Browse

You are looking at 1 - 10 of 4,716 items for :

  • Journal of Neurosurgery: Spine x
  • Refine by Access: all x
Clear All
Free access

Brian J. Park, Colin J. Gold, Royce W. Woodroffe, and Satoshi Yamaguchi

OBJECTIVE

The ability to utilize the T1 slope is often limited by poor visibility on cervical radiographs. The C7 slope has been proposed as a reliable substitute but may have similar limitations of visibility. Herein, the authors propose a novel method that takes advantage of the superior visibility on CT to accurately substitute for the radiographic T1 slope and compare the accuracy of this method with previously reported substitutes.

METHODS

Lateral neutral standing cervical radiographs and cervical CT scans were examined. When the T1 slope was clearly visible on radiographs, the C3–7 slopes and T1 slope were measured. In CT method 1, a direct method, the T1 slope was measured from the upper endplate of T1 to the bottom edge of the CT image, assuming the edge was parallel to the horizontal plane. In CT method 2, an overlaying method, the T1 slope was calculated by superimposing the C7 slope angle measured on a radiograph onto the CT scan and measuring the angle formed by the upper endplate of T1 and the superimposed horizontal line of the C7 slope. A Pearson correlation with linear regression modeling was performed for potential substitutes for the actual T1 slope.

RESULTS

Among 160 patients with available noninstrumented lateral neutral cervical radiographs, the T1 slope was visible in only 54 patients (33.8%). A total of 52 patients met the inclusion criteria for final analysis. The Pearson correlation coefficients between the T1 slope and the C3–7 slopes, CT method 1, and CT method 2 were 0.243 (p = 0.083), 0.292 (p = 0.035), 0.609 (p < 0.001), 0.806 (p < 0.001), 0.898 (p < 0.001), 0.426 (p = 0.002), and 0.942 (p < 0.001), respectively. Linear regression modeling showed R2 = 0.807 for the correlation between C7 slope and T1 slope and R2 = 0.888 for the correlation between T1 slope with the CT method 2 and actual T1 slope.

CONCLUSIONS

The C7 slope can be a reliable predictor of the T1 slope and is more accurate than more rostral cervical slopes. However, this study disclosed that the novel CT method 2, an overlaying method, was the most reliable estimate of true T1 slope with a greater positive correlation than C7 slope. When CT studies are available in patients with an invisible T1 slope on cervical radiographs, CT method 2 should be used as a substitute for the T1 slope.

Free access

Jacob K. Greenberg, Stephen Shelby Burks, Christopher F. Dibble, Saad Javeed, Vivek P. Gupta, Alexander T. Yahanda, Roberto J. Perez-Roman, Vaidya Govindarajan, Andrew T. Dailey, Sanjay Dhall, Daniel J. Hoh, Daniel E. Gelb, Adam S. Kanter, Eric O. Klineberg, Michael J. Lee, Praveen V. Mummaneni, Paul Park, Charles A. Sansur, Khoi D. Than, Jon J. W. Yoon, Michael Y. Wang, and Wilson Z. Ray

OBJECTIVE

Minimally invasive surgery (MIS) techniques can effectively stabilize and decompress many thoracolumbar injuries with decreased morbidity and tissue destruction compared with open approaches. Nonetheless, there is limited direction regarding the breadth and limitations of MIS techniques for thoracolumbar injuries. Consequently, the objectives of this study were to 1) identify the range of current practice patterns for thoracolumbar trauma and 2) integrate expert opinion and literature review to develop an updated treatment algorithm.

METHODS

A survey describing 10 clinical cases with a range of thoracolumbar injuries was sent to 12 surgeons with expertise in spine trauma. The survey results were summarized using descriptive statistics, along with the Fleiss kappa statistic of interrater agreement. To develop an updated treatment algorithm, the authors used a modified Delphi technique that incorporated a literature review, the survey results, and iterative feedback from a group of 14 spine trauma experts. The final algorithm represented the consensus opinion of that expert group.

RESULTS

Eleven of 12 surgeons contacted completed the case survey, including 8 (73%) neurosurgeons and 3 (27%) orthopedic surgeons. For the 4 cases involving patients with neurological deficits, nearly all respondents recommended decompression and fusion, and the proportion recommending open surgery ranged from 55% to 100% by case. Recommendations for the remaining cases were heterogeneous. Among the neurologically intact patients, MIS techniques were typically recommended more often than open techniques. The overall interrater agreement in recommendations was 0.23, indicating fair agreement. Considering both literature review and expert opinion, the updated algorithm indicated that MIS techniques could be used to treat most thoracolumbar injuries. Among neurologically intact patients, percutaneous instrumentation without arthrodesis was recommended for those with AO Spine Thoracolumbar Classification System subtype A3/A4 (Thoracolumbar Injury Classification and Severity Score [TLICS] 4) injuries, but MIS posterior arthrodesis was recommended for most patients with AO Spine subtype B2/B3 (TLICS > 4) injuries. Depending on vertebral body integrity, anterolateral corpectomy or mini-open decompression could be used for patients with neurological deficits.

