Browsing by Author "Isaacs, Robert E"
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Item Open Access A Multicenter Study of the Presentation, Treatment, and Outcomes of Cervical Dural Tears.(Global spine journal, 2017-04) O'Neill, Kevin R; Fehlings, Michael G; Mroz, Thomas E; Smith, Zachary A; Hsu, Wellington K; Kanter, Adam S; Steinmetz, Michael P; Arnold, Paul M; Mummaneni, Praveen V; Chou, Dean; Nassr, Ahmad; Qureshi, Sheeraz A; Cho, Samuel K; Baird, Evan O; Smith, Justin S; Shaffrey, Christopher; Tannoury, Chadi A; Tannoury, Tony; Gokaslan, Ziya L; Gum, Jeffrey L; Hart, Robert A; Isaacs, Robert E; Sasso, Rick C; Bumpass, David B; Bydon, Mohamad; Corriveau, Mark; De Giacomo, Anthony F; Derakhshan, Adeeb; Jobse, Bruce C; Lubelski, Daniel; Lee, Sungho; Massicotte, Eric M; Pace, Jonathan R; Smith, Gabriel A; Than, Khoi D; Riew, K DanielStudy design
Retrospective multicenter case series study.Objective
Because cervical dural tears are rare, most surgeons have limited experience with this complication. A multicenter study was performed to better understand the presentation, treatment, and outcomes following cervical dural tears.Methods
Multiple surgeons from 23 institutions retrospectively identified 21 rare complications that occurred between 2005 and 2011, including unintentional cervical dural tears. Demographic data and surgical history were obtained. Clinical outcomes following surgery were assessed, and any reoperations were recorded. Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA), Nurick classification (NuC), and Short-Form 36 (SF36) scores were recorded at baseline and final follow-up at certain centers. All data were collected, collated, and analyzed by a private research organization.Results
There were 109 cases of cervical dural tears among 18 463 surgeries performed. In 101 cases (93%) there was no clinical sequelae following successful dural tear repair. There were statistical improvements (P < .05) in mJOA and NuC scores, but not NDI or SF36 scores. No specific baseline or operative factors were found to be associated with the occurrence of dural tears. In most cases, no further postoperative treatments of the dural tear were required, while there were 13 patients (12%) that required subsequent treatment of cerebrospinal fluid drainage. Analysis of those requiring further treatments did not identify an optimum treatment strategy for cervical dural tears.Conclusions
In this multicenter study, we report our findings on the largest reported series (n = 109) of cervical dural tears. In a vast majority of cases, no subsequent interventions were required and no clinical sequelae were observed.Item Open Access A new non-enzymatic method for isolating human intervertebral disc cells preserves the phenotype of nucleus pulposus cells.(Cytotechnology, 2014-12) Tang, Xinyan; Richardson, William J; Fitch, Robert D; Brown, Christopher R; Isaacs, Robert E; Chen, JunCells isolated from intervertebral disc (IVD) tissues of human surgical samples are one of potential sources for the IVD cellular therapy. The purpose of this study was to develop a new non-enzymatic method, "tissue incubation", for isolating human IVD cells. The IVD tissues of annulus fibrosus (AF) and nucleus pulposus (NP) were incubated separately in tissue culture flasks with culture medium. After 7-10 days incubation, cells were able to migrate out of IVD tissues and proliferate in vitro. After 3-4 weeks culture, expanded cells were harvested by trypsinization, and the remaining tissues were transferred to a new flask for another round of incubation. The molecular phenotype of IVD cells from juvenile and adult human samples was evaluated by both flow cytometry analysis and immunocytochemical staining for the expression of protein markers of NP cells (CD24, CD54, CD239, integrin α6 and laminin α5). Flow cytometry confirmed that both AF and NP cells of all ages positively expressed CD54 and integrin α6, with higher expression levels in NP cells than in AF cells for the juvenile group sample. However, CD24 expression was only found in juvenile NP cells, and not in AF or older disc cells. Similar expression patterns for NP markers were also confirmed by immunocytochemistry. In summary, this new non-enzymatic tissue incubation method for cell isolation preserves molecular phenotypic markers of NP cells and may provide a valuable cell source for the study of NP regeneration strategies.Item Open Access Comparison of superior-level facet joint violations during open and percutaneous pedicle screw placement.(Neurosurgery, 2012-11) Babu, Ranjith; Park, Jong G; Mehta, Ankit I; Shan, Tony; Grossi, Peter M; Brown, Christopher R; Richardson, William J; Isaacs, Robert E; Bagley, Carlos A; Kuchibhatla, Maragatha; Gottfried, Oren NBackground
