Trends in the surgical treatment for spinal metastasis and the in-hospital patient outcomes in the United States from 2000 to 2009

Hypoalbuminemia as an Independent Risk Factor for Perioperative Complications Following Surgical Decompression of Spinal Metastases

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Malnutrition has been shown to be a risk factor for poor perioperative outcomes in multiple surgical subspecialties, but few studies have specifically investigated the effect of hypoalbuminemia in patients undergoing operative treatment of metastatic spinal tumors. The aim of this study was to assess the role of hypoalbuminemia as an independent risk factor for 30-day perioperative mortality and morbidity after surgical decompression of metastatic spinal tumors using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2011 to 2014.

METHODS

We identified 1498 adult patients in the ACS-NSQIP database who underwent laminectomy and excision of metastatic extradural spinal tumors. Patients were categorized into normoalbuminemic and hypoalbuminemic (ie, albumin level <3.5 g/dL) groups. Univariate and multivariate regression analyses were performed to examine the association between preoperative hypoalbuminemia and 30-day perioperative mortality and morbidity. Subgroup analysis was performed in the hypoalbuminemic group to assess the dose-dependent effect of albumin depletion.

RESULTS

Hypoalbuminemia was associated with increased risk of perioperative mortality, any complication, sepsis, intra- or postoperative transfusion, prolonged hospitalization, and non-home discharge. However, albumin depletion was also associated with decreased risk of readmission. There was an albumin level-dependent effect of increasing mortality and complication rates with worsening albumin depletion.

CONCLUSIONS

Hypoalbuminemia is an independent risk factor for perioperative mortality and morbidity following surgical decompression of metastatic spinal tumors with a dose-dependent effect on mortality and complication rates. Therefore, it is important to address malnutrition and optimize nutritional status prior to surgery.

Decompression and Instrumentation without Fusion for Spinal Metastases: Loosening Rate and Consequences

Background/Purpose

For patients with spinal metastases, decompression surgery was usually followed by instrumentation without fusion. Over time, mechanical stress would lead to loosening of implants. Yet, there is a lack of studies concerning the loosening rate, or the impact on patients when the implants are loosened. We aim at finding the postoperative loosening rate of implant, postoperative survivorship of patients, as well as their correlation with the mode of instrumentation.

Methods

A retrospective study including patients with metastatic spinal cord compression, who received decompression and instrumentation without fusion in a local hospital in Hong Kong from 2007 to 2014 was carried out. Patients with primary spinal tumour or prior spinal fusion were excluded. Demographics, tumour characteristics, mode of instrumentation, loosening rate of implants, as well as survivorship of patients were retrieved. Radiographs at 1 year postoperation were counter-examined by 2 Orthopaedic specialists on the Electronic Patient Record System.

Results

Total of 65 operations were retrieved. The age ranged from 27 to 84 years old. The most frequent primary source of malignancy was lung (26.5%), followed by breast (24.62%). Thoracic level (60%) was the most frequent site of spinal metastases. The survivorship at 1 year postoperation was 61.54%. The overall loosening rate of implants was 44.44%, with the Luque rods and sublaminar wire system being the most (70%). None of the cases required revision or removal of implants at 1 year postoperation.

Conclusion

The loosening rate of implants was high, and it is expected to grow even higher as oncological patients continue to improve in their survivorship with the medical advances such as target therapy. Yet there is still no definite evidence on how the implant loosening would affect patients’ quality of life and clinical performance.

