI, 0.62 to 0.91, P = 0.04). Age, race, and number of comorbidities had no notable effect on the overall or cause-specific risk of revision.

DISCUSSION

In this large database analysis, DD and mechanical failure were the most common etiologies comprising a 5-year revision rate of 16.5% after elective multilevel lumbar instrumented fusion in older patients. Revision operations and female patients carried the strongest risks for revision.

Preoperative Polypharmacy in Geriatric Patients is Associated with Increased 90-Day All-Cause Hospital Readmission After Surgery for Adult Spinal Deformity Patients

OBJECTIVE

To investigate the effect of preoperative polypharmacy (PP) on 90-day all-cause readmission rate in older adults undergoing corrective surgery for ASD.

METHODS

Older adults with a diagnosis of ASD undergoing spinal surgery at a quaternary medical center from January 2016 to March 2019 were enrolled in this study. Patients were dichotomized into two groups stratified by the number of preoperative prescription medications; with PP defined as 5 or more prescription medications. The primary outcome measure was 90-day all-cause readmission rate. Secondary outcomes included postoperative changes in health-related quality of life measures.

RESULTS

Among 161 patients (mean [SD], 69.59[8.79] years), 97 patients were included in PP cohort and 64 in non-polypharmacy (non-PP) cohort. Both groups were balanced at baseline. The duration of hospital (5.82[1.93] vs. 6.50[4.00] days), mean number of fusion levels, and duration of surgery was statistically similar between both groups (p>0.05). There was no difference in the proportion of patients discharged directly home (31.25% vs. 40.42%, p=0.36). 90-day all-cause readmission rate was 3-fold higher in the PP cohort compared with the non-PP cohort. After adjusting for preoperative patient optimization, ASA grade, surgical invasiveness, smoking, depression and baseline functional disability, older adults with PP had a 9.79 increased odds of 90-day all-cause hospital readmission (p=0.04). Change in HRQOL measures were similar between both groups.

CONCLUSION

This study's findings indicate that despite preoperative optimization, older adults exposed to polypharmacy are at a significantly increased risk of hospital readmission within 90-days of surgery.

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.

Long-length tomosynthesis and 3D-2D registration for intraoperative assessment of spine instrumentation

PURPOSE

A system for long-length intraoperative imaging is reported based on longitudinal motion of an O-arm gantry featuring a multi-slot collimator. We assess the utility of long-length tomosynthesis and the geometric accuracy of 3D image registration for surgical guidance and evaluation of long spinal constructs.

METHODS

A multi-slot collimator with tilted apertures was integrated into an O-arm system for long-length imaging. The multi-slot projective geometry leads to slight view disparity in both long-length projection images (referred to as 'line scans') and tomosynthesis 'slot reconstructions' produced using a weighted-backprojection method. The radiation dose for long-length imaging was measured, and the utility of long-length, intraoperative tomosynthesis was evaluated in phantom and cadaver studies. Leveraging the depth resolution provided by parallax views, an algorithm for 3D-2D registration of the patient and surgical devices was adapted for registration with line scans and slot reconstructions. Registration performance using single-plane or dual-plane long-length images was evaluated and compared to registration accuracy achieved using standard dual-plane radiographs.

RESULTS

Longitudinal coverage of ∼50-64 cm was achieved with a single long-length slot scan, providing a field-of-view (FOV) up to (40 × 64) cm², depending on patient positioning. The dose-area product (reference point air kerma × x-ray field area) for a slot scan ranged from ∼702-1757 mGy·cm², equivalent to ∼2.5 s of fluoroscopy and comparable to other long-length imaging systems. Long-length scanning produced high-resolution tomosynthesis reconstructions, covering ∼12-16 vertebral levels. 3D image registration using dual-plane slot reconstructions achieved median target registration error (TRE) of 1.2 mm and 0.6° in cadaver studies, outperforming registration to dual-plane line scans (TRE = 2.8 mm and 2.2°) and radiographs (TRE = 2.5 mm and 1.1°). 3D registration using single-plane slot reconstructions leveraged the ∼7-14° angular separation between slots to achieve median TRE ∼2 mm and <2° from a single scan.

CONCLUSION

The multi-slot configuration provided intraoperative visualization of long spine segments, facilitating target localization, assessment of global spinal alignment, and evaluation of long surgical constructs. 3D-2D registration to long-length tomosynthesis reconstructions yielded a promising means of guidance and verification with accuracy exceeding that of 3D-2D registration to conventional radiographs.

