Oblique axis body fracture-Pitfalls in management
ABSTRACT Transverse fractures through the body of the axis, rather than at the base of the odontoid are uncommon and management with an external orthosis is usually recommended. Oblique fractures through the body of the axis accompanying a hangman's fracture have not been reported and are not described as part of any classification system. Such fractures may be at high risk for treatment failure in an external orthosis.
We report on a case of an oblique axis fracture that failed treatment with external orthosis. Posterior instrumented fusion was employed successfully using a C1-C3 and C4 poly axial screw rod construct. Frameless stereotaxy and a biomodel were useful surgical adjuncts. Twelve month follow up revealed bony union in an asymptomatic patient.
Oblique fractures of the body of the axis can displace in a halo-thoracic orthosis. Serial radiological review is required to detect displacement prior to fracture union. Oblique fractures of the body of the axis can be managed surgically with preservation of atlanto-occipital motion, resulting in satisfactory clinical and radiological outcomes.
Article: Fractures of the C-2 vertebral body.[Show abstract] [Hide abstract]
ABSTRACT: Vertical C-2 body fractures are presented in 15 patients with clinical and imaging correlations that suggest the existence of a variety of mechanisms of injury. In these patients, clinical and imaging correlations were derived by: 1) defining the point of impact by clinical examination; 2) defining the point of impact by soft-tissue changes on cranial magnetic resonance (MR) imaging or computerized tomography (CT); 3) obtaining an accurate history of the mechanism of injury; and 4) spine imaging (x-ray studies, CT, and MR imaging) of the C-2 body fracture and surrounding bone and soft tissue. The cases presented involve the region located between the dens and the pars interarticularis of the axis. Although these fractures are rarely reported, they are not uncommon. An elucidation of their pathological anatomy helps to further the understanding of the mechanistic etiology of upper cervical spine trauma. A spectrum of mechanisms of injury causing upper cervical spine fractures was observed. The type of injury incurred is determined predominantly by the force vector applied during impact and the intrinsic strength and anatomy of C-2 and its surrounding spinal elements. From this clinical experience, two types of vertical C-2 body fractures are defined and presented: coronally oriented (Type 1) and sagittally oriented (Type 2). A third type of C-2 body fracture, the horizontal rostral C-2 fracture (Type 3), is added for completeness; this Type 3 fracture is the previously described Type III odontoid process fracture described by Anderson and D'Alonzo.Journal of Neurosurgery 09/1994; 81(2):206-12. DOI:10.3171/jns.1994.81.2.0206 · 3.23 Impact Factor
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ABSTRACT: The authors compared the biomechanical stability of two anterior fixation procedures--anterior C1-2 Harms plate/screw (AHPS) fixation and the anterior C1-2 transarticular screw (ATS) fixation; and two posterior fixation procedures--the posterior C-1 lateral mass combined with C-2 pedicle screw/rod (PLM/APSR) fixation and the posterior C1-2 transarticular screw (PTS) fixation after destabilization. Sixteen human cervical spine specimens (Oc-C3) were tested in three-dimensional flexion-extension, axial rotation, and lateral bending motions after destabilization by using an atlantoaxial C1-2 instability model. In each loading mode, moments were applied to a maximum of 1.5 Nm, and the range of motion (ROM), neutral zone (NZ), and elastic zone (EZ) were determined and values compared using the intact spine, the destabilized spine, and the postfixation spine. The AHPS method produced inferior biomechanical results in flexion-extension and lateral bending modes compared with the intact spine. The lateral bending NZ and ROM for this method differed significantly from the other three fixation techniques (p < 0.05), although statistically significant differences were not obtained for all other values of ROM and NZ for the other three procedures. The remaining three methods restored biomechanical stability and improved it over that of the intact spine. The PLM/APSR fixation method was found to have the highest biomechanical stiffness followed by PTS, ATS, and AHPS fixation. The PLM/APSR fixation and AATS methods can be considered good procedures for stabilizing the atlantoaxial joints, although specific fixation methods are determined by the proper clinical and radiological characteristics in each patient.Journal of Neurosurgery 03/2004; 100(3 Suppl Spine):277-83. DOI:10.3171/spi.2004.100.3.0277 · 3.23 Impact Factor
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ABSTRACT: A computer-based system has been developed for the integration and display of computerized tomography (CT) image data in the operating microscope in the correct perspective without requiring a stereotaxic frame. Spatial registration of the CT image data is accomplished by determination of the position of the operating microscope as its focal point is brought to each of three CT-imaged fiducial markers on the scalp. Monitoring of subsequent microscope positions allows appropriate reformatting of CT data into a common coordinate system. The position of the freely moveable microscope is determined by a non-imaging ultrasonic range-finder consisting of three spark gaps attached to the microscope and three microphones on a rigid support in the operating room. Measurement of the acoustic impulse transit times from the spark gaps to the microphones enables calculation of those distances and unique determination of the microscope position. The CT data are reformatted into a plane and orientation corresponding to the microscope's focal plane or to a deeper parallel plane if required. This reformatted information is then projected into the optics of the operating microscope using a miniature cathode ray tube and a beam splitter. The operating surgeon sees the CT information (such as a tumor boundary) superimposed upon the operating field in proper position, orientation, and scale.Journal of Neurosurgery 11/1986; 65(4):545-9. DOI:10.3171/jns.1986.65.4.0545 · 3.23 Impact Factor