Factors influencing early postoperative complications following surgery for symptomatic spinal metastasis: a single-center series and multivariate analysis

Patients presenting with neurological deficits and/or pain due to spinal metastasis usually require immediate or subacute surgical treatment. Nevertheless, it is unclear whether or not side effects of primary cancer location might influence postoperative complication rate. We therefore analyzed our spinal database to identify factors influencing early postoperative complications after surgery for symptomatic spinal metastases. From 2013 to 2017, 163 consecutive patients suffering from symptomatic spinal metastases were treated at our department. Early postoperative complications were defined as any postoperative event requiring additional medical or surgical treatment within 30 days of spinal surgery. A multivariate regression analysis was performed to identify independent predictors for postoperative complications after surgery for spinal metastasis. Overall, 39 of 163 patients who underwent spinal surgery for spinal metastasis developed early postoperative complications throughout the treatment course (24%). Preoperative ASA score ≥ 3 (p = 0.003), preoperative C-reactive protein level > 10 mg/l (p = 0.008), preoperative Karnofsky Performance Score < 60% (p = 0.03), radiation treatment within 2 months of surgery (p = 0.01), presence of diabetes mellitus (p = 0.008), and preoperative complete neurological impairment (p = 0.04) were significant and independent predictors for early postoperative complications in patients with surgery for spinal metastasis. The ability to preoperatively predict postoperative complication risk is valuable to select critically ill patients at higher risk requiring special attention. Therefore, the present study identified several significant and independent risk factors for the development of early postoperative complication in patients who underwent surgery for spinal metastasis.

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.

The Impact of Metastatic Spinal Tumor Location on 30-Day Perioperative Mortality and Morbidity After Surgical Decompression

STUDY DESIGN

A retrospective cohort study from 2011 to 2014 was performed using the American College of Surgeons National Surgical Quality Improvement Program database.

OBJECTIVE

The purpose of this study was to assess the impact of tumor location in the cervical, thoracic, or lumbosacral spine on 30-day perioperative mortality and morbidity after surgical decompression of metastatic extradural spinal tumors.

SUMMARY OF BACKGROUND DATA

Operative treatment of metastatic spinal tumors involves extensive procedures that are associated with significant complication rates and healthcare costs. Past studies have examined various risk factors for poor clinical outcomes after surgical decompression procedures for spinal tumors, but few studies have specifically investigated the impact of tumor location on perioperative mortality and morbidity.

METHODS

We identified 2238 patients in the American College of Surgeons National Surgical Quality Improvement Program database who underwent laminectomy for excision of metastatic extradural tumors in the cervical, thoracic, or lumbosacral spine. Baseline patient characteristics were collected from the database. Univariate and multivariate regression analyses were performed to examine the association between spinal tumor location and 30-day perioperative mortality and morbidity.

RESULTS

On univariate analysis, cervical spinal tumors were associated with the highest rate of pulmonary complications. Multivariate regression analysis demonstrated that cervical spinal tumors had the highest odds of multiple perioperative complications. However, thoracic spinal tumors were associated with the highest risk of intra- or postoperative blood transfusion. In contrast, patients with metastatic tumors in the lumbosacral spine had lower odds of perioperative mortality, pulmonary complications, and sepsis.

CONCLUSION

Tumor location is an independent risk factor for perioperative mortality and morbidity after surgical decompression of metastatic spinal tumors. The addition of tumor location to existing prognostic scoring systems may help to improve their predictive accuracy.

LEVEL OF EVIDENCE

3.

Interbody distraction and vertebral body reconstruction with polymethylmethacrylate for the treatment of pathological fractures

