Does Elective Admission vs. Emergency Department Presentation Affect Surgical Outcomes in Metastatic Spine Surgery?

INTRODUCTION

Approximately 20% of patients with metastatic spine disease develop symptomatic spinal cord compression, and these patients can present urgently to the emergency department (ED) or, in a more organized fashion, to a clinic. In a cohort of patients undergoing metastatic spine surgery, we sought to (1) determine the rate of ED presentation, (2) identify preoperative and perioperative risk factors associated with ED presentation, and (3) evaluate whether ED vs. clinic presentation impacts long-term outcomes.

METHODS

A single-institution, multi-surgeon, retrospective cohort study was undertaken of patients undergoing metastatic spinal tumor surgery between 02/2010 and 01/2021. The primary exposure variable was presentation setting, dichotomized to the ED vs. clinic. The primary outcomes were postoperative functional status, measured with the Karnofsky Performance Scale (KPS) and McCormick Scale (MMS), local recurrence (LR), and overall survival (OS). Secondary outcomes included complications and readmissions.

RESULTS

A total of 311 patients underwent metastatic spine surgery (51.7% ED vs. 48.3% clinic). Those presenting to the ED had higher rates of smoking (21.7% vs. 16.0%, p = 0.02), were more likely to have 2+ comorbidities (47.2% vs. 32.7%, p = 0.011), and were more likely to have public insurance (43.5% vs. 32.0%, p = 0.043). Preoperative KPS was lower in ED patients (p < 0.001), while the Bilsky score was higher (p = 0.049). ED patients had higher rates of oligometastatic disease (p = 0.049), higher total decompressed levels (p = 0.041), and higher rates of costotransversectomy (p = 0.031) compared to clinic patients. Length of stay was significantly longer for ED patients (7.7 ± 6.1 vs. 6.1 ± 5.8 days, p = 0.020), and they were less likely to be discharged home (52.2% vs. 69.3%, p = 0.025). ED presentation was significantly associated with shorter overall survival (HR =1.53 95% CI = 1.13-2.08, p = 0.006).

CONCLUSIONS

Of patients undergoing metastatic spine disease, approximately half presented through the ED vs. clinic. ED patients had higher rates of smoking, public insurance, and higher Bilsky score. ED patients also underwent more extensive surgery, had longer LOS, were less likely discharged home, and most importantly, had a shorter overall survival. These results suggest that initial presentation for patients undergoing surgery for metastatic spine disease significantly impacts outcomes, and signs/symptoms of metastatic spine disease should be recognized as soon as possible to prevent ED presentation.

Multimodality Imaging for 3D Printing and Surgical Rehearsal in Complex Spine Surgery

Surgery is the mainstay treatment of symptomatic spinal tumors. It aids in restoring functionality, managing pain and tumor growth, and improving overall quality of life. Over the past decade, advancements in medical imaging techniques combined with the use of three-dimensional (3D) printing technology have enabled improvements in the surgical management of spine tumors by significantly increasing the precision, accuracy, and safety of the surgical procedures. For complex spine surgical cases, the use of multimodality imaging is necessary to fully visualize the extent of disease, including both soft-tissue and bone involvement. Integrating the information provided by these examinations in a cohesive manner to facilitate surgical planning can be challenging, particularly when multiple surgical specialties work in concert. The digital 3-dimensional (3D) model or 3D rendering and the 3D printed model created from imaging examinations such as CT and MRI not only facilitate surgical planning but also allow the placement of virtual and physical surgical or osteotomy planes, further enhancing surgical planning and rehearsal. The authors provide practical information about the 3D printing workflow, from image acquisition to postprocessing of a 3D printed model, as well as optimal material selection and incorporation of quality management systems, to help surgeons utilize 3D printing for surgical planning. The authors also highlight the process of surgical rehearsal, how to prescribe digital osteotomy planes, and integration with intraoperative surgical navigation systems through a case-based discussion. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Translation and Cross-cultural Adaptation of the SOSG-OQ 2.0 Questionnaire into Brazilian Portuguese

Objective:  To perform the cross-cultural adaptation and translation into Brazilian Portuguese of the Spine Oncology Study Group - Outcomes Questionnaire 2.0 (SOSG-OQ 2.0) to enable its application to Brazilian patients and to allow Brazilian researchers to use a questionnaire that is on trend in the scientific literature. Materials and Methods:  The present is a basic, non-randomized, non-comparative study. The translation followed the proposal by Reichenheime and Moraes, mainly for the semantic equivalence and measurement equivalence sessions, as well as the recommendations by Coster and Mancini mainly in the translation stage. The stages were as follows: first - translation into Brazilian Portuguese; second - back-translation; third - semantic comparison; fourth - validation of the final construct. Results:  The translations of the SOSG-OQ 2.0 made by three translators presented a high degree of similarity for most questions. The translators kept all question titles and subtitles, as well as their internal and external orders. Two sworn translators, with native proficiency in English, performed the back-translation of the amalgamated text. Both back-translations were quite similar, and any differences were solved through consensus between the main author and the sworn translators, and the translated text was considered the final version. Conclusion:  The present study shows a translated version of the SOSG-OQ 2.0 with semantic validity with the original version published in English. As such, researchers can apply the questionnaire to the Brazilian population, adding another tool for spine surgeons to improve the monitoring of this complex group of patients.

Enhancing the referral process for surgical management of spinal metastases: insights from a 12-year, bi-institutional study of 533 patients

Introduction

Delayed surgical management of spinal metastases (SMs) can have detrimental effects on patient survival and quality of life, leading to pain and potential neurological impairment. This study aimed to assess the impact of delayed referral for SMs on clinical outcomes by analyzing patients managed in emergency situations.

Methods

We retrospectively reviewed the data of all patients admitted on either emergency or elective basis who underwent surgery for the treatment of neoplastic spine lesions at our two institutions (tertiary referral neurosurgical units) between January 2008 and December 2019.

Results

We analyzed 210 elective (EGp) and 323 emergency patients (UGp); emergencies increased significantly over the 12-year period, with a Friday peak (39.3%) and frequent neurological impairment (61.6% vs. 20%). Among the UGp patients, 186 (7.5%) had a previously monitored primitive cancer, including 102 (31.6%) with known SMs. On admission, 71 of the 102 (69.9%) patients presented with neurological deficits. UGp patients were more likely to undergo a single decompression without fixation. Outcomes at the 3-month follow-up were significantly worse for UGp patients ([very] poor, 29.2 vs. 13.8%), and the median overall survival for UGp patients was statistically lower. Risk factors for patients with SM undergoing emergency management included short delay between onset of symptoms and first contact with a spine surgeon, and an initial motor deficit.

Conclusion

Many patients with previously identified metastases, including those with neurological deficits, are urgently referred. Optimization is needed in the oncology pathway, and all stakeholders must be made aware of the factors contributing to the improvement in the clinical and radiological identification of potential complications affecting patient survival and quality of life.

Treatment progress of spinal metastatic cancer: a powerful tool for improving the quality of life of the patients

Spinal metastasis is a common secondary malignant tumor of the bone, often resulting in spinal cord and nerve root compression, leading to obvious pain and related compression symptoms. This condition has a high incidence and mortality rate. The treatment approach for most patients with spinal metastasis is primarily palliative. Consultation with a multidisciplinary team is widely accepted as a comprehensive treatment approach for patients with spinal metastases. With advancements in research and technology, the evaluation and treatment of spinal metastatic cancer are continuously evolving. This study provides an overview of surgical treatment, minimally invasive treatment, and radiotherapy for spinal metastatic cancer and also analyzes the clinical effects, advantages, and current limitations associated with various treatment approaches.

A Comparison of Prognostic Models to Facilitate Surgical Decision-Making for Patients With Spinal Metastatic Disease

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

Compare the performance of and provide cutoff values for commonly used prognostic models for spinal metastases, including Revised Tokuhashi, Tomita, Modified Bauer, New England Spinal Metastases Score (NESMS), and Skeletal Oncology Research Group model, at three- and six-month postoperative time points.

SUMMARY OF BACKGROUND DATA

Surgery may be recommended for patients with spinal metastases causing fracture, instability, pain, and/or neurological compromise. However, patients with less than three to six months of projected survival are less likely to benefit from surgery. Prognostic models have been developed to help determine prognosis and surgical candidacy. Yet, there is a lack of data directly comparing the performance of these models at clinically relevant time points or providing clinically applicable cutoff values for the models.

MATERIALS AND METHODS

Sixty-four patients undergoing surgery from 2015 to 2022 for spinal metastatic disease were identified. Revised Tokuhashi, Tomita, Modified Bauer, NESMS, and Skeletal Oncology Research Group were calculated for each patient. Model calibration and discrimination for predicting survival at three months, six months, and final follow-up were evaluated using the Brier score and Uno's C, respectively. Hazard ratios for survival were calculated for the models. The Contral and O'Quigley method was utilized to identify cutoff values for the models discriminating between survival and nonsurvival at three months, six months, and final follow-up.

