Spinal neoplastic instability: biomechanics and current management options

Molecular mechanism of mechanical pressure induced changes in the microenvironment of intervertebral disc degeneration

BACKGROUND

Lower back pain, as a typical clinical symptom of spinal degenerative diseases, is emerging as a major social problem. According to recent researches, the primary cause of this problem is intervertebral disc degeneration (IVDD). IVDD is closely associated with factors such as age, genetics, mechanical stimulation (MS), and inadequate nutrition. In recent years, an increasing number of studies have further elucidated the relationship between MS and IVDD. However, the exact molecular mechanisms by which MS induces IVDD remain unclear, highlighting the need for in-depth exploration and study of the relationship between MS and IVDD.

METHODS

Search for relevant literature on IVDD and MS published from January 1, 2010, to the present in the PubMed database.

RESULTS

One of the main causes of IVDD is MS, and loading modalities have an impact on the creation of matrix metalloproteinase, the metabolism of the cellular matrix, and other biochemical processes in the intervertebral disc. Nucleus pulposus cell death induced by MS, cartilage end-plate destruction accompanied by pyroptosis, apoptosis, iron death, senescence, autophagy, oxidative stress, inflammatory response, and ECM degradation interact with one another to form a cooperative signaling network.

CONCLUSION

This review discusses the molecular mechanisms of the changes in the microenvironment of intervertebral discs caused by mechanical pressure, explores the interaction between mechanical pressure and IVDD, and provides new insights and approaches for the clinical prevention and treatment of IVDD.

Surgical options for metastatic spine tumors: WFNS spine committee recommendations

Surgical treatments for metastatic spine tumors have evolved tremendously over the last decade. Improvements in immunotherapies and other medical treatments have led to longer life expectancy in cancer patients. This, in turn, has led to an increase in the incidence of metastatic spine tumors. Spine metastases remain the most common type of spine tumor. In this study, we systematically reviewed all available literature on metastatic spine tumors and spinal instability within the last decade. We also performed further systematic reviews on cervical metastatic tumors, thoracolumbar metastatic tumors, and minimally invasive surgery in metastatic spine tumors. Lastly, the results from the systematic reviews were presented to an expert panel at the World Federation of Neurosurgical Societies (WFNS) meeting, and their consensus was also presented.

Selection of bone graft type for the surgical treatment of thoracolumbar spinal tuberculosis based on the spinal instability neoplastic score: a retrospective single-center cohort study

OBJECTIVES

This study aimed to establish a standard for selecting bone graft type for thoracolumbar spinal tuberculosis surgery based on the spinal instability neoplastic score (SINS).

METHODS

Patients with thoracolumbar tuberculosis who underwent one-stage debridement posteriorly and instrumentation were divided into a structural bone graft group (SBG) (51 cases) and a non-structural bone graft group (NSBG) (54 cases) according to their SINS. SBG was performed when the SINS was ≥ 13 and NSBG was performed when it was 7 ≤ SINS ≤ 12. Baseline data, clinical outcomes, and imaging outcomes were collected and statistically analyzed between the two groups.

RESULTS

Significant improvements in clinical and imaging outcomes were achieved in both groups. Compared to the SBG group, the operation time of the NSBG group was shorter, the intraoperative blood loss of the NSBG group was less, the bone fusion time of the NSBG group was faster.

CONCLUSION

Non-structural and structural bone grafting can achieve comparable therapeutic effects in patients with spinal tuberculosis, and a suitable selection of bone grafts based on quantitative SINS will make full use of the advantages of different bone grafts.

Prescribing Exercise to Cancer Patients Suffering from Increased Bone Fracture Risk Due to Metastatic Bone Disease or Multiple Myeloma in Austria-An Inter- and Multidisciplinary Evaluation Measure

INTRODUCTION

In the current absence of specific functional fracture risk assessment technology, the planning of physical exercise interventions for cancer patients suffering from increased bone fracture risk remains a serious clinical challenge. Until a reliable, solely technical solution is available for the clinician, fracture risk assessment remains an inter- and multidisciplinary decision to be made by various medical experts. The aim of this short paper is depicting how this challenge should be approached in the clinical reality according to Austrian experts in cancer rehabilitation, presenting the best-practice model in Austria. Following referral from the specialist responsible for the primary cancer treatment (oncologist, surgeon, etc.), the physiatrist takes on the role of rehabilitation case manager for each individual patient. Fracture risk assessment is then undertaken by specialists in radiology, orthopedics, oncology, and radiation therapy, with the result that the affected bone regions are classified as being at highly/slightly/not increased fracture risk. Following internal clearance, exercise planning is undertaken by a specialist in exercise therapy together with the physiatrist based on the individual's fracture risk assessment. In the case in which the patient shows exercise limitations due to additional musculoskeletal impairments, adjuvant physical modalities such as physiotherapy should be prescribed to increase exercisability.

