OBJECTIVETo investigate appropriate ways for screw placement of pedicle of vertebral arch in the horizontal plane.

METHODSFifteen preserved thoracolumbar spine specimens (T(11)-L(5)) were used and divided into three groups at random. Firstly four anatomic parameters indicating screw positions in the horizontal plane were measured. Secondly the methods of Roy-camille, Magerl, and authors' segmental differences were used to place successively the screws of the pedicles with 5 mm, 6 mm, and 7 mm in diameter. Coincidences between the drilling point, drilling direction and pedicle axis, and ruptures of the pedicle as well as the length of the screw in the vertebral body were observed.

RESULTSFour anatomic parameters at various segments showed significant differences (P<0.05). The drilling point by the Roy-camille's method deviated medial to pedicle axis in most segments, and its drilling direction did not coincide well with most E-angles of the pedicles. The drilling point by Magerl's method coincided relatively well with pedicle axis in lumbar vertebrae, but there were still some differences between its drilling direction and E-angles of the pedicles. The method of segmental differences coincided the best with the pedicle axis. The lengths of screw in the vertebra were relatively long by both Magerl and segmental difference methods. When 5 mm diametral screw was used by the three methods, the rupture rate was very low. When 6 mm and 7 mm diametral screws were placed, the rupture rate was accordingly increased. Of the three methods, Roy-camille's method showed a relatively high rupture rate, while the method of segmental differences a comparatively low rupture rate. Various degrees of rupture of the pedicle of vertebral arch were found at the juncture of the thoracic and lumbar vertebrae when 6 mm or 7 mm diametral screws was used by any screw placement method. In contrast, the rupture was seldom seen at the lower lumbar vertebrae when 7 mm diametral screws were used.

CONCLUSIONSThe segmental difference method is proved to have the anatomic safety and screw biomechanical stability. It is appropriate to choose different diametral screws, different drilling points and directions according to different segments of the vertebra.

Cervical Vertebrae ; injuries ; Humans ; Spinal Injuries ; diagnosis ; therapy ; Thoracic Vertebrae ; injuries

Hangman's fractures are located in the region between facets of the axis, which are accompanied by an increasing rate recently. However,there are no uniform standards for the treatment, especially for the treatment of fractures of types II and IIa because the operative approaches which include anterior and posterior are supported by different groups. The article tried to make an analysis on pathological anatomy, mechanism, types and surgical treatment of Hangman's fractures.
Cervical Vertebrae ; injuries ; surgery ; Humans ; Spinal Fractures ; classification ; surgery

Cervical Cord ; Cervical Vertebrae/surgery* ; Humans ; Spinal Cord Injuries/etiology* ; Thyroidectomy/adverse effects*

OBJECTIVETo examine the contribution of flexion and extension radiographs in the evaluation of ligamentous injury in awake adults with acute blunt cervical spine trauma, who show loss of cervical lordosis and neck pain.

METHODSAll patients who presented to our emergency department following blunt trauma were enrolled in this study, except those with schiwora, neurological deficits or fracture demonstrated on cross-table cervical spine X-rays, and those who were either obtunded or presented after cervical spine surgery. Adequacy of flexion and extension views was checked by the neurosurgery and radiology team members. All these patients underwent cross-table cervical spine view followed by flexion/extension views based on the loss of lordosis on cross-table imaging and the presence of neck pain.

RESULTSA total of 200 cases were reviewed, of whom 90 (45%) underwent repeat X-rays because of either inadequate exposure or limited motion. None of the patients with loss of lordosis on cross-table view had positive flexion and extension views of cervical spine for instability.

CONCLUSIONSOur results show that in patients who underwent acute radiographic evaluation of blunt cervical spine trauma, flexion and extension views of the cervical spine are unlikely to yield positive results in the presence of axial neck pain and/or loss of cervical lordosis. We can also hypothesize that performing flexion and extension views will be more useful once the acute neck pain has settled.

