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Odontoid Lateral Mass Interval (OLMI) asymmetry and rotary subluxation: a retrospective study in cervical spine injury.

The aim of the study was to evaluate the significance of odontoid lateral mass interval (OLMI) asymmetry on open-mouth view, in neck injury patients who have otherwise normal cervical spine x-rays. Thirteen neck injury patients were reviewed. Average age was 23.5 years (range, 16-30 years) and average follow-up was 15 weeks (range, 6-39 weeks). All the patients, referred from the casualty department, had computed tomography (CT) scans because of the OLMI asymmetry to rule out rotary subluxation. Clinically none of the patients had torticollis. CT scans were reported normal except for OLMI asymmetry, in 11 patients. Two patients were reported as having rotary subluxation and one was found, after normal initial plain films, to have an undisplaced lateral mass fracture of the atlas with bony avulsion of the transverse ligament. The average OLMI asymmetry was 3.1 mm (range, 2-4 mm). The authors concluded that although OLMI asymmetry has low sensitivity and specificity for true subluxation or instability, it may be a sign of significant cervical injury and should be evaluated with CT.

Accidents, Traffic↗

Surgical management of remote, isolated type II odontoid fractures with atlantoaxial dislocation causing cervical compressive myelopathy.

OBJECTIVE: The remote (more than 6 mo after injury) and isolated (not associated with any other cervical spinal fractures) Type II fractures of the odontoid (RI IIO) are unique in being inherently unstable and prone to malunion or nonunion, leading to cervical compressive myelopathy. The present study discusses their surgical management. METHODS: Nineteen patients with RI IIO with atlantoaxial dislocation (AAD) causing compressive myelopathy were treated. Their preoperative disability was graded as Grade I: neurologically intact (presented with hyperreflexia and mild spasticity; n = 3); Grade II: independent with minor disability (n = 7); Grade III: partially dependent for daily needs (n = 6); and Grade IV: totally dependent (n = 3). They were classified as irreducible AAD caused by 1) malunited fracture of the odontoid (n = 2), 2) fixed anterolisthesis of the anterior arch of a C1-fractured odontoid complex (n = 3), and 3) fixed retrolisthesis of the anterior arch of a C1-fractured odontoid complex (n = 1); and reducible AAD caused by 1) mobile AAD (n = 11) and 2) hypermobile AAD (n = 2). The patients with irreducible AAD underwent a transoral decompression and posterior fusion; those with a malunited fracture underwent surgery immediately, whereas those with fixed anterolisthesis or retrolisthesis were initially placed in cervical traction. The patients with reducible AAD underwent a direct posterior fusion. In the patient with "hypermobile" AAD, a proper alignment of the fractured segment of the odontoid relative to the body of the axis in a neutral position of the neck was ensured before the posterior fusion was performed. RESULTS: At follow-up (mean, 15.37 +/- 9.67 mo), three patients in Grade I maintained their neurological status. Of the seven patients in Grade II and six in Grade III, five had improved to Grade I, and eight were in Grade II. The three patients in Grade IV improved to Grade I, II, and III, respectively. CONCLUSION: The patients with RI IIO may be divided into five groups on the basis of their differing management protocols. There is a considerable risk of delayed myelopathy unless surgical reduction and stabilization are performed. Posterior stabilization is the preferred option in dealing with these fractures. Despite the presence of severe neurological deficits and the prolonged duration of symptoms, a significant neurological improvement usually occurs after surgery.

Adolescent↗

Transoral odontoidectomy.

The transoral approach for odontoidectomy is described in detail, and the operating room setup and surgical positioning are demonstrated. We also discuss our methods of retractor placement and techniques for optimal surgical exposure. The microsurgical technique used for decompression is presented in detail. The surgical pearls and pitfalls of transoral odontoidectomy, learned from a 70-case experience, are described and illustrated.

Functional Laterality↗

[Combined atlantoaxial fractures].

