Pedicle Screw Placement in the Thoracolumbar Spine Using a Novel, Simple, Safe, and Effective Guide-Pin : A Computerized Tomography Analysis

현승재,Yongjung J. Kim,임승철,Gene Cheh,Samuel K. Cho 대한신경외과학회 2015 Journal of Korean neurosurgical society Vol.58 No.1

Objective : To improve pedicle screw placement accuracy with minimal radiation and low cost, we developed specially designed K-wire with a marker. To evaluate the accuracy of thoracolumbar pedicle screws placed using the novel guide-pin and portable X-rays. Methods : Observational cohort study with computerized tomography (CT) analysis of in vivo and in vitro pedicle screw placement. Postoperative CT scans of 183 titanium pedicle screws (85 lumbar and 98 thoracic from T1 to L5) placed into 2 cadavers and 18 patients were assessed. A specially designed guide-pin with a marker was inserted into the pedicle to identify the correct starting point (2 mm lateral to the center of the pedicle) and aiming point (center of the pedicle isthmus) in posteroanterior and lateral X-rays. After radiographically confirming the exact starting and aiming points desired, a gearshift was inserted into the pedicle from the starting point into the vertebral body through the center of pedicle isthmus. Results : Ninety-nine percent (181/183) of screws were contained within the pedicle (total 183 pedicle screws : 98 thoracic pedicle screws and 85 lumbar screws). Only two of 183 (1.0%) thoracic pedicle screws demonstrated breach (1 lateral in a patient and 1 medial in a cadaver specimen). None of the pedicle breaches were associated with neurologic or other clinical sequelae. Conclusion : A simple, specially designed guide-pin with portable X-rays can provide correct starting and aiming points and allows for accurate pedicle screw placement without preoperative CT scan and intraoperative fluoroscopic assistance.

Pedicle Screw Placement in the Thoracolumbar Spine Using a Novel, Simple, Safe, and Effective Guide-Pin : A Computerized Tomography Analysis

Hyun, Seung-Jae,Kim, Yongjung J.,Rhim, Seung-Chul,Cheh, Gene,Cho, Samuel K. The Korean Neurosurgical Society 2015 Journal of Korean neurosurgical society Vol.46 No.4

Objective : To improve pedicle screw placement accuracy with minimal radiation and low cost, we developed specially designed K-wire with a marker. To evaluate the accuracy of thoracolumbar pedicle screws placed using the novel guide-pin and portable X-rays. Methods : Observational cohort study with computerized tomography (CT) analysis of in vivo and in vitro pedicle screw placement. Postoperative CT scans of 183 titanium pedicle screws (85 lumbar and 98 thoracic from T1 to L5) placed into 2 cadavers and 18 patients were assessed. A specially designed guide-pin with a marker was inserted into the pedicle to identify the correct starting point (2 mm lateral to the center of the pedicle) and aiming point (center of the pedicle isthmus) in posteroanterior and lateral X-rays. After radiographically confirming the exact starting and aiming points desired, a gearshift was inserted into the pedicle from the starting point into the vertebral body through the center of pedicle isthmus. Results : Ninety-nine percent (181/183) of screws were contained within the pedicle (total 183 pedicle screws : 98 thoracic pedicle screws and 85 lumbar screws). Only two of 183 (1.0%) thoracic pedicle screws demonstrated breach (1 lateral in a patient and 1 medial in a cadaver specimen). None of the pedicle breaches were associated with neurologic or other clinical sequelae. Conclusion : A simple, specially designed guide-pin with portable X-rays can provide correct starting and aiming points and allows for accurate pedicle screw placement without preoperative CT scan and intraoperative fluoroscopic assistance.