OBJECTIVE Treatment of epidural spinal cord compression (ESCC) caused by tumor includes surgical decompression and stabilization followed by postoperative radiation. In the case of severe axial loading impairment, anterior column reconstruction is indicated. The authors describe the use of interbody distraction to restore vertebral body height and correct kyphotic angulation prior to reconstruction with polymethylmethacrylate (PMMA), and report the long-term durability of such reconstruction. METHODS A single institution, prospective series of patients with ESCC undergoing single-stage decompression, anterior column reconstruction, and posterior instrumentation from 2013 to 2016 was retrospectively analyzed. Several demographic, perioperative, and radiographic measurements were collected. Descriptive statistics were compiled, in addition to postoperative changes in anterior height, posterior height, and kyphosis. Paired Student t-tests were performed for each variable. Overall survival was calculated using the techniques described by Kaplan and Meier. RESULTS Twenty-one patients underwent single-stage posterior decompression with interbody distraction and anterior column reconstruction using PMMA. The median age and Karnofsky Performance Scale score were 61 years and 70, respectively. Primary tumors included renal cell (n = 8), lung (n = 4), multiple myeloma (n = 2), prostate (n = 2), and other (n = 5). Eighteen patients underwent a single-level vertebral body reconstruction and 3 underwent multilevel transpedicular corpectomies. The median survival duration was 13.3 months. In the immediate postoperative setting, statistically significant improvement was noted in anterior body height (p = 0.0017, 95% confidence interval [CI] -4.15 to -1.11) and posterior body height (p = 0.0116, 95% CI -3.14 to -0.45) in all patients, and improved kyphosis was observed in those with oblique endplates (p = 0.0002, 95% CI 11.16-20.27). In the median follow-up duration of 13.9 months, the authors observed 3 cases of asymptomatic PMMA subsidence. One patient required reoperation in the form of extension of fusion. CONCLUSIONS In situ interbody distraction allows safe and durable reconstruction with PMMA, restores vertebral height, and corrects kyphotic deformities associated with severe pathological fractures caused by tumor. This is accomplished with minimal manipulation of the thecal sac and avoiding an extensive 360° surgical approach in patients who cannot tolerate extensive surgery.

Systematic review and meta-analysis of effectiveness of preoperative embolization in surgery for metastatic spine disease

Background

Preoperative embolization (PE) may decrease intraoperative blood loss (IBL) in decompressive surgery of hypervascular spinal metastases. However, no consensus has been found in other metastases and no meta-analysis which reviewed the benefit of PE in spinal metastases has been conducted.

Objective

To assess IBL in spinal metastases surgery in a randomized controlled trial (RCT) and cohort studies comparing PE and a control group of non-embolized patients.

Methods

A systematic search of relevant publications in PubMed and EMBASE was undertaken. Inclusion criteria were RCTs and observational studies in patients with spinal metastases who underwent spine surgery and reported IBL. Meta-analysis was performed using standardized mean difference (SMD) and mean difference (MD) of IBL. Heterogeneity was assessed using the I2 statistic.

Results

A total of 265 abstracts (126 from PubMed and 139 from Embase) were identified through database searching. The reviewers selected six studies for qualitative synthesis and meta-analysis. The pooled SMD of the included studies was 0.58 (95% CI −0.10 to 1.25, p=0.09). Sensitivity analysis revealed that, if the study by Rehak et al was omitted, the pooled SMD was significantly changed to 0.88 (95% CI 0.39 to 1.36, p<0.001) and PE reduced the IBL significantly. The pooled MD was 708.3 mL (95% CI −224.4 to 1640.9 mL, p=0.14). If the results of the Rehak et al study were omitted, the pooled MD was significantly changed to 1226.9 mL (95% CI 345.8 to 2108.1 mL, p=0.006).

Conclusions

PE can be effective in reducing IBL in spinal metastases surgery in both renal cell carcinoma and mixed primary tumor groups.

The epidemiology of spinal tuberculosis in the United States: an analysis of 2002–2011 data

OBJECTIVE

The aim of this study was to investigate the incidence of spinal tuberculosis (TB) in the US between 2002 and 2011.

METHODS

The Nationwide Inpatient Sample database from 2002 to 2011 was used to identify patients with a discharge diagnosis of TB and spinal TB. Demographic and hospital data were obtained for all admissions, and included age, sex, race, comorbid conditions, insurance status, hospital location, hospital teaching status, and hospital region. The incidence rate of spinal TB adjusted for population growth was calculated after application of discharge weights.

