Jefferson R. Wilson, David W. Cadotte and Michael G. Fehlings
The object of this study was to identify, by means of a systematic review of the literature, the acute clinical predictors of neurological outcome, functional outcome, and survival after traumatic spinal cord injury (SCI).
A comprehensive computerized literature review search was performed, using MEDLINE, PubMed, EMBASE, CINAHL, and the Cochrane Database of Systematic Reviews. Selected articles were classified according to their level of evidence. Articles were then stratified into one of 3 domains depending on whether the primary focus was clinical prediction of 1) neurological outcome, 2) functional status, or 3) survival. For each study selected, clinical predictors related to patient demographic characteristics, injury mechanism, or neurological examination findings were extracted, and the individual relationship to outcome was defined.
The initial search resulted in 376 citations. After application of the inclusion and exclusion criteria and study review, 51 relevant articles were identified and graded. Of these, 25 provided predictors for neurological outcome, 22 for functional outcome, and 15 for survival, with several of the articles providing information on more than one type of outcome. All of the included studies were designated as providing Class I, II, or III levels of evidence. The severity of neurological injury (as measured by admission Americal Spinal Injury Association Impairment Scale grade, Frankel grade, or injury completeness), level of injury, and the presence of a zone of partial preservation were consistent predictors of neurological outcome. Severity of neurological injury, level of injury, reflex pattern, and age were consistent predictors of functional outcome. Finally, severity of neurological injury, level of injury, age, and the presence of multisystem trauma seen with higher-energy injury mechanisms were consistent predictors of survival.
On the basis on this review, the authors have identified a constellation of acute clinical features that may help to define an individual's profile for recovery and survival after SCI. This study will help to facilitate communication in the clinical realm and assist in classifying subsets of patients within future clinical studies.
Michael G. Fehlings, Jefferson R. Wilson and Madeleine O'Higgins
Krishna Kumar, Jefferson R. Wilson, Rod S. Taylor and Shivani Gupta
The long-term success of spinal cord stimulation is impeded by the high incidence of adverse events. The cost of complications to the healthcare budget is influenced by the time course needed to reverse the effect, and by the type of corrective measures required. Understanding the mechanism of complications and reducing them can improve the overall success rate and the cost factor.
The authors performed a retrospective analysis of data obtained in 160 patients treated during a 10-year period. For each category of complication, the level of healthcare resource use was assessed for each case and a unit cost was applied. The total cost of each complication was determined by summing across healthcare resource headings. All cost calculations were performed in Canadian dollars at 2005 prices.
To understand the mechanics of various hardware-related complications and how to avoid them, the authors have utilized the results of bench tests conducted at Medtronic, Inc.
Fifty-one adverse events occurred in 42 of the 160 patients. The complications were classified as either hardware related (39 events) or biological (12 events). The mean cost of complications during the 10-year study period was $7092 (range $130–$22,406).
Complications not only disrupt the effect of pain control but also pose an added expense to the already high cost of therapy. It is possible to reduce the complication rate, and thus improve the long-term success rate, by following the suggestions made in this paper, which are supported by the biomechanics of the human body and the implanted material.
Michael G. Fehlings and Jefferson R. Wilson
Jefferson R. Wilson and Michael G. Fehlings
Jefferson R. Wilson, Paul M. Arnold, Anoushka Singh, Sukhvinder Kalsi-Ryan and Michael G. Fehlings
While the majority of existing reports focus on complications sustained during the chronic stages after traumatic spinal cord injury (SCI), the objective in the current study was to characterize and quantify acute inpatient complications. In addition, the authors sought to create a prediction model using clinical variables documented at hospital admission to predict acute complication development.
Analyses were based on data from the Surgical Timing in Acute Spinal Cord Injury Study (STASCIS) data registry, which contains prospective information on adult patients with cervical SCIs who were enrolled at 6 North American centers over a 7-year period. All patients who underwent a standardized American Spinal Injury Association (ASIA) neurological examination within 24 hours of injury and whose follow-up information was available at the acute hospital discharge were included in the study. For purposes of classification, complications were divided into 5 major categories: 1) cardiopulmonary, 2) surgical, 3) thrombotic, 4) infectious, and 5) decubitus ulcer development. Univariate statistical analyses were performed to determine the relationship between complication occurrence and individual demographic, injury, and treatment variables. Multivariate logistic regression was subsequently performed to create a complication prediction model. Model discrimination was judged according to the area under the receiver operating characteristic curve.
Complete complication information was available for 411 patients at the acute care discharge. One hundred sixty patients (38.9%) experienced 240 complications. The mean age among those who experienced at least one complication was 45.9 years, as compared with 43.5 years among those who did not have a complication (p = 0.18). In the univariate analysis, patients with complications were less likely to receive steroids at admission (p = 0.01), had a greater severity of neurological injury as indicated by the ASIA Impairment Scale (AIS) grade at presentation (p < 0.01), and a higher frequency of significant comorbidity (p = 0.04). In a multivariate logistic regression model, a severe initial AIS grade (p < 0.01), a high-energy injury mechanism (p = 0.07), an older age (p = 0.05), the absence of steroid administration (p = 0.02), and the presence of comorbid illness (p = 0.02) were associated with a greater likelihood of complication development during the period of acute hospitalization. The area under the curve value for the full model was 0.75, indicating acceptable predictive discrimination.
