Lateral Mass Fractures Research Articles

Surgical treatment of cervical subluxation due to lateral mass fracture

Surgical treatment of cervical subluxation due to lateral mass fracture

C1 lateral mass-C2 pedicle screws and crosslink compression fixation for instable atlas fracture

To evaluate the feasibility and reliability of C(1) lateral-mass screw-C(2) pedicle screw and crosslink compression fixation for Jefferson fracture. Seventeen patients with atlas fracture, 12 males and 5 females, aged 42.5 (25 - 67), 4 of which with unstable atlas fracture, were treated. 11 cases underwent C(1) lateral mass and C(2) pedicle screws and crosslink fixation, 6 of which had axial instability and rupture of atlas transverse ligament, 1 had C(2) luminal fracture, and the other 4 had axial instability. With the assistant of regional anatomy study and fluoroscopy the C(1) lateral mass screw and C(2) pedicle screw were inserted properly. Connecting rods were applied into the two screws on each side. Crosslink between the two rods were applied, compressing to achieve the realignment of the C(1) lateral mass fracture and C(0)-C(1)-C(2) into anatomical position. C(1)-C(2) fusions with posterior bone graft were performed in the patients with axial instability or transverse ligament discontinuity. The operative time ranged from 90 to 176 min with an average of 124 min. The intra-operative blood loss ranged from 270 to 1200 ml with an average of 432 ml. Fluoroscopic examination was used for 18 seconds on average. There were no neurological deficits, vertebral artery related complications or other complications in all the patients. No neurological deficit was aggravated after the patient's mobilization with brace 5 days after operation. One case of vertebral artery rupture happened because of the use of electrocautery. The bleeding was stopped by the use of hemostatic sponge and bone cement without causing cerebral hemodynamic deficit. X-ray examination showed bone fusion and stability in all the patients three months after the operation. The restoration of the C(2) fracture was confirmed by CT scan. Osteosynthesis of the atlas by C(1) lateral-mass screw-C(2) pedicle screw and crosslink compression fixation is an ideal option for C(1) burst fracture with or without rupture of transverse ligament. The procedure allows a physiological reconstruction of the C(0)-C(1)-C(2) joint and short segmental solid fusion for Jefferson fracture.

Solitary isolated lateral mass fracture of the atlas

Atlas fractures are common injuries, occurring in 10% of all patients with cervical spine trauma. The unique anatomy of the atlas and the typical mechanisms of injury yield a predictable variety of injury patterns. It is common undergraduate teaching that fractures to ring structures, such as the atlas, must result in at least two breaks in the structure. An analogy is often made with a broken ‘‘Polo Mint’’. However, this is not always the case and is demonstrated below.

An unusual aetiology of unilateral vagal palsy: A case report

Vagal palsy is often a diagnostic challenge because the nerve can be affected anywhere along its course, from the point of exit from cranial vault through the jugular foramen upto its destination. This is a case report of a 78 year old lady who presented to our department with clinical features suggestive of unilateral vagal palsy and whose diagnostic evaluation revealed a Lateral Mass Fracture of Atlas vertebra with displacement of the fragment.

Distal humerus lateral condyle mass fracture and olecranon fracture in a 4-year-old female—review of literature

Summary A 4-year-old right hand dominant female presents to Accident and Emergency Department with what appears to be a multifragmented fracture of the left olecranon. Close inspection of the antero-posterior radiograph reveals an ipsilateral lateral mass fracture of the distal humerus. The injury is closed and there is no neurovascular defect. She subsequently underwent an open reduction and internal fixation of both fractures and had regained near normal movement by 8 weeks post-injury. An overview of lateral mass and olecranon fractures is given. To the best of our knowledge there are no reported cases in the literature of ipsilateral condylar and olecranon fractures in children.

