Direct osteosynthesis in the treatment of atlas burst fractures: a systematic review

PURPOSE

The treatment of unstable atlas fractures remains a controversial topic. The study aims at assessing the prognosis and efficacy of osteosynthesis for unstable atlas fractures through a review of the current literature and additionally aims to compare outcomes between the transoral and posterior approaches.

METHODS

A systematic review of databases including PubMed, EMBASE, Cochrane, Web of Science, CNKI, and Wanfang was conducted. Titles and abstracts were screened by two reviewers to identify studies meeting pre-defined inclusion criteria for comprehensive analysis.

RESULTS

The systematic review included 28 articles, 19 employing the posterior approach and 9 utilizing the transoral approach. It covered osteosynthesis in 297 patients with unstable atlas fractures, comprising 169 treated via the posterior approach and 128 via the transoral approach. Analysis revealed high healing rates and clinical improvement in both approaches, evidenced by improvements in the visual analog scale, range of motion, atlantodens interval, and lateral displacement distance post-surgery.

CONCLUSION

Osteosynthesis offers effective treatment for unstable atlas fractures. Both transoral and posterior approaches can achieve good clinical outcomes for fracture, and biomechanical studies have confirmed that osteosynthesis can maintain the stability of the occipitocervical region, preserve the motor function of the atlantoaxial and occipito-atlantoaxial joints, and greatly improve the quality of life of patients. However, variations exist in the indications and surgical risks associated with each method, necessitating their selection based on a thorough clinical evaluation of the patient's condition.

Posterior arch reconstruction in cervical surgery to restore the global biomechanics of the Atlas: a technical note

The posterior arch of the atlas is usually not considered one of the main stabilizers of the cranio-cervical junction, allowing surgeons to its removal when needed with a relative certainty to preserve the stability of the atlo-axial segment. However, these considerations do not reflect the importance to examine the integrity of the posterior arch in the whole biomechanics of the atlas. Authors like Gebauer and Panjabi revealed, respectively in experimental and clinical conditions, how the atlas responds to an axial loading force, proving that the whole atlas is involved into horizontal conversion of axial forces and providing evidence supporting the preservation of the posterior arch. Other authors evaluated the risk for anterior arch fracture following C1 laminectomy. In this technical note three different techniques of posterior atlas arch reconstruction after surgical iatrogenic disruption are presented, considering both neoplastic and degenerative disease.

Appropriateness of Cervical Magnetic Resonance Imaging in the Evaluation and Management of C1 Jefferson Fractures

BACKGROUND

Traditionally, C1 fractures have been designated as stable or unstable based on the inherent integrity of the transverse altantal ligament. The purpose of our study was to identify adult trauma patients with C1 fractures on cervical computed tomography and evaluate whether C1-C2 alignment differed in patients with and without an associated transverse atlantal ligament injury on follow-up cervical magnetic resonance imaging.

METHODS

Adult trauma patients who suffered a C1 fracture were identified retrospectively. The cervical computed tomography examinations for these patients were reviewed for the following: C1 fracture classification, anterior atlantodens interval (ADI) widening, asymmetry in the lateral atlantodens interval, C1 lateral mass offset, and atlantoaxial rotation.

RESULTS

Acute C1 fractures were grouped into those with an unequivocal transverse atlantal ligament injury (n = 12), and patients with an unequivocally intact transverse atlantal ligament (n = 20). Three patients were classified as indeterminate for transverse atlantal ligament injury. Statistically significant increases in lateral ADI asymmetry and combined C1 lateral mass offset were identified in patients with transverse atlantal ligament tears.

CONCLUSIONS

Lateral ADI asymmetry (using a cutoff of >3 mm), combined C1 lateral mass offset, and anterior ADI demonstrate robust specificity to "rule in" transverse atlantal ligament injury. Atlantoaxial alignment was overall relatively insensitive as a screening test although sensitivity can be improved using a cutoff of >2 mm for lateral ADI asymmetry. Our findings reinforce the role of cervical magnetic resonance imaging in the diagnostic workup and clinical management of trauma patients with an acute burst fracture of the C1 vertebra.

Direct Internal Fixation for Unstable Atlas Fractures

PURPOSE

To investigate the radiologic and clinical outcomes of direct internal fixation for unstable atlas fractures.

MATERIALS AND METHODS

This retrospective study included 12 patients with unstable atlas fractures surgically treated using C1 lateral mass screws, rods, and transverse connector constructs. Nine lateral mass fractures with transverse atlantal ligament (TAL) avulsion injury and three 4-part fractures with TAL injury (two avulsion injuries, one TAL substance tear) were treated. Radiologic outcomes included the anterior atlantodental interval (AADI) in flexion and extension cervical spine lateral radiographs at 6 months and 1 year after treatment. CT was also performed to visualize bony healing of the atlas at 6 months and 1 year. Visual Analog Scale (VAS) scores for neck pain, Neck Disability Index (NDI) values, and cervical range of motion (flexion, extension, and rotation) were recorded at 6 months after surgery.

RESULTS

The mean postoperative extension and flexion AADIs were 3.79±1.56 (mean±SD) and 3.13±1.01 mm, respectively. Then mean AADI was 3.42±1.34 and 3.33±1.24 mm at 6 months and 1 year after surgery, respectively. At 1 year after surgery, 11 patients showed bony healing of the atlas on CT images. Only one patient underwent revision surgery 8 months after primary surgery due to nonunion and instability findings. The mean VAS score for neck pain was 0.92±0.99, and the mean NDI value was 8.08±5.70.

CONCLUSION

C1 motion-preserving direct internal fixation technique results in good reduction and stabilization of unstable atlas fractures. This technique allows for the preservation of craniocervical and atlantoaxial motion.

