Christopher D. Witiw, Jonathan S. Citow, Howard J. Ginsberg, Julian Spears, Richard G. Perrin, Michael D. Cusimano and R. Loch Macdonald
Intraoperative radiographic localization within the cervical spine can be a challenge because of the anatomical relation of the musculoskeletal structures of the pectoral girdle. On standard cross-table lateral radiographs, these structures can produce shadowing that obscure the anatomical features of the cervical vertebrae, particularly at the caudal levels. Surgical guidelines recommend accurate intraoperative localization as a means to reduce wrong-level spine surgery, and unobstructed visualization is needed for fluoroscopy-guided placement of spinal instrumentation. In this article, the authors describe and evaluate a novel device designed to provide transient intraoperative caudal displacement of the shoulders to improve and simplify radiographic visualization of the cervical spine.
A 2-center prospective study was conducted to evaluate the device. The study included a total of 80 patients undergoing cervical spine surgery. The device was evaluated in a cohort of 50 patients undergoing elective single-level anterior discectomy and fusion and also in a second cohort of 30 patients at an independent institution. The patients in this second cohort were undergoing a variety of cervical spine procedures for multiple indications and were included in the study to allow the authors to assess the effectiveness of the device in a general neurosurgical practice. After the patients were anesthetized and positioned, consecutive standard cross-table lateral radiographs or intraoperative fluoroscopic were obtained before and after use of the device. The images were compared in order to determine the difference in lowest vertebral level visible.
There was an average difference in cervical spine visualization of +2.8 ± 0.9 vertebral levels in the first cohort, while in the second the improvement was +1.2 ± 0.7 levels (p < 0.0001 between cohorts, unpaired t-test). There was one complication, a minor shoulder abrasion, which required no specific management.
This device is safe and effective for increasing the radiographic visualization of the cervical spine for intraoperative localization.
Alireza Mansouri, Shervin Taslimi, Jetan H. Badhiwala, Christopher D. Witiw, Farshad Nassiri, Vincent J. J. Odekerken, Rob M. A. De Bie, Suneil K. Kalia, Mojgan Hodaie, Renato P. Munhoz, Alfonso Fasano and Andres M. Lozano
Deep brain stimulation (DBS) is effective in the management of patients with advanced Parkinson’s disease (PD). While both the globus pallidus pars interna (GPi) and the subthalamic nucleus (STN) are accepted targets, their relative efficacy in randomized controlled trials (RCTs) has not been established beyond 12 months. The objective of this study was to conduct a meta-analysis of RCTs to compare outcomes among adults with PD undergoing DBS of GPi or STN at various time points, including 36 months of follow-up.
The MEDLINE, Embase, CENTRAL, Web of Science, and CINAHL databases were searched. Registries for clinical trials, selected conference proceedings, and the table of contents for selected journals were also searched. Screens were conducted independently and in duplicate. Among the 623 studies initially identified (615 through database search, 7 through manual review of bibliographies, and 1 through a repeat screen of literature prior to submission), 19 underwent full-text review; 13 of these were included in the quantitative meta-analysis. Data were extracted independently and in duplicate. The Cochrane Collaboration tool was used to assess the risk of bias. The GRADE evidence profile tool was used to assess the quality of the evidence. Motor scores, medication dosage reduction, activities of daily living, depression, dyskinesias, and adverse events were compared. The influence of disease duration (a priori) and the proportion of male patients within a study (post hoc) were explored as potential subgroups.
Thirteen studies (6 original cohorts) were identified. No difference in motor scores or activities of daily living was identified at 36 months. Medications were significantly reduced with STN stimulation (5 studies, weighted mean difference [WMD] −365.46, 95% CI −599.48 to −131.44, p = 0.002). Beck Depression Inventory scores were significantly better with GPi stimulation (3 studies; WMD 2.53, 95% CI 0.99–4.06 p = 0.001). The motor benefits of GPi and STN DBS for PD are similar.
The motor benefits achieved with GPi and STN DBS for PD are similar. DBS of STN allows for a greater reduction of medication, but not as significant an advantage as DBS of GPi with respect to mood. This difference is sustained at 36 months. Further long-term studies are necessary.
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).
