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Pavitra Ravishankar, Edward Barksdale III, Robert D. Winkelman, Michael D. Kavanaugh, Dominic W. Pelle, Edward C. Benzel, Thomas E. Mroz, and Michael P. Steinmetz
Sameer A. Kitab, Andrew E. Wakefield, and Edward C. Benzel
OBJECTIVE
Roussouly lumbopelvic sagittal profiles are associated with distinct pathologies or distinct natural histories and prognoses. The associations between developmental lumbar spinal stenosis (DLSS) and native lumbopelvic sagittal profiles are unknown. Moreover, the relative effects of multilevel decompression on lumbar sagittal alignment, geometrical parameters of the pelvis, and compensatory mechanisms for each of the Roussouly subtypes are unknown. This study aimed to explore the association between DLSS and native lumbar lordosis (LL) subtypes. It also attempts to understand the natural history of postlaminectomy lumbopelvic sagittal changes and compensatory mechanisms for each of the Roussouly subtypes and to define the critical lumbar segment or specific lordosis arc that is recruited after relief of the stenosis effect.
METHODS
A total of 418 patients with multilevel DLSS were grouped into various Roussouly subtypes, and lumbopelvic sagittal parameters were prospectively compared at follow-up intervals of preoperative to < 2 years, 2 to < 5 years, and 5 to ≥ 10 years after laminectomy. The variables analyzed included LL, upper lordosis arc from L1 to L4, lower lordosis arc from L4 to S1, and segmental lordosis from L1 to S1. Pelvic parameters included pelvic incidence, sacral slope, pelvic tilt, and pelvic incidence minus LL values.
RESULTS
Of the 329 patients who were followed up throughout this study, 33.7% had Roussouly type 1 native lordosis, whereas the incidence rates of types 2, 3, and 4 were 33.4%, 21.9%, and 10.9%, respectively. LL was not reduced in any of the Roussouly subtypes after multilevel decompressions. Instead, LL increased by 4.5° (SD 11.9°—from 27.3° [SD 11.5°] to 31.8° [SD 9.8°]) in Roussouly type 1 and by 3.1° (SD 11.6°—from 41.3° [SD 9.5°] to 44.4° [SD = 9.7°]) in Roussouly type 2. The other Roussouly types showed no significant changes. Pelvic tilt decreased significantly—by 2.8°, whereas sacral slope increased significantly—by 2.9° in Roussouly type 1 and by 1.7° in Roussouly type 2. The critical lumbar segment that recruits LL differs between Roussouly subtypes. Increments and changes were sustained until the final follow-up.
CONCLUSIONS
The study findings are important in predicting patient prognosis, LL evolution, and the need for prophylactic or corrective deformity surgery. Multilevel involvement in DLSS and the high prevalence of Roussouly types 1 and 2 suggest that spinal canal dimensions are closely linked to the developmental evolution of LL.
Pranay Soni, Jeremy G. Loss, Callan M. Gillespie, Robb W. Colbrunn, Richard Schlenk, Michael P. Steinmetz, Pablo F. Recinos, Edward C. Benzel, and Varun R. Kshettry
OBJECTIVE
The direct lateral approach is an alternative to the transoral or endonasal approaches to ventral epidural lesions at the lower craniocervical junction. In this study, the authors performed, to their knowledge, the first in vitro biomechanical evaluation of the craniovertebral junction after sequential unilateral C1 lateral mass resection. The authors hypothesized that partial resection of the lateral mass would not result in a significant increase in range of motion (ROM) and may not require internal stabilization.
METHODS
The authors performed multidirectional in vitro ROM testing using a robotic spine testing system on 8 fresh cadaveric specimens. We evaluated ROM in 3 primary movements (axial rotation [AR], flexion/extension [FE], and lateral bending [LB]) and 4 coupled movements (AR+E, AR+F, LB + left AR, and LB + right AR). Testing was performed in the intact state, after C1 hemilaminectomy, and after sequential 25%, 50%, 75%, and 100% C1 lateral mass resection.
RESULTS
There were no significant increases in occipital bone (Oc)–C1, C1–2, or Oc–C2 ROM after C1 hemilaminectomy and 25% lateral mass resection. After 50% resection, Oc–C1 AR ROM increased by 54.4% (p = 0.002), Oc LB ROM increased by 47.8% (p = 0.010), and Oc–C1 AR+E ROM increased by 65.8% (p < 0.001). Oc–C2 FE ROM increased by 7.2% (p = 0.016) after 50% resection; 75% and 100% lateral mass resection resulted in further increases in ROM.
CONCLUSIONS
In this cadaveric biomechanical study, the authors found that unilateral C1 hemilaminectomy and 25% resection of the C1 lateral mass did not result in significant biomechanical instability at the occipitocervical junction, and 50% resection led to significant increases in Oc–C2 ROM. This is the first biomechanical study of lateral mass resection, and future studies can serve to validate these findings.
