4,323 results match your criteria Os Odontoideum

An Unusual Chordoma of the Odontoid Process: A Case Report and Literature Review.

J Am Acad Orthop Surg Glob Res Rev 2022 May 1;6(5). Epub 2022 May 1.

From the Department of Orthopaedics, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.

The aim of this study is to present a rare case of chordoma in the odontoid process in which the tumor involved the odontoid process and compressed the spinal cord at the craniocervical junction. We report on the effectiveness and successful outcome of anterior microscopic tumor resection combined with posterior occipitocervical fixation and review the current standard treatment. A 39-year-old man presented with sudden dyspnea and quadriparesis caused by an unknown tumor compression at C2. Read More

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Comment on Bunmaprasert et al. Reducible Nonunited Type II Odontoid Fracture with Atlantoaxial Instability: Outcomes of Two Different Fixation Techniques. 2021, , 7990.

Ayhan Kanat

Int J Environ Res Public Health 2022 Apr 20;19(9). Epub 2022 Apr 20.

Department of Neurosurgery, Medical Faculty, Recep Tayyip Erdogan University, Rize 53100, Turkey.

I read with great interest the paper of Bunmaprasert et al. [.. Read More

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[Research progress of causes and strategies in revision surgery for atlantoaxial dislocation].

Zhongguo Gu Shang 2022 May;35(5):495-9

Department of Spinal Surgery, China-Japan Friendship Hospital, Beijing 100029, China.

Atlantoaxial dislocation (AAD) is a kind of life-threatening atlantoaxial structural instability and a series of neurological dysfunction caused by common multidisciplinary diseases. The operation risk is extremely high because it is adjacent to the medulla oblongata and the location is deep. With the increase of the number of operations in the upper cervical region, postoperative complications such as failure of internal fixation, non fusion of bone graft and poor prognosis gradually increase. Read More

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Full-Endoscopic Anterior Odontoid Screw Fixation: A Novel Surgical Technique.

Orthop Surg 2022 May 20;14(5):990-996. Epub 2022 Apr 20.

Department of Neurosurgery, Seoul St. Mary's Hospital, Spine Center, College of medicine, Seoul, South Korea.

Objective: First, to propose a novel minimally invasive technique of full-endoscopic anterior odontoid fixation (FEAOF) that aims to reduce the risk of retropharyngeal approach (both open and percutaneous techniques) to anterior odontoid screw fixation. Second, to describe steps of the procedure and, lastly, to report the initial outcomes in patients treated with this novel technique.

Methods: Four non-consecutive patients who were diagnosed with a displaced odontoid fracture (Anderson-D'Alonzo classification type II and Grauer subclassification type A or B) from 2019 to 2020 underwent surgical fixation by our novel technique for anterior odontoid screw fixation. Read More

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Cervical myelopathy involving os odontoideum with retro-odontoid cyst and atlanto-axial instability: A case report.

Radiol Case Rep 2022 Jun 8;17(6):1982-1985. Epub 2022 Apr 8.

Radiology Department, Mohammed VI University Hospital, Faculty of Medicine, University Mohammed First, Oujda, Morocco.

Os odontoideum is an unusual anatomic variant of the dens of C2 defined as an independent ossicle separated from the axis; the etiology is a topic of debate, with investigative studies supporting congenital and traumatic origins, clinical manifestations vary from asymptomatic forms, underlying C1-C2 instability to compression of the spinal cord or vertebrobasilar ischemia. We report a case of a patient with a history of minor trauma 5 years ago, she suffered from neck pain. The clinical examination was normal. Read More

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Do the newly proposed realignment targets for C2 and T1 slope bridge the gap between radiographic and clinical success in corrective surgery for adult cervical deformity?

J Neurosurg Spine 2022 Apr 15:1-8. Epub 2022 Apr 15.

1Departments of Orthopaedic and Neurologic Surgery, NYU Langone Orthopedic Hospital, New York, New York.