CONCLUSION

Exercise prescription for cancer patients suffering from increased fracture risk is an inter- and multidisciplinary team decision for each individual patient.

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.

An Overview of Decision Making in the Management of Metastatic Spinal Tumors

INTRODUCTION

Spinal metastases are the most commonly encountered spinal tumors. With increasing life expectancy and better systemic treatment options, the incidence of patients seeking treatment for spinal metastasis is rising. Radical resections and conventional low-dose radiotherapy have given way to modern 'separation' surgeries and stereotactic body radiotherapy which entails lesser morbidity and improved local control. This article provides an overview of the decision making and currently available treatment options for metastatic spinal tumors.

METHODS

A MEDLINE literature search was made for studies in English language reporting on human subjects, describing results of various treatment options that are a part of multidisciplinary management of metastatic spinal tumors. The highest-quality evidence available in the literature was reviewed.

DISCUSSION

Treatment of patients with metastatic spinal tumors is largely palliative, with radiotherapy and selective surgery being the mainstays of management. Multidisciplinary management that incorporates factors like patient performance status, expected survival and systemic burden of disease and employs well-validated decision-making frameworks for guiding treatment holds the key to an effective palliative treatment strategy. Effective pain management, achieving local control, adequate neurological decompression in the setting of epidural cord compression and surgical stabilization for mechanical stabilization are the main goals of treatment.

CONCLUSION

The management of metastatic spinal tumors has been rapidly evolving; currently, limited decompression and stabilization followed by postoperative SBRT for local tumor control are associated with less morbidity and may be referred to as the current standard of care in these patients.

Pre-radiotherapy pain intensity and health-related quality of life in patients with bone metastases at various vertebral levels

PURPOSE

The spine is the most common site of bone metastasis from cancer and can be divided into 5 locational subsections, varying in mobility. The purpose of this research was to determine if the mobility of the metastases-bearing vertebral segment influenced pre-treatment pain intensity or health-related quality of life (HR-QoL) for patients about to receive palliative radiation therapy for painful spine metastasis.

METHODS

This study was a retrospective chart review of patients referred to the Palliative Radiation Oncology Program, about to receive radiation therapy for vertebral metastasis between January 2014 and June 2016. The main variables included patient-reported Edmonton Symptom Assessment Score pain intensity, the EQ-5D score for HR-QoL and the location of the vertebral metastasis (categorized using the SINS mobility score (mobile, junctional, semi-rigid, or rigid)). Various patient, disease and treatment characteristics were also collected, and entered into a multivariate analysis.

RESULTS

The eligible sample included 196 patients. Spinal metastases were distributed with approximately equal frequency (~27%) between the junctional, mobile and semi-rigid spine segments. Rigid spine was the least common site for spinal metastases (19%). Patients with metastatic disease in the mobile spine regions experienced greater pre-treatment pain compared to patients with disease in junctional subsections (Odds Ratio [OR] 1.37; p0.012). No relationship between HR-QOL and spinal mobility was found. Multivariate analysis also revealed that spinal metastases from a primary lung diagnosis reported worse pre-treatment pain compared to those from genitourinary cancers (OR 1.15; p0.05). Only age significantly influenced HR-QoL (75-95yrs vs. 35-55yrs; p0.041).

CONCLUSIONS

Patients referred to an RT clinic for the treatment of painful spinal metastases have a different distribution of disease throughout the spine compared to those referred for surgery or SBRT. Those with metastases in mobile spine segments were more likely to experience severe pre-treatment pain than those with metastases in junctional segments. Although further corroboration is needed, our results suggest that the mobility of the metastasis-bearing spinal section could be added to the existing list of predictors that aid clinicians in identifying patients that will benefit from closer follow-up or early intervention.

Spinal Instability Neoplastic Score (SINS): Reliability Among Spine Fellows and Resident Physicians in Orthopedic Surgery and Neurosurgery

STUDY DESIGN

Reliability analysis.

OBJECTIVES

The Spinal Instability Neoplastic Score (SINS) was developed for assessing patients with spinal neoplasia. It identifies patients who may benefit from surgical consultation or intervention. It also acts as a prognostic tool for surgical decision making. Reliability of SINS has been established for spine surgeons, radiologists, and radiation oncologists, but not yet among spine surgery trainees. The purpose of our study is to determine the reliability of SINS among spine residents and fellows, and its role as an educational tool.

METHODS

Twenty-three residents and 2 spine fellows independently scored 30 de-identified spine tumor cases on 2 occasions, at least 6 weeks apart. Intraclass correlation coefficient (ICC) measured interobserver and intraobserver agreement for total SINS scores. Fleiss's kappa and Cohen's kappa analysis evaluated interobserver and intraobserver agreement of 6 component subscores (location, pain, bone lesion quality, spinal alignment, vertebral body collapse, and posterolateral involvement of spinal elements).