Pranay Soni, Jeremy G. Loss, Callan M. Gillespie, Robb W. Colbrunn, Richard Schlenk, Michael P. Steinmetz, Pablo F. Recinos, Edward C. Benzel, and Varun R. Kshettry
OBJECTIVE
The direct lateral approach is an alternative to the transoral or endonasal approaches to ventral epidural lesions at the lower craniocervical junction. In this study, the authors performed, to their knowledge, the first in vitro biomechanical evaluation of the craniovertebral junction after sequential unilateral C1 lateral mass resection. The authors hypothesized that partial resection of the lateral mass would not result in a significant increase in range of motion (ROM) and may not require internal stabilization.
METHODS
The authors performed multidirectional in vitro ROM testing using a robotic spine testing system on 8 fresh cadaveric specimens. We evaluated ROM in 3 primary movements (axial rotation [AR], flexion/extension [FE], and lateral bending [LB]) and 4 coupled movements (AR+E, AR+F, LB + left AR, and LB + right AR). Testing was performed in the intact state, after C1 hemilaminectomy, and after sequential 25%, 50%, 75%, and 100% C1 lateral mass resection.
RESULTS
There were no significant increases in occipital bone (Oc)–C1, C1–2, or Oc–C2 ROM after C1 hemilaminectomy and 25% lateral mass resection. After 50% resection, Oc–C1 AR ROM increased by 54.4% (p = 0.002), Oc LB ROM increased by 47.8% (p = 0.010), and Oc–C1 AR+E ROM increased by 65.8% (p < 0.001). Oc–C2 FE ROM increased by 7.2% (p = 0.016) after 50% resection; 75% and 100% lateral mass resection resulted in further increases in ROM.
CONCLUSIONS
In this cadaveric biomechanical study, the authors found that unilateral C1 hemilaminectomy and 25% resection of the C1 lateral mass did not result in significant biomechanical instability at the occipitocervical junction, and 50% resection led to significant increases in Oc–C2 ROM. This is the first biomechanical study of lateral mass resection, and future studies can serve to validate these findings.
Robert D. Winkelman, Michael D. Kavanagh, Joseph E. Tanenbaum, Dominic W. Pelle, Edward C. Benzel, Thomas E. Mroz, and Michael P. Steinmetz
OBJECTIVE
On August 31, 2017, the state of Ohio implemented legislation limiting the dosage and duration of opioid prescriptions. Despite the widespread adoption of such restrictions, few studies have investigated the effects of these reforms on opioid prescribing and patient outcomes. In the present study, the authors aimed to evaluate the effect of recent state-level reform on opioid prescribing, patient-reported outcomes (PROs), and postoperative emergency department (ED) visits and hospital readmissions after elective lumbar decompression surgery.
METHODS
This study was a retrospective cohort study of patients who underwent elective lumbar laminectomy for degenerative disease at one of 5 hospitals within a single health system in the years prior to and after the implementation of the statewide reform (September 1, 2016–August 31, 2018). Patients were classified according to the timing of their surgery relative to implementation of the prescribing reform: before reform (September 1, 2016–August 31, 2017) or after reform (September 1, 2017– August 31, 2018). The outcomes of interest included total outpatient opioids prescribed in the 90 days following discharge from surgery as measured in morphine-equivalent doses (MEDs), total number of opioid refill prescriptions written, patient-reported pain at the first postoperative outpatient visit as measured by the Numeric Pain Rating Scale, improvement in patient-reported health-related quality of life as measured by the Patient-Reported Outcomes Measurement Information System–Global Health (PROMIS-GH) questionnaire, and ED visits or hospital readmissions within 90 days of surgery.
RESULTS
A total of 1031 patients met the inclusion criteria for the study, with 469 and 562 in the before- and after-reform groups, respectively. After-reform patients received 26% (95% CI 19%–32%) fewer MEDs in the 90 days following discharge compared with the before-reform patients. No significant differences were observed in the overall number of opioid prescriptions written, PROs, or postoperative ED or hospital readmissions within 90 days in the year after the implementation of the prescribing reform.
CONCLUSIONS
Patients undergoing surgery in the year after the implementation of a state-level opioid prescribing reform received significantly fewer MEDs while reporting no change in the total number of opioid prescriptions, PROs, or postoperative ED visits or hospital readmissions. These results demonstrate that state-level reforms placing reasonable limits on opioid prescriptions written for acute pain may decrease patient opioid exposure without negatively impacting patient outcomes after lumbar decompression surgery.