Christopher D. Witiw, Nataliya Tsapenko and Vincent C. Traynelis
Axial neck pain is common and often debilitating. Diagnosis of the specific pain source can be a challenge, and this confounds effective treatment. Cervical facet arthropathy is implicated in many of these cases. The diagnosis is readily made on conventional cross-sectional imaging modalities, particularly CT imaging. However, this modality falls short in determining if an osteoarthritic facet joint is truly the source of symptoms. Radionucleotide imaging presents a noninvasive radiological adjunct to conventional cross-sectional imaging in the workup of patients with suspected facetogenic pain. Herein, the authors present the patient-reported outcomes (PROs) following posterior instrumented arthrodesis of the subaxial cervical spine from a consecutive case series of patients with a diagnosis of cervical facet joint arthropathy and a concordant positive radionucleotide tracer uptake.
The clinical case series of patients treated by the senior author at a single tertiary care institution between September 2014 and April 2018 was reviewed. Patients were selected for inclusion if their primary symptom at presentation was axial neck pain without neurological deficits and if CT imaging revealed facet arthropathy of the cervical spine. These patients underwent radionucleotide imaging in the form of a planar 99mTc methylene diphosphonate (99mTc MDP) bone scintigraphy study. Those with a finding of radionucleotide tracer uptake at a location concordant with the facet arthropathy were selected to undergo posterior cervical instrumented arthrodesis of the affected levels. PROs were recorded at the time of surgical consultation (i.e., after nonoperative treatment) and at 6 weeks, 3 months, 6 months, and 1 year following surgery. These included neck and arm pain, the Neck Disability Index (NDI) and the 12-Item Short Form Health Survey responses.
A total of 11 patients were included in this retrospective case series. The average reported neck pain and NDI scores were high at baseline; 7.6 ± 2.3 and 37.1 ± 13.9 respectively. Twelve months after surgical intervention, a significant decrease in reported neck pain of −4.5 (95% CI −6.9, −2.1; p = 0.015) and a significant decrease in NDI of −20.0 (95% CI −29.4, −10.6; p = 0.014) was observed.
This case series represents the largest to date of patients undergoing surgical arthrodesis following a finding of facet arthropathy with a concordant positive radioisotope image study. These observations add support to a growing body of evidence that suggests the utility of radioisotope imaging for identification of a facetogenic pain generator in patients with primary axial neck pain and a finding of cervical facet arthropathy. These preliminary data should serve to promote future prospective, controlled studies on the incorporation of radionucleotide imaging into the workup of patients with suspected facetogenic pain of the cervical spine.
Christopher D. Witiw, Fabrice Smieliauskas, Sandra A. Ham and Vincent C. Traynelis
Cervical disc replacement (CDR) has emerged as an alternative to anterior cervical discectomy and fusion (ACDF) for the management of cervical spondylotic pathology. While much is known about the efficacy of CDR within the constraints of a well-controlled, experimental setting, little is known about general utilization. The authors present an analysis of temporal and geographic trends in “real-world” utilization of CDR among those enrolled in private insurance plans in the US.
Eligible subjects were identified from the IBM MarketScan Databases between 2009 and 2017. Individuals 18 years and older, undergoing a single-level CDR or ACDF for cervical radiculopathy and/or myelopathy, were identified. US Census divisions were used to classify the region where surgery was performed. Two-level mixed-effects regression modeling was used to study regional differences in proportional utilization of CDR, while controlling for confounding by regional case-mix differences.
A total of 47,387 subjects met the inclusion criteria; 3553 underwent CDR and 43,834 underwent ACDF. At a national level, the utilization of single-level CDR rose from 5.6 cases for every 100 ACDFs performed in 2009 to 28.8 cases per 100 ACDFs in 2017. The most substantial increases occurred from 2013 onward. The region of highest utilization was the Mountain region (Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Utah, and Wyoming), where 14.3 CDRs were performed for every 100 ACDFs (averaged over the 9-year period of study). This is in contrast to the East South Central region (Alabama, Kentucky, Mississippi, and Tennessee), where only 2.1 CDRs were performed for every 100 ACDFs. Patient factors that significantly increased the odds of undergoing a CDR were age younger than 40 years (OR 15.9 [95% CI 10.0–25.5]; p < 0.001), no clinical evidence of myelopathy/myeloradiculopathy (OR 1.5 [95% CI 1.4–1.7]; p < 0.001), and a Charlson Comorbidity Index score of 0 (OR 2.7 [95% CI 1.7–4.2]; p < 0.001). After controlling for these factors, significant differences in utilization rates remained between regions (chi-square test = 830.4; p < 0.001).
This US national level study lends insight into the rate of uptake and geographic differences in utilization of the single-level CDR procedure. Further study will be needed to ascertain specific factors that predict adoption of this technology to explain observed geographic discrepancies.