RESULTS

Total SINS scores showed near perfect interobserver (0.990) and intraobserver (0.907) agreement. Fleiss's kappa statistics revealed near perfect agreement for location; substantial for pain; moderate for alignment, vertebral body collapse, and posterolateral involvement; and fair for bone quality (0.948, 0.739, 0.427, 0.550, 0.435, and 0.382). Cohen's kappa statistics revealed near perfect agreement for location and pain, substantial for alignment and vertebral body collapse, and moderate for bone quality and posterolateral involvement (0.954, 0.814, 0.610, 0.671, 0.576, and 0.561, respectively).

CONCLUSIONS

The SINS is a reliable and valuable educational tool for spine fellows and residents learning to judge spinal instability.

Postoperative quality-of-life assessment in patients with spine metastases treated with long-segment pedicle-screw fixation

OBJECTIVE In recent decades, progress in the medical management of cancer has been significant, resulting in considerable extension of survival for patients with metastatic disease. This has, in turn, led to increased attention to the optimal surgical management of bone lesions, including metastases to the spine. In addition, there has been a shift in focus toward improving quality of life and reducing hospital stay for these patients, and many minimally invasive techniques have been introduced with the aim of reducing the morbidity associated with more traditional open approaches. The goal of this study was to assess the efficacy of long-segment percutaneous pedicle screw stabilization for the treatment of instability associated with thoracolumbar spine metastases in neurologically intact patients. METHODS This study was a retrospective review of data from a prospective database. The authors analyzed cases in which long-segment percutaneous pedicle screw fixation was performed for the palliative treatment of thoracolumbar spinal instability due to spinal metastases in neurologically intact patients. All of the patients included in the study underwent surgery between January 2014 and May 2015 at the authors' institution. Postoperative radiation therapy was planned within 10 days following the stabilization in all cases. Clinical and radiological follow-up assessments were planned for 3 days, 3 weeks, 6 weeks, 3 months, 6 months, and 1 year after surgery. Outcome was assessed by means of standard postoperative evaluation and oncological and spinal quality of life measures (European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Version 3.0 [EORTC QLQ-C30] and Oswestry Disability Index [ODI], respectively). Moreover, 5 patients were given an activity monitoring device for recording the distance walked daily; preoperative and postoperative daily distances were compared. RESULTS Data from 17 cases were analyzed. There were no complications, and patients showed improvement in pain level and quality of life from the early postoperative period on. The mean ODI score was 62.7 (range 40-84) preoperatively, 35.4 (range 24-59) on postoperative Day 3, and 46.1 (range 30-76) at 3 weeks, 37.6 (range 25-59) at 6 weeks, 34.0 (range 24-59) at 3 months, 39.1 (range 22-64) at 6 months, and 30.0 (range 20-55) at 1 year after screw placement. The mean ODI was significantly improved in the first 45 days (p < 0.001). Improvement was also evident in scores for functional and symptomatic scales of the EORTC QLQ-C30. All patients underwent postoperative radiation therapy within 10 days (mean 7.5). All patients (n = 5) with an activity monitoring device showed improvement in daily walking distance. CONCLUSIONS Less-invasive palliative treatment for advanced spinal metastases is promising as part of a multidisciplinary approach to the care of patients with metastatic disease. The results of this study indicate that percutaneous surgery may allow for rapid improvement in quality of life and walking ability for patients with thoracolumbar instability due to spine metastases. Long-segment percutaneous screw fixation followed by early radiation therapy appears to be a safe and effective treatment option for providing solid and durable stability and improved quality of life for these patients.

Is there a relationship between spinal instability in neoplastic disease and Tokuhashi scoring system?

Spinal instability neoplastic score (SINS) classification evaluates spinal stability by adding together six radiographic and clinical components. The objective of this study was to verify the association between SINS and Tokuhashi scoring system (TSS) score. Fifty-eight patients with vertebral metastases were admitted from 2010 to 2014 at Hospital do Servidor Público Estadual de São Paulo. They were evaluated according to their SINS and Tokuhashi SS score. Fourteen patients (24.13 %) scored from 0 to 6 points (stable spine), 37 (63.79 %) scored from 7 to 12 (potentially unstable), and 7 (12.06 %) scored from 13 to 18 (unstable). In stable spine patients according to SINS, the mean TSS score was 9.2. In potentially unstable spine patients, the mean TSS score was 8.24. In unstable spine patients, mean TSS score was 6.28. There was a statistically significant difference of the TSS score between stable and unstable patients. After evaluating TSS score in each patient, the worse the SINS, the worse was also the TSS score.

Modern surgical techniques for management of soft tissue sarcomas involving the spine: outcomes and complications

Several types of soft tissue sarcomas may locally extend to the spine. The best therapeutic strategy for such lesions strongly depends on the histological diagnosis. In this article the authors provide an up-to-date review of current guidelines regarding the management of soft tissue sarcomas involving the spine. Special attention is given to outcomes and complications of modern surgical series in order to highlight current challenges in the management of such lesions.