Anterior Atlas Fracture After C1 Laminectomy Which Was Successfully Treated by Brace Therapy: A Case Report

CASE

We report a case of a 67-year-old male patient who underwent a C1 laminectomy with laminoplasty at C2-3 because of cervical ossification of the posterior longitudinal ligament. At 6 weeks after surgery, neck pain occurred after minor trauma without neurological deterioration. Computed tomography (CT) demonstrated C1 anterior atlas fracture with a 3-mm gap. After a 3-month brace therapy using a Philadelphia collar, the patient's neck pain disappeared with complete bone union according to the CT.

CONCLUSION

Among 14 cases that were reported previously, none of the adult patients achieved bone union by brace therapy. Therefore, this is the only case report in which bone union could be achieved by brace therapy.

Conservative treatment and outcome of upper cervical spine fractures in young children: A STROBE-compliant case series

Cervical spine (C-spine) fractures in young children are very rare, and little information on treatment modalities and functional, radiographic, and patient-reported outcome exists. In this 2-center, retrospective case series, we assessed subjective and functional mid-term outcomes in children aged ≤5 years whose C-spine fractures were treated nonoperatively.Between 2000 and 2018, 6 children (median age at injury: 23.5 months; range: 16-31 months) with C1 or C2 injuries were treated with Minerva cast/brace or soft collar brace at 1 of the 2 study centers. Two patients suffered C1 fractures, and 4 patients had lysis of the odontoid synchondrosis. Overall, 3 children had sustained polytrauma. One child died due to the consequences of massive head injury.For the primary outcome parameter, we recorded subjective symptoms such as pain and functional restrictions due to the sequelae of C-spine injuries at follow-up.Based on medical records, we also assessed the causes of injury, diagnostic procedures, treatments and complications, and time to fracture consolidation.Median follow-up of the 5 surviving children was 51 months (range: 36-160 months). At the latest follow-up, 4 of 5 children did not complain of any pain. One child who sustained an open head injury in combination with a subluxation of the odontoid and undisplaced fracture of the massa lateralis reported occasional headache. All patients experienced complete fracture healing and normal range of motion of the cervical spine.Median duration of cast/brace treatment was 8.5 weeks. Fracture healing was confirmed by computed tomography in all patients.All C-spine injuries were managed with either Minerva cast/Halo brace or soft collar brace without complications.In our retrospective case series, nonoperative treatment of atlas fractures and dislocations or subluxations of the odontoid in young children using Minerva casts or prefabricated Halo braces resulted in good subjective and functional outcomes at mid-term. We observed no complications of conservative treatment of C1 and C2 injuries in young children.

Multiple Fractures of Cervical Vertebrae Combined with Arcuate Foramen and Vertebral Artery Occlusion: A Case Report and Literature Review

BACKGROUND

The arcuate foramen is a complete or partial bony bridge over the vertebral artery groove of atlas. The mechanism of the arcuate foramen is not clearly understood. Omission of the arcuate foramen sometimes causes lethal iatrogenic injury during spinal surgery.

CASE PRESENTATION

We describe a patient who was diagnosed with multiple fractures of the cervical vertebrae, arcuate foramen, and right vertebral artery occlusion based on clinical and radiological exams. After conservative treatment, he resumed a normal and productive life.

CONCLUSIONS

Arcuate foramen is a common variation that causes symptoms such as dizziness, headache, and migraine. If the patient does not develop severe symptoms, conservative treatment can achieve very good results without the necessity to remove the bone bridge. When serious symptoms occur, surgical treatment to resect the bony ridges can relieve the symptoms dramatically.

Treatment strategy of unstable atlas fracture: A retrospective study of 21 patients

At present, the posterior cervical approach with open reduction and internal fixation (ORIF) remains a commonly effective treatment for unstable Atlas fracture. However, the inserted screws into the C1 lateral mass of some unstable atlas fracture are very difficult, so that the operation is forced to change into C0 to C2 fusion. In order to improve the successful rate of lateral mass screw placement, we introduced a method of fixing lateral mass with a towel clamp in posterior transpedicular fixation, and explore the efficacy and feasibility.Twenty-one consecutive patients with unstable atlas fracture were treated via this method from October 2012 to July 2017. All cases had neck pain and restricted motion of neck movement on admission. Electronic medical records and pre- and postoperative radiographs were reviewed. Screw and rod placement, bone fusion, and spinal cord integrity were assessed via long-term follow-up with anteroposterior and lateral radiographs and computed tomography. Follow-up included clinical assessment of neurological function, assessment of pain using the visual analog scale (VAS), and assessment of the activities of daily living using the neck disability index (NDI).The mean follow-up duration was 22.1 months (range: 12-54 months). No screw loosening or breakage, plate displacement, neurovascular injury, and severe complications occurred during follow-up. The mean operative time was 112.4 ± 14.9 min (range: 82-135 min), and mean blood loss was 386.2 ± 147.9 mL (range: 210-850 mL). One patient experienced continuous neck pain postoperatively, but this gradually disappeared with analgesic administration. At final follow-up, all patients had bone fusion, the VAS scores and NDI were significantly improved compared with preoperatively.Fixing the C1 lateral mass with a towel clamp during posterior transpedicular fixation for unstable atlas fracture appears to be a safe and reliable method, with the advantages of being a simple technique with few complications.

Traumatic combined vertical atlanto-occipital and atlanto-axial dislocations with 2-part fracture of the atlas: Two case reports

RATIONALE

To our knowledge, this is the first report of traumatic combined vertical atlanto-occipital dislocation (AOD) and atlanto-axial dislocation (AAD) with 2-part fracture of the atlas.