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.

Enhanced perioperative care and decreased cost and length of stay after elective major spinal surgery

OBJECTIVEThe purpose of this study was to compare total cost and length of stay (LOS) between spine surgery patients enrolled in an enhanced perioperative care (EPOC) pathway and patients receiving traditional perioperative care (TRDC).METHODSAll spine surgery candidates were screened for inclusion in the EPOC pathway. This cohort was compared to a retrospective cohort of patients who received TRDC and a concurrent group of patients who met inclusion criteria but did not receive the EPOC (no pathway care [NOPC] group). Direct and indirect costs as well as hospital and intensive care LOSs were analyzed between the 3 groups.RESULTSTotal costs after pathway implementation decreased by $19,344 in EPOC patients compared to a historical cohort of patients who received TRDC and $5889 in a concurrent cohort of patients who did not receive EPOC (NOPC group). Hospital and intensive care LOS were significantly lower in EPOC patients compared to TRDC and NOPC patients.CONCLUSIONSThe implementation of a multimodal EPOC pathway decreased LOS and cost in major elective spine surgeries.

Outcomes and Quality of Life Improvement After Multilevel Spinal Fusion in Elderly Patients

STUDY DESIGN

Retrospective case series.

OBJECTIVES

Both the rate and complexity of spine surgeries in elderly patients has increased. This study reports the outcomes of multilevel spine fusion in elderly patients and provides evidence on the appropriateness of complex surgery in elderly patients.

METHODS

We identified 101 patients older than70 years who had ≥5 levels of fusion. Demographic, medical, and surgical data, and change between preoperative and >500 days postoperative health survey scores were collected. Health surveys were visual analogue scale (VAS), EuroQoL 5 Dimensions (EQ-5D), Oswestry Disability Index (ODI), Scoliosis Research Society questionnaire (SRS-30), and Short Form health survey (SF-12) (physical composite score [PCS] and mental composite score [MCS]). Minimal clinically important differences (MCIDs) were defined for each survey.

RESULTS

Complications included dural tears (19%), intensive care unit admission (48%), revision surgery within 2 to 5 years (24%), and death within 2 to 5 years (16%). The percentage of patients who reported an improvement in health-related quality of life (HRQOL) of at least an MCID was: VAS Back 69%; EQ-5D 41%; ODI 58%; SRS-30 45%; SF-12 PCS 44%; and SF-12 MCS 48%. Improvement after a primary surgery, as compared with a revision, was on average 13 points higher in ODI (P = .007). Patients who developed a surgical complication averaged an improvement 11 points lower on ODI (P = .042). Patients were more likely to find improvement in their health if they had a lower American Society of Anesthesiologists or Charlson Comorbidity Index score or a higher metabolic equivalent score.

CONCLUSIONS

In multilevel surgery in patients older than 70 years, complications are common, and on average 77% of patients attain some improvement, with 51% reaching an MCID. Physiological status is a stronger predictor of outcomes than chronological age.

Evolution in Surgical Approach, Complications, and Outcomes in an Adult Spinal Deformity Surgery Multicenter Study Group Patient Population

STUDY DESIGN

Retrospective review of a prospectively collected multicenter database.

OBJECTIVES

To evaluate the evolution of surgical treatment strategies, complications, and patient-reported outcomes for adult spinal deformity (ASD) patients.

SUMMARY OF BACKGROUND DATA

ASD surgery is associated with high complication rates. Evolving treatment strategies may reduce these risks.

METHODS

Adult patients undergoing ASD surgery from 2009 to 2016 were analyzed (n = 905). Preoperative and surgical parameters were compared across years. Subgroup analysis of 436 patients with minimum two-year follow-up was also performed.