RESULTS

A total of 75,858 patients with a diagnosis of TB were identified, of whom 2789 had a diagnosis of spinal TB (3.7%); this represents an average of 278.9 cases per year between 2002 and 2011. The incidence of spinal TB decreased significantly—from 0.07 cases per 100,000 persons in 2002 to 0.05 cases per 100,000 in 2011 (p < 0.001), corresponding to 1 case per 2 million persons in the latter year. The median age for patients with spinal TB was 51 years, and 61% were male; 11.6% were patients with diabetes, 11.4% reported recent weight loss, and 8.1% presented with paralysis. There were 619 patients who underwent spinal surgery for TB, with the most common location being the thoracolumbar spine (61.9% of cases); 50% of patients had instrumentation of 3 or more spinal segments.

CONCLUSIONS

During the examined 10-year period, the incidence of spinal TB was found to significantly decrease over time in the US, reaching a rate of 1 case per 2 million persons in 2011. However, the absolute reduction was relatively small, suggesting that although it is uncommon, spinal TB remains a public health concern and most commonly affects male patients approximately 50 years of age. Approximately 20% of patients with spinal TB underwent surgery, most commonly in the thoracolumbar spine.

Outcomes and effectiveness of posterior occipitocervical fusion for suboccipital spinal metastases

OBJECTIVE The incidence of suboccipital spinal metastases is rare but has increased given cancer patients' longer life expectancies. Operative treatment in this region is often challenging because of limited fixation points due to tumor lysis, as well as adjacent neural and vascular anatomy. Few studies have reported on this population of cancer patients. The purpose of this study was to evaluate clinical outcomes and complications of patients with suboccipital spinal metastases who had undergone posterior occipitocervical fixation. METHODS A single-institution database was reviewed to identify patients with suboccipital metastases who had undergone posterior-only instrumented fusion between 1999 and 2014. Clinical presentation, perioperative complications, and postoperative results were analyzed. Pain was assessed using the visual analog scale. Survival analysis was performed using a Kaplan-Meier curve. The revised Tokuhashi and the Tomita scoring systems were used for prognosis prediction. RESULTS Fifteen patients were identified, 10 men and 5 women with mean age of 64.8 ± 11.8 years (range 48-80 years). Severe neck pain without neurological deficit was the most common presentation. Primary tumors included lung, breast, bladder, myeloma, melanoma, and renal cell cancers. All tumors occurred in the axis vertebra. Preoperative Tokuhashi and Tomita scores ranged from 5 to 13 and 3 to 7, respectively. All patients had undergone occipitocervical fusion of a mean of 4.6 levels (range 2-7 levels). Median survival was 10.3 months. In all cases, neck pain markedly improved and patients were able to resume activities of daily living. The average postoperative pain score was significantly improved as compared with the average preoperative score (1.90 ± 2.56 and 5.50 ± 2.99, respectively, p = 0.01). Three patients experienced postoperative medical complications including urinary tract infection, deep vein thrombosis, myocardial infarction, and cardiac arrhythmia. In the follow-up period, no wound infections or reoperations occurred and no patients experienced spinal cord deficits from tumor recurrence. CONCLUSIONS Posterior-only occipitocervical stabilization was highly effective at relieving patients' neck pain. No instrumentation failures were noted, and no neurological complications or tumor progression causing spinal cord deficits was noted in the follow-up period.

Perioperative Complications of Spinal Metastases Surgery

The incidence of symptomatic spinal metastasis has increased due to treatment improvements and longer patient survival. More patients with spinal tumors are choosing operative treatment with an associated increased rate of perioperative complications. Operative metastatic disease treatment complication rates have also increased with overall rates ranging from 5.3% to 76.20%. The common surgical-related complications are iatrogenic dural injury and wound complications. The most common postoperative medical complications are delirium, pneumonia, and deep vein thrombosis. Risk factors for perioperative complications after spinal metastatic surgery include older age, multilevel of spinal metastases, preoperative irradiation, low preoperative Karnofsky Performance Score (10-40) and multiple comorbidities. Charlson Comorbidity Index and New England Spinal Metastasis Score were significant predictor of 30-day complications. The reoperation rate is 10.7%, and the reoperation is most commonly performed in the same admission. In addition, the 30-day mortality rate in this patient population is ∼7% (0.9%-13%) and is influenced by the type of cancer, disease burden, and patient comorbidities. We reviewed the prevalence and risk factors of common perioperative complications that occur with surgical treatment of metastatic spine disease, in an effort to guide the spine surgeon in anticipating and potentially avoiding these complications.