PURPOSE OF THE STUDY: Combined fractures of the atlas and epistropheus account for 3 % of all acute injuries to the cervical spine. In relation to all C1 and C2 injuries this is 43 % and 16 %, respectively. The aim of this study is to evaluate a group of patients with combined C1-C2 fractures and to suggest an effective therapeutic procedure. MATERIAL: In the years 1996 to 2003, a total of 16 patients with trauma to the atlantoaxial complex were treated at the Orthopedic Department of the Third Faculty of Medicine, Charles University, Prague (1996-2001) and the Department of Spinal Surgery of the University Hospital in Motol, Prague (2001-2003). These injuries included a combined fracture of the dens (Anderson and D'Alonzo type II) and of the atlas posterior arch in six patients, a type II dens fracture combined with Jefferson fracture in two patients, a type III fracture of the dens with a lateral mass fracture in two patients, hangman's fracture with posterior arch fracture in three patients, a type II fracture of the dens with anterior arch fracture in one patient, a fracture of the C2 body with Jefferson fracture in one patient and a fracture of the C2 body with fracture of the lateral mass in one patient. Two patients were treated conservatively and 14 underwent surgery. On admission neurological deficit was found in five patients. METHODS: Fourteen patients were operated on. Direct osteosynthesis of the dens, with motion in the atlantoaxial complex preserved, was performed in five patients. Seven patients underwent C1-C2 fixation that, in one, involved the C1-C3 segments; five patients were treated by Harms fixation with polyaxial screws from the posterior approach, two by the Magerl or Gallie techniques and one patient required occipito-cervical fixation of C0-C2. The patient with a hangman's fracture combined with fracture of the atlas posterior arch was treated by discectomy of C2-C3, tricortical graft from the iliac crest and plate application. The patients used Philadelphia collars for 6 to 12 weeks according to the type of injury and their bone quality. RESULTS: Three patients (two undergoing direct osteosynthesis of the dens and one with occipito-cervical fixation) reported intermittent upper neck pain that required taking analgesics. The patient treated by occipito-cervical fixation repeatedly complained of restriction of rotational head movement by about 50 %. Radiograms of the cervical spine in both flexion and extension taken at 12- to 14-week follow-up all showed stable C0-C1 and C1-C2 segments. In the five patients undergoing direct osteosynthesis of the dens, complete bony union was found on X-ray and CT examination by 6 to 24 weeks postoperatively. Similarly, full instrumented fusion was achieved by 12 to 24 weeks postoperatively in the seven patients treated by dorsal fixation. The patient with anterior C2-C3 fixation showed, on X-ray images, a completely remodeled segment at 24 weeks after surgery. There was one intraoperative complication involving management of profuse bleeding from the venous plexus along the greater occipital nerve. No other complications related to the surgical procedure were recorded and no injury to the spinal cord, nerve roots or the vertebral artery was observed. None of the patients experienced any deterioration of neurological findings during the early postoperative period. One patient had to undergo resuturing of the operative wound from the posterior approach, because of subcutaneous necrosis that had failed to heal. No instrumentation failure or infection, regarded as late complications, were recorded. DISCUSSION: At our Department we prefer early operative treatment involving spondylodesis in the shortest segment possible, with special emphasis on preserving rotational C1-C2 movement. Therefore, in some cases, we use only temporary stabilization with removal of instrumentation after 3 to 4 months. In this group the most frequent fractures were those combined with type II fractures of the dens. In such cases we always prefer direct osteosynthesis of the dens or, if this is not possible, the Harms technique of C1-C2 fixation, possibly only temporary. We believe, in agreement with Guilot and Fesser, that a potential failure of conservative therapy may result in a longer convalescent period and that patients should always be informed about these issues. In contrast to Guilot and Fesser we treat combined hangman's fractures from the anterior approach, by discectomy, tricortical graft and plate application. CONCLUSIONS: Combined atlantoaxial fractures are serious, life-threatening injuries which, because of their diversity, require an individual approach to each patient. Early surgery is recommended with increasing frequency, particularly in the cases with persisting dislocation or instability. At the same time it is necessary to ensure that motion restriction of the cervical spine be minimal.

Adult↗

Tuberculosis of the odontoid bone: a rare but treatable cause of quadriplegia.

Radiologic investigation plays an important role in the diagnosis and management of tuberculosis of the odontoid bone. Immediate confirmation of the condition by examination of tissue and surgery may save lives and reduce the morbidity rate substantially. When the clinical history is appropriate, a diagnosis of tuberculosis is strongly suggested by plain films of the cervical spine showing precervical swelling of the soft tissues, narrowing of the disk spaces and focal erosion of the bones and by computed tomography scans demonstrating details of the soft-tissue abnormality, focal bony erosion and sclerosis.