Superior-level facet joint violation by pedicle screws may result in increased stress to the level above the instrumentation and may contribute to adjacent segment disease. Previous studies have evaluated facet joint violations in open or percutaneous screw cases, but there are no reports describing a direct institutional comparison.Objective
To compare the incidence of superior-level facet violation for open vs percutaneous pedicle screws and to evaluate patient and surgical factors that affect this outcome.Methods
We reviewed 279 consecutive patients who underwent an index instrumented lumbar fusion from 2007 to 2011 for degenerative spine disease with stenosis with or without spondylolisthesis. We used a computed tomography grading system that represents progressively increasing grades of facet joint violation. Patient and surgical factors were evaluated to determine their impact on facet violation.Results
Our cohort consisted of 126 open and 153 percutaneous cases. Percutaneous procedures had a higher overall violation grade (P = .02) and a greater incidence of high-grade violations (P = .006) compared with open procedures. Bivariate analysis showed significantly greater violations in percutaneous cases for age < 65 years, obesity, pedicle screws at L4, and 1- and 2-level surgeries. Multivariate analysis showed the percutaneous approach and depth of the spine to be independent risk factors for high-grade violations.Conclusion
This study demonstrates greater facet violations for percutaneously placed pedicle screws compared with open screws.Item Open Access Esophageal Perforation Following Anterior Cervical Spine Surgery: Case Report and Review of the Literature.(Global spine journal, 2017-04) Hershman, Stuart H; Kunkle, William A; Kelly, Michael P; Buchowski, Jacob M; Ray, Wilson Z; Bumpass, David B; Gum, Jeffrey L; Peters, Colleen M; Singhatanadgige, Weerasak; Kim, Jin Young; Smith, Zachary A; Hsu, Wellington K; Nassr, Ahmad; Currier, Bradford L; Rahman, Ra'Kerry K; Isaacs, Robert E; Smith, Justin S; Shaffrey, Christopher; Thompson, Sara E; Wang, Jeffrey C; Lord, Elizabeth L; Buser, Zorica; Arnold, Paul M; Fehlings, Michael G; Mroz, Thomas E; Riew, K DanielMulticenter retrospective case series and review of the literature.To determine the rate of esophageal perforations following anterior cervical spine surgery.As part of an AOSpine series on rare complications, a retrospective cohort study was conducted among 21 high-volume surgical centers to identify esophageal perforations following anterior cervical spine surgery. Staff at each center abstracted data from patients' charts and created case report forms for each event identified. Case report forms were then sent to the AOSpine North America Clinical Research Network Methodological Core for data processing and analysis.The records of 9591 patients who underwent anterior cervical spine surgery were reviewed. Two (0.02%) were found to have esophageal perforations following anterior cervical spine surgery. Both cases were detected and treated in the acute postoperative period. One patient was successfully treated with primary repair and debridement. One patient underwent multiple debridement attempts and expired.Esophageal perforation following anterior cervical spine surgery is a relatively rare occurrence. Prompt recognition and treatment of these injuries is critical to minimizing morbidity and mortality.Item Open Access Identifying molecular phenotype of nucleus pulposus cells in human intervertebral disc with aging and degeneration.