Massive blood loss in elective spinal and orthopedic surgery: Retrospective review of intraoperative transfusion strategy

OBJECTIVE

To evaluate the perioperative dynamics of hematologic changes and transfusion ratio in patients undergoing a major spinal surgery accompanied with massive bleeding defined as blood loss >5 liters.

DESIGN

Retrospective cohort study.

SETTING

Operating room of a university-affiliated hospital.

PATIENTS

Adult patients who underwent elective neurosurgical, orthopedic, or combined spinal surgical procedure between 2008 and 2012.

METHODS

Patients who underwent a major spinal or orthopedic surgery and who experienced major bleeding (>5 L) during surgery were identified and selected for final analysis. The following information was analyzed: demographics, clinical diagnoses, hematologic parameters, estimated intraoperative blood loss, blood product transfusions, and survival 1 year after surgery.

RESULTS

During the study period, 25 patients, who underwent 28 spinal procedures, experienced intraoperative blood loss >5 L. Mean patient age was 50.5 years and 56.4% were males. The majority of patients underwent procedures to manage spinal metastases. Median estimated intraoperative blood loss was 11.25 L (IQR 6.35-22 L) and median number of units (U) transfused was 24.5 U (IQR 14.0-32.5 U) of packed red blood cells (RBCs), 24.5 U (IQR 14.0-34.0 U) of fresh frozen plasma (FFP), and 4.5 U (IQR 3.0-11.5 U) of platelets (PLTs). The blood product transfusion ratio was 1 and 4 for RBC:FFP, and RBC:PLT, respectively. Hematocrit, hemoglobin, PLTs, partial thromboplastin, prothrombin time, INR, and, fibrinogen varied significantly throughout the procedures. However, acid-base status did not change significantly during surgery. Patients' survival at 1 year was 79.17%.

CONCLUSION

Our results indicate that a 1:1 RBC:FFP and 4:1 RBC:PLT transfusion ratio was associated with significant intraoperative variations in coagulation variables but stable intraoperative acid-base parameters. This transfusion ratio helped clinicians to achieve postoperative coagulation parameters not significantly different to those at baseline. Future studies should assess if more liberal transfusion strategies or point of care monitoring might be warranted in patients undergoing spinal surgery at risk of major blood loss.

Prediction of Quality of Life and Survival After Surgery for Symptomatic Spinal Metastases: A Multicenter Cohort Study to Determine Suitability for Surgical Treatment

BACKGROUND

Surgery for symptomatic spinal metastases aims to improve quality of life, pain, function, and stability. Complications in the postoperative period are not uncommon; therefore, it is important to select appropriate patients who are likely to benefit the greatest from surgery. Previous studies have focused on predicting survival rather than quality of life after surgery.

OBJECTIVE

To determine preoperative patient characteristics that predict postoperative quality of life and survival in patients who undergo surgery for spinal metastases.

METHODS

In a prospective cohort study of 922 patients with spinal metastases who underwent surgery, we performed preoperative and postoperative assessment of EuroQol EQ-5D quality of life, visual analog score for pain, Karnofsky physical functioning score, complication rates, and survival.

RESULTS

The primary tumor type, number of spinal metastases, and presence of visceral metastases were independent predictors of survival. Predictors of quality of life after surgery included preoperative EQ-5D (P = .002), Frankel score (P < .001), and Karnofsky Performance Status (P < .001).

CONCLUSION

Data from the largest prospective surgical series of patients with symptomatic spinal metastases revealed that tumor type, the number of spinal metastases, and the presence of visceral metastases are the most useful predictors of survival and that quality of life is best predicted by preoperative Karnofsky, Frankel, and EQ-5D scores. The Karnofsky score predicts quality of life and survival and is easy to determine at the bedside, unlike the EQ-5D index. Karnofsky score, tumor type, and spinal and visceral metastases should be considered the 4 most important prognostic variables that influence patient management.