RESULTS

From 2009 to 2016, there was a significant increase in the mean preoperative age (52 to 63.1, p < .001), body mass index (26.3 to 32.2, p = .003), Charlson Comorbidity index (1.4 to 2.2, p < .001), rate of previous spine surgery (39.8% to 53.1%, p = .01), and baseline disability (visual analog scale [VAS] back and leg pain) scores (p < .01), Oswestry Disability Index, and 22-item Scoliosis Research Society Questionnaire scores (p < .001). Preoperative Schwab sagittal alignment modifiers and overall surgical invasiveness index were similar across time. Three-column osteotomy utilization decreased from 36% in 2011 to 16.7% in 2016. Lateral lumbar interbody fusion increased from 6.4% to 24.1% (p = .004), anterior lumbar interbody fusion decreased from 22.9% to 16.7% (p = .043), and transforaminal lumbar interbody fusion/posterior lumbar interbody fusion utilization remained similar (p = .448). Use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in 2012 was 84.6%, declined to 58% in 2013, and rebounded to 76.3% in 2016 (p = .006). Tranexamic acid use increased rapidly from 2009 to 2016 (13.3% to 48.6%, p < .001). Two-year follow-up sagittal vertical axis, pelvic tilt, pelvic incidence-lumbar lordosis, and maximum Cobb angles were similar across years. Intraoperative complications decreased from 33% in 2010 to 9.3% in 2016 (p < .001). Perioperative (<30 days, <90 days) complications peaked in 2010 (42.7%, 46%) and decreased by 2016 (24.1%, p < .001; 29.6%, p = .007). The overall complication rate decreased from 73.2% in 2008-2014 patients to 62.6% in 2015-2016 patients (p = .03). Two-year health-related quality of life outcomes did not significantly differ across the years (p > .05).

CONCLUSIONS

From 2009 to 2016, despite an increasingly elderly, medically compromised, and obese patient population, complication rates decreased. Evolving strategies may result in improved treatment of ASD patients.

LEVEL OF EVIDENCE

Level IV.

Elective lumbar fusion in the United States: national trends in inpatient complications and cost from 2002-2014

BACKGROUND

Elective fusions for degenerative spine disease have increased over the past two decades in the United States, with variability in complications and hospital costs. The additional service costs associated with adverse perioperative events remain unknown. Our objective is to improve understanding of trends in safety and cost of elective lumbar fusions on a national scale.

METHODS

A weighted sample of 1,526,386 adults undergoing elective lumbar fusion for degenerative indications were identified in the National Inpatient Sample (NIS) years 2002-2014. Twelve categories of major complications by system, and patient/hospital variables, were evaluated as predictors of the overall reimbursed cost. Mean differences (B) and 95% confidence intervals [95% CI] are reported. Significance is assessed at p<0.001.

RESULTS

Nineteen percent of patients experienced inpatient complication. After adjusting for inflation, the mean overall cost was $32802±19557. Costs increased with presence of each of the 12 categories of complications, and by number of levels fused. Rates of most frequent complications and their adjusted cost-of-care were acute postoperative anemia (11.2%, B=$1817 [$1722-$1913], p<0.001), renal/urinary (1.9%, B=$510 [$288-$732], p<0.001), pulmonary (1.8%, B=$6014 [$5785-6243], p<0.001) and gastrointestinal (1.8%, B=$3699 [$3490-$3908, p<0.001). The costliest adverse events were infection (B=$15882 [$15424-$16339], p<0.001), thromboembolism (B=$8856 [$8400-$9311], p<0.001), hematoma/seroma/vascular (B=$8050 [$7784-$8316], p<0.001).

CONCLUSIONS

The number of elective lumbar fusions for degenerative spine disease increased 276% in the United States from 2002-2014 with growing surgeon preference for lateral techniques, and an increasing proportion of combined anterior and posterior approaches. Overall complication rates decreased from 2002-2014, despite an older patient population. After adjusting for inflation, cost was relatively stable across years 2002-2014. Complications by system were associated with increased cost, underscoring the need to address sources of complications and optimize early postoperative recovery in order to reduce healthcare expenditure.

Postoperative Radiographic Evaluation Following Adult Spine Deformity Correction: The Impact on Subsequent Management and Associated Risk of Radiation Exposure

BACKGROUND

During the follow-up visits after Adult Spine Deformity (ASD) surgery, obtaining surveillance radiographs is a usual practice, and this study tried to identify evidence to support or refute such practice.

METHODS

This is a retrospective, diagnostic case series (Level IV) of 49 patients. We identified the abnormal radiographic findings and their association with need for revision surgery. We determined the odds of obtaining an abnormal radiographs that lead to revision surgery at each of the given time intervals of follow-up. We also estimated the risk versus benefit of obtaining radiographs at each of the given time intervals of follow-up.

RESULTS

We identified a total of 11 individual types of abnormal postoperative radiographic findings. Of them, the two radiographic findings that always needed revision surgery because of the associated clinical presentation were pedicle screw pullout and bilateral rod fracture. One abnormal radiographic finding that was never associated with revision surgery was the halo around a pedicle screw. In each of the given postoperative time intervals of follow-up at which the routine radiographs were obtained, we noted that the odds of noticing abnormal radiographic finding that lead to revision surgery was always >1. We found that the cumulative hazard rate for exposure to radiation was significantly higher during the initial follow-up visits when compared to subsequent follow-up visits.