History of Spinal Deformity Surgery Part I: The Pre-modern Era

Samuel K. Cho,김용정 대한척추신경외과학회 2011 Neurospine Vol.8 No.1

Spinal deformity is one of the oldest known diseases that date back thousands of years in human history. It appears in fairy tales and mythologies in association with evil as its dramatic appearance in patients suffering from the disease easily lent itself to be thought of as a form of divine retribution. The history of spinal deformity dates back to prehistoric times. The early attempts to treat patients suffering from this disease started from Hippocrates age. Side traction or axial traction and cast immobilization were the only possible option prior to the discovery of anesthesia. The first surgical attempts to correct scoliosis occurred in the mid 19th century with percutaneous myotomies of the vertebral musculature followed by postoperative bracing, which outcomes were very quite horrifying. Hibbs’ fusion operation had become a realistic treatment option to halt the progression of deformity in the early 20th century. Harrington’s introduction of the internal fixation device to treat paralytic scoliosis in 1960’s started revolution on deformity correction surgery. Luque developed a segmental spinal using sublaminar wiring technique in 1976 and Cotrel developed Cotrel-Dubousset (CD) instrumentation, which was a posterior segmental instrumentation system that used pedicle and laminar hooks on either thoracic or lumbar spine and pedicle screws on the lumbar spine.

Commentary on “The Posterior Cranial Vertical Line: A Novel Radiographic Marker for Classifying Global Sagittal Alignment”

Samuel K. Cho 대한척추신경외과학회 2023 Neurospine Vol.20 No.3

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History of Spinal Deformity Surgery Part II: The Modern Era

Samuel K. Cho,김용정 대한척추신경외과학회 2011 Neurospine Vol.8 No.1

Following Dwyer introduction of anterior spinal instrumented fusion surgery, Zielke, Moss-Miami, and Kaneda had made a significant progression on anterior spinal instrumented fusion which allowed excellent correction without significant loss of correction or implant failure. King and Moe deveoped classification of thoracic major curve following Harrington rod intrumentation. King classification presented a stable vertebra concept and selective fusion concept. Surgical classification of Adolescent Idiopathic Scoliosis (AIS) developed by Harms study group provided a more sophisticated two dimensional understanding of curve nature. Surgical intervention of adult scoliosis and sagittal imbalance is still challenging and evolving. Several evidences such as sacropelvic fixation and bone morphogenetic protein helped us to deal with adult deformity. The surgical decision making on spinal deformity surgery is still yet evolving. Following Dwyer introduction of anterior spinal instrumented fusion surgery, Zielke, Moss-Miami, and Kaneda had made a significant progression on anterior spinal instrumented fusion which allowed excellent correction without significant loss of correction or implant failure. King and Moe deveoped classification of thoracic major curve following Harrington rod intrumentation. King classification presented a stable vertebra concept and selective fusion concept. Surgical classification of Adolescent Idiopathic Scoliosis (AIS) developed by Harms study group provided a more sophisticated two dimensional understanding of curve nature. Surgical intervention of adult scoliosis and sagittal imbalance is still challenging and evolving. Several evidences such as sacropelvic fixation and bone morphogenetic protein helped us to deal with adult deformity. The surgical decision making on spinal deformity surgery is still yet evolving.

Pseudarthrosis of the Cervical Spine: Risk Factors, Diagnosis and Management

Dante Leven,Samuel K. Cho 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.4

Cervical myelopathy and radiculopathy are common pathologies that often improve with spinal decompression and fusion. Postoperative complications include pseudarthrosis, which can be challenging to diagnose and manage. We reviewed the literature with regard to risk factors, diagnosis, controversies, and management of cervical pseudarthrosis.

Anterior Reconstruction Techniques for Cervical Spine Deformity

Murray Echt,Christopher Mikhail,Steven J. Girdler,Samuel K. Cho 대한척추신경외과학회 2020 Neurospine Vol.17 No.3

Cervical spine deformity is an uncommon yet severely debilitating condition marked by its heterogeneity. Anterior reconstruction techniques represent a familiar approach with a range of invasiveness and correction potential—including global or focal realignment in the sagittal and coronal planes. Meticulous preoperative planning is required to improve or prevent neurologic deterioration and obtain satisfactory global spinal harmony. The ability to perform anterior only reconstruction requires mobility of the opposite column to achieve correction, unless a combined approach is planned. Anterior cervical discectomy and fusion has limited focal correction, but when applied over multiple levels there is a cumulative effect with a correction of approximately 6° per level. Partial or complete corpectomy has the ability to correct sagittal deformity as well as decompress the spinal canal when there is anterior compression behind the vertebral body. If pathoanatomy permits, a hybrid discectomy-corpectomy construct is favored over multilevel corpectomies. The anterior cervical osteotomy with bilateral complete uncinectomy may be necessary for angular correction of fixed cervical kyphosis, and is particularly useful in the midcervical spine. A detailed understanding of the patient’s local anatomy, careful attention to positioning, and avoiding long periods of retraction time will help prevent complications and iatrogenic injury.