RESULTS

Each of the models demonstrated similar performance in predicting survival at three months, six months, and final follow-up. Cutoff scores that best differentiated patients likely to survive beyond three months included the Revised Tokuhashi score=10, Tomita score=four, Modified Bauer score=three, and NESMS=one.

CONCLUSION

We found comparable efficacy among the models in predicting survival at clinically relevant time points. Cutoff values provided herein may assist surgeons and patients when deciding whether to pursue surgery for spinal metastatic disease.

LEVEL OF EVIDENCE

4.

Clinical evaluation of vertebral body replacement of carbon fiber-reinforced polyetheretherketone in patients with tumor manifestation of the thoracic and lumbar spine

PURPOSE

Radiolucent anterior and posterior implants by carbon fiber-reinforced polyetheretherketone (CFR PEEK) aim to improve treatment of primary and secondary tumors of the spine during the last years. The aim of this study was to evaluate clinical and radiological outcomes after dorsoventral instrumentation using a CFR PEEK implant in a cohort of patients representing clinical reality.

METHODS

A total of 25 patients with tumor manifestation of the thoracic and lumbar spine underwent vertebral body replacement (VBR) using an expandable CFR PEEK implant between January 2021 and January 2022. Patient outcome, complications, and radiographic follow-up were analyzed.

RESULTS

A consecutive series aged 65.8 ± 14.7 (27.6-91.2) years were treated at 37 vertebrae of tumor manifestation, including two cases (8.0%) of primary tumor as well as 23 cases (92.0%) of spinal metastases. Overall, 26 cages covering a median of 1 level (1-4) were implanted. Duration of surgery was 134 ± 104 (65-576) min, with a blood loss of 792 ± 785 (100-4000) ml. No intraoperative cage revision was required. Surgical complications were reported in three (12.0%) cases including hemothorax in two cases (one intraoperative, one postoperative) and atrophic wound healing disorder in one case. In two cases (8.0%), revision surgery was performed (fracture of the adjacent tumorous vertebrae, progressive construct failure regarding cage subsidence). No implant failure was observed.

CONCLUSION

VBR using CFR PEEK cages represents a legitimate surgical strategy which opens a variety of improvements-especially in patients in need of postoperative radiotherapy of the spine and MRI-based follow-up examinations.

Applications of Carbon Fiber Instrumentation in Spinal Oncology: Recent Innovations in Spinal Instrumentation and 2-Dimensional Illustrative Operative Video

BACKGROUND

The management of spinal oncology necessitates a multimodal approach, with surgical intervention, radiation-based therapy, and postoperative advanced imaging. These systems must work well together to provide optimal patient outcomes. Traditional metallic spinal implants produce image artifacts and lead to radiation dose attenuation, which inhibit both disease monitoring and disease treatment, respectively.

OBJECTIVE

To demonstrate the feasibility of an improved biomaterial implant that provides structural stability, while also allowing for disease monitoring and treatment in spinal oncology patients.

METHODS

From February 2021 to September 2021, 3 patients with spinal oncologic deformity requiring resection and posterior spinal stabilization underwent fixation with polyether ether ketone-carbon fiber implants at a single academic institution.

RESULTS

Patient ages ranged from 23 to 74 years (mean: 44.7 years). All patients underwent posterior spinal fixation using standard approaches. They each received polyether ether ketone-carbon fiber pedicle screw and rod implants, placed in standard fashion. There were no dural tears, postoperative wound infections, or other complications related to their treatment. Postoperative surveillance revealed gross total resection of the targeted tumor on postoperative radiographic imaging.

CONCLUSION

Polyether ether ketone-carbon fiber implants are a safe and effective option for the treatment of thoracolumbar posterior spinal pathology. The utilization of this novel type of instrumentation in posterior spinal approaches may provide benefit to patients with spinal tumors over existing forms of posterior spinal instrumentation.

Outcome of Surgical Treatment for Metastatic Spinal Cord Compression: A Single-Center Retrospective Study

Objective  The spinal column is one of the most prevalent regions for metastasis, with an increasing frequency of spinal metastases. Spinal cord metastatic tumor damages the vertebral body, weakens the spinal support, and exerts mass effect on the spinal cord. Overzealous surgical intervention does not provide any additional benefit in most of the spinal metastasis due to shorter life expectancy. The principal goal of this study is to analyze the outcome of various surgical treatments offered to patients with metastatic spinal cord compression (MSCC). Methods  Retrospective cohort study including all patients that underwent surgical intervention for MSCC from March 2013 to March 2020. Results  A total of 198 patients were included, 113 males and 85 females; the mean age was 62 years. The most common primary cancer was prostate (21.71%) followed by hematological (20.07%) and lung (16.66%). At 6-month postsurgery, 68.68% of patients were Frankel grade D or E (vs. 23.23% preoperatively), 16.6% were grade C (vs 57% preoperatively), and 14.64% were grade A or B (vs. 19.69% preoperatively). Pain on numeric rating scale was decreased from 6.38 ± 3.08 to 3.39 ± 0.73 at 24 hours postsurgery and 1.94 ± 0.67 at 6 months. Conclusion  This study found that the majority of patients, undergoing minimally invasive spinal stabilization and decompression for metastatic spinal tumors, have better quality of life, analgesia, and mobility. In conclusion, treatment for spinal metastases should be individualized and a multidisciplinary approach is needed.

Customized Multilevel 3D Printing Implant for Reconstructing Spine Tumor: A Retrospective Case Series Study in a Single Center

Objective

To investigate the clinical efficacy and safety of 3D printed artificial vertebral body for patients who underwent multilevel total en bloc spondylectomy (TES) and analyze whether it could reduce the incidence of implant subsidence.

Methods

This is a retrospective study. From January 2017 to May 2018, eight consecutive cases with spine tumor undergoing multilevel TES were analyzed. All patients underwent X‐ray and CT examinations to evaluate the stability of internal fixation during the postoperative follow‐up. Demographic, surgical details, clinical data, and perioperative complications was collected. Visual analog scale, Frankel score, and spinal instability neoplastic score (SINS) classification were also recorded.

Results

There were six cases of primary spinal tumor and two cases of metastatic spinal tumor. All patients achieved remarkable pain relief and improvement in neurological function. Five patients underwent operation through the posterior approach, one patient underwent operation through the anterior approach and the remaining two patients through a combined anterior and posterior approach. At the last follow‐up period, X‐rays showed that the 3D printed artificial vertebral body of all cases matched well, and the fixation was reliable. Hardware failure such as loosening, sinking, breaking, and displacement wasn't observed during the follow‐up period.

Conclusion

3D printed customized artificial vertebral body can provide satisfying good clinical and radiological outcomes for patients who have undergone multilevel TES.

Surgical strategy for metastatic spinal tumor patients with surgically challenging situation

The incidence of spinal metastasis is increasing as cancer patients live longer owing to the improvement of cancer treatments. However, traditional surgery (TS) which fixates at least 2 levels above and 2 levels below the affected vertebrae is sometimes difficult to perform as it is burdensome to the patients. In this article, we introduce our experience and strategy in treating spinal metastasis, focusing particularly on challenging cases. We retrospectively reviewed the data of 110 patients who underwent spinal surgery for metastatic spinal tumors from April 2018 to March 2020. Among them, 5 patients who received anterior approach surgery were excluded. The remaining 105 patients were enrolled. In addition to TS, we also performed cervical pedicle screw, cervicothoracic junction fixation, thoracolumbar short fixation, and decompression surgery, depending on the characteristics of the tumor. The overall survival was analyzed, and the local tumor control rate was evaluated using magnetic resonance imaging. Perioperative clinical characteristics including Spine Oncology Study Group Outcomes Questionnaire, visual analog scale, Eastern Cooperative Oncology Group performance score, and Karnofsky Performance Score were also investigated. The overall survival rate was 57.9% at 1 year, and the local tumor control rate was 81.1% after surgery. There was a statistically significant difference according to the type of the tumor in the survival analysis: the overall survival rates were 72.7% for favorable tumors and 48.6% for unfavorable tumors at 12 months after surgery (P = .04). Spine Oncology Study Group Outcomes Questionnaire, visual analog scale, Eastern Cooperative Oncology Group performance score, and Karnofsky Performance Score was improved after surgery. All surgical methods, including TS, cervical pedicle screw, cervicothoracic junction fixation, thoracolumbar short fixation, and decompression surgery, showed good clinical and radiological outcomes. Optimized surgical methods show similarly good clinical outcomes in managing spinal metastasis as TS.

