OBJECTIVE: To investigate the possible mechanism and fracture stability of subtypes of type B Hangman's fracture by using imaging observation. METHODS: Patients with type B Hangman's fractures admitted to multiple centers between January 2008 and October 2023 were selected as the research objects. The clinical data and imaging data of patients who met the selection criteria were extracted. The patients' age, gender, cause of fracture, disease duration, visual analogue scale (VAS) score of neck pain, neck disability index (NDI), and American Spinal Injury Association (ASIA) classification of spinal cord function were collected. Based on the imaging data, the anatomical structure of the contralateral superior articular process fracture, the relationship between the superior articular process fracture line and the position of the odontoid process, the associated posterior vertebral wall fracture and its classification, the incidence of vertebral arch floating and C _{2, 3} instability were observed. The superior articular fracture angle (SAFA), superior articular fracture displacement distance (SAFD), and C ₂ vertebral body rotation (VBRA) were measured. According to the anatomical structure of the contralateral superior articular process fracture, the patients were divided into a pedicle fracture group (POA group), a inferior articular process fracture group (IAP group), and a laminar fracture group (CSL group). The baseline data and imaging indexes were analyzed between groups, and the imaging anatomical characteristics of each subtype of fracture were observed to explore its possible mechanism and fracture stability. RESULTS: A total of 86 cases of type B Hangman's fractures were collected. There were 67 males and 19 females. The mean age was 51.0 years (range, 21-78 years). There were 48 cases of pedicle fracture (POA group), 25 cases of inferior articular process fracture (IAP group), and 13 cases of laminar fracture (CSL group). There was no significant difference in age, gender, cause of fracture, disease duration, VAS score of neck pain, and NDI between groups ( P>0.05). However, the incidence of spinal cord injury in POA group was the highest ( P<0.05). The incidences of superior articular process fracture line posterior to the odontoid process and posterior vertebral wall fracture in POA group were the highest ( P<0.05). The incidences of vertebral arch floating and C _{2, 3} instability in IAP group were the highest ( P<0.05). There were significant differences in SAFA and VBRA between groups ( P<0.05). There was no significant difference in SAFD between groups ( P>0.05). The differences in the incidences of fracture displacement>3 mm and VBRA>5° between groups were significant ( P<0.05). There were 78 cases of unstable Hangman's fracture, including 2 cases of simple C _2、3 instability, 22 cases of simple axis rotation and displacement instability, 8 cases of simple vertebral arch floating instability, and the rest of the patients had two or more types of instability. CONCLUSION The mechanism of different subtypes of type B Hangman's fracture may be that the lateral mass of the rotation of the atlas applied the overextension compression force to the unilateral superior articular process of the axis vertebra, and the contralateral pedicle, inferior articular process and lamina fractures were caused by direct violence or/and rotational violence to different degrees. The decomposition of this type of fracture into C _{2, 3} intervertebral, axis vertebra body displacement and rotation and vertebral arch floating instability is beneficial to the treatment and surgical approach selection.
Humans ; Spinal Fractures/surgery* ; Male ; Female ; Cervical Vertebrae/diagnostic imaging* ; Middle Aged ; Adult ; Tomography, X-Ray Computed ; Aged ; Odontoid Process/injuries* ; Fracture Fixation, Internal/methods* ; Young Adult

OBJECTIVETo summarize the techniques and evaluate the therapeutic effect of posterior fixation and fusion in the treatment of Os odontoideum complicated by atlantoaxial dislocation.

METHODSFrom March, 2007 to October, 2010, 10 patients with Os odontoideum (including 6 male and 4 female patients aged from 20 to 65 years, mean 39.8 years) were treated in our hospital. Before and after the operation, the patients underwent X ray, CT and MRI examinations to measure and evaluate the degree of dislocation and neural compression. After preoperative traction for 1-2 weeks, all the 10 patients showed deductible atlantoaxial dislocation. Through a posterior approach, Atlantoaxial pedicle screws fixation were performed in 9 cases, and C2/3 pedicle-Occiput screw fixation was performed in 1 case. All the patients wore cervical collars as external support for 3 months after the operation.