Objective: Surgical correction of cervical deformity (CD) has been associated with superior alignment and functional outcomes. It has not yet been determined whether baseline or postoperative T1 slope (T1S) and C2 slope (C2S) correlate with health-related quality-of-life (HRQoL) metrics and radiographic complications, such as distal junctional kyphosis (DJK) and distal junctional failure (DJF). The objective of this study was to determine the impact of T1S and C2S deformity severity on HRQoL metrics and DJF development in patients with CD who underwent a cervical fusion procedure. Read More

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Evaluating trabecular microstructure of mandible and axis in osteoporosis, diabetes and chronic kidney disease using cone beam computed tomography.

Oral Radiol 2022 Mar 30. Epub 2022 Mar 30.

Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Gazi University, Ankara, Turkey.

Objectives: Like other bones, the mandible and cervical vertebrae are affected by several systemic diseases. The aim of this study is to evaluate the effects of osteoporosis (OP), diabetes mellitus (DM), and dialysis-indicated advanced chronic kidney disease (CKD), which are the most effective systemic diseases on the bone metabolism, on the trabecular microstructure of the mandible and cervical vertebrae using cone beam computed tomography (CBCT).

Methods: 81 patients who signed our informed consent form are involved in the study. Read More

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The Results of Interfacetal Fusion Using Local Bone Combined With an Atlantoaxial Instrumentation.

Oper Neurosurg (Hagerstown) 2022 May;22(5):284-289

Department of Neurological Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.

Background: Many studies have described different C1-2 fusion techniques that have evolved over time. We introduced an easy and effective C1-2 fusion technique using local bone chips combined with atlantoaxial instrumentation.

Objective: To identify the efficacy of interfacetal fusion using local bone combined with atlantoaxial instrumentation by assessment of clinical outcomes and fusion rate. Read More

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An Unusual Presentation of Retro-Odontoid Intradural Pannus Managed With an Endoscopic Endonasal Transclival Approach.

Oper Neurosurg (Hagerstown) 2022 May;22(5):e220

Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA.

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Comprehensive analysis of pedicle screw implantation in the C7 vertebra using computed tomography-based three-dimensional models.

BMC Surg 2022 Mar 14;22(1):96. Epub 2022 Mar 14.

Department of Orthopedics, Hospital Affiliated 5 to Nantong University (Taizhou People's Hospital), Taizhou, 225300, Jiangsu, China.

Background: From a biomechanical point of view, pedicle screws (PS) are better than other kinds of screws for implantation in the seventh cervical vertebra (C7). However, the application of PS is limited because of the high risk of severe complications. It is essential to define the optimal entry point and trajectory. Read More

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Isolated atlas-duplication as a manifestation of persistent proatlas: a case report.

Surg Radiol Anat 2022 Apr 14;44(4):595-598. Epub 2022 Mar 14.

Department of Neuroradiology, Neurological and Neurosurgical Hospital P. Wertheimer, East Group Hospital, 69500, Hospices Civils de Lyon. 59 Bd PinelBron, France.

Purpose: Atlas-duplication is an exceedingly rare dysplasia of the craniocervical junction. To the best of our knowledge, only two cases of atlas-duplication have been reported and these were associated with complete anterior rachischisis and os odontoideum. We aimed to report a case of isolated atlas-duplication of incidental finding and without attributable symptoms which makes it unique. Read More

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Odontoid Fractures: A Standard Review of Current Concepts and Treatment Recommendations.

J Am Acad Orthop Surg 2022 Mar;30(6):e561-e572

From the Department of Orthopaedic Surgery, Wellstar Atlanta Medical Center, Atlanta, GA.

Odontoid fractures represent the most common fractures involving C2 and the most common cervical spine fractures in patients older than 65 years. Despite their increasing frequency, optimal management of these injuries remain a subject to debate. Although types I and III injuries have relatively good healing potential with nonsurgical treatment, type II fractures carry a higher risk for nonunion. Read More

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C-arm Free O-arm Navigated Posterior Atlantoaxial Fixation in Down Syndrome: A Technical Note.

Acta Med Okayama 2022 Feb;76(1):71-78

Department of Orthopaedic Surgery, Okayama University Hospital.