PATIENT CONCERNS

The first case was of a 31-year-old woman admitted to the emergency room comatose after a traffic accident. The second case was of a 21-year-old woman admitted to the emergency room comatose after a fall.

DIAGNOSES

Traumatic combined vertical AOD and AAD with 2-part fractures of the atlas was diagnosed using plain radiography, 2-dimensional computed tomography, and/or magnetic resonance imaging of the cervical spine.

INTERVENTION

The first patient received immediate intubation and cardiopulmonary resuscitation in the emergency room. The second patient also received immediate intubation in the emergency room. After her vitals stabilized, she underwent occipitocervical fusion with instrumentation.

OUTCOMES

The first patient died 2 days after the accident. The second patient remained quadriplegic in a ventilatory-dependent state at 1 year after surgery. She continues to receive comprehensive rehabilitation.

LESSONS

Immediate respiratory support and surgical stabilization are important for saving lives in this kind of extremely unstable and fatal complex upper cervical spine injury.

Radiologic criteria to predict injury of the transverse atlantal ligament in unilateral sagittal split fractures of the C1 lateral mass

Unilateral sagittal split fracture (USSF) of the C1 lateral mass (LM) has been recently recognized as a rare variant of C1 atlas fracture. To date, there has been no study to investigate whether radiologic criteria can be applied to determine the presence or absence of transverse atlantal ligament (TAL) injury in USSF of the C1 LM.Twenty six consecutive cases of USSF of the C1 LM were included in this study. According to Dickman classification, 16 cases were TAL injury, and 10 cases were TAL intact. Radiologic parameters were measured and compared between the 2 groups.Total LM displacement (LMD) of the 2 sides (5.9 ± 2.0 mm vs 1.2 ± 2.0 mm), unilateral LMD of the fracture side (4.3 ± 1.2 mm vs 1.0 ± 1.1 mm), atlanto-dental interval (ADI) (2.0 ± 0.9 mm vs 1.5 ± 0.4 mm), and fracture gap (6.9 ± 2.7 mm vs 2.1 ± 1.1 mm) were statistically higher in the TAL injury group than the TAL intact group. However, basion-dental interval, clivus canal angle, and atlanto-occipital joint axis angle were not different between the 2 groups. Total LMD and unilateral LMD positively correlated with ADI and fracture gap. The incidence of fracture gap larger than 7 mm was statistically higher in the TAL injury group than the TAL intact group (81% vs 30%).In conclusion, total LMD > 5.9 mm or unilateral LMD > 4.3 mm suggests the presence of TAL injury in USSF of the C1 LM. The possibility of diagnostic error for TAL injury can be further reduced in USSF of the C1 LM by considering the fracture gap larger than 7 mm.

Comparison of radiological and clinical outcomes after surgical reduction with fixation or halo-vest immobilization for treating unstable atlas fractures

BACKGROUND

Unstable atlas fractures with concomitant transverse atlantal ligament (TAL) injury may be conservatively managed by halo-vest immobilization (HVI) or surgically treated by various fixation techniques. Many surgeons prefer surgical management due to complications, nonunion, and further dislocations with HVI. There are no comparative studies on surgical and nonsurgical management of unstable atlas fractures. We retrospectively assessed the radiological and clinical outcomes of surgical reduction with fixation vs. non-operative treatments for unstable atlas fractures with TAL rupture.

METHODS

We analyzed records of 24 patients (15 men, 9 women; mean age, 48.3 years) with at least 1 year of follow-up. They underwent HVI or surgical reduction with fixation for unstable atlas fracture combined with TAL injury. Clinical outcomes, including neck visual analog scale and neck disability index (NDI), and radiological measurements, including degree of fracture displacement, atlantodental interval (ADI), range of motion (ROM), cervical alignment, fusion rate, and time-to-fusion, were assessed.

RESULTS

Of the 24 patients, 13 were treated by surgical reduction with fixation (C1 lateral mass screw-C2 pedicle screw with a cross-link) and 11 by HVI. A significant reduction in lateral displacement of fractured lateral masses was identified in surgical reduction with fixation (3.21 ± 1.21 mm) compared with HVI (0.97 ± 2.69 mm). The mean reduction in ADI was 1.47 ± 1.08 mm with surgical fixation and 0.66 ± 1.02 mm with HVI. The bony rate and time-to-fusion were 100% and 14.91 ± 3.9 weeks with surgical reduction, and 72.7% and 22.31 ± 10.85 weeks with HVI. The postoperative neck pain relief and NDI after surgical fixation were higher than those after HVI.

CONCLUSIONS

Compared with HVI, surgical reduction with fixation reduces fractured lateral mass displacements, increases fusion rate, and reduces time-to-fusion while maintaining cervical curvature and improving neck pain and daily activities.

Cervical nodal metastasis after malignant conversion of sinonasal inverted papilloma: Report of a rare case and literature review

Malignant conversion of sinonasal inverted papilloma (SNIP) occurs in approximately ten percent of cases. These tumors are classically described as locally destructive, but without metastatic potential. Only four cases of malignant conversion with cervical nodal metastases have been described in the English literature. We present the rare case of a 61-year-old Caucasian male with a nasopharyngeal recurrence of malignant SNIP with cervical and retropharyngeal nodal metastases. The patient underwent endoscopic transpterygoid with nasoseptal flap reconstruction, followed by staged bilateral and retropharyngeal node dissection. Histopathology of the specimens demonstrated poorly differentiated invasive nonkeratinizing squamous cell carcinoma with inverted-type features. Three months after surgery, the patient suffered from C1-C2 fractures consistent with osteoradionecrosis and expired. Although the rate of malignant conversion of SNIP is low, this case highlights the need for aggressive, definitive treatment and surveillance.