RESULTSThe mean operative time was 3 h in these patients with a mean intraoperative blood loss of 420 ml. The symptoms were relieved after the surgery in all the patients, who showed no neck pain or neurological defects. The patients were followed up for 6 to 52 months (mean 22 months), and bony fusion was observed in all the 10 cases within 6 to 8 months without such complications as internal fixation failure or redislocation of the atlas.

CONCLUSIONPatients with Os odontoideum complicated by atlantoaxial dislocation should undergo surgical stabilization to avoid severe neurological injury. Pedicle screw instrument in the atlas allows restoration of the spinal stability, short-segment fusion, and maximal preservation of the mobility of the neck.

Adult ; Aged ; Atlanto-Axial Joint ; injuries ; Bone Transplantation ; Female ; Fracture Fixation, Internal ; methods ; Humans ; Joint Dislocations ; complications ; surgery ; Joint Loose Bodies ; complications ; surgery ; Male ; Middle Aged ; Odontoid Process ; pathology ; Spinal Fusion ; methods ; Treatment Outcome ; Young Adult

OBJECTIVETo evaluate the therapeutic effects of atlantoaxial pedicle screw in treating odontoid process fracture by location through inferior and inner wall of atlas and superior and inner wall of axis.

METHODSFrom June 2006 to September 2010, 12 patients with odontoid process fracture were treated with the atlantoaxial pedicle screw fixation by location through inferior and inner wall of atlas and superior and inner wall of axis. There were 8 males and 4 females, ranging in age from 18 to 62 years, with an average of 37.9 years. According to classification of Anderson, type II was in 10 cases and type III was in 2 cases. Fresh fracture was in 9 cases and old fracture was in 3 cases. All patients had symptoms such as cervical pain, stiffness and limitation of activity and 9 cases with symptoms were found physical signs of cervical spinal injury. According to grade of ASIA, grade C was in 4 cases and grade D was in 5 cases.

RESULTSThere were no severe complications such as injuries of vertebral artery, nerve root and spinal cord during operation. The mean time of follow-up was 14 months (6 to 24 months). The X-ray film and CT scanning showed that all patients had steady bony union and all screws were in the proper position, no screws loosening or breaking were found. Clinical symptoms of all patients improved significantly. Nine patients with spinal injury before operation, of which nerve function obtained improvement, grade C was in 1 case, grade D was in 2 cases and grade E was in 6 cases according to grade of ASIA.

CONCLUSIONLocation through inferior and inner wall of atlas and superior and inner wall of axis is an effective method for the atlantoaxial pedicle screw implantation; atlantoaxial pedicle screw could be accurately and safely implanted thought this way.

Adolescent ; Adult ; Bone Screws ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Odontoid Process ; diagnostic imaging ; injuries ; physiopathology ; surgery ; Recovery of Function ; Spinal Fractures ; diagnostic imaging ; physiopathology ; surgery ; Tomography, X-Ray Computed ; Young Adult

OBJECTIVETo explore the efficacy of anterior percutaneous screw fixation in the treatment of odontoid process fractures in aged people.

METHODSFrom February 2001 to April 2009, 15 elderly patients with odontoid fracture were treated with anterior percutaneous screw fixation,including 13 males and 2 females; the average age was 69.3 years (ranged, 60 to 86 years). According to Anderson classification, there were 10 patients with type II fractures (type II A in 7 cases, type II B in 3 cases, based on Eysel and Roosen classification), 4 patients with shallow type III fractures, 1 patient with deep type III fractures. Thirteen patients were fresh fractures, 2 patients were obsolete fractures. All patients had varying degrees of neck or shoulder pain, and limit activity of neck. There were 4 patients with neural symptoms including 2 grade D and 2 grade C according to Frankel classification. All the patients were followed up and were assessed by radiology. Clinical examination included neck activity, neurological function and the degree of neck pain. Radiology examinations including anteroposterior, lateral, open mouth position and flexion-extension radiographs of cervical vertebra were performed.