These results will help clinicians to identify patients with cervical SCIs at greatest risk for complication development and thus allowing for the institution of aggressive complication prevention measures.
Spine trauma: the challenges in assessing outcomes
Michael G. Fehlings and Jefferson R. Wilson
Michael G. Fehlings and Jefferson R. Wilson
Lindsay Tetreault, Jefferson R. Wilson, Mark R. N. Kotter, Aria Nouri, Pierre Côté, Branko Kopjar, Paul M. Arnold and Michael G. Fehlings
The minimum clinically important difference (MCID) is defined as the minimum change in a measurement that a patient would identify as beneficial. Before undergoing surgery, patients are likely to inquire about the ultimate goals of the operation and of their chances of experiencing meaningful improvements. The objective of this study was to define significant predictors of achieving an MCID on the modified Japanese Orthopaedic Association (mJOA) scale at 2 years following surgery for the treatment of degenerative cervical myelopathy (DCM).
Seven hundred fifty-seven patients were prospectively enrolled in either the AOSpine North America or International study at 26 global sites. Fourteen patients had a perfect preoperative mJOA score of 18 and were excluded from this analysis (n = 743). Data were collected for each participating subject, including demographic information, symptomatology, medical history, causative pathology, and functional impairment. Univariate log-binominal regression analyses were conducted to evaluate the association between preoperative clinical factors and achieving an MCID on the mJOA scale. Modified Poisson regression using robust error variances was used to create the final multivariate model and compute the relative risk for each predictor.
The sample consisted of 463 men (62.31%) and 280 women (37.69%), with an average age of 56.48 ± 11.85 years. At 2 years following surgery, patients exhibited a mean change in functional status of 2.71 ± 2.89 points on the mJOA scale. Of the 687 patients with available follow-up data, 481 (70.01%) exhibited meaningful gains on the mJOA scale, whereas 206 (29.98%) failed to achieve an MCID. Based on univariate analysis, significant predictors of achieving the MCID on the mJOA scale were younger age; female sex; shorter duration of symptoms; nonsmoking status; a lower comorbidity score and absence of cardiovascular disease; and absence of upgoing plantar responses, lower-limb spasticity, and broad-based unstable gait. The final model included age (relative risk [RR] 0.924, p < 0.0001), smoking status (RR 0.837, p = 0.0043), broad-based unstable gait (RR 0.869, p = 0.0036), and duration of symptoms (RR 0.943, p = 0.0003).
In this large multinational prospective cohort, 70% of patients treated surgically for DCM exhibited a meaningful functional gain on the mJOA scale. The key predictors of achieving an MCID on the mJOA scale were younger age, shorter duration of symptoms, nonsmoking status, and lack of significant gait impairment.
Jetan H. Badhiwala, Farshad Nassiri, Christopher D. Witiw, Alireza Mansouri, Saleh A. Almenawer, Leodante da Costa, Michael G. Fehlings and Jefferson R. Wilson
Intraoperative neurophysiological monitoring (IONM) is a useful adjunct in spine surgery, with proven benefit in scoliosis-correction surgery. However, its utility for anterior cervical discectomy and fusion (ACDF) is unclear, as there are few head-to-head comparisons of ACDF outcomes with and without the use of IONM. The authors sought to evaluate the impact of IONM on the safety and cost of ACDF.
This was a retrospective analysis of data from the National (Nationwide) Inpatient Sample of the Healthcare Cost and Utilization Project from 2009 to 2013. Patients with a primary procedure code for ACDF were identified, and diagnosis codes were searched to identify cases with postoperative neurological complications. The authors performed univariate and multivariate logistic regression for postoperative neurological complications with use of IONM as the independent variable; additional covariates included age, sex, surgical indication, multilevel fusion, Charlson Comorbidity Index (CCI) score, and admission type. They also conducted propensity score matching in a 1:1 ratio (nearest neighbor) with the use of IONM as the treatment indicator and the aforementioned variables as covariates. In the propensity score–matched cohort, they compared neurological complications, length of stay (LOS), and hospital charges (in US dollars).
A total of 141,007 ACDF operations were identified. IONM was used in 9540 cases (6.8%). No significant association was found between neurological complications and use of IONM on univariate analysis (OR 0.80, p = 0.39) or multivariate regression (OR 0.82, p = 0.45). By contrast, age ≥ 65 years, multilevel fusion, CCI score > 0, and a nonelective admission were associated with greater incidence of neurological complication. The propensity score–matched cohort consisted of 18,760 patients who underwent ACDF with (n = 9380) or without (n = 9380) IONM. Rates of neurological complication were comparable between IONM and non-IONM (0.17% vs 0.22%, p = 0.41) groups. IONM and non-IONM groups had a comparable proportion of patients with LOS ≥ 2 days (19% vs 18%, p = 0.15). The use of IONM was associated with an additional $6843 (p < 0.01) in hospital charges.
The use of IONM was not associated with a reduced rate of neurological complications following ACDF. Limitations of the data source precluded a specific assessment of the effectiveness of IONM in preventing neurological complications in patients with more complex pathology (i.e., ossification of the posterior longitudinal ligament or cervical deformity).