Rare atlas fracture detected using postmortem computed tomography: A case report

We report the autopsy of a traffic accident victim with a rare atlas fracture. The deceased was 52-year-old man found dead on the road because of a traffic accident. We performed a postmortem computed tomography and an autopsy on the body. The sagittal reformation image of postmortem computed tomography showed a vertically separated anterior arch of atlas, suggesting a "horizontal fracture." Therefore, we assumed that cervical hyperextension may have been one of the forces that affected him during the accident. Minor spinal cord injury was also noted. In this case, postmortem computed tomography played an important role in detecting the spinal cord injury, considering the mechanism of the traffic accident, and supported the autopsy.

[Classification of upper cervical fractures: a review]

Upper cervical fracture-dislocations are series of pathological injuries occurred in occipital, atlas and axis caused by traumatic impact, which often results in severe clinical consequences, such as paraplegia, quadriplegia, and even death. In light of the potential severe clinical outcomes, it is important to define the type of upper cervical fracture-dislocations depending on which the clinician can deal with the disease properly. Owing to its specific anatomical structures, the upper cervical fractures occurr to the unique osseous structures or ligamentous connections always present in predictable patterns. Common fracture include occipital condylar fracture, atlanto-occipital dislocation, atlas fracture, and the three types of fractures of axis, including odontoid fracture, Hangman's fracture and axis body fracture. In this paper we will review the literatures about the classification and management of upper cervical fracture, to help the clinicians to treat their patients better.

Posterior arthrodesis of C1-C3 for the stabilization of multiple unstable upper cervical fractures with spinal cord compromise: A case report and literature review

BACKGROUND

Multiple fractures of the atlas and axis are rare. The management of multiple fragment axis fractures and unstable atlas fractures is still challenging for the spinal surgeon. There are no published reports of similar fractures with 3-part fracture of axis associated with an unstable atlas fracture.

CASE SUMMARY

We present a patient with concurrent axis and atlas fractures, which have not been reported. The patient suffered hyperextension injury with neck pain and numbness of the bilateral upper extremity associated with weakness after a 2-m fall. The axis fractures included an odontoid type IIA fracture and traumatic spondylolisthesis of C2-C3. The atlas fracture was unstable. The neurological examination manifested as central canal syndrome, which was due to the hyperextension injury of cervical spine and spondylolisthesis of C2-C3. The patient was diagnosed as multiple unstable upper cervical fractures with spinal cord compromise. We performed posterior arthrodesis of C1-C3. Postoperatively, the patient showed neurological improvement, and C1-C3 had fused at the 3-month follow-up.

CONCLUSION

Posterior arthrodesis of C1-C3 could provide a stable fixation for the 3 parts of axis (an odontoid type IIA fracture and traumatic spondylolisthesis of C2-C3) combined an unstable atlas fracture. Both the patient and the doctor were satisfied with the results of the treatment. So posterior arthrodesis of C1-C3 is a suitable treatment option for the treatment of a concurrent unstable atlas fracture and multiple fractures of the axis.

[Study on the clinical value of cervical spondylosis with articulatio atlantoepistrophica sublaxation]

OBJECTIVE

To explore the effect of articulatio atlantoepistrophica sublaxation on the pathogenesis of cervical spondylosis, and provide a thread for diagnosis and treatment of cervical spondylosis with manipulation.

METHODS

There were two groups in the study, which were non cervical spondylosis group and cervical spondylosis group. There were 333 patients in cervical spondylosis group, included 119 males and 214 females with the mean age of(48.11±12.21) years old. The patients were recruited from clinic service of orthopaedics in Shuguang Hospital between March 2006 and December 2008. There were 73 subjects in non cervical spondylosis group, included 18 males and 55 females with the mean of(45.99±11.47) years old. The subjects were recruited from undergraduate students, postgraduate, advanced study persons, and community personnel. The position relation of the atlanto axial joint was observed by cervical X rays with opening position, and the incidence rate of articulatio atlantoepistrophica sublaxation was compared between two groups, and their clinical characteristics were analyzed.

RESULTS

The incidence of articulatio atlantoepistrophica sublaxation in cervical spondylosis group was 81.38%(271/333)and was more than non cervical spondylosis group(P<0.01). Furthermore, the pattern of the articulatio atlantoepistrophica sublaxation in cervical spondylosis group was complicated and diversified, which was 50.55% (137/271)with single moving sublaxation, 7.01%(19/271) with revolving sublaxation, 42.44%(115/271) with single moving and revolving sublaxation.

CONCLUSIONS

The articulatio atlantoepistrophica sublaxation may be a X ray diagnostic indication to the cervical spondylosis, which should be grouping studied in clinic. It will provide guidance for the diagnosis and treatment of cervical spondylosis.

Endoscopic removal of bullets from the cranial ridge junction region via transoral and transnasal approaches: Two case reports and review of literature

Endoscopes in otolaryngology may facilitate accessing the lumens and sites such as upper cervical spine with minimally invasive surgical exposure. Here, we present 2 interesting cases of youth who underwent endoscopic removal of bullets in the cranial ridge junction region.The first case was a 20-year-old young man who underwent a gunshot in the face. A CT scan showed that a metallic foreign body located inside the right lateral body of Atlas that presented a comminuted fracture. The second case a 36-year-old man who also underwent a gunshot in the face. CT scan showed a foreign body lodged in the soft tissues before the right anterior arch of Atlas cone (C1) that presented a fracture. The bullets in these 2 patients were removed under the endoscopes with minimal damage, respectively. The patients were discharged without neck activity obstacle.The advantage of endoscopic technique is obvious because limited visualization does not damage surrounding tissues, thus decreasing surgical complications. This was an interesting experience of surgical operation in this region.