Adult↗

[Instability of the atlantodental joint as a trauma sequela].

In the region of the upper cervical spine a wide variety of morphological and functional positions is possible. This makes diagnosis and expert evaluation of whiplash injuries to the cervical spine very difficult. The problem is discussed with reference to a case report of a so-called whiplash injury. The upper cervical spine must be investigated in flexion and extension by means of MRT and/or CT as soon as possible.

Adult↗

[Upper cervical spine injuries and their diagnostic features].

The upper cervical spine includes the articulations of the occiput with atlas and the atlas with the axis, as well as the bony structures of the base of the skull, axis, and atlas. The unique anatomy of the upper cervical spine and the typical mechanisms of injury yield a predictable variety of injury patterns. Injuries to this area include occipital condyle fractures, occipitoatlantal dislocations, subluxations and dislocations of the atlantoaxial articulation, atlas fractures, odontoid fractures, and fractures of the arch of the axis. Injuries to this region are relatively common and can be easily overlooked because patients with the upper cervical injury may have an associated head injury, which can alter their level of consciousness and complicate obtaining an accurate history and physical examination. The complex regional anatomy and overlying structures make plain radiographic images difficult to interpret. Delayed recognition can result in significant disability. A thorough understanding of the clinical presentation, radiographic assessment, and mechanisms of injury can minimize morbidity and enhance treatment effectiveness for the more common upper cervical ligamentous and bony injuries.

Atlanto-Axial Joint↗

[Osteoblastoma of the dens axis in a 14-year-old boy. A case report].

We present a case of osteoblastoma of C1 in a 14-year-old boy. The case deserves attention because it is a conglomerate of issues important from the point of view of clinical practice. Key issues associated with this interdisciplinary pathology are discussed, such as diagnostic problems, stabilisation of the cervical spine and extensive surgery associated with the risk of severe bleeding in a Jehovah Witness. A short review of pertinent literature is included.

Adolescent↗

[Radiologic diagnosis of cervical spine injuries].

This investigation was designed to evaluate the radiological methods used for diagnosis of cervical spine injuries. In the time from 1977 to 1990, a total of 102 patients with 113 fractures or fracture-dislocations of several segments of the cervical spine were diagnosed and treated in the University Surgical Clinic in Graz; 36 of these patients had lesions of the upper cervical spine and 66, lesions of the lower cervical spine. All trauma patients with disturbances of consciousness or neck discomfort reported on questioning or elicited by palpation underwent three-view radiographic screening for cervical spine injuries (lateral, AP and open-mouth views). This led us to suspect cervical spine injuries in all 102 patients. Computerized tomography was performed in 76 cases, which yielded additional information in 55 cases about the middle and posterior column and the adjacent vertebral bodies. In 13 cases conventional tomograms were important to confirm the diagnosis of dens fracture. Except for the diagnosis of hanged-man and dens fractures, computerized tomography is accepted as the second step for the evaluation of cervical spine injuries. We performed 8 investigations with magnetic resonance imaging in 7 patients, and noted spinal cord lesions of low signal intensity in 3 of these cases.

Cervical Vertebrae↗

A cadaveric study comparing standard fluoroscopy with fluoroscopy-based computer navigation for screw fixation of the odontoid.

Although direct osteosynthesis of certain types of odontoid fractures may increase union and decrease the need for prolonged immobilization, screw fixation remains a technically demanding procedure. This study compares radiation exposure, surgical time, and accuracy of hardware placement using standard fluoroscopy versus computer-assisted fluoroscopy-based navigation ("virtual fluoroscopy") to assist with the placement of odontoid screws. Twenty-two cadavers were divided into two groups and underwent placement of a single odontoid screw using either standard fluoroscopic or virtual fluoroscopic guidance. Following screw placement, dissection of the C1-C2 segments was performed to assess accuracy. A significant reduction in fluoroscopy time was noted with the computer-based fluoroscopy technique, whereas the surgical time was not found to differ significantly between the techniques. No critical breaches (those risking neurovascular injury) were noted in either group, and the rate of noncritical breaches did not differ. The authors conclude that fluoroscopy-based virtual navigation appears to have a safety profile similar to standard fluoroscopy while allowing a reduction in radiation exposure.

Bone Screws↗

[The indications for occipito-cervical fixation. A report of three cases].