Systemic considerations for the surgical treatment of spinal metastatic disease: a scoping literature review

Systemic assessment is a pillar in the neurological, oncological, mechanical, and systemic (NOMS) decision-making framework for the treatment of patients with spinal metastatic disease. Despite this importance, emerging evidence relating systemic considerations to clinical outcomes following surgery for spinal metastatic disease has not been comprehensively summarised. We aimed to conduct a scoping literature review of this broad topic. We searched MEDLINE, Embase, Scopus, Cochrane Central Register of Controlled Trials, Web of Science, and CINAHL databases from Jan 1, 2000, to July 31, 2021. 61 articles were included, accounting for a total of 22 335 patients. Preoperative systemic variables negatively associated with postoperative clinical outcomes included demographics (eg, older age [>60 years], Black race, male sex, low or elevated body-mass index, and smoking status), medical comorbidities (eg, cardiac, pulmonary, hepatic, renal, endocrine, vascular, and rheumatological), biochemical abnormalities (eg, hypoalbuminaemia, atypical blood cell counts, and elevated C-reactive protein concentration), low muscle mass, generalised motor weakness (American Spinal Cord Injury Association Impairment Scale grade and Frankel grade) and poor ambulation, reduced performance status, and systemic disease burden. This is the first comprehensive scoping review to broadly summarise emerging evidence relevant to the systemic assessment component of the widely used NOMS framework for spinal metastatic disease decision making. Medical, surgical, and radiation oncologists can consider these findings when prognosticating spinal metastatic disease-related surgical outcomes on the basis of patients' systemic condition. These factors might inform a shared decision-making approach with patients and their families.

The performance of frailty in predictive modeling of short-term outcomes in the surgical management of metastatic tumors to the spine

BACKGROUND CONTEXT

The concept of frailty has become increasingly recognized, and while patients with cancer are at increased risk for frailty, its influence on perioperative outcomes in metastatic spine tumors is uncertain. Furthermore, the impact of frailty can be confounded by comorbidities or metastatic disease burden.

PURPOSE

The purpose of this study was to evaluate the influence of frailty and comorbidities on adverse outcomes in the surgical management of metastatic spine disease.

STUDY DESIGN/SETTING

Retrospective analysis of a nationwide database to include patients undergoing spinal fusion for metastatic spine disease.

PATIENT SAMPLE

A total of 1,974 frail patients who received spinal fusion with spinal metastasis, and 1,975 propensity score matched non-frail patients.

OUTCOME MEASURES

Outcomes analyzed included mortality, complications, length of stay (LOS), nonroutine discharges and costs.

METHODS

A validated binary frailty index (Johns Hopkins Adjusted Clinical Groups) was used to identify frail and non-frail groups, and propensity score-matched analysis (including demographics, comorbidities, surgical and tumor characteristics) was performed. Sub-group analysis of levels involved was performed for cervical, thoracic, lumbar and junctional spine. Multivariable-regression techniques were used to develop predictive models for outcomes using frailty and the Elixhauser Comorbidity Index (ECI).

RESULTS

7,772 patients underwent spinal fusion with spinal metastasis, of which 1,974 (25.4%) patients were identified as frail. Following propensity score matching for frail (n=1,974) and not-frail (n=1,975) groups, frailty demonstrated significantly greater medical complications (OR=1.58; 95% CI 1.33-1.86), surgical complications (OR=1.46; 95% CI 1.15-1.85), LOS (OR=2.65; 95% CI 2.09-3.37), nonroutine discharges (OR=1.79; 95% CI 1.46-2.20) and costs (OR=1.68; 95% CI 1.32-2.14). Differences in mortality were only observed in subgroup analysis and were greater in frail junctional and lumbar spine subgroups. Models using ECI alone (AUC=0.636-0.788) demonstrated greater predictive ability compared to those using frailty alone (AUC=0.633-0.752). However, frailty combined with ECI improved the prediction of increased LOS (AUC=0.811), cost (AUC=0.768), medical complications (AUC=0.723) and nonroutine discharges (AUC=0.718). Predictive modeling of frailty in subgroups demonstrated the greatest performance for mortality (AUC=0.750) in the lumbar spine, otherwise performed similarly for LOS, costs, complications, and discharge across subgroups.

CONCLUSIONS

A high prevalence of frailty existed in the current patient cohort. Frailty contributed to worse short-term adverse outcomes and could be more influential in the lumbar and junctional spine due to higher risk of deconditioning in the postoperative period. Predictions for short term outcomes can be improved by adding frailty to comorbidity indices, suggesting a more comprehensive preoperative risk stratification should include frailty.

Anterior Corpectomy and Plating with Carbon-PEEK Instrumentation for Cervical Spinal Metastases: Clinical and Radiological Outcomes

Background: Anterior cervical corpectomy and plating has been recognized as a valuable approach for the surgical treatment of cervical spinal metastases. This study aimed to report the surgical, clinical and radiological outcomes of anterior carbon-PEEK instrumentations for cervical spinal metastases. Methods: Demographical, clinical, surgical and radiological data were collected from 2017 to 2020. The Neck Disability Index (NDI) questionnaire for neck pain, EORTC QLQ-C30 questionnaire for quality of life, Nurick scale for myelopathy and radiological parameters (segmental Cobb angle and cervical lordosis) were collected before surgery, at 6 weeks postoperatively and follow-up. Results: Seventeen patients met inclusion criteria. Mean age was 60.9 ± 7.6 years and mean follow-up was 12.9 ± 4.0 months. The NDI (55.4 ± 11.7 to 25.1 ± 5.4, p < 0.001) scores and the EORTC QLQ-C30 global health/QoL significantly improved postoperatively and at the last follow-up. The segmental Cobb angle (10.7° ± 5.6 to 3.1° ± 2.2, p < 0.001) and cervical lordosis (0.9° ± 6.7 to −6.2 ± 7.8, p = 0.002) significantly improved postoperatively. Only one minor complication (5.9%) was recorded. Conclusions: Carbon/PEEK implants represent a safe alternative to commonly used titanium ones and should be considered in cervical spinal metastases management due to their lower artifacts in postoperative imaging and radiation planning. Further larger comparative and cost-effectiveness studies are needed to confirm these results.

10-Year Trends in the Surgical Management of Patients with Spinal Metastases: A Scoping Review

BACKGROUND

Spinal metastases are present in approximately 20% of patients with cancer, giving a risk for neurologic dysfunction and instability. In already frail patients, surgeons strive to improve quality of life. Our goal was to review a 10-year trend in the surgical management of spinal metastases.

METHODS

A scoping review was performed systematically using PubMed to assess trends in surgical treatment for spinal metastases. The search terms used were: metastas∗, "neoplasm metastasis"[Mesh], "Spine"[Mesh], spine, spinal, "vertebral column," "vertebral body," laser, robot, radiofrequency, screws, fixation, "separation surgery," corpectomy, vertebrectomy, spondylectomy, vertebroplasty, kyphoplasty, surgery, "open surgery," "mini open surgery," "minimally invasive surgery," endoscopy, thoracoscopy, corpectom∗, vertebrectom∗, spondylectom∗, "en bloc," and MIS. The variables of interest were neurologic improvement, tumor recurrence, reoperation, and overall survival.

RESULTS

A total of 2132 articles were found within the primary query. Fifty-six studies were selected for final review. The results were organized into main surgical practices: decompression, mechanical stabilization, and pain management. For separation surgery, clinical outcomes were overall 1-year survival, 40.7%-78.4%; recurrence rate, 4.3%-22%; reoperation, 5%; and complications, 5.4%-14%. For corpectomy, clinical outcomes were overall 1-year survival, 30%-92%; reoperation, 1.1%-50%; and recurrence rate, of 1.1%-28%. Complications and reoperations with spinal instrumentation were 0%-13.6% and 0%-15%, respectively. Cement augmentation achieved pain reduction rates of 56%-100%, neurologic improvement/stability 84%-100%, and complication rates 6%-56%. Laser achieved local tumor control rate of 71%-82% at 1 year follow-up, reoperation rate of 15%-31%, and complication rate of 5%-26%.

CONCLUSIONS

Minimally invasive techniques for decompression and stabilization seem to be the preferred method to surgically treat metastatic spine disease, with good outcomes. More research with high level of evidence is required to support the long-term outcomes of these approaches.

Evolution of materials for implants in metastatic spine disease till date - Have we found an ideal material?

"Metastatic Spine Disease" (MSD) often requires surgical intervention and instrumentation with spinal implants. Ti6Al4V is widely used in metastatic spine tumor surgery (MSTS) and is the current implant material of choice due to improved biocompatibility, mechanical properties, and compatibility with imaging modalities compared to stainless steel. However, it is still not the ideal implant material due to the following issues. Ti6Al4V implants cause stress-shielding as their Young's modulus (110 gigapascal [GPa]) is higher than cortical bone (17-21 GPa). Ti6Al4V also generates artifacts on CT and MRI, which interfere with the process of postoperative radiotherapy (RT), including treatment planning and delivery. Similarly, charged particle therapy is hindered in the presence of Ti6Al4V. In addition, artifacts on CT and MRI may result in delayed recognition of tumor recurrence and postoperative complications. In comparison, polyether-ether-ketone (PEEK) is a promising alternative. PEEK has a low Young's modulus (3.6 GPa), which results in optimal load-sharing and produces minimal artifacts on imaging with less hinderance on postoperative RT. However, PEEK is bioinert and unable to provide sufficient stability in the immediate postoperative period. This issue may possibly be mitigated by combining PEEK with other materials to form composites or through surface modification, although further research is required in these areas. With the increasing incidence of MSD, it is an opportune time for the development of spinal implants that possess all the ideal material properties for use in MSTS. Our review will explore whether there is a current ideal implant material, available alternatives and whether these require further investigation.