Management of upper cervical spine injuries: a review

Upper cervical spine injuries are commonly associated with trauma and require significant forces to produce. When these injuries occur they can have devastating functional consequences. The distinctive anatomy of the upper cervical spine leads injuries to occur in predictable patterns. Injuries can occur to the unique osseus structures or ligamentous connections. Common injuries include occipital condylar fractures, atlanto-occipital dislocation, fractures of the ring of C1, ligamentous injuries involving the ring of C1, and the three types of fractures of C2, pars fractures, odontoid fractures and C2 body fractures. We present these common injuries found in the occipital-atlantoaxial complex and their management based on the current and historical literature.

C1 fracture in a patient with a congenital cleft in the posterior arch: report on a failed conservative treatment

Unstable burst fractures of the atlas require sufficient immobilisation either with an external device or by surgical fusion. In patients with pre-existing congenital atlantal defects the decision whether to recommend non-operative or operative therapy is difficult. Treatment options are controversially discussed and standardised guidelines are not available. Although most surgeons advise operative fusion or osteosynthesis in atlanto-axial instability, non-operative immobilisation can be successful. We report on a patient with an unstable C1 burst fracture with a congenital posterior cleft in the atlantal arch who was treated with cervical extension and halovest immobilisation. Although callus bridging was initially observed, 9 months after the injury there was no sufficient fracture consolidation and surgical fusion had to be advised. While non-operative treatment may work in patients without congenital defects of the C1 arch, such is not recommended in patients who present with this anomaly.

[Transoral plate internal fixation for treatment of instability atlas fracture]

OBJECTIVE

To evaluate the efficacy and safety of transoral plate internal fixation for instability atlas fracture.

METHODS

A retrospective study was performed in eight patients with instability atlas fractures, who were treated by a transoral plate internal fixation from July 2007 to June 2011. There were 6 males and 2 females,with an average age of 39.5 years old ranging from 23 to 48 years. Among them, 5 case were falling injury, 3 cases were traffic accident injury. Three patients had bilateral fractures of the anterior arch (prehalf Jefferson fractures, Landells type I), 5 had anterior are fracture associated posterior are fracture (Half-ring Jefferson fractures, Landells type II), and 2 had anterior and posterior are fracture associated with single lateral mass fractures (Landells type III).

RESULTS

All patients were followed up for 6 to 24 months after operation (av- eraged 13 months), and all the patients had the clinical symptoms improved to some extent. Operation time ranged from 80 to 140 min (averaged 98 min); the intra-operative blood loss was 120 to 300 ml (averaged 180 ml); and the average fluoroscopic time was 55 s. No patients happened neurological and vertebral artery injuries-related complications or other complications after operation. The followed-up X-ray and CT manifested osseous fusion in all the 8 patients,no loosening or breakage of the screws.

CONCLUSION

Transoral plate internal fixation for instability atlas fracture is a reliable and safety technique that allows maintenance of rotatory mobility in the C1,2 joint and restoration of congruency in the atlanto-occipital and atlanto-axial joints.

Biomechanics of sports-induced axial-compression injuries of the neck

CONTEXT

Head-first sports-induced impacts cause cervical fractures and dislocations and spinal cord lesions. In previous biomechanical studies, researchers have vertically dropped human cadavers, head-neck specimens, or surrogate models in inverted postures.

OBJECTIVE

To develop a cadaveric neck model to simulate horizontally aligned, head-first impacts with a straightened neck and to use the model to investigate biomechanical responses and failure mechanisms.

DESIGN

Descriptive laboratory study.

SETTING

Biomechanics research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Five human cadaveric cervical spine specimens.

INTERVENTION(S)

The model consisted of the neck specimen mounted horizontally to a torso-equivalent mass on a sled and carrying a surrogate head. Head-first impacts were simulated at 4.1 m/s into a padded, deformable barrier.

MAIN OUTCOME MEASURE(S)

Time-history responses were determined for head and neck loads, accelerations, and motions. Average occurrence times of the compression force peaks at the impact barrier, occipital condyles, and neck were compared.

RESULTS

The first local compression force peaks at the impact barrier (3070.0 ± 168.0 N at 18.8 milliseconds), occipital condyles (2868.1 ± 732.4 N at 19.6 milliseconds), and neck (2884.6 ± 910.7 N at 25.0 milliseconds) occurred earlier than all global compression peaks, which reached 7531.6 N in the neck at 46.6 milliseconds (P < .001). Average peak head motions relative to the torso were 6.0 cm in compression, 2.4 cm in posterior shear, and 6.4° in flexion. Neck compression fractures included occipital condyle, atlas, odontoid, and subaxial comminuted burst and facet fractures.

CONCLUSIONS

Neck injuries due to excessive axial compression occurred within 20 milliseconds of impact and were caused by abrupt deceleration of the head and continued forward torso momentum before simultaneous rebound of the head and torso. Improved understanding of neck injury mechanisms during sports-induced impacts will increase clinical awareness and immediate care and ultimately lead to improved protective equipment, reducing the frequency and severity of neck injuries and their associated societal costs.

[Lateral mass screws of the atlas combined with vertebra dentata pedicle screws for treatment of upper cervical vertebral instability]

OBJECTIVE

To evaluate the therapeutic effects of fixation and fusion with lateral mass screws of the atlas and vertebra dentata pedicle screws for the treatment of upper vertebral instability.

METHODS

Ten patients with atlantoaxial instability, including 3 with old odontoid fracture and 7 with fresh odontoid fracture (Aderson II) received surgeries for fixation and fusion with lateral mass screws of the atlas and vertebra dentata pedicle screws.