Cervical spinal canal narrowing can lead to injury of the spinal cord and neurological symptoms including neck pain, headache, weakness and parasthesisas. According to previous and recent clinical researches, we investigated the geometric parameters of normal cervical spinal canal including the sagittal and transverse diameters as well as Torg ratio. The mean sagittal diameter of cervical spinal canal at C(1) to C(7) ranges from 15.33 mm to 20.46 mm, the mean transverse diameter at the same levels ranges from 24.45 mm to 27.00 mm and the mean value of Torg ratio is 0.96. With respect to narrow cervical spinal canal, the following charaterstics are found: firstly, extension of the cervical spine results in statistically significant stenosis as compared with the flexed or neutral positions; secondly, females sustain cervical spinal canal narrowing more easily than males; finally, the consistent narrowest cervical canal level is at C(4) for all ethnicity, but there is a slight variation in the sagittal diameter of cervical spinal stenosis (less than or equal to 14 mm in Whites, less than or equal to 12 mm in Japanese, less than or equal to 13.7 mm in Chinese). Narrow sagittal cervical canal diameter brings about an increased risk of neurological injuries in traumatic, degenerative and inflammatory conditions and is related with extension of cervical spine, gender, as well as ethnicity. It is hoped that this review will be helpful in diagnosing spinal cord and neurological injuries with the geometric parameters of cervical spine in the future.
Cervical Vertebrae ; injuries ; Humans ; Magnetic Resonance Imaging ; Spinal Canal ; Spinal Cord Injuries ; diagnosis ; Spinal Stenosis

Whiplash injury is a common injures in our daily lives, but the mechanism of it and the best treatment is largely unknown. The development of chronic pain and disability following whiplash injury is not uncommon and results in substantial social and economic costs. Clinical manifestation and recovery time are difference, which make it difficult for doctor diagnosis and treatment. The current study have shown that the social class, severity of collision, compensation and lawsuit, physical and psychological factors were relevant predictors for the outcome of whiplash. This article is try to overview the status quo of the whiplash injury.
Cervical Vertebrae ; injuries ; Humans ; Prognosis ; Whiplash Injuries ; diagnosis ; pathology ; physiopathology ; therapy

A 24-year-old male was transferred to the emergency department while being in the state of quadriplegia with a history of performing Parkour sport, which is also called double front flip. Neurological examination revealed that the patient's muscle power was 0/5 at all extremities. The patient did not show any sense of light touch or pain in his extremities. In radiological studies, cervical spine X-ray and CT scan images showed C4-C5 subluxation with bilateral locked facets and spinal cord injury. The results of this very rare case study revealed that exercising Parkour sport without taking into account safety standards could result in irreversible injuries to the cervical spinal cord with fatal outcome.
Cervical Vertebrae ; Humans ; Male ; Radiography ; Running ; injuries ; Spinal Cord Injuries ; diagnostic imaging ; etiology ; Young Adult

Adult ; Aged ; Cervical Vertebrae ; injuries ; Diagnostic Errors ; Female ; Humans ; Male ; Middle Aged ; Whiplash Injuries ; diagnosis

STUDY DESIGN: Cadaveric study. PURPOSE: The purpose of this study was to assess the accuracy and feasibility of cervical pedicle screw (CPS) insertion into the subaxial cervical spine placed using a patient-specific drill guide template constructed from a stereolithographic model. OVERVIEW OF LITERATURE: CPS fixation is an invaluable tool for posterior cervical fixation because of its biomechanical advantages. The major drawback is its narrow corridor that allows very little clearance for neural and vascular injuries. METHODS: Fifty subaxial pedicles of the cervical vertebrae from five cadavers were scanned into thin slices using computed tomography (CT). Digital imaging and communications in medicine images of the cadaver spine were digitally processed and printed to scale as a three-dimensional (3D) model. Drill guide templates were manually moulded over the 3D-printed models incorporating pins inserted in the pedicles. The drill guide templates were used for precise placement of the drill holes in the pedicles of cadaveric specimens for pedicle screw fixation. RESULTS: The instrumented cadaveric spines were subjected to CT to assess the accuracy of our pedicle placement by an external observer. Our patient-specific drill guide template had an accuracy of 94%. CONCLUSIONS: The use of a patient-specific drill guide constructed using stereolithography improved the accuracy of CPS placement in a cadaveric model.
Cadaver ; Cervical Vertebrae ; Female ; In Vitro Techniques* ; Pedicle Screws* ; Printing, Three-Dimensional ; Spine* ; Vascular System Injuries