CONCLUSIONS

Spine trauma experts endorsed a range of strategies for treating thoracolumbar injuries but felt that MIS techniques were an option for most patients. The updated treatment algorithm may provide a foundation for surgeons interested in safe approaches for using MIS techniques to treat thoracolumbar trauma.

Free access

Scott L. Zuckerman, Christopher S. Lai, Yong Shen, Nathan J. Lee, Mena G. Kerolus, Alex S. Ha, Ian A. Buchanan, Eric Leung, Meghan Cerpa, Ronald A. Lehman, and Lawrence G. Lenke

OBJECTIVE

The authors’ objectives were: 1) to evaluate the incidence and risk factors of iatrogenic coronal malalignment (CM), and 2) to assess the outcomes of patients with all three types of postoperative CM (iatrogenic vs unchanged/worsened vs improved but persistent).

METHODS

A single-institution, retrospective cohort study was performed on adult spinal deformity (ASD) patients who underwent > 6-level fusion from 2015 to 2019. Iatrogenic CM was defined as immediate postoperative C7 coronal vertical axis (CVA) ≥ 3 cm in patients with preoperative CVA < 3 cm. Additional subcategories of postoperative CM were unchanged/worsened CM, which was defined as immediate postoperative CVA within 0.5 cm of or worse than preoperative CVA, and improved but persistent CM, which was defined as immediate postoperative CVA that was at least 0.5 cm better than preoperative CVA but still ≥ 3 cm; both groups included only patients with preoperative CM. Immediate postoperative radiographs were obtained when the patient was discharged from the hospital after surgery. Demographic, radiographic, and operative variables were collected. Outcomes included major complications, readmissions, reoperations, and patient-reported outcomes (PROs). The t-test, Kruskal-Wallis test, and univariate logistic regression were performed for statistical analysis.

RESULTS

In this study, 243 patients were included, and the mean ± SD age was 49.3 ± 18.3 years and the mean number of instrumented levels was 13.5 ± 3.9. The mean preoperative CVA was 2.9 ± 2.7 cm. Of 153/243 patients without preoperative CM (CVA < 3 cm), 13/153 (8.5%) had postoperative iatrogenic CM. In total, 43/243 patients (17.7%) had postoperative CM: iatrogenic CM (13/43 [30.2%]), unchanged/worsened CM (19/43 [44.2%]), and improved but persistent CM (11/43 [25.6%]). Significant risk factors associated with iatrogenic CM were anxiety/depression (OR 3.54, p = 0.04), greater preoperative sagittal vertical axis (SVA) (OR 1.13, p = 0.007), greater preoperative pelvic obliquity (OR 1.41, p = 0.019), lumbosacral fractional (LSF) curve concavity to the same side of the CVA (OR 11.67, p = 0.020), maximum Cobb concavity opposite the CVA (OR 3.85, p = 0.048), and three-column osteotomy (OR 4.34, p = 0.028). In total, 12/13 (92%) iatrogenic CM patients had an LSF curve concavity to the same side as the CVA. Among iatrogenic CM patients, mean pelvic obliquity was 3.1°, 4 (31%) patients had pelvic obliquity > 3°, mean preoperative absolute SVA was 8.0 cm, and 7 (54%) patients had preoperative sagittal malalignment. Patients with iatrogenic CM were more likely to sustain a major complication during the 2-year postoperative period than patients without iatrogenic CM (12% vs 33%, p = 0.046), yet readmission, reoperation, and PROs were similar.

CONCLUSIONS

Postoperative iatrogenic CM occurred in 9% of ASD patients with preoperative normal coronal alignment (CVA < 3 cm). ASD patients who were most at risk for iatrogenic CM included those with preoperative sagittal malalignment, increased pelvic obliquity, LSF curve concavity to the same side as the CVA, and maximum Cobb angle concavity opposite the CVA, as well as those who underwent a three-column osteotomy. Despite sustaining more major complications, iatrogenic CM patients did not have increased risk of readmission, reoperation, or worse PROs.

