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 osteosynthesis with a new self-designed lateral mass screw-plate system for unstable atlas burst fractures.

BACKGROUND: In the treatment of unstable atlas fractures using the combined anterior-posterior approach or the posterior monoaxial screw-rod system, factors such as severe trauma or complex surgical procedures still need to be improved despite the favourable reduction effect. This research described and evaluated a new technique for the treatment of unstable atlas fracture using a self-designed lateral mass screw-plate system. METHODS: A total of 10 patients with unstable atlas fractures using this new screw-plate system from January 2019 to December 2021 were retrospectively reviewed. All patients underwent posterior open reduction and internal fixation (ORIF) with a self-designed screw-plate system. The medical records and radiographs before and after surgery were noted. Preoperative and postoperative CT scans were used to determine the type of fracture and evaluate the reduction of fracture. RESULTS: All 10 patients were successfully operated with this new system, with an average follow-up of 16.7 ± 9.6 months. A total of 10 plates were placed, and all 20 screws were inserted into the atlas lateral masses. The mean operating time was 108.7 ± 20.1 min and the average estimated blood loss was 98.0 ± 41.3 ml. The lateral mass displacement (LMD) averaged 7.1 ± 1.9 mm before surgery and almost achieved satisfactory reduction after surgery. All the fractures achieved bony healing without reduction loss or implant failure. No complications (vertebral artery injury, neurologic deficit, or wound infection) occurred in these 10 patients. At the final follow-up, the anterior atlantodens interval (AADI) was 2.3 ± 0.8 mm and the visual analog scale (VAS) was 0.6 ± 0.7 on average. All patients preserved almost full range of motion of the upper cervical spine and achieved a good clinical outcome at the last follow-up. CONCLUSIONS: Posterior osteosynthesis with this new screw-plate system can provide a new therapeutic strategy for unstable atlas fractures with simple and almost satisfactory reduction.

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.

Upper Cervical Trauma.

Craniocervical injuries (CCJs) account for 10% to 30% of all cervical spine trauma. An increasing number of patients are surviving these injuries due to advancements in automobile technology, resuscitation techniques, and diagnostic modalities. The leading injury mechanisms are motor vehicle crashes, falls from height, and sports-related events. Current treatment with urgent rigid posterior fixation of the occiput to the cervical spine has resulted in a substantial reduction in management delays expedites treatment of CCJ injuries. Within CCJ injuries, there is a spectrum of instability, ranging from isolated nondisplaced occipital condyle fractures treated nonoperatively to highly unstable injuries with severely distracted craniocervical dissociation. Despite the evolution of understanding and improvement in the management of cases regarding catastrophic failure to diagnose, subsequent neurologic deterioration still occurs even in experienced trauma centers. The purpose of this article is to review the injuries that occur at the CCJ with the accompanying anatomy, presentation, imaging, classification, management, and outcomes.

Anterior reduction and C1-ring osteosynthesis with Jefferson-fracture reduction plate (JeRP) via transoral approach for unstable atlas fractures.

BACKGROUND: To introduce a novel transoral instrumentation in the treatment of unstable fractures of the atlas. METHODS: From January 2008 to May 2018, 22 patients with unstable C1 fractures who received Jefferson-fracture reduction plate (JeRP) via transoral approach were retrospectively analyzed. The case history and the radiographs before and after surgery were noted. The type of fracture, the reduction of the fracture, and position of the internal fixation were assessed through preoperative and postoperative CT scans. RESULTS: All 22 patients successfully underwent anterior C1-ring osteosynthesis using the JeRP system, with a follow-up of 26.84 ± 9.23 months. Among them, 9 patients had transverse atlantal ligament (TAL) injury, including 3 in Dickman type I and 6 in type II. The preoperative lateral mass displacement (LMD) decreased from 7.13 ± 1.46 mm to 1.02 ± 0.65 mm after the operation. Bone union was achieved in all patients without implant failure or loss of reduction. There were no surgery-related complications, such as wound infection, neurological deficit, or vertebral artery injury. However, atlantoaxial dislocation occurred in 3 patients with Dickman type I TAL injury 3 months postoperatively without any neurological symptoms or neck pain. CONCLUSIONS: Transoral C1-ring osteosynthesis with JeRP is an effective surgical strategy to treat unstable atlas fractures with a safe, direct, and satisfactory reduction. The primary indication for the JeRP system is an unstable fracture (Gehweiler type I/III) or/ and TAL injury (Dickman type II).

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.

3D-Printed Screw-Rod Auxiliary System for Unstable Atlas Fractures: A Retrospective Analysis.