Daniel Lubelski, James Feghali, Amy S. Nowacki, Vincent J. Alentado, Ryan Planchard, Kalil G. Abdullah, Daniel M. Sciubba, Michael P. Steinmetz, Edward C. Benzel, and Thomas E. Mroz
OBJECTIVE
Patient demographics, comorbidities, and baseline quality of life (QOL) are major contributors to postoperative outcomes. The frequency and cost of lumbar spine surgery has been increasing, with controversy revolving around optimal management strategies and outcome predictors. The goal of this study was to generate predictive nomograms and a clinical calculator for postoperative clinical and QOL outcomes following lumbar spine surgery for degenerative disease.
METHODS
Patients undergoing lumbar spine surgery for degenerative disease at a single tertiary care institution between June 2009 and December 2012 were retrospectively reviewed. Nomograms and an online calculator were modeled based on patient demographics, comorbidities, presenting symptoms and duration of symptoms, indication for surgery, type and levels of surgery, and baseline preoperative QOL scores. Outcomes included postoperative emergency department (ED) visit or readmission within 30 days, reoperation within 90 days, and 1-year changes in the EuroQOL-5D (EQ-5D) score. Bootstrapping was used for internal validation.
RESULTS
A total of 2996 lumbar surgeries were identified. Thirty-day ED visits were seen in 7%, 30-day readmission in 12%, 90-day reoperation in 3%, and improvement in EQ-5D at 1 year that exceeded the minimum clinically important difference in 56%. Concordance indices for the models predicting ED visits, readmission, reoperation, and dichotomous 1-year improvement in EQ-5D were 0.63, 0.66, 0.73, and 0.84, respectively. Important predictors of clinical outcomes included age, body mass index, Charlson Comorbidity Index, indication for surgery, preoperative duration of symptoms, and the type (and number of levels) of surgery. A web-based calculator was created, which can be accessed here: https://riskcalc.org/PatientsEligibleForLumbarSpineSurgery/.
CONCLUSIONS
The prediction tools derived from this study constitute important adjuncts to clinical decision-making that can offer patients undergoing lumbar spine surgery realistic and personalized expectations of postoperative outcome. They may also aid physicians in surgical planning, referrals, and counseling to ultimately lead to improved patient experience and outcomes.
Rupesh Kotecha, Martin C. Tom, Mihir Naik, Lilyana Angelov, Edward C. Benzel, Chandana A. Reddy, Richard A. Prayson, Iain Kalfas, Richard Schlenk, Ajit Krishnaney, Michael P. Steinmetz, William Bingaman, John H. Suh, and Samuel T. Chao
OBJECTIVE
The authors sought to describe the long-term recurrence patterns, prognostic factors, and effect of adjuvant or salvage radiotherapy (RT) on treatment outcomes for patients with spinal myxopapillary ependymoma (MPE).
METHODS
The authors reviewed a tertiary institution IRB-approved database and collected data regarding patient, tumor, and treatment characteristics for all patients treated consecutively from 1974 to 2015 for histologically confirmed spinal MPE. Key outcomes included relapse-free survival (RFS), postrecurrence RFS, failure patterns, and influence of timing of RT on recurrence patterns. Cox proportional hazards regression and Kaplan-Meier analyses were utilized.
RESULTS
Of the 59 patients included in the study, the median age at initial surgery was 34 years (range 12–74 years), 30 patients (51%) were female, and the most common presenting symptom was pain (n = 52, 88%). Extent of resection at diagnosis was gross-total resection (GTR) in 39 patients (66%), subtotal resection (STR) in 15 (25%), and unknown in 5 patients (9%). After surgery, 10 patients (17%) underwent adjuvant RT (5/39 GTR [13%] and 5/15 STR [33%] patients). Median follow-up was 6.2 years (range 0.1–35.3 years). Overall, 20 patients (34%) experienced recurrence (local, n = 15; distant, n = 5). The median RFS was 11.2 years (95% CI 77 to not reached), and the 5- and 10-year RFS rates were 72.3% (95% CI 59.4–86.3) and 54.0% (95% CI, 36.4–71.6), respectively.
STR was associated with a higher risk of recurrence (HR 6.45, 95% CI 2.15–19.23, p < 0.001) than GTR, and the median RFS after GTR was 17.2 years versus 5.5 years after STR. Adjuvant RT was not associated with improved RFS, regardless of whether it was delivered after GTR or STR. Of the 20 patients with recurrence, 12 (60%) underwent salvage treatment with surgery alone (GTR, n = 6), 4 (20%) with RT alone, and 4 (20%) with surgery and RT. Compared to salvage surgery alone, salvage RT, with or without surgery, was associated with a significantly longer postrecurrence RFS (median 9.5 years vs 1.6 years; log-rank, p = 0.006).
CONCLUSIONS
At initial diagnosis of spinal MPE, GTR is key to long-term RFS, with no benefit to immediate adjuvant RT observed in this series. RT at the time of recurrence, however, is associated with a significantly longer time to second disease recurrence. Surveillance imaging of the entire neuraxis remains crucial, as distant failure is not uncommon in this patient population.