RESULTS

No spinal cord or vertebral artery injuries occurred in these patients after the surgery. The follow-up duration ranged from 3 to 15 months with an average of 8 months. The postoperative JOA scores were from l3.2 to l6.8, with an average of l4.8. Clinical improvement was achieved in 87.5% of the patients, and the implanted bones all fused successfully without internal fixation rupture or mobilization.

CONCLUSION

Lateral mass screws of the atlas combined with vertebra dentata pedicle screws allows three-dimensional fixation for treatment of atlantoaxial instability.

[Application of spiral CT reconstruction in the forensic identification of atlantoaxial injuries]

OBJECTIVE

To evaluate diagnostic value of spiral CT reconstruction in atlantoaxial injuries.

METHODS

The images of 25 cases of spiral CT reconstruction were analyzed and compared with images of CT scan and X-ray.

RESULTS

In 7 cases of odontoid process fracture, X-ray demonstrated 4 cases and CT demonstrated 5 cases, whereas the spiral CT reconstruction diagnosed 7 cases, which could display the displacement of fracture clearly. The X-ray and CT showed asymmetric space between left and right gaps of atlantoaxial joint in 6 cases, while spiral CT reconstruction showed normal and excluded the possibility of atlantoaxial dislocation. There was one case of lateral atlantoaxial joint dislocation, which was demonstrated by the spiral CT reconstruction clearly but not by the X-ray and CT scan. There were 3 cases of atlantoaxial congenital deformity (1 case of absence of both posterior arch of atlas and odontoid process and 2 cases of maldevelopment of the odontoid process), which were displayed clearly by spiral CT reconstruction, but misdiagnosed as odontoid process fracture and atlantoaxial subluxation by X-ray and CT scan.

CONCLUSION

Spiral CT reconstruction can provide the most accurate and integrity imaging information and is very useful in the diagnosis of atlantoaxial injuries and deformity.

Bilateral atlas laminar hook combined with transarticular screw fixation for an unstable bursting atlantal fracture

INTRODUCTION

The unstable atlas burst fracture ("Jefferson fracture") is a fracture of the anterior and posterior atlantal arch with rupture of the transverse atlantal ligament and an incongruence of the atlanto-occipital and the atlanto-axial joint facets. The posterior atlantoaxial fusion is frequently used to reconstruct the stability of atlantoaxial joint. Conventional posterior atlantoaxial fixations are associated with high rates of pseudoarthrosis and chronic atlantoaxial instability. As a modified three-point fixation the bilateral C1-2 transarticular screws combined with C1 laminar hook and bone grafts can provide best biomechanical stability, but no standard protocol has been reported for the use of this fusion technique. A retrospective review of clinical series should be conducted to evaluate the clinical outcome of bilateral atlas laminar hook combined with transarticular screw fixation for unstable bursting atlantal fracture.

MATERIALS AND METHODS

From March 2002 to March 2006, there were total 12 cases of unstable atlantal bursting fractures, 10 males and 2 females, age ranging 18-54, with mean of 36 years old. All patients were operated on posterior atlantoaxial fusion using bilateral atlas laminar hook combined with transarticular screw fixation after atlantoaxial joint were reduced and followed up for 12-24 months. The medical records and radiographs of the 12 patients were reviewed. Each patient underwent a complete cervical radiograph series including lateral flexion-extension view and a computed topographic scan. The Frankel grades and ASIA scores were applied to assess the neurologic status.

RESULTS

In all patients, a good bony fusion of the atlanto-axial segment was achieved. All patients showed significant improvement of the neurologic defect and no instability on their follow-up plain radiographs and computerized tomography in follow-up interval.

CONCLUSIONS

For the patients who suffer from the unstable bursting atlantal fracture, the nonoperative methods could carry some clinical complications including infection, nerve injury, etc. and is frequently failure, Posterior atlantoaxial fusion using bilateral atlas laminar hook combined with transarticular screw fixation is an effective treatment.

[Clinical application of multi-spiral CT thinner scanning and reconstruction in the diagnosis of atlantoaxial fracture and dislocation]

OBJECTIVE

To evaluate the value of multi-spiral CT thinner scanning and three-dimensional and multi-planar reconstruction in the diagnosis of atlantoaxial fracture and dislocation.

METHODS

Sixty-nine patients suffered from atlantoaxial injuries included 54 males and 15 females with an average age of 46.5 years ranging from 17 to 73. Roentgenograph, multi-spiral CT thinner scanning, three dimensional reconstruction (3D) and multi-planar reconstruction (MPR) were applied for patients before and after surgery.

RESULTS

Multi-spiral CT thinner scanning and reconstruction provided clear images for all subjects. There were 49 odontoid bone fractures (Anderson type II 35, type III 14), 9 cases combined injuries of C1 and C2 (Jeffson's fracture associated with Hangman fracture), 6 of C1 burst fractures and 5 of C2 vertebral body fractures. While only 38 cases (38/69) were correctly diagnosed according to roentgenographs, 23 missed diagnosis, 6 couldn't be diagnosed clearly and 2 misdiagnosis. The position of internal fixation could be seen clearly in CT imaging after surgery. There were two screws perforated the lateral wall of C1 and three perforated the superior wall.

CONCLUSION

The multi-spiral CT thinner-scanning, three dimensional reconstruction (3D) and multi-planar reconstruction (MPR) provide clear imagings to diagnose the details of atlantoaxial fractures and dislocations, and to select the therapeutic regimen. It can also be used to check the position of the internal fixation after surgeries. So it can be the first eikonic choice for atlantoaxial injuries.