(Journal of orthopaedic research : official publication of the Orthopaedic Research Society, 2016-08) Tang, Xinyan; Jing, Liufang; Richardson, William J; Isaacs, Robert E; Fitch, Robert D; Brown, Christopher R; Erickson, Melissa M; Setton, Lori A; Chen, JunPrevious study claimed that disc degeneration may be preceded by structure and matrix changes in the intervertebral disc (IVD) which coincide with the loss of distinct notochordally derived nucleus pulposus (NP) cells. However, the fate of notochordal cells and their molecular phenotype change during aging and degeneration in human are still unknown. In this study, a set of novel molecular phenotype markers of notochordal NP cells during aging and degeneration in human IVD tissue were revealed with immunostaining and flow cytometry. Furthermore, the potential of phenotype juvenilization and matrix regeneration of IVD cells in a laminin-rich pseudo-3D culture system were evaluated at day 28 by immunostaining, Safranin O, and type II collagen staining. Immunostaining and flow cytometry demonstrated that transcriptional factor Brachyury T, neuronal-related proteins (brain abundant membrane attached signal protein 1, Basp1; Neurochondrin, Ncdn; Neuropilin, Nrp-1), CD24, and CD221 were expressed only in juvenile human NP tissue, which suggested that these proteins may be served as the notochordal NP cell markers. However, the increased expression of CD54 and CD166 with aging indicated that they might be referenced as the potential biomarker for disc degeneration. In addition, 3D culture maintained most of markers in juvenile NP, and rescued the expression of Basp1, Ncdn, and Nrp 1 that disappeared in adult NP native tissue. These findings provided new insight into molecular profile that may be used to characterize the existence of a unique notochordal NP cells during aging and degeneration in human IVD cells, which will facilitate cell-based therapy for IVD regeneration. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1316-1326, 2016.Item Open Access Intrawound Vancomycin Decreases the Risk of Surgical Site Infection After Posterior Spine Surgery: A Multicenter Analysis.(Spine, 2018-01) Devin, Clinton J; Chotai, Silky; McGirt, Matthew J; Vaccaro, Alexander R; Youssef, Jim A; Orndorff, Douglas G; Arnold, Paul M; Frempong-Boadu, Anthony K; Lieberman, Isador H; Branch, Charles; Hedayat, Hirad S; Liu, Ann; Wang, Jeffrey C; Isaacs, Robert E; Radcliff, Kris E; Patt, Joshua C; Archer, Kristin RStudy design
Secondary analysis of data from a prospective multicenter observational study.Objective
The aim of this study was to evaluate the occurrence of surgical site infection (SSI) in patients with and without intrawound vancomycin application controlling for confounding factors associated with higher SSI after elective spine surgery.Summary of background data
SSI is a morbid and expensive complication associated with spine surgery. The application of intrawound vancomycin is rapidly emerging as a solution to reduce SSI following spine surgery. The impact of intrawound vancomycin has not been systematically studied in a well-designed multicenter study.Methods
Patients undergoing elective spine surgery over a period of 4 years at seven spine surgery centers across the United States were included in the study. Patients were dichotomized on the basis of whether intrawound vancomycin was applied. Outcomes were occurrence of SSI within postoperative 30 days and SSI that required return to the operating room (OR). Multivariable random-effect log-binomial regression analyses were conducted to determine the relative risk of having an SSI and an SSI with return to OR.Results
.: A total of 2056 patients were included in the analysis. Intrawound vancomycin was utilized in 47% (n = 966) of patients. The prevalence of SSI was higher in patients with no vancomycin use (5.1%) than those with use of intrawound vancomycin (2.2%). The risk of SSI was higher in patients in whom intrawound vancomycin was not used (relative risk (RR) -2.5, P < 0.001), increased number of levels exposed (RR -1.1, P = 0.01), and those admitted postoperatively to intensive care unit (ICU) (RR -2.1, P = 0.005). Patients in whom intrawound vancomycin was not used (RR -5.9, P < 0.001), increased number of levels were exposed (RR-1.1, P = 0.001), and postoperative ICU admission (RR -3.3, P < 0.001) were significant risk factors for SSI requiring a return to the OR.Conclusion
The intrawound application of vancomycin after posterior approach spine surgery was associated with a reduced risk of SSI and return to OR associated with SSI.Level of evidence