The surgical treatment of pediatric atlantoaxial subluxation (AAS) in Down syndrome (DS) remains technically challenging due to radiation exposure and complications such as vertebral artery injury and nonunion. The established treatment is fixation with a C1 lateral mass screw and C2 pedicle screw (modified Goel technique). However, this technique requires fluoroscopy for C1 screw insertion. Read More

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February 2022

Sex-specific differences in ossification patterns of the atlas and axis: a computed tomography study.

World J Pediatr 2022 04 25;18(4):263-270. Epub 2022 Feb 25.

Department of Cardiac Surgery, Children's Hospital, Zhejiang University School of Medicine, Administrative Building, No. 3333 Binsheng Road, Hangzhou 310052, China.

Background: We investigated the sex-specific differences in ossification patterns of the first two cervical vertebrae in Chinese children.

Methods: A retrospective computed tomography (CT) study was performed between June 2016 and December 2020. Patients younger than 16 years with cervical CT images acquired ≤ 1. Read More

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Asymmetry of the C2 pars interarticularis: a clinical anatomical study with relevance to screw placement.

Surg Radiol Anat 2022 Mar 25;44(3):423-429. Epub 2022 Feb 25.

Department of Neurosurgery, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, 131 S. Robertson St. Suite 1300, New Orleans, LA, 70112, USA.

Purpose: Potential asymmetries of the C2 posterior elements pose a problem for the spine surgeon seeking to make the best choice for spinal stabilization while reducing morbidity.

Methods: A digital caliper was used to measure the pars interarticularis height and length on left and right sides of 25 adult C2 vertebrae. The pars interarticularis was defined as the bone between the posterior most aspect of the superior articular process and the anterior most aspect of the inferior articular process of C2. Read More

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The predictive ability of occipital to C3 angle for dysphagia after occipitocervical fusion in patients with combined C2-3 Klippel-Feil syndrome.

BMC Musculoskelet Disord 2022 Feb 7;23(1):123. Epub 2022 Feb 7.

Department of Orthopedics, |Orthopedic Research Institute, West China Hospital, Sichuan University, No. 37 Guo Xue Xiang, Chengdu, 610041, Sichuan, China.

Background: Improper occipitocervical alignment after occipitocervical fusion (OCF) may lead to devastating complications, such as dysphagia and/or dyspnea. The occipital to C2 angle (O-C2a), occipital and external acoustic meatus to axis angle (O-EAa) have been used to evaluate occipitospinal alignment. However, it may be difficult to identify the inferior endplate of the C2 vertebra in patients with C2-3 Klippel-Feil syndrome (KFS). Read More

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February 2022

A well-differentiated liposarcoma of the prevertebral space: a case report.

Transl Cancer Res 2021 Jul;10(7):3600-3604

Department of Otolaryngology, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, China.

Liposarcoma is common in adults; however, it very rarely occurs in the retropharyngeal space, and to date, no cases of liposarcoma in the prevertebral space have been reported. A 78-year-old man presented at the Otolaryngology Department with a 1-month history of dyspnea and dysphonia. Magnetic resonance imaging of the neck reveled a retropharyngeal mass extending from the superior margin of the axis to the level of the 7 cervical vertebra. Read More

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Cervical Myelopathy Due to Idiopathic Retro-odontoid Pseudotumor.

World Neurosurg 2022 Apr 7;160:e256-e260. Epub 2022 Jan 7.

Department of Orthopaedics, Shanghai Changzheng Hospital, Naval Medical University, Shanghai, China. Electronic address:

Objective: A retro-odontoid pseudotumor (ROP) is commonly associated with atlantoaxial instability or rheumatoid arthritis. However, ROP in the absence of atlantoaxial instability or rheumatoid arthritis, which is termed idiopathic ROP (IROP), is a rare condition. The pathomechanisms and optimal treatment strategies for IROP remain controversial. Read More

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Computed tomography features of presumed normal mandibular and medial retropharyngeal lymph nodes in dogs.

Can J Vet Res 2022 Jan;86(1):27-34

Department of Small Animal Clinical Sciences (Belotta, Sukut, Lowe, MacDonald, Gagnon, Mayer) and Department of Large Animal Clinical Sciences (Waldner), Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan S7K 3J9; Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado 80523, USA (Randall).