Free access

Satoshi Inami, Hiroshi Moridaira, Daisaku Takeuchi, Tsuyoshi Sorimachi, Haruki Ueda, Hiromichi Aoki, Takuya Iimura, Yutaka Nohara, and Hiroshi Taneichi

OBJECTIVE

Previous studies have demonstrated that Lenke lumbar modifier A contains 2 distinct types (AR and AL), and the AR curve pattern is likely to develop adding-on (i.e., a progressive increase in the number of vertebrae included within the primary curve distally after posterior surgery). However, the results of anterior surgery are unknown. The purpose of this study was to present the surgical results in a cohort of patients undergoing scoliosis treatment for type 1AR curves and to compare anterior and posterior surgeries to consider the ideal indications and advantages of anterior surgery for type 1AR curves.

METHODS

Patients with a Lenke type 1 or 2 and lumbar modifier AR (L4 vertebral tilt to the right) and a minimum 2-year postoperative follow-up were included. The incidence of adding-on and radiographic data were compared between the anterior and posterior surgery groups. The numbers of levels between the end, stable, neutral, and last touching vertebra to the lower instrumented vertebra (LIV) were also evaluated.

RESULTS

Forty-four patients with a mean follow-up of 57 months were included. There were 14 patients in the anterior group and 30 patients in the posterior group. The main thoracic Cobb angle was not significantly different between the groups preoperatively and at final follow-up. At final follow-up, the anterior group had significantly less tilting of the LIV than the posterior group (−0.8° ± 4.5° vs 3° ± 4°). Distal adding-on was observed in no patient in the anterior group and in 6 patients in the posterior group at final follow-up (p = 0.025). In the anterior group, no LIV was set below the end vertebra, and all LIVs were set above last touching vertebra. The LIV was significantly more proximal in the anterior group than in the posterior surgery patients without adding-on for all reference vertebrae (p < 0.001).

CONCLUSIONS

This is the first study to investigate the surgical results of anterior surgery for Lenke type 1AR curve patterns, and it showed that anterior surgery for the curves could minimize the distal extent of the instrumented fusion without adding-on. This would leave more mobile disc space below the fusion.

Free access

Norimasa Ikeda, Shunsuke Fujibayashi, Bungo Otsuki, Kazutaka Masamoto, Takayoshi Shimizu, Yu Shimizu, Koichi Murata, and Shuichi Matsuda

OBJECTIVE

The goal of this study was to investigate clinical outcomes and risk factors for the progression of sacroiliac joint (SIJ) degeneration and bone formation after S2 alar-iliac screw (S2AIS) insertion.

METHODS

Using preoperative and follow-up CT scan findings (median follow-up 26 months, range 16–43 months), the authors retrospectively studied 100 SIJs in 50 patients who underwent S2AIS placement. The authors measured the progression of SIJ degeneration and bone formation after S2AIS insertion, postoperative new-onset SIJ pain, S2AIS-related reoperation, and instrumentation failures. Stepwise multivariate logistic regression modeling was performed to clarify the risk factors associated with the progression of SIJ degeneration.

RESULTS

Significant progression of SIJ degeneration was observed in 10% of the group with preoperative SIJ degeneration (p = 0.01). Bone formation was observed in 6.9% of joints. None of the patients with these radiographic changes had new-onset SIJ pain or underwent reoperation related to instrumentation failures. Multivariate logistic regression analysis revealed that preoperative SIJ degeneration (p < 0.01) and a young age at surgery (p = 0.03) significantly affected the progression of SIJ degeneration.

CONCLUSIONS

The progression of SIJ degeneration and bone formation neither led to major screw-related complications nor affected the postoperative clinical course during the median follow-up period of 26 months. Although S2AIS insertion is a safe procedure for most patients, the results of this study suggested that preoperative degeneration and younger age at surgery affected SIJ degeneration after S2AIS insertion. Further long-term observation may reveal other effects of S2AIS insertion on SIJ degeneration.

Free access

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.

Free access

Ferran Pellisé, Miquel Serra-Burriel, Alba Vila-Casademunt, Jeffrey L. Gum, Ibrahim Obeid, Justin S. Smith, Frank S. Kleinstück, Shay Bess, Javier Pizones, Virginie Lafage, Francisco Javier S. Pérez-Grueso, Frank J. Schwab, Douglas C. Burton, Eric O. Klineberg, Christopher I. Shaffrey, Ahmet Alanay, Christopher P. Ames, and on behalf of the International Spine Study Group (ISSG) and European Spine Study Group (ESSG)

OBJECTIVE

The reported rate of complications and cost of adult spinal deformity (ASD) surgery, associated with an exponential increase in the number of surgeries, cause alarm among healthcare payers and providers worldwide. The authors conjointly analyzed the largest prospective available ASD data sets to define trends in quality-of-care indicators (complications, reinterventions, and health-related quality of life [HRQOL] outcomes) since 2010.