2.Item Open Access Proinflammatory cytokine expression profile in degenerated and herniated human intervertebral disc tissues.(Arthritis and rheumatism, 2010-07) Shamji, Mohammed F; Setton, Lori A; Jarvis, Wingrove; So, Stephen; Chen, Jun; Jing, Liufang; Bullock, Robert; Isaacs, Robert E; Brown, Christopher; Richardson, William JObjective
Prior reports document macrophage and lymphocyte infiltration with proinflammatory cytokine expression in pathologic intervertebral disc (IVD) tissues. Nevertheless, the role of the Th17 lymphocyte lineage in mediating disc disease remains uninvestigated. We undertook this study to evaluate the immunophenotype of pathologic IVD specimens, including interleukin-17 (IL-17) expression, from surgically obtained IVD tissue and from nondegenerated autopsy control tissue.Methods
Surgical IVD tissues were procured from patients with degenerative disc disease (n = 25) or herniated IVDs (n = 12); nondegenerated autopsy control tissue was also obtained (n = 8) from the anulus fibrosus and nucleus pulposus regions. Immunohistochemistry was performed for cell surface antigens (CD68 for macrophages, CD4 for lymphocytes) and various cytokines, with differences in cellularity and target immunoreactivity scores analyzed between surgical tissue groups and between autopsy control tissue regions.Results
Immunoreactivity for IL-4, IL-6, IL-12, and interferon-gamma (IFNgamma) was modest in surgical IVD tissue, although expression was higher in herniated IVD samples and virtually nonexistent in control samples. The Th17 lymphocyte product IL-17 was present in >70% of surgical tissue fields, and among control samples was detected rarely in anulus fibrosus regions and modestly in nucleus pulposus regions. Macrophages were prevalent in surgical tissues, particularly herniated IVD samples, and lymphocytes were expectedly scarce. Control tissue revealed lesser infiltration by macrophages and a near absence of lymphocytes.Conclusion
Greater IFNgamma positivity, macrophage presence, and cellularity in herniated IVDs suggests a pattern of Th1 lymphocyte activation in this pathology. Remarkable pathologic IVD tissue expression of IL-17 is a novel finding that contrasts markedly with low levels of IL-17 in autopsy control tissue. These findings suggest involvement of Th17 lymphocytes in the pathomechanism of disc degeneration.Item Open Access Rare Complications of Cervical Spine Surgery: Horner's Syndrome.(Global spine journal, 2017-04) Traynelis, Vincent C; Malone, Hani R; Smith, Zachary A; Hsu, Wellington K; Kanter, Adam S; Qureshi, Sheeraz A; Cho, Samuel K; Baird, Evan O; Isaacs, Robert E; Rahman, Ra'Kerry K; Polevaya, Galina; Smith, Justin S; Shaffrey, Christopher; Tortolani, P Justin; Stroh, D Alex; Arnold, Paul M; Fehlings, Michael G; Mroz, Thomas E; Riew, K DanielA multicenter retrospective case series.Horner's syndrome is a known complication of anterior cervical spinal surgery, but it is rarely encountered in clinical practice. To better understand the incidence, risks, and neurologic outcomes associated with Horner's syndrome, a multicenter study was performed to review a large collective experience with this rare complication.We conducted a retrospective multicenter case series study involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network. Medical records for 17 625 patients who received subaxial cervical spine surgery from 2005 to 2011 were reviewed to identify occurrence of 21 predefined treatment complications. Descriptive statistics were provided for baseline patient characteristics. Paired t test was used to analyze changes in clinical outcomes at follow-up compared to preoperative status.In total, 8887 patients who underwent anterior cervical spine surgery at the participating institutions were screened. Postoperative Horner's syndrome was identified in 5 (0.06%) patients. All patients experienced the complication following anterior cervical discectomy and fusion. The sympathetic trunk appeared to be more vulnerable when operating on midcervical levels (C5, C6), and most patients experienced at least a partial recovery without further treatment.This collective experience suggests that Horner's syndrome is an exceedingly rare complication following anterior cervical spine surgery. Injury to the sympathetic trunk may be limited by maintaining a midline surgical trajectory when possible, and performing careful dissection and retraction of the longus colli muscle when lateral exposure is necessary, especially at caudal cervical levels.