Predicting Surgical Complications in Adult Patients Undergoing Anterior Cervical Discectomy and Fusion Using Machine Learning

Varun Arvind,Jun S. Kim,Eric K. Oermann,Deepak Kaji,Samuel K. Cho 대한척추신경외과학회 2018 Neurospine Vol.15 No.4

Objective: Machine learning algorithms excel at leveraging big data to identify complex patterns that can be used to aid in clinical decision-making. The objective of this study is to demonstrate the performance of machine learning models in predicting postoperative complications following anterior cervical discectomy and fusion (ACDF). Methods: Artificial neural network (ANN), logistic regression (LR), support vector machine (SVM), and random forest decision tree (RF) models were trained on a multicenter data set of patients undergoing ACDF to predict surgical complications based on readily available patient data. Following training, these models were compared to the predictive capability of American Society of Anesthesiologists (ASA) physical status classification. Results: A total of 20,879 patients were identified as having undergone ACDF. Following exclusion criteria, patients were divided into 14,615 patients for training and 6,264 for testing data sets. ANN and LR consistently outperformed ASA physical status classification in predicting every complication (p<0.05). The ANN outperformed LR in predicting venous thromboembolism, wound complication, and mortality (p<0.05). The SVM and RF models were no better than random chance at predicting any of the postoperative complications (p<0.05). Conclusion: ANN and LR algorithms outperform ASA physical status classification for predicting individual postoperative complications. Additionally, neural networks have greater sensitivity than LR when predicting mortality and wound complications. With the growing size of medical data, the training of machine learning on these large datasets promises to improve risk prognostication, with the ability of continuously learning making them excellent tools in complex clinical scenarios.

Biomaterials in Spinal Implants: A Review

Andrew Warburton,Steven J. Girdler,Christopher M. Mikhail,Amy Ahn,Samuel K. Cho 대한척추신경외과학회 2020 Neurospine Vol.17 No.1

The aim to find the perfect biomaterial for spinal implant has been the focus of spinal research since the 1800s. Spinal surgery and the devices used therein have undergone a constant evolution in order to meet the needs of surgeons who have continued to further understand the biomechanical principles of spinal stability and have improved as new technologies and materials are available for production use. The perfect biomaterial would be one that is biologically inert/compatible, has a Young’s modulus similar to that of the bone where it is implanted, high tensile strength, stiffness, fatigue strength, and low artifacts on imaging. Today, the materials that have been most commonly used include stainless steel, titanium, cobalt chrome, nitinol (a nickel titanium alloy), tantalum, and polyetheretherketone in rods, screws, cages, and plates. Current advancements such as 3-dimensional printing, the ProDisc-L and ProDisc-C, the ApiFix, and the Mobi-C which all aim to improve range of motion, reduce pain, and improve patient satisfaction. Spine surgeons should remain vigilant regarding the current literature and technological advancements in spinal materials and procedures. The progression of spinal implant materials for cages, rods, screws and plates with advantages and disadvantages for each material will be discussed.

Decision Making Algorithm for Adult Spinal Deformity Surgery

Kim, Yongjung J.,Hyun, Seung-Jae,Cheh, Gene,Cho, Samuel K.,Rhim, Seung-Chul The Korean Neurosurgical Society 2016 Journal of Korean neurosurgical society Vol.59 No.4

Adult spinal deformity (ASD) is one of the most challenging spinal disorders associated with broad range of clinical and radiological presentation. Correct selection of fusion levels in surgical planning for the management of adult spinal deformity is a complex task. Several classification systems and algorithms exist to assist surgeons in determining the appropriate levels to be instrumented. In this study, we describe our new simple decision making algorithm and selection of fusion level for ASD surgery in terms of adult idiopathic idiopathic scoliosis vs. degenerative scoliosis.