RESULTSAfter surgery, all patients were followed up,and the duration ranged from 6 to 60 months (averaged 31.3 months). Two patients died of other diseases during the follow-up period (18 and 22 months after surgery respectively). All patients got satisfactory results, and all screws were in good position. As the screw was too long, esophagus was compressed by screw tail in one case. One case showed fibrous union, 12 cases had achieved solid bony union, 2 cases showed nonunion without clinical symptoms. The rotation of neck in 3 cases was mildly limited,the neck function of the remaining patients were normal. Four patients with symptoms nerve injuries improved after operation (Frankel E in 3 cases, Frankel D in 1 case). The symptom of neck pain had a significant improvement after surgery (P < 0.001). The VAS score decreased from preoperative (6.07 +/- 1.44) (4 to 8 scores),to postoperative (1.13 +/- 0.92) (0 to 3 scores). And there were no severe postoperative complications.

CONCLUSIONThe anterior percutaneous screw fixation is less traumatic than conventional approaches for aged people in dealing with odontoid process fractures. Most patients will achieve satisfactory clinical results, as long as the general conditions of them are comprehensively assess. However, this procedure should not be used in patients with comminuted odontoid fractures or severe osteoporosis.

Aged ; Aged, 80 and over ; Bone Screws ; Female ; Follow-Up Studies ; Fracture Fixation, Internal ; instrumentation ; Fractures, Bone ; diagnostic imaging ; physiopathology ; surgery ; Humans ; Male ; Middle Aged ; Odontoid Process ; diagnostic imaging ; injuries ; physiopathology ; surgery ; Skin ; Tomography, X-Ray Computed

Adult ; Atlanto-Axial Joint ; surgery ; Bone Screws ; Female ; Fractures, Bone ; diagnostic imaging ; pathology ; physiopathology ; surgery ; Humans ; Male ; Middle Aged ; Odontoid Process ; injuries ; Tomography, X-Ray Computed

Adult ; Female ; Fracture Fixation, Internal ; methods ; Humans ; Male ; Middle Aged ; Odontoid Process ; injuries ; Perioperative Nursing ; Postoperative Care ; Spinal Fractures ; surgery

INTRODUCTIONAlthough uncommon, fractures of the os odontoideum are known to occur in children under 7 years old, following acute trauma.

CLINICAL PICTUREWe report a case of chronic subluxation of the os odontoideum resulting in cervical myelopathy in a child with Beare-Stevenson cutis gyrata syndrome after surgery to the head and neck.

TREATMENT AND OUTCOMEThe patient was initially put in a Halo vest, following which occipital cervical fusion was performed.

CONCLUSIONSubluxations and fractures at the odontoid synchondrosis are rare but should be anticipated in young children with risk factors for instability of the cervical spine.

Abnormalities, Multiple ; diagnostic imaging ; Acanthosis Nigricans ; congenital ; Cervical Vertebrae ; diagnostic imaging ; Child ; Craniofacial Abnormalities ; diagnostic imaging ; Female ; Fractures, Bone ; surgery ; Humans ; Neck ; surgery ; Occipital Bone ; surgery ; Odontoid Process ; diagnostic imaging ; pathology ; Skin Abnormalities ; diagnostic imaging ; Surgical Procedures, Operative ; Syndrome ; Tomography, X-Ray Computed ; Uvula ; abnormalities