Lesions of the cranio-vertebral junction which affect bony structures and ligaments may cause instability and compression of the nervous and vascular structures. The goal of surgery is decompression of these structures and stabilization. The paper presents indications for performing the stabilisation procedure with CCD implementation in three patients suffering respectively from rheumatoid arthritis and neoplastic disease. In one patient spinal instability and spinal cord compression were due to rheumatoid disease and surgery included anterior spinal decompression in connection with posterior stabilisation. In two patients with neoplasms the retromandibular decompression with posterior stabilisation was performed.

Adolescent↗

Odontoid synchondrosis fractures in children.

OBJECT: Odontoid synchondrosis fractures, although rare in the overall incidence of spinal trauma, are one of the more common fractures in young children. The goal of this study was to evaluate the demographic data, incidence of neurological deficits, treatment strategies, and outcomes in a combined series of odontoid synchondrosis fractures treated at the authors' institution and reported in other series. METHODS: In a retrospective chart review, the authors identified four odontoid synchondrosis fractures treated at their hospital since January 2000; these were combined with cases reported in six other series in the literature, yielding a total of 55 patients. Data regarding the patients' age, sex, delayed diagnosis, odontoid displacement, neurological deficits, treatment, and fusion status were collected. The patients' ages ranged from 9 months to 7 years (mean 2.8 years), with neither sex predominating. Diagnosis was delayed in eight cases. The orientation of the odontoid fracture was reported for 36 patients, with 94% experiencing anterior displacement. Spinal cord injury (SCI) was noted in 15 patients, including 11 with complete injuries and eight with SCI at the cervicothoracic junction. Forty-two (93%) of 45 patients with fractures initially treated with external immobilization attained fusion. Eight patients were treated with surgery; four initially, with no attempt at conservative therapy, three after failed halo immobilization, and one after nonunion because of delayed diagnosis. CONCLUSIONS: Odontoid synchondrosis fractures can be difficult to diagnose. In children younger than 7 years of age who present with neck pain or neurological deficits attributable to SCI, this fracture should be suspected. Given the high rate of fusion attained with conservative therapy, it is recommended for most synchondrosis fractures, although surgery may be warranted for individual cases.

Cartilage, Articular↗

Management of odontoid fractures with anterior screw fixation.

Type II odontoid fractures are prone to undergo nonunion. Stabilization of such fractures with anterior screw fixation provides rigid internal fixation and preserves C1-C2 motion. During a 5-year period, 17 patients with displaced type II fractures of the odontoid were treated Thirteen were male and four were female with a mean age of 38.2 years. All patients were operated on for anterior screw fixation within a mean of 10.1 days from injury. Postoperatively, the patients were evaluated clinically and radiologically at regular intervals. With a mean follow-up of 3.2 years, union was observed in 16 of 17 patients (94%). One patient developed nonunion for which he required C1-C2 fusion subsequently. Screw back-out by a few millimeters was seen in another patient resulting in mild restriction of neck movements. No approach-related complications were noted. Anterior odontoid screw fixation has relatively low complication and high fusion rates. It not only restores normal anatomy but also gives better functional results by preserving intrinsic C1-C2 motion. Thus it should be considered the treatment of choice in acute displaced type II odontoid fractures.

Adolescent↗

[Delayed progressive kyphotic deformity of cervical vertebra in a patient with odontoid fracture].

This 75-year-old male who fell from a 1-m hight road shoulder subsequently suffered persistent neck pain. On admission to our institute he exhibited no neurological abnormalities. CT scan revealed an odontoid Anderson type III fracture. We selected conservative treatment with external fixation using a hard collar. No cervical deformity was recognized over the course of a month and he was transferred to another hospital for rehabilitation. As a cervical X-ray performed a month later disclosed a progressive kyphotic deformity, he was readmitted to our institute for surgery. He underwent internal fixation with a Ransford loop between the occipital bone and the C3 lamina. During the operation we noted that his bone was very fragile. His postoperative course was uneventful and he exhibited no neurological deficits; his cervical alignmen stabilized completely. At his 2nd admission, his bone mineral density was 0.767 g/cm2, 64% of the young adult mean and thus indicative of severe osteoporosis. We conclude that careful observation and appropriate internal fixation are necessary in osteoporotic patients who manifest deformity following an odontoid fracture.

Aged↗