[Traumatic atlas fracture in a child following fall on head]

An 8-year-old girl presented at the Accident & Emergency Department with torticollis and neck pain after falling on her head from a climbing frame. A computed tomography scan revealed a Gehweiler type 1 avulsion fracture combined with widening of an anatomically variant single anterior synchondrosis. The child was successfully treated with halter traction, painkillers and bed rest. Physicians should look out for upper cervical spine injury in children who sustained a cranial axial load injury. Differential diagnosis between pain-reactive muscular torticollis and atlantoaxial rotatory subluxation is essential. Children presenting with posttraumatic torticollis require a conventional or dynamic computed tomography scan.

Perimortem weapon trauma in an adult male skeleton from the Italic necropolis of Opi Val Fondillo (VI-V century BC; Central Italy)

The author describes weapon traumatic lesions in an adult male skeleton, that was excavated in the Italic necropolis of Opi Val Fondillo, Central Italy. The preservation of the skeleton is very good. The skull shows a linear lesion across the diploE of the right parietal and occipital bones; the edge of the traumatic lesion is smooth and perpendicular to the bone surface. The injury was probably inflicted with a sharp-edged weapon and the violence of the stroke caused the detachment of bone fragments and fractures that radiate from the point of impact. A sharp-edged linear traumatic lesion, probably inflicted with a blade, is visible on the ventral surface of the vertebral bodies of atlas and axis; the blade detached the right transverse process of the atlas and penetrated in the vertebral body of the axis. Another sharp-edged linear traumatic injury is observed on the anterior surface of the body of thoracic vertebrae. There are no traumatic lesions of the ribs and the last injury was probably inflected down with a blade, while the body lying on the ground. The posterior surface of the diaphysis of the right femur shows an incomplete perimortem fracture, probably due to a compression down upon. Probably the adult male was killed during a fight and enemy had done with him, while he was lying on the ground holding fast his legs strongly. A comparison is made between the lesions and the modality of combat as well as the type of the weapons used by the Samnitic warriors.

Case report: nonoperative treatment of an unstable Jefferson fracture using a cervical collar

The treatment of unstable burst fractures of the atlas (Jefferson fractures) is controversial. Unstable Jefferson fractures have been managed successfully with either immobilization, typically halo traction or halo vest, or surgery. We report a patient with an unstable Jefferson fracture treated nonoperatively with a cervical collar, frequent clinical examinations, and flexion-extension radiographs. Twelve months after treatment, the patient achieved painless union of his fracture. The successful treatment confirms prior studies reporting unstable Jefferson fractures have been treated nonoperatively. The outcome challenges the clinical relevance of treatment algorithms that rely on the "rules of Spence" to guide treatment of unstable Jefferson fractures and illustrates instability may not necessarily be present in patients with considerable lateral mass widening. Additionally, it emphasizes a more reliable way of assessing C1-C2 stability in unstable Jefferson fractures is by measuring the presence and extent of anterior subluxation on lateral flexion and extension views.

Traumatic rotary posterior dislocation of the atlas on the axis without fracture. Report of a case and review of literature

BACKGROUND

Traumatic rotary posterior dislocation of C1 on C2 without fracture (TRPDAAWF) is a very rare complication in severe accidents, and its pathophysiology is still under debate.

CASE DESCRIPTION

Although 6 similar cases have been reported previously, we report the lessons learned during handling of the patient. A young man who is a victim of severe car crash injury, with neglected displacement of the intact odontoid process to the front of the anterior arch of C1, is reported. Some problematic and life-threatening events in the management of the case are presented.

CONCLUSIONS

We report a new and rare case of TRPDAAWF. It is hypothesized that a similar situation could only be possible if rotary subluxation of C1 on C2 follows a severe hyperextension injury; otherwise, traumatic fracture of the odontoid process might have been inevitable.

A single fracture in the ring of vertebrae below the atlas: report of four cases

A single fracture of the ring of a vertebra is a rare injury of the spine. In this report, we present five single fractures of the posterior ring of the cervical spine below the atlas from four patients after motor vehicle accidents. Initial radiographs failed to show any of these fractures; all were detected by computed tomography. Single ring fractures are stable and none of our patients presented with a neurological deficit. Patients were treated conservatively with a cervical collar or a cervicothoracic brace. They all recovered without any neurological abnormalities.

[Application of atlas pedicle screw system fixation and fusion for treatment of upper cervical disease]

OBJECTIVE

To explore the feasibilities, methods, outcomes and indications of atlas pedicle screw system fixation and fusion for the treatment of upper cervical diseases.

METHODS

From October 2004 to January 2006, 17 patients with upper cervical diseases were treated with atlas pedicle screw system fixation and fusion. There were 13 males and 4 females, ageing 19 to 52 years. Of 17 cases, there were 14 cases of atlantoaxial dislocation (including 3 cases of congenital odontoid disconnection,4 cases of old odontoid fracture, 2 cases of new odontoid fracture (type II C), 3 cases of rupture of the transverse ligament, and 2 cases of atlas fracture; 2 cases of tumor of C2; 1 case of giant neurilemoma of C2.3 with instability after the resection of tumors. JOA score before operation was 8.3+/-3.0.

RESULTS

The mean operative time and bleeding amount were 2.7 hours (2.1-3.4 hours) and 490 ml (300-750 ml) respectively. No injuries to the vertebral artery and spinal cord were observed. The medial-superior cortex of lateral mass was penetrated by 1 C1 screw approximately 3 mm without affecting occipito-atlantal motions. All patients were followed up 3-18 months. The clinical symptoms were improved in some extents and the screws were verified to be in a proper position, no breakage or loosening of screw and rob occurred. All patients achieved a solid bone fusion after 3-6 months. JOA score 3 months after operation was 14.6+/-2.2. JOA improvement rates were 73%-91% (mean 82%).

CONCLUSION

The atlas pedicle screw system fixation and fusion is feasible for the treatment of upper cervical diseases and has better outcomes, wider indications if conducted properly.