Cervical spine injuries associated with lateral mass and facet joint fractures: diagnosis and treatment strategies

Purpose of study: The objectives of this study were to analyze the surgical results of cervical spine injuries associated with lateral mass and facet joint fractures retrospectively and to clarify the surgical indication and treatment strategies for these injuries.Methods used: From 1991 to 1999, 30 patients including 20 lateral mass fractures and 8 facet joint fractures received surgical treatments in our institution. The average age at surgery was 46 years. The injury types according to Allen's classification were compressive-extension in 26, lateral flexion in 3, and distractive-flexion in 1 patient. All patients, except one who required osteosynthesis for the separation fracture of the lateral mass, received exclusive posterior fusion with cervical pedicle screw system. From X-rays and magnetic resonance imaging (MRI) analyses, the fractures were classified into subtypes. The translation of fractured and adjacent vertebrae in the sagittal and coronal planes, vertebral body destruction and signal changes of disc and spinal ligaments (ALL, PLL, SSL and ISL) on MRI were evaluated. The number of stabilized segments and the spinal alignment were also evaluated at follow-up.of findings: The lateral mass fractures were divided into the following four subtypes: separation fracture in 11, comminution type in 4, split type in 5 and traumatic spondylolysis in 2. The superior and inferior articular process fractures and combination of both fractures were seen in six, one and one patient, respectively. The anterior translation of fractured vertebra was demonstrated in 77% of lateral mass fractures, whereas 24% and 10% of anterior translation was observed even in cephalad and caudal adjacent vertebrae, respectively. The alignment change in coronal plane was detected in 33% of lateral mass fractures. On MRI, the signal changes in ALL and disc were demonstrated in 76% and 25% of caudal and cephalad segments adjacent to fractured vertebra, respectively. The number of stabilized segments were 1.4, 1.67 and 2 in separation, comminution and split type, respectively. The fusion was completely achieved in all patients. However, the preservation of spinal segments resulted in fusion with the mild anterior translation in six patients.Relationship between findings and existing knowledge: Little is known about the detailed fracture type of lateral mass/facet fractures, initial instability, and a frequency of soft tissue injury. This study first analyzed these parameters.Overall significance of findings: The evaluation of spinal instability as well as the assessment of soft tissue injury on initial MRI was essential for the diagnosis and treatment of lateral mass and facet fractures. We successfully saved the stabilized segments in separation fractures or fractures with mild comminution based on the adjacent disc and ligaments evaluation. However, severely comminuted lateral mass fractures with coronal plane malalignment required two-level posterior fixation. The exclusive posterior stabilization with cervical pedicle screw system provides a short fusion as well as a normal spinal alignment even in the lateral mass fractures with severe spinal instability.Disclosures: Device or drug: cervical pedicle screw. Status: not approved.Conflict of interest: No conflicts.

The management of unilateral lateral mass/facet fractures of the subaxial cervical spine: the use of magnetic resonance imaging to predict instability.

Retrospective review of the clinical course and cervical spine plain radiographs, computed tomography, and magnetic resonance imaging of 24 consecutive patients for a 2-year period with a unilateral lateral mass/facet fracture. To propose a treatment algorithm for the management of unilateral lateral mass/facet fractures of the subaxial cervical spine based on ligamentous injury detected by magnetic resonance imaging. There have been no previous reports of the use of magnetic resonance imaging to predict clinical instability. A retrospective review of the clinical course of all unilateral mass/facet fractures identified over a 2-year period was conducted. All cervical spine plain radiographs, computed tomography scans, and magnetic resonance images were reviewed by a neuroradiologist blinded to the clinical course of the patient. Magnetic resonance T1-weighted and inversion recovery images were used to evaluate the integrity of the facet region, interspinous ligament, anterior longitudinal ligament, and posterior longitudinal ligament. Twenty-four unilateral lateral mass/facet fractures were identified. Only six initial cervical spine series demonstrated a bony abnormality at the level of the fracture. The fractures were identified by computed tomography and were almost all nondisplaced or minimally displaced. Less than half of the fractures extended ventrally to involve the transverse process or foramen transversarium or dorsally to involve the lamina. Twelve fractures were nonoperatively treated and 12 were treated surgically for stabilization. Ten patients in the operative group presented with or developed a subluxation. Nine of these patients had injury to at least three of the four ligaments evaluated by magnetic resonance imaging. In the nonoperative group, only three patients had extensive ligamentous injury at the level of the fracture. All three of these patients were lost to follow-up. Plain radiographs of the cervical spine lack sensitivity to detect the presence of lateral mass/ facet fractures. The appearance of the fracture on computed tomography does not indicate instability. The degree of ligamentous injury at the level of the fracture demonstrated on magnetic resonance imaging correlates with instability in this series. Operative stabilization may be indicated for unilateral lateral mass fractures that present with a subluxation or that have injury to at least three of the following ligaments: the facet region, the interspinous ligament, the anterior longitudinal ligament, and the posterior longitudinal ligament. However, before a definitive management plan can be formulated, results from this small series require further validation.