OBJECTIVE: To develop and validate the efficacy of a 3D-printed screw-rod auxiliary system for unstable atlas fractures. METHODS: This research is a retrospective analysis, and a total of 14 patients, including 11 males and three females, were enrolled in our hospital from January 2017 to March 2019 who underwent occipitocervical fusion assisted by the 3D-printed screw-rod auxiliary system were reviewed, and with an average age of 53.21 ± 14.81 years, an average body mass index (BMI) of 23.61 ± 1.93 kg/m2 . The operation time, blood loss and radiation times during the operation were recorded. The maximum fracture displacement values of pre- and post-operation were measured based on CT imaging. All screw grades were evaluated after surgery. The occipital-cervical 2 (O-C2 ) angle and occipitocervical inclination (OCI) angle of pre-operation, post-operation and the last following-up were measured. The dysphagia scale 3 months after surgery and at the last follow-up, the Neck Disability Index (NDI) 3 months after surgery and at the last follow-up were assessed. RESULTS: All patients were completed the surgery successfully. There was no patient with severe dysphagia or aggravation of nerve injury. The follow-up was from 12 to 14 months, and with an average of 12.5 months. The average surgery time, average blood loss and average radiation times for the 14 patients were 112.14 min, 171.43 mL and 5.07 times, respectively. There was a significant difference in maximum fracture displacement between pre- and post-operation values (P < 0.05). A total of 56 screws were inserted in 14 patients, among them, three screws were classified as grade 1, and the other screws were classified as grade 0. There was a significant difference in the O-C2 between pre-operation and 3 days after operation (P = 0.002); There was a significant difference in OCI angles between pre-operation and 3 days after operation (P < 0.05); there was no significant difference in the O-C2 or OCI angle between 3 days after the operation and the last follow-up (P = 0.079; P = 0.201). The dysphagia scales of two patients were assessed as mild at 3 months after surgery, and the others were assessed as normal at 3 months after surgery. All patients' dysphagia scores returned to normal at the last follow-up. The average NDI and average neck Visual Analogue Scale (VAS) scores at the last follow-up were 2.53 and 8.41, respectively. CONCLUSION: It can objectively restore the OCI to normal with few post-operative complications under the assistance of a screw-rod auxiliary system to perform occipitocervical fusion for unstable atlas fractures and atlantooccipital joint instability.

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

ABSTRACT: 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.

Risk Factors for Transverse Ligament Disruption and Vertebral Artery Injury Following an Atlas Fracture.

BACKGROUND: Atlas fracture occurs in 3%-13% of all cervical spinal injuries and is often associated with other injuries. The factors associated with concomitant transverse ligament disruption and vertebral artery injury remain underexamined. METHODS: We retrospectively reviewed 97 consecutive cases of atlas fractures. We analyzed demographic and clinic characteristics, including mechanism of injury, fracture type, and associated injuries. We identified factors independently associated with vertebral artery injury and/or transverse ligament disruption. RESULTS: On multivariable analysis, vertebral artery injury was independently, positively associated with injury to the transverse ligament (odds ratio [OR], 8.51 [1.17, 61.72], P = 0.034), associated facial injury (OR, 7.78 [1.05, 57.50]; P = 0.045), intoxication at presentation (OR, 51.42 [1.10, 2408.82]; P = 0.045), and negatively associated with type 3 fractures (OR, 0.081 [0.0081, 0.814]; P = 0.033). There was a trend toward a positive association with a violence mechanism of injury (OR, 33.47 [0.75, 1487.89]; P = 0.070). Transverse ligament injury was independently associated with other injuries to the spine (OR, 13.07362 [2.43, 70.28]; P = 0.003), atlantodental interval (OR, 2.63 [1.02, 6.75]; P = 0.045), lateral mass displacement (OR, 1.78 [1.32, 2.39]; P < 0.001), and male sex (OR, 7.07 [1.47, 34.06]; P = 0.015). There was a trend toward a positive association with injury to the vertebral artery (OR, 5.13 [0.96, 27.35]; P = 0.056). CONCLUSIONS: Among patients with atlas fractures, vertebral artery injury and transverse ligament disruption are associated with each other. Mechanism of injury, fracture type, and intoxication at the time of injury were associated with vertebral artery injury, and atlantodental interval and lateral mass displacement are associated with magnetic resonance imaging-confirmed injury to the transverse ligament.

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.

Motion-preserving treatment of unstable atlas fracture: transoral anterior C1-ring osteosynthesis using a laminoplasty plate.

BACKGROUND: C1-ring osteosynthesis is a valid alternative to posterior C1-C2 or C0-C2 fusion to preserve important C1-C2 motion in the treatment of unstable atlas fractures. Nevertheless, the fixation instruments used in current studies for transoral anterior C1-ring osteosynthesis were not suitable for anterior anatomy of the atlas or did not have reduction mechanism. We therefore present this report to investigate preliminary clinical effects of transoral anterior C1-ring osteosynthesis using a laminoplasty plate in unstable atlas fractures. METHODS: From January 2014 to December 2017, 13 patients with unstable atlas fractures were retrospectively reviewed. All patients were treated with transoral anterior C1-ring osteosynthesis using a laminoplasty plate. Pre- and postoperative images were obtained to assess reduction of the fracture, internal fixation placement, and bone union. Neurological function, range of motion, and pain levels were evaluated clinically on follow-up. RESULTS: The surgeries were successfully performed in all cases. The average follow-up duration was 16.6 ± 4.4 months (range 12-24 months). One patient suffered screw loosening after operation and underwent replacement operation subsequently. Satisfactory clinical outcomes were achieved in all patients with ideal fracture reduction, reliable plate placement, well-preserved range of motion, and neck pain alleviation. All patients achieved bone union of fractures without loss of reduction or implant failure or C1-C2 instability during the follow-up. No vascular or neurological complication was noted during the operation and follow-up. CONCLUSIONS: Transoral anterior C1-ring osteosynthesis using a laminoplasty plate is a effective surgical treatment for unstable atlas fractures. This technique has a ingenious reduction mechanism, and can provide satisfactory bone union and preservation of C1-C2 motion.