A Web-Based Calculator for Predicting the Occurrence of Wound Complications, Wound Infection, and Unplanned Reoperation for Wound Complications in Patients Undergoing Surgery for Spinal Metastases

BACKGROUND

In the present study, we identified the risk factors for wound complications, wound infection, and reoperation for wound complications after spine metastasis surgery and deployed the resultant model as a web-based calculator.

METHODS

Patients treated at a single comprehensive cancer center during a 7-year period were included. The demographics, pathology, comorbidities, laboratory values, and operative details were collected. Factors with P < 0.15 on univariable regression were entered into multivariable logistic regression to generate predictive models internally validated using 1000 bootstrapped samples.

RESULTS

Of the 330 patients included, 29 (7.6%) had experienced a surgical site infection. The independent predictive factors for wound-related complications were a higher Charlson comorbidity index (CCI; odds ratio [OR], 1.41 per point; P < 0.01), Karnofsky performance scale score ≤70 (OR, 2.14; P = 0.04), lower platelet count (OR, 0.49 per 10⁵/μL; P < 0.01), revision versus index surgery (OR, 3.10; P = 0.02), and increased incision length (OR, 1.21 per level; P = 0.02). Wound infection was associated with a higher CCI (OR, 1.60 per point; P < 0.01), a lower platelet count (OR, 0.35 per 10⁵/μL; P < 0.01), revision surgery (OR, 4.63; P = 0.01), and a longer incision length (OR, 1.25 per level; P = 0.03). Unplanned reoperation for wound complications was predicted by a higher CCI (OR, 1.39 per point; P = 0.003), prior irradiation (OR, 2.52; P = 0.04), a lower platelet count (OR, 0.57 per 10⁵/μL; P = 0.02), and revision surgery (OR, 3.34; P = 0.03), The optimism-corrected areas under the curve were 0.75, 0.81, and 0.72 for the wound complication, infection, and reoperation models, respectively.

CONCLUSIONS

Low platelet counts, poorer health status, more invasive surgery, and revision surgery all independently predicted the risk of wound complications, including infection and unplanned reoperation for infection. Validation of the calculators in a prospective study is merited.

Radiotherapy and Surgical Advances in the Treatment of Metastatic Spine Tumors: A Narrative Review

Spine tumors encompass a wide range of diseases with a commensurately broad spectrum of available treatments, ranging from radiation for spinal metastases to highly invasive en bloc resection for primary vertebral column malignancies. This high variability in treatment approaches stems both from variability in the goals of surgery (e.g., oncologic cure vs. symptom palliation) and from the significant advancements in surgical technologies that have been made over the past 2 decades. Among these advancements are improvements in surgical technique, namely minimally invasive approaches, increased availability of focused radiation modalities (e.g., proton therapy and linear accelerator devices), and new surgical technologies, such as carbon fiber-reinforced polyether ether ketone rods. In addition, several groups have described nonsurgical interventions, such as vertebroplasty and kyphoplasty for spinal instability secondary to pathologic fracture, and lesion ablation with spinal laser interstitial thermoablation, radiofrequency ablation, or cryoablation. We provide an overview of the latest technological advancements in spinal oncology and their potential usefulness for modern spinal oncologists.

The History of Neurosurgical Spinal Oncology: From Inception to Modern-Day Practices

The neurosurgical management of spinal neoplasms has undergone immense development in parallel with advancements made in general spine surgery. Laminectomies were performed as the first surgical procedures used to treat spinal neoplasms. Since then, neurosurgical spinal oncology has started to incorporate techniques that have developed from recent advances in minimally invasive spine surgery. Neurosurgery has also integrated radiotherapy into the treatment of spine tumors. In this historical vignette, we present a vast timeline spanning from the Byzantine period to the current day and recount the major advancements in the management of spinal neoplasms.

The role of gene therapy as a valuable treatment modality for multiple spinal pathologies

The world of biomedical research has led to several breakthroughs in the treatment of various spinal pathologies. As we investigate chronic pathologies of the spine, we start to unravel the underlying molecular mechanisms through a careful analysis of mutated genetic sequences. Investigations have led to gene therapy being explored for its potential as a treatment modality. Despite only about 2% of current gene therapy trials being centered for spinal pathologies, spinal diseases are valuable targets in gene therapy administration. Through a comprehensive literature review, our objective is to discuss the molecular mechanisms behind gene therapy for spinal pathologies, the genetic targets, along with the outcomes, success, and possible pitfalls in gene therapy research and administration. The emerging development of robotic technologies and intelligent carriers are recognized as a promising innovative technique for increasing the efficiency of gene therapy and potentially resolving spinal pathologies.

Sarcopenia as a Prognostic Factor for 90-Day and Overall Mortality in Patients Undergoing Spine Surgery for Metastatic Tumors: A Multicenter Retrospective Cohort Study

BACKGROUND

Novel methods in predicting survival in patients with spinal metastases may help guide clinical decision-making and stratify treatments regarding surgery vs palliative care.

OBJECTIVE

To evaluate whether the frailty/sarcopenia paradigm is predictive of survival and morbidity in patients undergoing surgery for spinal metastasis.

METHODS

A total of 271 patients from 4 tertiary care centers who had undergone surgery for spinal metastasis were identified. Frailty/sarcopenia was defined by psoas muscle size. Survival hazard ratios were calculated using multivariate analysis, with variables from demographic, functional, oncological, and surgical factors. Secondary outcomes included improvement of neurological function and postoperative morbidity.

RESULTS

Patients in the smallest psoas tertile had shorter overall survival compared to the middle and largest tertile. Psoas size (PS) predicted overall mortality more strongly than Tokuhashi score, Tomita score, and Karnofsky Performance Status (KPS). PS predicted 90-d mortality more strongly than Tokuhashi score, Tomita score, and KPS. Patients with a larger PS were more likely to have an improvement in deficit compared to the middle tertile. PS was not predictive of 30-d morbidity.

CONCLUSION

In patients undergoing surgery for spine metastases, PS as a surrogate for frailty/sarcopenia predicts 90-d and overall mortality, independent of demographic, functional, oncological, and surgical characteristics. The frailty/sarcopenia paradigm is a stronger predictor of survival at these time points than other standards. PS can be used in clinical decision-making to select which patients with metastatic spine tumors are appropriate surgical candidates.

Feasibility of salvage decompressive surgery for pending paralysis due to metastatic spinal cord compression

OBJECTIVE

Metastatic spinal cord compression (MSCC) is a frequent phenomenon in cancer disease, often leading to severe neurological deficits. Especially in patients with complete motor paralysis, regaining the ability to walk is an important treatment goal. Our study, therefore, aimed to assess the neurological outcome of patients with MSCC and complete motor paralysis after decompressive surgery.

METHODS

Patients with MSCC and complete motor paralysis, surgically treated by decompressive surgery between 2004-2014 at a single institution were retrospectively analyzed. Clinical patient data were collected from medical records. To assess the neurological outcome, Frankel grade (FG) at admission and discharge were compared. Statistical analysis was performed to identify factors associated with an ambulatory status after surgery.

RESULTS

Twenty-eight patients were included in this study. The majority of metastases (57 %) were located in the thoracic spine and 75 % showed extraspinal tumor spread. The median interval between loss of ambulation and surgery was 35 h (IQR: 29-70). Posterior circumferential decompression without stabilization was performed in all cases within 24 h of admission. Neurological function improved in 17 patients (63 %) and seven (26 %) even regained the ability to walk following surgery. The rate of complications was low (7%). In statistical analysis, only the Karnofsky Performance Index (KPI) displayed a significant predictive value for an ambulatory status at discharge.

CONCLUSIONS

Our findings indicate that severely affected MSCC patients with complete motor paralysis might benefit from decompressive surgery even when the loss of ambulation occurred more than 24 h ago.

Radiofrequency Ablation for the Palliative Treatment of Bone Metastases: Outcomes from the Multicenter OsteoCool Tumor Ablation Post-Market Study (OPuS One Study) in 100 Patients

PURPOSE

To evaluate the effectiveness of radiofrequency (RF) ablation as measured by change in worst pain score from baseline to 3 mo after RF ablation for the palliative treatment of painful bone metastases.

MATERIALS AND METHODS

One hundred patients (mean age, 64.6 y) underwent RF ablation for metastatic bone disease and were followed up to 6 mo. Subjects' pain and quality of life were measured before RF ablation and postoperatively by using the Brief Pain Index and European Quality of Life questionnaires. Opioid agent use and device-, procedure-, and/or therapy-related adverse events (AEs) were collected.

RESULTS

Eighty-seven patients were treated for tumors involving the thoracolumbar spine and 13 for tumors located in the pelvis and/or sacrum. All ablations were technically successful, and 97% were followed by cementoplasty. Mean worst pain score decreased from 8.2 ± 1.7 at baseline to 3.5 ± 3.2 at 6 mo (n = 22; P < 0.0001 for all visits). Subjects experienced significant improvement for all visits in average pain (P < .0001), pain interference (P < .0001), and quality of life (P < .003). Four AEs were reported, of which 2 resulted in hospitalization for pneumonia and respiratory failure. All 30 deaths reported during the study were attributed to the underlying malignancy and not related to the study procedure.