Ghaith Habboub, Matthew M. Grabowski, Michael L. Kelly, and Edward C. Benzel
Philina Yee, Joseph E. Tanenbaum, Dominic W. Pelle, Don Moore, Edward C. Benzel, Michael P. Steinmetz, and Thomas E. Mroz
OBJECTIVE
Under the Bundled Payments for Care Improvement (BPCI) initiative, Medicare reimburses for lumbar fusion without adjusting for underlying pathology. However, lumbar fusion is a widely used technique that can treat both degenerative and traumatic pathologies. In other surgical cohorts, significant heterogeneity exists in resource use when comparing procedures for traumatic versus degenerative pathologies. If the same were true for lumbar fusion, BPCI would create a financial disincentive to treat specific patient populations. The goal of this study was to compare hospital resource use for lumbar fusion between 2 patient populations: patients with spondylolisthesis and patients with lumbar vertebral fracture.
METHODS
The authors compared the hospital resource use of two lumbar fusion cohorts that BPCI groups into the same payment bundle for lumbar fusion: patients with spondylolisthesis and patients with lumbar vertebral fracture. National Inpatient Sample data from 2013 were queried for patients who underwent lumbar fusion for lumbar vertebral fracture or spondylolisthesis. Hospital resource use was measured using length of stay (LOS), direct hospital costs, and odds of discharge to a post-acute care facility and compared using multivariable linear and logistic regression. All models adjusted for patient demographics, 29 comorbidities, and hospital characteristics.
RESULTS
After adjusting for patient demographics, insurance status, hospital characteristics, and 29 comorbidities, spondylolisthesis patients had a mean LOS that was 36% shorter (95% CI 26%–44%, p < 0.0001), a mean cost that was 13% less (95% CI 3.7%–21%, p < 0.0001), and 3.2 times greater odds of being discharged home (95% CI 2.5–5.4, p < 0.0001) than lumbar vertebral fracture patients.
CONCLUSIONS
Under the proposed DRG (diagnosis-related group)–based BPCI, hospitals would be reimbursed the same amount for lumbar fusion regardless of the diagnosis. However, compared with fusion for spondylolisthesis, fusion for lumbar vertebral fracture was associated with longer LOS, greater direct hospital costs, and increased likelihood of being discharged to a post-acute care facility. These findings suggest that the BPCI episode of care for lumbar fusion dis-incentivizes treatment of trauma patients.
Jaes C. Jones, Jacob A. Miller, Dattanand M. Sudarshana, Nicolas R. Thompson, Edward C. Benzel, and Thomas E. Mroz
OBJECTIVE
In 2009, 2 randomized controlled trials demonstrated no improvement in pain following vertebral augmentation compared with sham surgery. However, a recent randomized trial demonstrated significant pain relief in patients following vertebroplasty compared to controls treated with conservative medical management. This study is a retrospective review of prospectively collected patient-reported quality of life (QOL) outcomes. The authors hypothesized that vertebral augmentation procedures offer a QOL benefit, but that this benefit would be diminished in patients with a history of depression and/or in patients undergoing vertebral augmentation at more than 1 level.
METHODS
Multivariable linear regression was used to identify predictors of postoperative pain assessed using the Pain Disability Questionnaire (PDQ), Patient Health Questionnaire 9 (PHQ-9), and EQ-5D scores. Eleven candidate predictors were selected a priori: age, sex, smoking history, coronary artery disease, depression, diabetes, procedure location (thoracic, lumbar), BMI, prior spine surgery, procedure indication (metastases, osteoporosis/osteopenia, other), and number of levels (1, 2, 3, or more).
RESULTS
A total of 143 patients were included in the study. For each 10-year increase in age, postoperative PDQ scores decreased (improved) by 9.7 points (p < 0.001). Patients with osteoporosis/osteopenia had significantly higher (worse) postoperative PDQ scores (+17.97, p = 0.028) than patients with metastatic lesions. Male sex was associated with higher (worse) postoperative PHQ-9 scores (+2.48, p = 0.010). Compared to single-level augmentation, operations at 2 levels were associated with significantly higher PHQ-9 scores (+2.58, p = 0.017). Current smokers had significantly lower PHQ-9 scores (−1.98, p = 0.023) than never smokers. No predictors were associated with significantly different EQ-5D score.
CONCLUSIONS
Variables associated with worse postoperative PDQ scores included younger age and osteoporosis/osteopenia. Variables associated with decreased (better) postoperative PHQ-9 scores included female sex, single operative vertebral level, and positive smoking status (i.e., current smoker). These clinically relevant predictors may permit identification of patients who may benefit from vertebral augmentation.