METHODS

This is an observational prospective longitudinal cohort study. Patients underwent surgery between January 2010 and December 2016, with > 2 years of follow-up data. Demographic, surgical, radiological, and HRQOL (i.e., Oswestry Disability Index, SF-36, Scoliosis Research Society-22r) data obtained preoperatively and at 3, 6, 12, and 24 months after surgery were evaluated. Trends and changes in indicators were analyzed using local regression (i.e., locally estimated scatterplot smoothing [LOESS]) and adjusted odds ratio (OR).

RESULTS

Of the 2286 patients included in the 2 registries, 1520 underwent surgery between 2010 and 2016. A total of 1151 (75.7%) patients who were treated surgically at 23 centers in 5 countries met inclusion criteria. Patient recruitment increased progressively (2010–2011 vs 2015–2016: OR 1.64, p < 0.01), whereas baseline clinical characteristics (age, American Society of Anesthesiologists class, HRQOL scores, sagittal deformity) did not change. Since 2010 there has been a sustained reduction in major and minor postoperative complications observed at 90 days (major: OR 0.59; minor: OR 0.65; p < 0.01); at 1 year (major: OR 0.52; minor: 0.75; p < 0.01); and at 2 years of follow-up (major: OR 0.4; minor: 0.80; p < 0.01) as well as in the 2-year reintervention rate (OR 0.41, p < 0.01). Simultaneously, there has been a slight improvement in the correction of sagittal deformity (i.e., pelvic incidence–lumbar lordosis mismatch: OR 1.11, p = 0.19) and a greater gain in quality of life (i.e., Oswestry Disability Index 26% vs 40%, p = 0.02; Scoliosis Research Society-22r, self-image domain OR 1.16, p = 0.13), and these are associated with a progressive reduction of surgical aggressiveness (number of fused segments: OR 0.81, p < 0.01; percent pelvic fixation: OR 0.66, p < 0.01; percent 3-column osteotomies: OR 0.63, p < 0.01).

CONCLUSIONS

The best available data show a robust global improvement in quality metrics in ASD surgery over the last decade. Surgical complications and reoperations have been reduced by half, while improvement in disability increased and correction rates were maintained, in patients with similar baseline characteristics.

Free access

Haruo Kanno, Toshimi Aizawa, Ko Hashimoto, Eiji Itoi, and Hiroshi Ozawa

OBJECTIVE

Various surgical procedures are used to manage thoracic myelopathy due to ossification of the posterior longitudinal ligament (OPLL). However, the outcomes of surgery for thoracic OPLL are generally unfavorable in comparison to surgery for cervical OPLL. Previous studies have shown a significant risk of perioperative complications in surgery for thoracic OPLL. Thus, a safe and secure surgical method to ensure better neurological recovery with less perioperative complications is needed. The authors report a novel concept of anterior decompression through a posterior approach aimed at anterior shift of the OPLL during surgery rather than extirpation or size reduction of the OPLL. This surgical technique can securely achieve anterior shift of the OPLL using a curved drill, threadwire saw, and curved rongeur. The preliminary outcomes were investigated to evaluate the safety and efficacy of this technique.

METHODS

This study included 10 consecutive patients who underwent surgery for thoracic OPLL. Surgical outcomes, including the ambulatory status, Japanese Orthopaedic Association (JOA) score, and perioperative complications, were investigated retrospectively. In this surgery, pedicle screws are introduced at least three levels above and below the corresponding levels. The laminae, facet joints, transverse processes, and pedicles are then removed bilaterally at levels wherein subsequent anterior decompression is performed. For anterior decompression, the OPLL and posterior portion of the vertebral bodies are partially resected using a high-speed drill with a curved burr, enabling the removal of osseous tissues just ventral to the spinal cord without retracting the dural sac. To securely shift the OPLL anteriorly, the intact PLL and posterior portion of the vertebral bodies cranial and caudal to the lesion are completely resected using a threadwire saw and/or curved rongeur. Rods are connected to the screws, and bone grafting is performed for posterolateral fusion.

RESULTS

Five patients were nonambulatory before surgery, but all were able to walk at the final follow-up. The average JOA score before surgery and at the final follow-up was 3.2 and 8.8 points, respectively. Notably, the mean recovery rate of JOA score was 72%. Furthermore, no patients showed neurological deterioration postoperatively.