CONCLUSIONS

Results from this study show rapid (within 3 d) and statistically significant pain improvement with sustained long-term relief through 6 mo in patients treated with RF ablation for metastatic bone disease.

Influence of preoperative biological parameters on postoperative complications and survival in spinal bone metastasis. A multicenter prospective study

INTRODUCTION

Onset of spinal bone metastasis is a turning point in the progression of tumoral disease; although incidence is increasing, management is not standardized. Various prognostic scores are available, but advances in medical and surgical treatment have made them less well adapted, and sometimes discordant for a given patient. It would therefore be useful to develop new prognostic instruments. The aim of the present study was to identify biologic risk factors for onset of postoperative complications and death following spinal bone metastasis surgery.

MATERIAL AND METHODS

A prospective multicenter study included all patients operated on for spinal bone metastasis between November 2015 and May 2017. The main epidemiologic data and biologic data (CRP, albuminemia, calcemia) were collected preoperatively. Surgical strategy, death and/or postoperative complications were collected prospectively.

RESULTS

Five of the initial 264 patients died during the immediate postoperative course, and 107 within 6 months. At 1 year, 57 patients remained alive. Twenty-six (10%) were lost to follow-up. Preoperative albuminemia<35g/L (29% of patients), calcemia>2.6 nmol/L (8%) and CRP>10mg/L (47.5%) were associated with significantly elevated mortality. Only CRP elevation correlated with postoperative complications rate.

CONCLUSION

The study confirmed the prognostic value of 3 biologic parameters (CRP level, albuminemia, calcemia) for survival after spinal bone metastasis surgery. A hybrid score taking account of not only clinical but also biologic parameters should be developed to improve estimation of survival.

Assessment of Spinal Tumor Treatment Using Implanted 3D-Printed Vertebral Bodies with Robotic Stereotactic Radiotherapy

To investigate the feasibility and early efficacy of 3D-printed vertebral body implantation combined with robotic radiosurgery in the treatment of spinal tumors. This study included 14 patients with spinal tumors from December 2017 to June 2018. Before surgery, all patients were subjected to CT scan and 3D data of the corresponding vertebral segments were collected. Titanium alloy formed 3D-printed vertebral body implantation and robotic stereotactic radiotherapy were performed because of the risk of postoperative residual, high risk of recovery, or recurrence after surgery. The main outcomes included the remission of symptoms, vertebral body stability, robotic stereotactic surgical precision, and local tumor control. All patients received complete and successful combination therapy, and all healed primarily without complications. The error of the coverage accuracy for robotic radiosurgery was less than 0.5 mm, and the error of the rotation angle was less than 0.5°. The therapeutic toxicity was limited (mainly in grades 1–2), and adverse events were uncommon. The evaluation of vertebral body stability and histocompatibility for all patients met the postoperative clinical requirements. For patients with post spinal injury, the pain symptoms were reduced or disappeared (93%), and nerve function was improved or even recovered after treatment (100%). During our follow-up period, most tumors were locally well controlled (93%). 3D- printed vertebral body implantation combined with robotic radiosurgery may offer a new treatment of spinal tumors.

Chinese clinical trial registry: ChiCTR-ONN-17013946.

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With the development of 3D printing and robotic radiotherapy technology, the outcome of spinal tumors has been shown to have improving opportunities

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In this study, 14 patients with spinal tumor were treated by 3D printing vertebral body implantation combined with robotic radiotherapy, and the results showed that treatment could achieve requirements of spinal function perfectly and precisely kill the tumor

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3D printing vertebral body implantation combined with robotic stereotactic radiotherapy might be a treatment revolution for spinal tumors

Metallic implants and CT artefacts in the CTV area: Where are we in 2020?

Radiation therapy (RT) is one of the main modalities of cancer treatment worldwide with computed tomography (CT), as the most commonly used imaging method for treatment planning system (TPS). Image reconstruction errors may greatly affect all the radiation therapy planning process, such as target delineation, dose calculation and delivery, particularly with particle therapy. Metallic implants, such as hip and spinal implants, and dental filling significantly deteriorate image quality. These hardware structures are often very complex in geometry leading to geometric complex artefacts in the clinical target volume (CTV) area, rendering the delineation of CTV challenging. In our review, we focus on the methods to overcome artefact consequences on CTV delineation: 1- medical approaches anticipating issues associated with imaging artefacts during preoperative multidisciplinary discussions while following standard recommendations; 2- common metal artefact reduction (MAR) methods such as manually override artefact regions, ballistics avoiding beam paths through implanted materials, megavoltage-CT (MVCT); 3- prospects with radiolucent implants, MAR algorithms and various methods of dual energy computed tomography (DECT). Despite substantial and broad evidence for their benefits, there is still no universal solution for cases involving implanted metallic devices. There is still a high need for research efforts to adapt technologies to our issue: "how do I accurately delineate the ideal CTV in a metal artefact area?"

Muscle Flap Closure following Complex Spine Surgery: A Decade of Experience

BACKGROUND

Advances in surgical technology and adjuvant therapies along with an aging and increasingly morbid U.S. population have led to an increase in complex spine surgery. With this increase comes an elevated risk of complications, including those related to the surgical wound, with some studies demonstrating wound complication incidences approaching 45 percent. The authors hypothesize that immediate muscle flap closure improves outcomes in high-risk patients.

METHODS

Three hundred one consecutive index cases of spinal wound closure using local muscle flaps performed by the senior author at a single institution between 2006 and 2018 were reviewed. The primary outcome was major wound complication (reoperation and/or readmission because of surgical-site infection, late infection, dehiscence, seroma, or hematoma). Logistic regression analysis was performed to identify predictors of this endpoint.

RESULTS

Major wound complications occurred in 6.6 percent of patients (reoperation, 3.6 percent; readmission, 3.0 percent), with a 6.0 percent infection rate and five cases requiring instrumentation removal because of infection. Risk factors identified included radiotherapy (OR, 5.9; p = 0.004), age 65 years or older (OR, 2.8; p = 0.046), and prior spine surgery (OR, 4.3; p = 0.027). The incidence of major wound complication increased dramatically with each additional risk factor. Mean drain dwell duration was 21.1 ± 10.0 days and not associated with major wound complications, including infection (OR, 1.04; p = 0.112).

CONCLUSIONS

Immediate local muscle flap closure following complex spine surgery on high-risk patients is associated with an acceptable rate of wound complications and, as these data demonstrate, is safe and effective. Consideration should be given to immediate muscle flap closure in appropriately selected patients.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Treatment Strategy for Metastatic Spinal Tumors: A Narrative Review

Metastatic spinal tumors are common, and their rising incidence can be attributed to the expanding aging population and increased survival rates among cancer patients. The decision-making process in the treatment of spinal metastasis requires a multidisciplinary approach that includes medical and radiation oncology, surgery, and rehabilitation. Various decision-making systems have been proposed in the literature in order to estimate survival and suggest appropriate treatment options for patients experiencing spinal metastasis. However, recent advances in treatment modalities for spinal metastasis, such as stereotactic radiosurgery and minimally invasive surgical techniques, have reshaped clinical practices concerning patients with spinal metastasis, making a demand for further improvements on current decision-making systems. In this review, recent improvements in treatment modalities and the evolution of decision-making systems for metastatic spinal tumors are discussed.

Conventional Radiotherapy and Stereotactic Radiosurgery in the Management of Metastatic Spine Disease

Spinal metastases are a common manifestation of malignant tumors that can cause severe pain, spinal cord compression, pathological fractures, and hypercalcemia, and these clinical manifestations will ultimately reduce the health-related quality of life and even shorten life expectancy in patient with cancer. Effective management of spinal bone metastases requires multidisciplinary collaboration, including radiologists, surgeons, radiation oncologists, medical oncologists, and pain specialists. In the past few decades, conventional radiotherapy has been the most common form of radiotherapy, which can achieve favorable local control and pain relief; however, it lacks precise methods of delivering radiation and thus cannot provide sufficient tumoricidal dose. The advent of stereotactic radiosurgery has changed this situation by using highly focused radiation beams guided by 3-dimensional imaging to deliver a high biologic equivalent dose to the target region, and the spinal cord can be identified and excluded from the target volume to reduce the risk of radiation-induced myelopathy. Separation surgery can provide a 2- to 3-mm safe separation of tumor and spinal cord to avoid radiation-induced damage to the spinal cord. Targets for separation surgery include decompression of metastatic epidural spinal cord compression and spinal stabilization without partial or en bloc tumor resection. Combined with conventional radiotherapy, stereotactic radiosurgery can provide better local tumor control and pain relief. Several scoring systems have been developed to estimate the life expectancy of patients with spinal metastases treated with radiotherapy. Thorough understanding of radiotherapy-related knowledge including the dose-fractionation schedule, separation surgery, efficacy and safety, scoring systems, and feasibility of combination with other treatment methods is critical to providing optimal patient care.

Incidence and Risk Factors for Implant Failure in Spinal Metastasis Surgery

STUDY DESIGN

Retrospective study.