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 ±â€Š14.9 min (range: 82-135 min), and mean blood loss was 386.2 ±â€Š147.9 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.

Fusión occipito-cervical en fractura inestable de atlas tipo Jefferson / Occipito-cervical fusion in unstable fracture of Jefferson type atlas

Resumen Las fracturas del Atlas representan el segundo tipo más común de lesiones de la columna cervical alta. Con este trabajo se persigue describir la fijación occipito-cervical como tratamiento de la fractura de atlas tipo Jefferson inestable. Se presenta paciente que sufre trauma raquimedular, después de aplicarle un minucioso examen físico y la tomografía axial computada de columna cervical se detecta una fractura tipo Jefferson de atlas con más de 7 mm de separación de sus fragmentos. Al ser esta una fractura inestable de la región cervical alta se decide realizar una fijación occipito-cervical como método de tratamiento de esta lesión. La evolución postquirúrgica del paciente transcurrió sin complicaciones (AU).

Summary Atlas fractures represent the second most common type of upper cervical spine injury. This work aims to describe the occipito-cervical fixation as a treatment for the unstable Jefferson-type atlas fracture. A patient suffering from spinal cord trauma is presented, after applying a thorough physical examination and the computed tomography of the cervical spine, a Jefferson type fracture of atlas with more than 7 mm of separation of its fragments is detected. As this is an unstable fracture of the upper cervical region, it was decided to perform an occipito-cervical fixation as a treatment method for this lesion. The postoperative evolution of the patient was uneventful (AU).

Posterior Arch Screw for Type II Odontoid Fracture: An Alternative Procedure.

BACKGROUND/OBJECTIVE: Atlantoaxial fusion procedures may be difficult in situations such as high-riding vertebral artery, a narrow C2 pedicle, and the presence of ponticulus posticus-arcuate foramen. With respect to vertebral artery (VA) anomalies, persistent first intersegmental artery, extracranial origin of the posterior inferior cerebellar artery at the C1-C2 level, and fenestration of the VA are all major risk factors for VA injury in C1-C2 fusion surgeries. METHODS: To safeguard the VA, we designed the unilateral fusion procedure (all screws lie in the ipsilateral side, either the right side or left side): a unilateral transarticular screw combined with an ipsilateral-side C1 posterior arch screw and a C2 laminar screw (LS), with both C1-C2 screws inserted from opposite side, although the trajectory will be on the same side. In addition to atlantoaxial stabilization with screws and rod, autograft bony fusion was performed on the same side as modified Brook's procedure and augmented with sublaminar tapping. RESULTS: We present a series of 3 cases operated for odontoid fracture with associated high risk for fusion on one side alone. The fact that the chance of VA injury is high in transarticular screw, in lateral mass screw, less in pars screw, and pedicle screw is well known. Alternate screw placement to avoid VA injury would be a posterior arch screw for C1 and laminar screw for C2, which was adopted in our technique. CONCLUSIONS: We combined a unilateral transarticular screw and modified Brook's procedure with sublaminar tapping for additional augmentation of fusion. We would like to highlight this C1 posterior arch screw as an alternative procedure for atlantoaxial fusion.

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.

Synchondral Fracture of the Posterior "Hemiarch" of Pediatric Atlas with Cerebrospinal Fluid Fistula following a Penetrating Neck Injury.

INTRODUCTION: As such, the incidence of spinal fractures in young children is less than that of adults due to an increased pliability of the immature bones. The presence of unfused synchondroses in these children predisposes them to an infrequent pattern of fractures that traverse through ossification centers. Such synchondral injuries are uncommonly reported in the C1 and C2 vertebrae. Those that have been occasionally described in C1 involved the anterior synchondrosis. Furthermore, penetrating injuries to a pediatric spine are relatively rare. CASE PRESENTATION: In this context, we present a 4-year-old child in whom a penetrating injury to an immature atlas led to an unusual disjunction of the posterior synchondrosis with fracture displacement of the posterior "hemiarch" of the atlas that plunged into the dura, resulting in a cerebrospinal fluid fistula. CONCLUSION: We discuss the possible mechanism and considerations in the management of this unique presentation. Such an atypical fracture pattern involving the posterior hemi ring of the pediatric atlas is previously unknown.