CONCLUSION

This study finds evidence to support the practice of routine postoperative radiographic evaluation of patients who come for follow-up after ASD surgery.

The Effectiveness of Full-body EOS Compared With Conventional Chest X-ray in Preoperative Evaluation of the Chest for Patients Undergoing Spine Operations: A Preliminary Study

STUDY DESIGN

A prospective radiographic comparative study.

OBJECTIVE

The aim of this study was to compare full-body EOS with conventional chest X-ray (CXR) for use in the preoperative evaluation of the chest in patients undergoing spine operations.

SUMMARY OF BACKGROUND DATA

The full-body EOS reproduces an image of the chest similar to a routine CXR. The potential for the former replacing the latter is plausible. This is especially applicable in spine patients who would routinely have a preoperative full-body EOS performed.

METHODS

A radiographic comparative study of 266 patients was conducted at a single tertiary center from January 2013 to July 2016. Each patient had EOS and CXR done in random order <2 weeks apart. Two radiologists reported the image findings using a checklist. A third radiologist was consulted in cases of discrepancy. Interobserver agreement was calculated using Gwet AC1 and a comparison between EOS and CXR findings was analyzed using paired Chi-squared test. Multivariate analysis was performed to identify predictors for abnormal radiological findings. The institutional ethics committee approved this prospective study and waiver of informed consent was obtained.

RESULTS

There were 84 males (31.6%) and 182 females (68.4%). The mean age was 38.9 years (SD = 25.0 years). High interobserver agreement was found for EOS and CXR (Gwet AC1 0.993 and 0.988, respectively). There were no significant differences between both imaging modalities. Rare diagnoses precluded comparison of certain conditions. Age >18 years [odds ratio (OR) 7.69; P = 0.009] and American Society of Anesthesiologists physical status 3 (OR 6.64; P = 0.018) were independent predictors of abnormal radiological findings.

CONCLUSION

EOS is not inferior to, and may be used to replace CXR in preoperative radiological screening of thoracic conditions especially in low-risk patients ≤18 years old and patients with ASA <3. Preoperative assessment should never rely on a single modality. High-risk patients should be sent for a thorough work-up before spine surgery.

LEVEL OF EVIDENCE

4.

Surgeon Reimbursement Relative to Hospital Payments for Spinal Fusion: Trends From 10-year Medicare Analysis

STUDY DESIGN

Retrospective, economic analysis.

OBJECTIVE

The aim of this study was to analyze the trend in hospital charge and payment adjusted to corresponding surgeon charge and payment for cervical and lumbar fusions in a Medicare sample population from 2005 to 2014.

SUMMARY OF BACKGROUND DATA

Previous studies have reported trends and variation in hospital charges and payments for spinal fusion, but none have incorporated surgeon data in analysis. Knowledge of the fiscal relationship between hospitals and surgeons over time will be important for stakeholders as we move toward bundled payments.

METHODS

A 5% Medicare sample was used to capture hospital and surgeon charges and payments related to cervical and lumbar fusion for degenerative disease between 2005 and 2014. We defined hospital charge multiplier (CM) as the ratio of hospital/surgeon charge. Similarly, the hospital/surgeon payment ratio was defined as hospital payment multiplier (PM). The year-wise and regional trend in patient profile, length of stay, discharge disposition, CM, and PM were studied for all fusion approaches separately.

RESULTS

A total of 40,965 patients, stratified as 15,854 cervical and 25,111 lumbar fusions, were included. The hospital had successively higher charges and payments relative to the surgeon from 2005 to 2014 for all fusions with an inverse relation to hospital length of stay. Increasing complexity of fusion such as for anterior-posterior cervical fusion had higher hospital reimbursements per dollar earned by the surgeon. There was regional variation in how much the hospital charged and received per surgeon dollar.

CONCLUSION

Hospital charge and payment relative to surgeon had an increasing trend despite a decreasing length of stay for all fusions. Although the hospital can receive higher payments for higher-risk patients, this risk is not reflected proportionally in surgeon payments. The shift toward value-based care with shared responsibility for outcomes and cost will likely rely on better aligning incentives between hospital and providers.

LEVEL OF EVIDENCE

3.