PURPOSE

To investigate the incidence of symptomatic and asymptomatic implant failure in spinal metastasis surgery and identify potential risk factors.

OVERVIEW OF LITERATURE

Surgical stabilization with instrumentation is an established method for the treatment of spinal metastasis. However, very few studies have investigated the incidence and risk factors for implant failure after spinal instrumentation surgery for the treatment of spinal metastasis.

METHODS

This study recruited 88 patients who received surgical stabilization with instrumentation for the treatment of spinal metastasis. Their medical records and postoperative X-rays were reviewed for evidence of implant failure. Statistical analysis with logistic regression was performed to assess nine potential risk factors for the development of implant failure, including patient's age at operation, gender, survival, primary tumor, spinal level involved, construct length, decompression levels, fusion material utilization, and radiotherapy application either before or after surgery, to identify potential contributing risk factors.

RESULTS

Implant failure was identified in nine out of 88 cases (10.2%) with two cases requiring implant removal: one case included a progressive kyphosis that resulted in nonhealing sore and the other involved a deep-seated wound infection that spread to the implants. Another case required wound debridement due to superficial wound infection. The remaining six cases were asymptomatic, despite postoperative X-rays demonstrating evidence of implant failure. No patient required implant revision. Logistic regression analysis demonstrated that patients who received radiotherapy either before or after surgery were less likely to develop implant failure.

CONCLUSIONS

The development of radiological implant failure following surgical treatment of spinal metastasis is common. However, symptomatic implant failure leading to revision surgery is uncommon. Our findings suggest that radiotherapy, either before or after spinal surgery, is not associated with the development of implant failure.

Minimally Invasive Pedicle Screw Fixation Combined with Percutaneous Kyphoplasty Under O-Arm Navigation for the Treatment of Metastatic Spinal Tumors with Posterior Wall Destruction

OBJECTIVE

To evaluate the safety and efficacy of O-arm-guided minimally invasive pedicle screw fixation combined with percutaneous kyphoplasty for metastatic spinal tumors with posterior wall destruction.

METHODS

Patients who underwent minimally invasive pedicle screw fixation combined with percutaneous kyphoplasty for pathological vertebral fractures with posterior wall defects from January 2015 to December 2017 were followed up for 1 year. Visual analogue scale (VAS), SF-36 scores, middle vertebral height, posterior vertebral height, and the accuracy of pedicle screws were assessed preoperatively, postoperatively, and 1 year after surgery. The operation time, time from operation to discharge, blood loss, volume of bone cement, and leakage of bone cement were recorded.

RESULTS

Twenty-three patients (13 females and 10 males) who met our criteria were followed up for 1 year. The operation time of these patients was 162.61 ± 33.47 min, the amount of bleeding was 230.87 ± 93.76 mL, the time from operation to discharge was 4.35 ± 2.42 days, and the volume of bone cement was 3.67 ± 0.63 mL. The VAS score decreased from 7.04 ± 1.07 to 2.65 ± 0.93 before surgery (P = 0.000) and remained at 2.57 ± 0.79 1 year after surgery. Compared with the preoperative SF-36 scores for physical pain, physiological function, energy, and social function, the postoperative scores were significantly improved (P = 0.000). The height of the middle vertebral body increased from 14.47 ± 2.96 mm before surgery to 20.18 ± 2.94 mm (P = 0.000), and remained at 20.44 to 3.01 mm 1 year after surgery. The height of the posterior vertebral body increased from 16.56 ± 3.07 mm before operation to 22.79 ± 4.00 mm (P = 0.000), and 22.45 ± 3.88 mm 1 year after surgery. The 23 patients had a total of 92 pedicle screws; 85 screws were Grade A and 7 screws were Grade B. There was no leakage of bone cement after surgery.

CONCLUSION

In the short term, O-arm-guided minimally invasive pedicle screw fixation combined with kyphoplasty is safe and effective in the treatment of metastatic spinal tumors with posterior wall destruction.

The Role of Minimal Access Surgery in the Treatment of Spinal Metastatic Tumors

STUDY DESIGN

Literature review.

OBJECTIVE

To provide an overview of the recent advances in minimal access surgery (MAS) for spinal metastases.

METHODS

Literature review.

RESULTS

Experience gained from MAS in the trauma, degenerative and deformity settings has paved the road for MAS techniques for spinal cancer. Current MAS techniques for the treatment of spinal metastases include percutaneous instrumentation, mini-open approaches for decompression and tumor resection with or without tubular/expandable retractors and thoracoscopy/endoscopy. Cancer care requires a multidisciplinary effort and adherence to treatment algorithms facilitates decision making, ultimately improving patient outcomes. Specific algorithms exist to help guide decisions for MAS for extradural spinal metastases. One major paradigm shift has been the implementation of percutaneous stabilization for treatment of neoplastic spinal instability. Percutaneous stabilization can be enhanced with cement augmentation for increased durability and pain palliation. Unlike osteoporotic fractures, kyphoplasty and vertebroplasty are known to be effective therapies for symptomatic pathologic compression fractures as supported by high level evidence. The integration of systemic body radiation therapy for spinal metastases has eliminated the need for aggressive tumor resection allowing implementation of MAS epidural tumor decompression via tubular or expandable retractors and preliminary data exist regarding laser interstitial thermal therapy and radiofrequency ablation for tumor control. Neuronavigation and robotic systems offer increased precision, facilitating the role of MAS for spinal metastases.

CONCLUSIONS

MAS has a significant role in the treatment of spinal metastases. This review highlights the current utilization of minimally invasive surgical strategies for treatment of spinal metastases.

SPINAL METASTASIS: DIAGNOSIS, TREATMENT AND PROGNOSIS - INTEGRATIVE REVIEW FROM 2012 TO 2017

ABSTRACT Care of the patient with spinal metastasis is challenging. The topic of this article is the treatment and prognosis of spinal metastases, aiming to enumerate and analyze literature that addresses this treatment and prognosis. The methodology used was an integrative review in the Virtual Health Library. Nineteen articles were identified demonstrating that there is research and scientific production in this area. The thematic units and their categories are: treatment decision - prognostic scales or clinical neurological evaluation; types of treatment - minimally invasive and/or traditional; and effectiveness of prognostic scales higher or lower probability of success, which provide insight into the different possibilities of patient evaluation and their applicability in practice. When making the diagnosis, planning the treatment, and establishing a prognosis, the professional must be in sync with current precepts and act based on the objective and subjective characteristics of the patients, such as beliefs and values, which although immeasurable, influence the survival and the effectiveness of treatment. Level of evidence I; Integrative Review.

An Independent Interobserver Reliability and Intraobserver Reproducibility Evaluation of Spinal Instability Neoplastic Score and Kostuik Classification Systems for Spinal Tumor

BACKGROUND

Most patients with spinal tumors suffer no symptoms or have mild symptoms, but about 14% of patients have refractory pain caused by mechanical instability, or symptoms of spinal cord damage caused by epidural spinal cord compression. The Spinal Instability Neoplastic Score (SINS) and Kostuik classification are commonly used to evaluate spinal stability, and help to make a more detailed operation plan. The objectives of this study are to evaluate the reliability and reproducibility of the SINS and Kostuik classification, and to explore their clinical application value.

METHODS

All 80 patients with spinal tumors were enrolled. Six spine surgeons who have certain clinical experience were selected. Patients were scored according to the SINS scoring system and classification was determined according to the Kostuik system. We used Fleiss and Cohen κ values to check the coefficient consistency for multifactors. We used Cohen κ value to check the interobserver reliability and intraobserver reproducibility. After 12 weeks, we repeated the analysis.

RESULTS

The interobserver reliability and intraobserver reproducibility of the SINS scoring system were near perfect with values of 0.831 and 0.874, respectively. The interobserver reliability and intraobserver reproducibility of the Kostuik classification system were moderate with values of 0.505 and 0.595, respectively.

CONCLUSIONS

Compared with the Kostuik classification system, the SINS scoring system has better interobserver reliability and intraobserver reproducibility, which can be widely used in clinical practice and has great significance in the decision-making of spinal tumor treatment. Although the Kostuik classification system is often used in clinical practice, it shows inferior reliability and reproducibility in our study.

Association of spinal instability due to metastatic disease with increased mortality and a proposed clinical pathway for treatment

OBJECTIVE

Multidisciplinary treatment including medical oncology, radiation oncology, and surgical consultation is necessary to provide comprehensive therapy for patients with spinal metastases. The goal of this study was to review the use of radiation therapy and/or surgical intervention and their impact on patient outcomes.

METHODS

In this retrospective series, the authors identified at their institution those patients with spinal metastases who had received radiation therapy alone or had undergone surgery with or without radiation therapy within a 6-year period. Data on patient age, chemotherapy, surgical procedure, radiation therapy, Karnofsky Performance Status (KPS), primary tumor pathology, Spinal Instability Neoplastic Score (SINS), and survival after treatment were collected from the patient electronic medical records. N - 1 chi-square testing was used for comparisons of proportions. The Student t-test was used for comparisons of means. A p value < 0.05 was considered statistically significant. A survival analysis was completed using a multivariate Cox proportional hazards model.