Evaluation of Scoring Systems and Prognostic Factors in Patients With Spinal Metastases From Lung Cancer

STUDY DESIGN

A retrospective study of 180 patients with lung cancer spinal metastases, wherein prognostic score-predicted survival was compared with actual survival.

OBJECTIVE

To evaluate and compare the accuracy of prognostic scoring systems in lung cancer spinal metastases.

SUMMARY OF BACKGROUND DATA

The modified Tokuhashi, Tomita, modified Bauer, and Oswestry scores are currently used to guide decisions regarding operative treatment of patients with spinal metastases. The best system for predicting survival in patients with lung cancer spinal metastases remains undetermined. The high incidence of spinal metastases from lung cancer and improved survival of patients treated with systemic therapy warrants evaluation of these scoring systems in this particular context.

METHODS

Patients with lung cancer spinal metastases treated at our institution between May 2001 and August 2012 were studied. Fifty-one patients were treated surgically. The primary outcome measure was survival from the time of diagnosis. Scoring-predicted survival was compared with actual survival. Potential prognostic factors were investigated using Cox regression analyses. Predictive values of each scoring system for 3- and 6-month survival were measured via receiver operating characteristic (ROC) curves.

RESULTS

Histological subtype (P = 0.015), sex (P = 0.001), Karnofsky performance scale (P = 0.001), extent of neurological palsy (P = 0.002), and visceral metastases (P = 0.037) are significant predictors of survival. Besides the Oswestry spinal risk index, no significant differences were found between different prognostic subgroups within the individual scoring systems. Although the modified Bauer score was most accurate, all four scoring systems had areas under the ROC curve 0.5 or less.

CONCLUSION

Although better prognostic scores correlated with longer survival, all four scoring systems are inaccurate in prognosticating patients with lung cancer spinal metastases. Specific lung cancer histology appears prognostic and should be considered, especially given the increased survival of patients receiving new targeted therapies appropriate to their disease.

LEVEL OF EVIDENCE

3.

The role of specialist units to provide focused care and complication avoidance following traumatic spinal cord injury: a systematic review

OBJECTIVE

Current recommendations for traumatic spinal cord injury treatment recommend immediate transfer to a spinal injury unit (SIU) where available following patient stabilisation. Although transfer is dependent on a variety of factors, the largest review was unable to justify implementation of such units on the basis of insufficient and lack of quality data in favour of care at the SIU as opposed to non-SIU centres. Our study sought to investigate: are subspecialty spinal injury units (SIUs) able to provide superior care compared with traditional trauma/rehab units? Is the standard of care of acute spinal cord injured patients to be managed in SIU's?

METHOD

A literature search was conducted across five major databases using the key terms: "spinal cord injury" AND "Spinal Injury Unit" OR "spinal rehabilitation" OR "spinal injury centre" OR "specialist care" OR "care requirements."

RESULTS

After review of over 500 studies, only 9 met inclusion criteria, 3 of which were past reviews. There were no relevant RCT's obtained. Standardised roles of global SIU units are needed to deliver equitable and high quality care as current evidence demonstrates variable standards of care and service (mean LOS range: 16-174 days). There is low quality evidence supporting earlier admission into SIU units being associated with improved neurological outcome, complication rates and reduced LOS, despite variations in the definition of "early admission" across studies.

CONCLUSIONS

Our review demonstrates a lack of standardisation within SIU on a global scale, with significantly different outcomes reported across published studies. New and higher quality evidence directly comparing SIU to non-SIU based care is required. Earlier transfer (<24 h) to SIU following initial injury and stabilisation is advised.