CONCLUSIONS

The surgical technique is a useful alternative for safely achieving sufficient anterior decompression through a posterior approach and may consequently reduce the risk of postoperative neurological deterioration and improve surgical outcomes in patients with thoracic OPLL.

Free access

Jacob K. Greenberg, Derek S. Brown, Margaret A. Olsen, and Wilson Z. Ray

OBJECTIVE

The Affordable Care Act expanded Medicaid eligibility in many states, improving access to some forms of elective healthcare in the United States. Whether this effort increased access to elective spine surgical care is unknown. This study’s objective was to evaluate the impact of Medicaid expansion under the Affordable Care Act on the volume and payer mix of elective spine surgery in the United States.

METHODS

This study evaluated elective spine surgical procedures performed from 2011 to 2016 and included in the all-payer State Inpatient Databases of 10 states that expanded Medicaid access in 2014, as well as 4 states that did not expand Medicaid access. Adult patients aged 18–64 years who underwent elective spine surgery were included. The authors used a quasi-experimental difference-in-difference design to evaluate the impact of Medicaid expansion on hospital procedure volume and payer mix, independent of time-dependent trends. Subgroup analysis was conducted that stratified results according to cervical fusion, thoracolumbar fusion, and noninstrumented surgery.

RESULTS

The authors identified 218,648 surgical procedures performed in 10 Medicaid expansion states and 118,693 procedures performed in 4 nonexpansion states. Medicaid expansion was associated with a 17% (95% CI 2%–35%, p = 0.03) increase in mean hospital spine surgical volume and a 23% (95% CI −0.3% to 52%, p = 0.054) increase in Medicaid volume. Privately insured surgical volumes did not change significantly (incidence rate ratio 1.13, 95% CI −5% to 34%, p = 0.18). The increase in Medicaid volume led to a shift in payer mix, with the proportion of Medicaid patients increasing by 6.0 percentage points (95% CI 4.1–7.0, p < 0.001) and the proportion of private payers decreasing by 6.7 percentage points (95% CI 4.5–8.8, p < 0.001). Although the magnitude of effects varied, these trends were similar across procedure subgroups.

CONCLUSIONS

Medicaid expansion under the Affordable Care Act was associated with an economically and statistically significant increase in spine surgery volume and the proportion of surgical patients with Medicaid insurance, indicating improved access to care.

Free access

Lei Cheng, Leiming Wang, Qingyu Yao, Longbing Ma, Wanru Duan, Jian Guan, Can Zhang, Kai Wang, Zhenlei Liu, Xingwen Wang, Zuowei Wang, Hao Wu, Zan Chen, and Fengzeng Jian

OBJECTIVE

Primary spinal cord H3 K27M-mutant diffuse midline glioma (DMG) is a rare and devastating pathological entity. However, little attention has been paid to this disease. As a result, its clinicoradiological characteristics have yet to be described. The aim of this study was to describe the clinicoradiological characteristics of primary intramedullary H3 K27M-mutant DMG and to compare this tumor with the H3 K27 wild-type to explore potential features that could differentiate the two.

METHODS

A total of 59 patients with pathologically confirmed intramedullary astrocytoma were included in this study. The cohort was divided into an H3 K27M-mutant group and H3 K27 wild-type group based on the status of H3 K27M according to an immunohistochemistry method. Demographic data, MRI features, and molecular information were collected. Multivariate logistic regression was conducted to investigate variables that might have a role in differentiating an H3 K27M DMG from an H3 K27 wild-type tumor.

RESULTS

Only symptom duration showed an independent association with the H3 K27M mutation (OR 0.82, 95% CI 0.68–0.94, p = 0.016). Patients with spinal cord H3 K27M-mutant DMG had a shorter symptom duration than patients with H3 K27 wild-type glioma. No significant difference was found in terms of MRI features between the H3 K27M-mutant and H3 K27 wild-type groups. Additionally, H3 K27M-mutant DMG frequently demonstrated overexpression of p53. Survival outcome did not show a statistical difference between the H3 K27-mutant subgroup and H3 K27 wild-type subgroup in histologically high-grade astrocytoma.

CONCLUSIONS

Symptom duration was associated with an H3 K27M mutation in intramedullary astrocytoma. MRI features were heterogeneous, and no imaging feature was able to predict the H3 K27M mutation. The H3 K27M mutation did not impact survival outcome in spinal histologically high-grade astrocytoma.