RESULTS

Two hundred thirty patients with spinal metastases were identified, 109 of whom had undergone surgery with or without radiation therapy. Among the 104 patients for whom the surgical details were reviewed, 34 (33%) had a history of preoperative radiation to the surgical site but ultimately required surgical intervention. In this surgical group, a significantly increased frequency of death within 30 days was noted for the SINS unstable patients (23.5%) as compared to that for the SINS stable patients (2.3%; p < 0.001). The SINS was a significant predictor of time to death among surgical patients (HR 1.11, p = 0.037). Preoperative KPS was not independently associated with decreased survival (p > 0.5) on univariate analysis. One hundred twenty-six patients met the criteria for inclusion in the radiation-only analysis. Ninety-eight of these patients (78%) met the criteria for potential instability (PI) at the time of treatment, according to the SINS system. Five patients (5%) with PI in the radiation therapy group had a documented neurosurgical or orthopedic surgery consultation prior to radiation therapy.

CONCLUSIONS

At the authors' institution, patients with gross mechanical instability per the SINS system had an increased rate of 30-day postoperative mortality, which remained significant when controlling for other factors. Surgical consultation for metastatic spine patients receiving radiation oncology consultation with PI is low. The authors describe an institutional pathway to encourage multidisciplinary treatment from the initial encounter in the emergency department to expedite surgical evaluation and collaboration.

Research on the predicting power of the revised Tokuhashi system: how much time can surgery give to patients with short life expectancy?

Object

The primary treatment option for symptomatic metastatic spinal tumors is surgery. Prognostic systems are designed to assist in the establishment of the indication and the choice of surgical methodology. The best-known prognostic system is the revised Tokuhashi system, which has a predictive ability of about 60%. In our study, we are attempting to find the reason for its poor predictive ability, despite its proper separation ability.

Methods

We have designed a one-center-based retrospective clinical trial, by which we would like to test the feasibility and the inaccuracy of the revised Tokuhashi system. In our database, there are 329 patients who underwent surgery. Statistical analysis was performed.

Results

A significant increase in survival time was observed in the ‘conservative’ category. Earlier studies reported OS 0.15 at the 180-day control time, in contrast with our 0.38 OS value. The literature suggested supportive care for this category, but in our population, every patient underwent surgery. Our population passes the 0.15 OS value on day 475. We propose an adjustment of the Tokuhashi category scores. We observed significant success in resolving pain. Motor functions were improved or stabilized compared to changes in vegetative dysfunction.

Conclusion

According to our results, the Tokuhashi scoring system makes very conservative predictions and prefers non-surgical palliative or supportive care. Surgical treatment increases the life expectancy of patients in poor condition. We propose modifying the therapeutic options of the revised Tokuhashi system, taking into consideration modern spine surgery techniques.

Instrumented surgical treatment for metastatic spinal tumors: is fusion necessary?

OBJECTIVE

The goal of this study was to evaluate the radiographic and clinical results of instrumentation surgery without fusion for metastases to the spine.

METHODS

Between 2010 and 2017, patients with spinal tumors who underwent instrumentation without fusion surgery were consecutively evaluated. Preoperative and postoperative clinical data were evaluated. Data were inclusive for last follow-up and just prior to death if the patient died. Instrumentation-related complications included screw migration, screw or rod breakage, cage migration, and screw loosening.

RESULTS

Excluding patients who died within 6 months, a total of 136 patients (140 operations) were recruited. The average follow-up duration was 16.5 months (median 12.4 months). The pain visual analog scale score decreased from 6.4 to 2.5 (p < 0.001) and the Eastern Cooperative Oncology Group scale score improved (p < 0.001). There were only 3 cases (2.1%) of symptomatic instrumentation-related complications that resulted in revisions. There were 6 cases of nonsymptomatic complications. The most common complication was screw migration or pull-out (5 cases). There were 3 cases of screw or rod breakage and 1 case of cage migration. Two-thirds of the cases of instrumentation-related complications occurred after 6 months, with a mean postoperative period of 1 year.

CONCLUSIONS

The current study reported successful outcomes with very low complication rates after nonfusion surgery for patients with spinal metastases, even among those who survived for more than 6 months. More than half of the instrumentation-related complications were asymptomatic and did not require revision. The results suggest that nonfusion surgery might be sufficient for a majority of patients with spinal metastases.

The "Friday peak" in surgical referrals for spinal metastases: lessons not learned. A retrospective analysis of 201 consecutive cases at a tertiary center

BACKGROUND

Spinal cord compression and fracture are potential complications of spine metastasis (SM). Rapid management by an expert team can reduce these adverse developments. Delays in seeking therapeutic advices, which lead to the need for sub-optimal emergency procedures, were already demonstrated nearly 20 years ago. We aimed to analyze the current weak points of referrals for vertebral metastasis so as to improve the care pathways.

METHODS

We retrospectively reviewed the data of all patients admitted on an emergency or elective basis who underwent palliative surgery for the treatment of neoplastic spine lesions in our institution (tertiary referral neurosurgical unit) between January 2009 and December 2016.

RESULTS

This retrospective study included 201 patients, 121 men and 80 women (mean age 65.1 years ± 10.9). Cancer was known for 59.7% of cases. Patients were neurologically asymptomatic in 52.7% of cases (Frankel E), and 123 (60.7%) were hospitalized for emergency reasons, including 51 (41.5% of emergencies) on a Friday (p < 0.0001). A significant increase in emergencies occurred over the studied period (p = 0.0027). The "emergency" group had significantly unfavorable results in terms of neurological status (p < 0.001), the occurrence of complications (p = 0.04), the duration of hospitalization (p = 0.02), and the clinical evolution (p = 0.04). Among 123 patients hospitalized for emergency reasons, 65 (52.8%) had known cancers, of which 33 had an identified SM, including 22 with neurological deficits (Frankel A-D), without prior surgical assessment (17.8% of emergencies).

CONCLUSION

Too many patients with previously identified metastases are referred for emergency reasons, including with a neurological deficit. Optimizing upstream pathways and referrals is imperative for improving the management of these patients. Involving a spine surgeon at the slightest symptom or an abnormal image is critical for defining the best treatment upstream. The use of telemedicine and the development of dedicated tumor boards are ways of improving this involvement.

Image guidance in spine tumor surgery

Beginning with basic stereotactic operative methods in neurosurgery, intraoperative navigation and image guidance systems have since become the norm in that field. Following the introduction of image guidance into spinal surgery, there has been a dramatic increase in its utilization across disciplines and pathologies. Spine tumor surgery encompasses a wide range of complex surgical techniques and treatment strategies. Similarly to deformity correction and trauma surgery, spine navigation holds potential to improve outcomes and optimize surgical technique for spinal tumors. Recent data demonstrate the applicability of neuro-navigation in the field of spinal oncology, particularly for spinal stabilization, maximizing extent of resection and integration of minimally invasive therapies. The rapid introduction of new, less invasive, and ablative surgical techniques in spine oncology coupled with the rising incidence of spinal metastatic disease make it imperative for spine surgeons to be familiar with the indications for and limitations of imaging guidance. Herein, we provide a practical, current concepts narrative review on the use of spinal navigation in three areas of spinal oncology: (a) extent of tumor resection, (b) spinal column stabilization, and (c) focal ablation techniques.

Treatment, complications, and outcomes of metastatic disease of the spine: from Patchell to PROMIS

Spinal metastases are common in patients with cancer. As cancer treatments improve and these patients live longer, the number who present with metastatic spine disease will increase. Treatment strategies for these patients continues to evolve. In particular, since the prospective randomized controlled study in 2005 by Patchell et al. showed increased survival with decompressive surgical treatment of spinal metastases, there is a growing body of literature focusing on surgical management and complications of surgery for this disease. Surgery is often one component of a multimodal treatment approach with chemotherapy and radiation, which makes it difficult to parse the benefits of each individual treatment in outcome studies. Additionally, there has been more recent emphasis placed on patient-reported outcomes (PRO) after treatment for metastatic spine disease. In this review, we summarize treatments of metastatic spinal disease, possible perioperative complications, and validated tools used to assess outcomes for these patients.

Review of robotic-assisted surgery: what the future looks like through a spine oncology lens

Recent advancements in medical technology have led to the emergence of robotic-assisted surgery with the hope of creating a safer and more efficient surgical environment for the patient and surgical team. Spine surgery and spine tumor surgery involve challenging anatomy and demand highly precise surgical maneuvers, creating an important niche for robotic systems. While still in its infancy, robotics in spine surgery have proven successful in pedicle screw placement. Similarly, robotics has begun to be used for accurate resections and surgical planning in tumor surgery. As future studies are published and robotics systems continue to evolve, we can expect more tactile haptic feedback and implementation of useful instruments to improve preoperative planning, resection guidance, and reconstruction during spine tumor surgery.

Open Kyphoplasty for Metastatic Spine Disease: A Retrospective Clinical Series

OBJECTIVE

Symptomatic metastatic spine disease (MSD), is a challenging disease involving 3%-20% of patients with bone metastases. Different surgical options are available and must be tailored to the general and neurologic conditions of the patients. Open kyphoplasty (OKP) refers to decompressive hemilaminectomy, associated with a contralateral percutaneous kyphoplasty, and in some cases, to a posterior stabilization. The aim of the study was to critically review our experience during the last decade with OKP in patients with cancer.