Survival and clinical outcomes in patients with metastatic epidural spinal cord compression after spinal surgery: a prospective, multicenter, observational cohort study

Background

High quality studies have been challenging to undertake in patients with metastatic epidural spinal cord compression. Nonetheless, in the article “Survival and Clinical Outcomes in Surgically Treated Patients With Metastatic Epidural Spinal Cord Compression: Results of the Prospective Multicenter AOSpine Study” recently published in the Journal of Clinical Oncology, our team provided convincing evidence that spinal surgery improves overall quality of life in patients with this potentially devastating complication of cancer. Considering that metastatic spinal lesions treated with surgery have the highest mean cost among all oncological musculo-skeletal issues, it is essential to provide high quality data to optimize the therapeutic approaches and cost-effective use of health care resources.

Main body

Although the AOSpine Study provided high quality prospective data, it was primarily limited by the lack of non-operative controls and the relatively small sample size. Given the dearth of medical equipoise and the fundamental difference between patients deemed to be adequate surgical candidates and those who are not amenable to operative intervention, conducting a randomized controlled trial in this patient population was not felt to be ethically or medically feasible. Consequently, the optimal option to overcome limitations of both the lack of controls and the relatively small sample size is through collection of large prospective datasets through rigorously developed and maintained registries.

Conclusions

With the alarming increase in the incidence of cancer in China and China’s parallel growing cancer control efforts, China would offer a fantastic platform to set up a national metastatic spinal lesion registry. Such registry would not only enhance metastatic epidural spinal cord compression translational research but also optimize patient care.

The Elixhauser comorbidity method outperforms the Charlson index in predicting inpatient death after orthopaedic surgery

BACKGROUND

Scores derived from comorbidities can help with risk adjustment of quality and safety data. The Charlson and Elixhauser comorbidity measures are well-known risk adjustment models, yet the optimal score for orthopaedic patients remains unclear.

QUESTIONS/PURPOSES

We determined whether there was a difference in the accuracy of the Charlson and Elixhauser comorbidity-based measures in predicting (1) in-hospital mortality after major orthopaedic surgery, (2) in-hospital adverse events, and (3) nonroutine discharge.

METHODS

Among an estimated 14,007,813 patients undergoing orthopaedic surgery identified in the National Hospital Discharge Survey (1990-2007), 0.80% died in the hospital. The association of each Charlson comorbidity measure and Elixhauser comorbidity measure with mortality was assessed in bivariate analysis. Two main multivariable logistic regression models were constructed, with in-hospital mortality as the dependent variable and one of the two comorbidity-based measures (and age, sex, and year of surgery) as independent variables. A base model that included only age, sex, and year of surgery also was evaluated. The discriminative ability of the models was quantified using the area under the receiver operating characteristic curve (AUC). The AUC quantifies the ability of our models to assign a high probability of mortality to patients who die. Values range from 0.50 to 1.0, with 0.50 indicating no ability to discriminate and 1.0 indicating perfect discrimination.

RESULTS

Elixhauser comorbidity adjustment provided a better prediction of in-hospital case mortality (AUC, 0.86; 95% CI, 0.86-0.86) compared with the Charlson model (AUC, 0.83; 95% CI, 0.83-0.84) and to the base model with no comorbidities (AUC, 0.81; 95% CI, 0.81-0.81). In terms of relative improvement in predictive performance, the Elixhauser measure performed 60% better than the Charlson score in predicting mortality. The Elixhauser model discriminated inpatient morbidity better than the Charlson measure, but the discriminative ability of the model was poor and the difference in the absolute improvement in predictive power between the two models (AUC, 0.01) is of dubious clinical importance. Both comorbidity models exhibited the same degree of discrimination for estimating nonroutine discharge (AUC, 0.81; 95% CI, 0.81-0.82 for both models).

CONCLUSIONS

Provider-specific outcomes, particularly inpatient mortality, may be evaluated differently depending on the comorbidity risk adjustment model selected. Future research assessing and comparing the performance of the Charlson and Elixhauser measures in predicting long-term outcomes would be of value.

LEVEL OF EVIDENCE

Level II, prognostic study. See the Instructions for Authors for a complete description of levels of evidence.