A validation of the Oswestry Spinal Risk Index

The Oswestry Spinal Risk Index (OSRI) in assessing prognosis of patients with spinal metastases

Introduction

The Oswestry Spinal Risk Index (OSRI) was designed to predict life expectancy of patients presenting with spinal metastases. It integrates the most predictive items of existing scores and is calculated using not more than two items: General condition and primary tumor.

Research question

The purpose of this study was to externally validate the OSRI in a large cohort and to compare it with the established scores.

Material and methods

We retrospectively identified 211 consecutive surgical patients with symptomatic spinal metastases. We collected clinical and radiographic data, such as Karnofsky Performance Score (KPS), Frankel Status, primary tumor pathology and metastatic spread to calculate the Tokuhashi score, Tomita score, modified Bauer score and the OSRI. Logistic regression models, Kaplan-Meyer-curves, discriminant power and variance analyses were applied using Harrell’s C-index and Cox and Snell’s Pseudo R².

Results

Predicted and actual survival of our cohort’s patients correlated significantly in each investigated scoring systems (p < 0.001). In test quality measurements Tokuhashi score performed best (C = 0.7204; R² = 0.3619), followed by OSRI (C = 0.7023; R² = 0.2612), Tomita (C = 0.6748; R² = 0.2818) and modified Bauer score (C = 0.6653; R² = 0.2486). Accuracy of predicted life expectancy was highest in modified Bauer score and OSRI.

Discussion and conclusion

Compared to the original scores, the OSRI provided equal or even superior results in assessing our study population’s life expectancy. Its particular advantage lies in the simplicity of its application, which well meets the demands of surgical decision-making in daily practice.

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Prognosis prediction in patients with spinal metastases.

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Calculation of Oswestry Spinal Risk Index.

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Comparison of prognosis scores in spinal metastases.

Scoring Algorithms for Predicting Survival Prognosis in Patients With Metastatic Spinal Disease: The Current Status and Future Directions

Various survival scoring systems have been developed to help surgeons select the best candidates for appropriate therapies in patients with metastatic spinal disease. This study aims to discuss the current status and future directions of scoring systems for the prediction of survival prognosis in these patients. The search terms "spine metastases," "metastatic spinal disease," and "metastatic spinal cord compression" were combined with "survival prognosis," "scoring system," and "score" to elicit relevant literatures in PubMed and Embase databases. As a result, 159 articles were selected from PubMed, and 246 articles were extracted from Embase. After reviewing each article, we carefully included and analyzed 74 articles about the development and evaluation of scoring systems for predicting survival prognosis in spine metastases. In this review, those scoring systems were stratified into the historic scoring systems and the modern scoring systems on the basis of the proposed time. The historic scoring systems, including the original/revised Tokuhashi scoring system, the Bauer scoring system, the Tomita scoring system, and the Linden scoring system, and the modern scoring systems, such as the Lei scoring system, the Bartels scoring system, the Mizumoto scoring system, the Bollen scoring system, the Rades scoring system, Oswestry Spinal Risk Index, and the Choi risk calculator, were introduced and discussed in this review. Besides, the clinical effectiveness and pitfalls of the existing systems and the future directions of the next generation of scoring systems were also addressed and discussed. We recommended these scoring systems as preferable reference tools to help doctors to select surgical candidates. In patients with long-term life expectancy, radical surgery, such as wide or marginal excision, can be considered in patients with neurological deficits, spine instability, or severe back pain. Besides, with the advancement and improvement of medical technologies, surgical procedures are changing, which can affect surgical indications such as vertebroplasty, minimal invasive surgery, and percutaneous stabilization, which can also be used in patients with spine instability or severe back pain, and do not require much recovery; hence, they can even be used in patients with relative short-term life expectancy. However, the decision about the treatment of patients with metastatic spinal disease is so complicated and should never rely on prognostic scores alone. The final therapeutic decision should be made by interdisciplinary corporations of oncologists, radiologists, and spinal surgeons. Besides, individual intentions should be respected.

A Personalized Medicine Approach for the Management of Spinal Metastases with Cord Compression: Development of a Novel Clinical Prediction Model for Postoperative Survival and Quality of Life

Surgery should be considered for patients with metastatic epidural spinal cord compression (MESCC) with a life expectancy of ≥3 months. Given the heterogeneity of the clinical presentation and outcomes, clinical prognostic models (CPMs) can assist in tailoring a personalized medicine approach to optimize surgical decision-making. We aimed to develop and internally validate the first CPM of health-related quality of life (HRQoL) and a novel CPM to predict the survival of patients with MESCC treated surgically. Using data from 258 patients (AOSpine North America MESCC study and Nottingham MESCC registry), we created 1-year survival and HRQoL CPMs using a Cox model and logistic regression analysis with manual backward elimination. The outcome measure for HRQoL was the minimal clinical important difference in EuroQol 5-dimension questionnaire scores. Internal validation involved 200 bootstrap iterations, and calibration and discrimination were evaluated. Longer survival was associated with a higher SF-36 physical component score (hazard ratio [HR], 0.96). In contrast, primary tumor other than breast, thyroid, or prostate (unfavorable: HR, 2.57; other: HR, 1.20), organ metastasis (HR, 1.51), male sex (HR, 1.58), and preoperative radiotherapy (HR, 1.53) were not (c-statistic, 0.69; 95% confidence interval, 0.64-0.73). Karnofsky performance status <70% (odds ratio [OR], 2.50), living in North America (OR, 4.06), SF-36 physical component score (OR, 0.95) and SF-36 mental component score (OR, 0.96) were associated with the likelihood of achieving a minimal clinical important difference improvement in the EuroQol 5-Dimension Questionnaire score at 3 months (c-statistic, 0.74; 95% confidence interval, 0.68-0.79). The calibration for both CPMs was very good. We developed and internally validated the first CPMs of survival and HRQoL at 3 months postoperatively in patients with MESCC using the TRIPOD (transparent reporting of a multivariable prediction model for individual prognosis or diagnosis) guidelines. A web-based calculator is available (available at: http://spine-met.com) to assist with clinical decision-making.