Intra-operative Iso-C3D navigation for pedicle screw instrumentation of hangman's fracture: a case report

Pedicle screw instrumentation of the upper cervical spine is rarely performed in trauma surgery because of the risk of damaging neurovascular structures. We report successful treatment of an unstable hangman's fracture with posterior pedicle screw fixation using Iso-C3D fluoroscopy-based computer navigation guidance. Postoperative computed tomographic images confirmed accurate placement of the pedicle screws. The navigation system is useful, especially in an unstable upper cervical spine injury where the likelihood of change in the inter-segmental relationship is maximal before and after positioning for surgery. The navigation system has the advantage of data acquisition after patient positioning, thus making safe pedicle fixation of the C1 and C2 vertebrae possible despite fractured posterior elements.

A single fracture in the atlas ring: report of two cases and a review of the literature

Atlas fractures commonly present more than two breaks in its ring structure because of the unique anatomy and the mechanism of injury. The incidence of a single break in the atlas ring is exceedingly rare. However, we encountered two cases of a single fracture of the atlas. One patient was struck by a falling tree on the right side of the head and the other was involved in a motor vehicle accident. Radiographs of the cervical spine failed to show a single fracture or other abnormalities. Computed tomography demonstrated the single fracture. The patients were treated conservatively with a cervical collar, and they both recovered completely. In this article, we present two cases of a single fracture of the atlas with a review of the literature.

Anteroposterior spondyloschisis of the atlas. Two case reports and literature review

Congenital bony defects of the atlas are uncommon; with isolated posterior clefts being the most frequent anomaly and combined anterior and posterior defects the least common, occurring in only 0.3-0.7% of the population. These anomalies can cause confusion, particularly in the setting of trauma when appearances on plain radiography may be misinterpreted as representing a fracture. Two cases of anteroposterior spondyloschisis are presented and the pathology, diagnosis and the clinical relevance of such defects discussed with reference to previous published literature.

A congenital anomaly of the atlas as a diagnostic dilemma: a case report

OBJECTIVE

The purpose of this case report is to draw attention to the differences between a Jefferson fracture and a congenital anomaly of the anterior and/or the posterior arch of the atlas.

CLINICAL FEATURES

A 42-year-old woman visited the chiropractic practice complaining of headache, neck pain, dizziness, and numbness in both of her arms after she fell vertically and directly on her head twice on a playground. Before this fall, she had no such complaints. After taking x-rays of the cervical spine, a Jefferson fracture was suspected.

INTERVENTION AND OUTCOME

After computed tomography and magnetic resonance imaging scanning, the patient was diagnosed with a congenital anomaly that looked very similar to a Jefferson fracture. After instability of the cervical spine was excluded by the neurosurgeon, chiropractic treatment was delivered. After 6 treatments, the complaints were significantly reduced.

CONCLUSION

It is important to be familiar with the differences between a congenital anomaly of the atlas and a Jefferson fracture and to exclude instability of the upper cervical spine before treatment is started.

Die direkte Osteosynthese instabiler Atlasfrakturen Gehweiler Typ III

This retrospective study evaluates eight patients with unstable fractures of the atlas vertebra, treated operatively in the Central Clinic Bad Berka between January 1995 and December 2001. In all cases, we were confronted with unstable and dislocated type III fractures according to Gehweiler, caused by an injured transverse ligament. Mean age was 34 years (range 20-49) in two women and six men. We introduce a new technique of direct reconstruction of the atlas vertebra. This technique leads to a stable ring construct that allows compression osteosynthesis of the fracture. Spinal fusion can be avoided, as can postoperative immobilization, since sufficient stability for functional postoperative treatment is achievable. The follow-up control 38 months (range 6-75) after surgery showed solid bony fusion in all cases, in one case after revision surgery. All patients showed good functional results, there was no need for analgesics and all patients could be reintegrated into their former occupation.

Bilateral occipital condylar fracture with associated haematomas

Occipital condylar fractures (OCFs) seem to be rare. The exact incidence is unknown, but a few studies reported a 3-4% incidence of OCFs in patients with severe head injury and altered Glasgow Coma Scale score. The low incidence of OCFs and missed diagnoses in these patients may result in late neurological deficits. We report the history of a patient with bilateral OCFs, a combined fracture of the anterior arcus of the atlas and associated retropharyngeal and epidural cervical haematomas, who presented without life-threatening symptoms or neurological deficits.

Fractures of the atlas: can we rely on the NICE guidelines for imaging the cervical spine after head injury?

We describe a patient who was not thought to fulfil the NICE criteria for imaging the cervical spine after head injury but who had two fractures of the atlas, thus rendering the vertebral ring unstable. The reasons for missing this injury in the emergency department are discussed.

Fracture of the atlas through a synchondrosis of the anterior arch complicated by atlantoaxial rotatory fixation in a four-year-old child

Fracture of the atlas is rare in children. We report a case of fracture of the atlas through a synchondrosis of the anterior arch complicated by atlantoaxial rotatory fixation in a four-year-old girl.

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

OBJECTIVES

To evaluate the feasibility and reliability of C(1) lateral-mass screw-C(2) pedicle screw and crosslink compression fixation for Jefferson fracture.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Axial loading with hyperflexion injury to the atlas resulting in crushed lateral masses

A 40-year-old man was involved in an ATV accident, in which he landed on the top of his head. There was no neurological deficit. A plain radiograph showed prevertebral soft tissue swelling at the atlas and axis level. Computed tomography (CT) demonstrated vertical fractures of the anterior aspects of both lateral masses of the atlas, extending to the junction of the lateral mass with the anterior arch bilaterally. There was no lateral offset of the lateral masses. The mechanism of injury is believed to be axial loading along with hyperflexion.