In order to provide anatomical basis for transoral approach (TOA) in dealing with the ventro lesions of craniocervical junction, and the design and application of artificial atlanto-odontoid joint, microsurgical dissecting was performed on 8 fresh craniocervical specimens layer by layer through transoropharyngeal approach. The stratification of posterior pharyngeal wall, course of vertebral artery, adjacent relationship of atlas and axis and correlative anatomical parameters of replacement of artificial atlanto-odontoid joint were observed. Besides, 32 sets of atlanto-axial joint in adults' fresh bony specimens were measured with a digital caliper and a goniometer, including the width of bony window of anterior arch of atlas, the width of bony window of axis vertebra, the distance between superior and inferior two atlas screw inserting points, the distance between two axis screw inserting points etc. It was found that the width of atlas and axis which could be exposed were 40.2+/-3.5 mm and 39.3+/-3.7 mm respectively. The width and height of posterior pharyngeal wall which could be exposed were 40.1+/-5.2 mm and 50.2+/-4.6 mm respectively. The distance between superior and inferior two atlas screw inserting points was 28.0+/-2.9 mm and 24.0+/-3.5 mm respectively, and the distance of bilateral axis screw inserting points was 18.0+/-1.2 mm. The operative exposure position through TOA ranged from inferior part of the clivus to the superior part of the C3 vertebral body. Posterior pharyngeal wall consisted of 5 layers and two interspaces: mucosa, submucosa, superficial muscular layer, anterior fascia of vertebrae, anterior muscular layer of vertebrae and posterior interspace of pharynx, anterior interspace of vertebrae. This study revealed that it had the advantages of short operative distance, good exposure and sufficient decompression in dealing with the ventro lesions from the upper cervical to the lower clivus through the TOA. The replacement of artificial atlanto-odontoid joint is suitable and feasible. The design of artificial atlanto-odontoid joint should be based on the above data.
Atlanto-Axial Joint/*anatomy & histology ; Atlanto-Axial Joint/*surgery ; Bone Plates ; Bone Screws ; Cadaver ; Cervical Vertebrae/*anatomy & histology ; Cervical Vertebrae/surgery ; Equipment Design ; Internal Fixators ; Joint Prosthesis ; Models, Anatomic ; Odontoid Process/*surgery ; Prosthesis Design

OBJECTIVETo evaluate the feasibility, safety and efficacy of atlas pedicle screws system fixation and fusion for the treatment of upper cervical diseases.

METHODSTwenty-three consecutive patients with upper cervical disorders requiring stabilization, including 19 cases of atlantoaxial dislocation (4 congenital odontoid disconnections, 6 old odontoid fractures, 4 fresh odontoid fractures of Aderson II C, 3 ruptures of the C(1) transverse ligament, and 2 fractures of C(1)), 2 cases of C2 tumor (instability after the resection of the tumors), and 2 giant neurilemomas of C(2)-C(3)(instability after resection of the tumors), were treated by posterior fixation and fusion with the atlas pedicle screw system, in which the screws were inserted through the posterior arch of C1. The operative time, bleeding volume and complications were reported. All patients were immobilized without external fixation or with rigid cervical collars for 1-3 months. All patients were followed up and evaluated with radiographs and CT.

RESULTSIn the 23 patients, 46 C(1) pedicle screws, 42 C(2) pedicle screws and 6 lower cervical lateral mass screws and 2 lower cervical pedicle screws were placed. The mean operative time and bleeding volume was 2.7 hours and 490 ml respectively. No intraoperative complications were directly related to surgical technique. No neurological, vascular or infective complications were encountered. All patients were followed up for 3-36 months (average 15 months). Firm bony fusion was documented in all patients after 3-6 months. One patient with atlas fracture showed anterior occipitocervical fusion. There was no implant failure.

CONCLUSIONSPosterior fixation and fusion of the atlas pedicle screw system is feasible and safe for the treatment of upper cervical diseases, and may be applicable to a larger number of patients.

Adult ; Bone Screws ; Cervical Atlas ; diagnostic imaging ; injuries ; pathology ; surgery ; Feasibility Studies ; Female ; Fracture Fixation, Internal ; instrumentation ; Humans ; Joint Dislocations ; diagnostic imaging ; surgery ; Male ; Middle Aged ; Odontoid Process ; abnormalities ; diagnostic imaging ; pathology ; surgery ; Spinal Fractures ; diagnostic imaging ; surgery ; Spinal Fusion ; instrumentation ; Spinal Neoplasms ; diagnostic imaging ; pathology ; surgery ; Tomography, X-Ray Computed ; Treatment Outcome

Axis, Cervical Vertebra ; injuries ; Cervical Atlas ; injuries ; Fracture Fixation, Internal ; instrumentation ; methods ; Humans ; Odontoid Process ; injuries ; Spinal Fractures ; diagnosis ; surgery ; Spinal Fusion