The Role of Prognostic Scoring Systems in Assessing Surgical Candidacy for Patients With Vertebral Metastasis: A Narrative Review

STUDY DESIGN

Narrative review.

OBJECTIVES

To review the relevant literature regarding scoring systems for vertebral metastases and quantify their role in contemporary orthopedic practice.

METHODS

A literature search of PubMed, Google Scholar, and Embase was performed on February 7, 2017. Eight scoring systems were selected for detailed review-7 of which were scores focused solely on patient prognosis (Tokuhashi, Tomita, Bauer, Oswestry Spinal Risk Index, Van der Linden, Rades, and Katagiri). The eighth system reviewed was the Spinal Instability Neoplastic Score, which examines for impending spinal instability in patients with vertebral metastases and represents a novel approach compared with hitherto scoring systems.

RESULTS

The Bauer and Oswestry Spinal Risk Index have the most accurate prognostic predictive ability, with the newer Oswestry Spinal Risk Index being favored by the contemporary literature as it demands less investigation and is therefore more readily accessible. There was a growing trend in studies designed to customize scoring systems for individual cancer pathological subtypes. The Spinal Instability Neoplastic Score shows good reliability for predicting instability among surgeons and oncologists.

CONCLUSIONS

The increased understanding of cancer pathology and subsequent development of customized treatments has led to prolonged survival. For patients with vertebral metastases, this affects surgical candidacy not only on the basis of prognosis but also provides prolonged opportunity for the development of spinal instability. Scoring systems have a useful guidance role in these deciding for/against surgical intervention, but in order to remain contemporary ongoing review, development, and revalidation is mandatory.

Management - spinal metastases

Due to a worldwide increase of cancer incidence and a longer life expectancy of patients with metastatic cancer, a rise in the incidence of symptomatic vertebral metastases has been observed. Metastatic spinal disease is one of the most dreaded complications of cancer as it is not only associated with severe pain, but also with paralysis, sensory loss, sexual dysfunction, urinary and fecal incontinency when the neurologic elements are compressed. Rapid diagnosis and treatment have been shown to improve both the quality and length of remaining life. This chapter on vertebral metastases with epidural disease and intramedullary spinal metastases will be discussed in terms of epidemiology, pathophysiology, demographics, clinical presentation, diagnosis, and management. With respect to treatment options, our review will summarize the evolution of conventional palliative radiation to modern stereotactic body radiotherapy for spinal metastases and the surgical evolution from traditional open procedures to minimally invasive spine surgery. Lastly, we will review the most common clinical prediction and decision rules, framework and algorithms, and guidelines that have been developed to guide treatment decision making.

Sternal metastasis - the forgotten column and its effect on thoracic spine stability

Sternal metastases are not studied extensively in the literature. There is a paucity of information on their role in metastatic disease. The concept of the fourth column was described by Berg in 1993, and has been proven in case report, clinically and biomechanical studies. The role of the sternum as a support to the thoracic spine is well documented in the trauma patients, but not much is known about its role in cancer patients. This review examines what is known on the role of the fourth column. Following this we have identified two likely scenarios that sternal metastases may impact management: (1) sternal pathological fracture increases the mobility of the semi-rigid thorax with the loss of the biomechanical support of the sternum-rib-thoracic spine complex; and (2) a sternal metastasis increases the risk of fracture, and while being medical treated the thoracic spine should be monitored for acute kyphosis and neurological injury secondarily to the insufficiency of the fourth column.

[Role of surgery in the management of vertebral metastases. General revue]

The spine is the most common site of skeletal metastases. Treatment decisions for patients with spinal metastases can be challenging and greatly depend on survival prognosis. Surgery remains a valuable weapon in the therapeutic arsenal. A review of the literature describing the role of surgery, the various surgical approaches and the prognostic scores available for the management of spinal metastases was performed and summarized. Surgery for spinal metastases has 3 main objectives: management of pain, achievement of mechanical stability and preservation or restoration of neurological function. A variety of surgical approaches are available and depend on location of tumor, presence of instability, neurological status, oncologic prognosis, general performance status and subsequent treatment measures. The goal of any therapeutic course for a spinal metastasis is the best oncologic and functional result with the least aggressive treatment. Novelty surgical and adjunctive measures allow a multidisciplinary approach to the metastatic spine.