Computed tomographic (CT) features of lymph nodes are used for diagnosis, staging, and response evaluation in veterinary patients. The objectives of this study were to describe maximum short- and long-axis transverse diameters (SATD and LATD, respectively), volume, and attenuation of presumed normal canine mandibular lymph nodes (MLNs) and medial retropharyngeal lymph nodes (MRLNs), to investigate the effect of variables on these features, and to describe inter-observer reliability of transverse diameter and attenuation measurement. Computed tomography studies of 161 dogs were retrospectively reviewed. Read More

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January 2022

Posterior First and Second Cervical Vertebrae Fusion by Screw Fixation Technique using the Modern Pre-fabricated Template Method on Cadaver Samples.

Malays Orthop J 2021 Nov;15(3):58-64

Department of Neurosurgery, Tehran University of Medical Sciences, Tehran, Iran.

Introduction: C1 lateral mass and C2 pedicular screws insertion are used for C1-C2 posterior fusion. Fluoroscopy Guided technique is routinely used for screw placement but it is associated with risk of injury to spinal cord and vertebral artery. 3D printing has developed rapidly in the fields of medicine. Read More

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November 2021

The Effect of Hounsfield Unit Value with Conventional Computed Tomography and Intraoperative Distraction on Postoperative Intervertebral Height Reduction in Patients Following Stand-Alone Anterior Cervical Discectomy and Fusion.

J Korean Neurosurg Soc 2022 Jan 29;65(1):96-106. Epub 2021 Dec 29.

Department of Neurosurgery, Pusan National University Yangsan Hospital, Yangsan, Korea.

Objective: The most common complication of anterior cervical discectomy and fusion (ACDF) is cage subsidence and maintenance of disc height affects postoperative clinical outcomes. We considered cage subsidence as an inappropriate indicator for evaluating preservation of disc height. Thus, this study aimed to consider patients with complications such as reduced total disc height compared to that before surgery and evaluate the relevance of several factors before ACDF. Read More

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January 2022

Predicting development of severe clinically relevant distal junctional kyphosis following adult cervical deformity surgery, with further distinction from mild asymptomatic episodes.

J Neurosurg Spine 2021 Dec 17:1-8. Epub 2021 Dec 17.

13Department of Neurological Surgery, University of California, San Francisco, California.

Objective: This retrospective cohort study aimed to develop a formal predictive model distinguishing between symptomatic and asymptomatic distal junctional kyphosis (DJK). In this study the authors identified a DJK rate of 32.2%. Read More

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December 2021

Surgical Management for Posterior Atlantoaxial Dislocation without Fracture and Atlantoaxial Dynamic Test to Confirm the Integrity of the Transverse Ligament: A Case Report.

Orthop Surg 2022 Feb 15;14(2):451-455. Epub 2021 Dec 15.

Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang, China.

Background: Traumatic posterior atlantoaxial dislocation (PAAD) without fracture of the odontoid process is a rare injury. Closed reduction by skull traction under C-arm fluoroscopic guidance and open reduction have been reported previously for the treatment of PAAD.

Objective: To report a rare case of PAAD without fracture treated by closed manual reduction and posterior fixation. Read More

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February 2022

Wright's Technique with the Addition of Visualized Axial Cortical Windows in Odontoid Fractures.

Orthop Surg 2022 Feb 16;14(2):443-450. Epub 2021 Dec 16.

Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.

This study sought to investigate and evaluate a modified axial translaminar screw fixation for treating odontoid fractures. We performed a retrospective study at Wenzhou Medical University Affiliated Second Hospital between March 2016 and June 2018. We retrospectively collected and analyzed the medical records of 23 cases with odontoid fractures. Read More

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February 2022

Morphometrics of nuchal ligament in greyhound in different neck and body positions.

Anat Histol Embryol 2022 Jan 9;51(1):143-152. Epub 2021 Dec 9.

Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria, Australia.