METHODS

Fifty-three patients with cancer underwent OKP for symptomatic MSD. The Tokuhashi score and Spinal Instability Neoplastic Score were calculated for each patient. Length of hospital stay, perioperative complications, incidence of adjacent-level fractures, and median survival after surgery were evaluated. Karnofsky Performance Status, visual analog scale, and Dennis Pain Score were calculated preoperatively, postoperatively, and at last follow-up.

RESULTS

Median Tokuhashi score and Spinal Instability Neoplastic Score were 10 and 10, respectively. The mean volume of filling material inserted was 3.6 mL. Median operative time was 180 minutes. Complications included 8 leakages (15%), 2 permanent motor deficits (3.8%), and 2 asymptomatic pulmonary embolisms (3.8%). Mean length of hospital stay was 7 days. A significant improvement was observed in Karnofsky Performance Status, visual analog scale score, and Dennis Pain Score (P < 0.0001). Median follow-up was 16 months and overall survival 22 months.

CONCLUSIONS

OKP was an effective treatment of symptomatic MSDs in selected oncologic patients with low Tokuhashi scores. It relieved lateral epidural compressions, expanded indications of palliative surgery in patients who were not otherwise surgical candidates, and rapidly dealt with cement leakages.

Prediction Accuracy of Common Prognostic Scoring Systems for Metastatic Spine Disease: Results of a Prospective International Multicentre Study of 1469 Patients

STUDY DESIGN

A prospective multicenter cohort study.

OBJECTIVE

To assess the clinical accuracy of six commonly cited prognostic scoring systems for patients with spinal metastases.

SUMMARY OF BACKGROUND DATA

There are presently several available methods for the estimation of prognosis in metastatic spinal disease, but none are universally accepted by surgeons for clinical use. These scoring systems have not been rigorously tested and validated in large datasets to see if they are reliable enough to inform day-to-day patient management decisions. We tested these scoring systems in a large cohort of patients. A total of 1469 patients were recruited into a secure internet database, and prospectively collected data were analyzed to assess the accuracy of published prognostic scoring systems.

METHODS

We assessed six prognostic scoring systems, described by the first authors Tomita, Tokuhashi, Bauer, van der Linden, Rades, and Bollen. Kaplan-Meier survival estimates were created for different patient subgroups as described in the original publications. Harrell's C-statistic was calculated for the survival estimates, to assess the concordance between estimated and actual survival.

RESULTS

All the prognostic scoring systems tested were able to categorize patients into separate prognostic groups with different overall survivals. However none of the scores were able to achieve "good concordance" as assessed by Harrell's C-statistic. The score of Bollen and colleagues was found to be the most accurate, with a Harrell's C-statistic of 0.66.

CONCLUSION

No prognostic scoring system was found to have a good predictive value. The scores of Bollen and Tomita were the most effective with Harrell's C-statistic of 0.66 and 0.65, respectively. Prognostic scoring systems are calculated using data from previous years, and are subject to inaccuracies as treatments advance in the interim. We suggest that other methods of assessing prognosis should be explored, such as prognostic risk calculation.

LEVEL OF EVIDENCE

3.

Cement-augmented pedicle screw insertion assisted by spinal robotic systems for widespread spinal metastases

Widespread spinal metastases can obscure bone landmarks and severely hinder surgical safety during pedicle screw insertion. Robot-assisted spinal surgery has demonstrated an excellent safety profile for pedicle screw insertion. Moreover, spinal surgery robotic systems can facilitate pedicle screw insertion with high-accuracy. We present a patient who had breast cancer with widespread spinal metastases, pathological vertebral fracture, and spinal cord compression with a challenge of intraoperative image recognition. To overcome this problem, she received surgical decompression and stabilization through the insertion of cement-augmented pedicle screws with the assistance of a spinal robotic system. At the 1-year follow-up, no implant loosening was observed, and the patient exhibited notable physical improvements, demonstrating that cement-augmented pedicle screw insertion with the assistance of spinal robotic systems is an effective method for treating widespread spinal metastases.

Retrospective multicenter study by the French Spine Society of surgical treatment for spinal metastasis in France

INTRODUCTION

The occurrence of spinal metastasis is a turning point in the progression of cancer. The optimal management has not been well defined. The aim of this study was to identify the various treatments currently being used in France and to determine the benefits of surgical treatment.

MATERIAL AND METHODS

The records of patients treated between 2011 and 2015 at seven spine surgery centers in France were reviewed retrospectively. The pain level (VAS), McAfee scale, walking ability and Frankel Grade were evaluated at inclusion and at 6-months postoperative. The Tomita and Tokuhashi prognostic scores were also determined.

RESULTS

The cohort consisted of 319 patients. Preoperatively, 63.5% of patients could walk without assistance and 66% were Frankel Grade E. Twenty percent of patients were bed-ridden according to the Karnofsky Performance Status. According to the Tokuhashi criteria, 44% were predicted to have less than 6 months to live. The Tomita score recommended palliative surgery in 48% of cases. Potentially unstable lesions were present in 67% of patients. The surgical indication was made because of a neurological deficit in 40% of cases, to alleviate pain in 30% of cases, and for an instability in 30% of cases. Spinal cord decompression and posterior fixation were the most common procedures. The overall complication rate was 38.6%. At 6-months postoperative, 24 patients had died of the 245 available for review. Only 13 patients could not walk (5.3%), 69.4% of patients were Frankel Grade E and pain levels were significantly lower that preoperatively (2.4 vs. 4.6, p<0.001).

DISCUSSION

This study's findings are evidence of the difficulties encountered when treating spinal metastases. The main prognostic scores do not appear to be valid for these patients. A large number of patients were operated urgently because of a neurological deficit, before the treatment could be discussed in a multidisciplinary team (MDT) meeting. Nevertheless, the surgical treatment of these patients is associated with an acceptable complication rate and clinical improvement.

CONCLUSION

Surgical treatment of spinal metastases is not well standardized; thus many different strategies are used. There is evidence that it improves the quality of life in most patients by reducing their pain and allowing them to walk again. However, this treatment must be discussed in the context of an MDT meeting before it is carried out. These patients should be evaluated early on by a spine surgeon to reduce the need for emergency surgery when a neurological deficit appears.

Use of Bone Morphogenetic Protein-2 in Vertebral Column Tumor Surgery: A National Investigation

OBJECTIVE

To report the rate of bone morphogenetic protein-2 (BMP-2) use in vertebral column tumor surgery.

METHODS

The Nationwide Inpatient Sample database (2012-2014) was queried to identify patients who underwent spinal fusion for vertebral column tumors (primary benign, primary malignant, or metastatic). The rate of BMP-2 use was calculated, and patient and operative factors associated with its use were also investigated.

RESULTS

We identified 9375 patients who underwent fusion surgery for spinal tumors between 2012 and 2014, with 540 cases using BMP-2 (5.8%). Preoperative diagnosis revealed that the rate of BMP-2 use in primary benign tumor surgery was 4.9%, 7.6% for primary malignant tumors, and 5.7% for metastatic lesions (P = 0.607). The overall complication rate was 13.2% (13.4% in the NO-BMP-2 group vs. 11.1% in the BMP-2 group; P = 0.504). Patients who received this growth factor were less likely to have epidural spinal cord compression at presentation (37.0% vs. 49.2%; P = 0.014), and more likely to have elective surgery (53.7% vs. 37.7%; P < 0.001). Analysis of hospital location indicated that the highest use of BMP-2 was in the South (7.4% rate; P = 0.002). There was no statistical difference between age, sex, insurance status, comorbidities, the presence of a pathologic fracture, or the use of inpatient radiotherapy or chemotherapy between patients who received BMP-2 and controls.

CONCLUSIONS

BMP-2 has been used off-label to promote arthrodesis; however, its use in patients with spinal tumors is controversial. In this national study, BMP-2 use was highest in the South, in patients without epidural cord compression at presentation, and in elective cases.

Surgical management of spinal metastases

INTRODUCTION

Metastatic spinal disease is a source of significant morbidity in patients with cancer. Recent advancements in adjuvant oncologic therapy has led to increased survival for many patients who harbor neoplastic disease. As a result of this, the chance of developing metastatic spinal disease over the course of a cancer patient's lifespan has increased. Symptomatic metastatic spinal disease can cause significant morbidity including severe pain, neurologic deficit, and loss of ambulation. Current treatment of these patients typically involves the use of multiple modalities, including surgery, radiation, and chemotherapy. Areas covered: An extensive literature review was performed to support the author's opinion on the matter of surgical management of spinal metastatic disease. Pubmed was utilized as a primary search engine. Expert commentary: Despite advances in chemotherapy and radiation therapy, surgery remains a mainstay in many of these patients, particularly with those with either significant metastatic spinal epidural compression or spinal instability. This review discusses the surgical management of metastatic spinal disease including a framework for decision making and technical considerations when deciding to operate on these patients.