Flexion failure of posterior cervical lateral mass screws. Influence of insertion technique and position.

The strength of posterior cervical lateral mass fixation was evaluated in a cadaver model for two techniques of screw insertion. To compare the flexion failure strengths of posterior cervical plate fixation for two techniques of screw placement at the superior and inferior screw hole positions, and to evaluate the effect of bone mineral density on fixation strength. Biomechanical analyses of various screw insertion techniques for posterior cervical lateral mass fixation have never evaluated the effect of screw position along the plate. Individual C3-C6 segments of 24 human cadaveric cervical spines were used. The spinous process and lamina were removed to simulate a postlaminectomy situation. Vertebral body bone mineral density for each specimen was determined by dual-energy radiograph absorption scanning. In each lateral mass, a bicortical 3.5-mm screw was placed using either the Magerl or Roy-Camille insertion technique through an end hole of a titanium bone plate. For "superior" screws, the plate was directed caudally; for "inferior" screws, the plate was directed cranially. Screw violation of the surrounding facet joint was noted. An increasing flexion moment was applied by loading the plate 4 cm from the screw head at a rate of 10 cm/min using a servohydraulic testing machine until screw failure. For the superior screw hole position, the Magerl screw sustained a significantly higher average moment to failure (190.2 Ncm) than the Roy-Camille screw (138.7 Ncm; P < 0.05). For the inferior screw hole position, there was no significant difference in flexion failure strength between the two techniques (Magerl screws, 287.7 Ncm; Roy-Camille screws, 308.2 Ncm). For each insertion technique, inferior screws were nearly twice as strong as superior screws (P < 0.01). Violation of the inferior articular process occurred with 53% of Roy-Camille screws and with none of the Magerl screws. Lateral mass fracture on screw insertion occurred with 6% of the Roy-Camille screws and with 7% of the Magerl screws. Significant correlation between screw path length and load to failure was found only at the superior screw hole position. Correlation with vertebral body bone mineral density was significant at both positions. The Magerl technique has advantages over the Roy-Camille technique for placing the end screws when performing posterior cervical lateral mass plate fixation, providing greater strength superiorly and not violating unfused facet joints inferiorly. Evaluation of bone mineral density by dual-energy radiographic absorption scanning is predictive of failure strength for both test modes.

Sagittally Oriented Fractures of the Lateral Masses of the Cervical Vertebrae

Lateral flexion of the cervical spine may cause a sagittally oriented fracture of the lateral mass with shearing of all or part of the lateral mass away from the vertebral body. We report 22 patients with 24 sagittal fractures of the cervical lateral masses. Cross-table lateral roentgenograms suggested the presence of a sagittal lateral mass fracture in two thirds of the cases based upon malalignment or widening of the facet joints, displaced fracture fragments, subluxation of the spine, or rotation of the spine above the level of abnormality. However, the cross-table lateral roentgenogram was normal in one third of cases. Oblique roentgenograms were available in eight cases; these were positive in five, equivocal in one, and negative in two. Visible fracture lines, often associated with lateral displacement of part or all of the lateral mass, allowed all 24 fractures to be detected on the supine anteroposterior view films. Sagittal lateral mass fractures were unstable in 59% (13/22) of the cases; neurologic deficits, including quadriplegia, hemiplegia, and radiculopathy, were present in 45% (10/22). Computed tomography and complex-motion tomography were useful in confirming the sagittal lateral mass fracture and in detecting other associated fractures.

Cervical spinal fractures: CT detection.

Although computed tomography (CT) is commonly used in addition to plain radiographs to evaluate cervical spinal fractures, it may fail to detect some clinically significant fractures. Cervical spinal fractures were produced in cadavers, studied with CT, and documented by cryomicrotomy. The CT scans were interpreted independent of the anatomic sections. Pedicle and lateral mass fractures were regularly unrecognized on CT scans. In these cases, widening and hemarthrosis of the adjacent facet joints were evident. A widened facet joint is an indirect sign of an occult cervical spinal fracture.