This study was conducted to describe the morphometrics of nuchal ligament and investigate the effects of different neck and body positions on the nuchal ligament in greyhounds. Nine adult greyhounds cadavers without any locomotion abnormalities were dissected through the neck musculature on the left side to expose the nuchal ligament. Three pins were placed to mark regions of interest on the nuchal ligament: at one cm cranial to the site of origin (the most dorsal point of the spinous process of the first thoracic vertebra), at the midpoint of the nuchal ligament and one cm caudal to the nuchal ligament site of insertion (close to the caudal aspect of the spinous process of the axis). Read More

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January 2022

Evaluation of external stabilization of type II odontoid fractures in geriatric patients-An experimental study on a newly developed cadaveric trauma model.

PLoS One 2021 29;16(11):e0260414. Epub 2021 Nov 29.

BG Trauma Center Ludwigshafen, Clinic for Trauma and Orthopaedic Surgery, University of Heidelberg, Ludwigshafen on the Rhine, Germany.

Background: Along with the growing geriatric population, the number of odontoid fractures is steadily increasing. However, the effectiveness of immobilizing geriatric odontoid fractures using a cervical collar has been questioned. The aim of the present study is to analyze the physiological and pathological motion in odontoid fractures and to assess limitation of motion in the cervical spine when applying a cervical collar. Read More

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January 2022

Introducing a new possible predisposing risk factor for odontoid type 2 fractures after cervical trauma; Ponticulus posticus anomaly of C1 vertebra.

J Clin Neurosci 2022 Feb 25;96:194-198. Epub 2021 Nov 25.

Recep Tayyip Erdogan University, Medical Faculty, Department of Radiology, Rize, Turkey.

Objective: Ponticulus posticus is an anomaly of the atlas. Odontoid fracture type 2 fracture occurs by hyperflexion, hyperextension, lateral flexion, and a combination of these movements. The presence of Ponticulus Posticus anomaly may affect the occurrence of odontoid fractures of the C2 vertebra. Read More

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February 2022

Pediatric cervical kyphosis in the MRI era (1984-2008) with long-term follow up: literature review.

Childs Nerv Syst 2022 02 22;38(2):361-377. Epub 2021 Nov 22.

Department of Neurosurgery, Rush University Medical Center, Chicago, IL, USA.

Objective: Cervical kyphosis is rare in the pediatric population. It may be syndromic or acquired secondary to laminectomy, neoplasia, or trauma. Regardless, this should be avoided to prevent progressive spinal deformity and neurological deficit. Read More

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February 2022

Bilateral medial medullary syndrome following anterior screw fixation of type 2 odontoid fracture, a case report of two patients.

Spinal Cord Ser Cases 2021 11 20;7(1):101. Epub 2021 Nov 20.

Department of Orthopaedics and Trauma Surgery, Medical University Innsbruck, Innsbruck, Austria.

Introduction: Medial medullary syndrome (MMS) has not been reported after anterior screw fixation of an odontoid type 2 fracture.

Case Presentation: We report on two cases who suffered from an unstable type 2 odontoid fracture following a skiing and a domestic fall accident. Prior to anterior screw fixation surgery both patients presented without neurologic deficits but postoperatively developed a bilateral MMS, including an incomplete tetraparesis, impaired sensation of position and movement as well as tactile discrimination and paralysis of the tongue muscle with deviation to the paralyzed side. Read More

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November 2021

Surgical Outcomes for C Tear Drop Fractures: Clinical Relevance to Hangman's Fracture and C Discoligamentous Injury.

Orthop Surg 2021 Dec 17;13(8):2363-2372. Epub 2021 Nov 17.

Department of Orthopaedic Surgery, Chonnam National University Medical School and Hospital, Gwangju, Republic of Korea.

Objective: To analyze characteristics of surgically managed tear drop (TD) fractures of the C axis associated with other injuries such as hangman's fracture and C discoligamentous injury as well as treatment outcomes.

Methods: A total of 14 patients (eight men and six women) with TD fractures of the C , who were surgically treated at four national trauma centers of tertiary university hospitals from January 2000 to December 2017, were included in this retrospective study. The mean age of the patients was 45. Read More

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December 2021