Does fracture-extension into the pars interarticularis alter outcomes in odontoid failure? a technical note on pars interarticularis osteotomy and atlantoaxial distraction arthrodesis.

PURPOSE: Odontoid process fractures can extend rostral into the C2 arch. We investigated the clinical impact of a concurrent fracture of the pars interarticularis on odontoid failure. To overcome the surgical challenges related to the morphology of these fractures, we describe a novel surgical strategy using atlantoaxial joint distraction arthrodesis. METHODS: We conducted a single centre cohort study of 13 consecutive patients with odontoid fractures extending into the pars treated between June 2016 and June 2018. Criteria for a stable fibrous non-union were: Atlanto-Dens Interval (ADI) < 3 mm, Posterior Atlanto-Dens Interval (PADI) > 14 mm and lack of symptomatic motion at the fracture site. Atlantoaxial instability was defined as greater than 50% subluxation across the C1-C2 joint. Return to pre-injury performance status was considered a satisfactory clinical outcome. RESULTS: The mean age of the patient population was 77.2 years (SD 11.9). The mean follow-up time was 15 months (SD 5.2). 69% had an associated atlantoaxial instability (P-value 0.0005). Cervical orthosis treatment was associated with a high non-union rate (70%) (P-value 0.04) although it did not affect the overall clinical outcome. 2 cases presented with cord compression were treated surgically with pars interarticularis osteotomy and atlantoaxial distraction arthrodesis. CONCLUSIONS: Odontoid fracture with extension into the pars interarticularis often present with atlantoaxial instability and may result in stable fibrous non-union if treated non-operatively. The C1-C2 segment can be stabilised with atlantoaxial distraction arthrodesis achieved through an osteotomy of the pars interarticularis.

The spectrum of traumatic injuries at the craniocervical junction: a review of imaging findings and management.

The craniocervical junction is an area with unique biomechanical properties and injuries conferred often represent high-impact trauma. The vital structures traversing this region are susceptible to injury with frequent, only subtle findings identified on unenhanced CT, with MRI and CT angiography often revealing the full extent of injuries. This article reviews the osseous and ligamentous anatomy of the region and common injury patterns. Endovascular and neurosurgical management will also be discussed.

Neuroendovascular Surgery Applications in Craniocervical Trauma.

Cerebrovascular injuries resulting from blunt or penetrating trauma to the head and neck often lead to local hemorrhage and stroke. These injuries present with a wide range of manifestations, including carotid or vertebral artery dissection, pseudoaneurysm, occlusion, transection, arteriovenous fistula, carotid-cavernous fistula, epistaxis, venous sinus thrombosis, and subdural hematoma. A selective review of the literature from 1989 to 2023 was conducted to explore various neuroendovascular surgical techniques for craniocervical trauma. A PubMed search was performed using these terms: endovascular, trauma, dissection, blunt cerebrovascular injury, pseudoaneurysm, occlusion, transection, vasospasm, carotid-cavernous fistula, arteriovenous fistula, epistaxis, cerebral venous sinus thrombosis, subdural hematoma, and middle meningeal artery embolization. An increasing array of neuroendovascular procedures are currently available to treat these traumatic injuries. Coils, liquid embolics (onyx or n-butyl cyanoacrylate), and polyvinyl alcohol particles can be used to embolize lesions, while stents, mechanical thrombectomy employing stent-retrievers or aspiration catheters, and balloon occlusion tests and super selective angiography offer additional treatment options based on the specific case. Neuroendovascular techniques prove valuable when surgical options are limited, although comparative data with surgical techniques in trauma cases is limited. Further research is needed to assess the efficacy and outcomes associated with these interventions.

A Biomechanical Assessment of Shaken Baby Syndrome: What About the Spine?

BACKGROUND: Shaken baby syndrome occurs following inertial loading of the pediatric head, resulting in retinal hemorrhaging, subdural hematoma, and encephalopathy. However, the anatomically vulnerable cervical spine receives little attention. Automotive safety literature is replete with biomechanical data involving forward-facing pediatric surrogates in frontal collisions, an environment analogous to shaking. Publicly available data involving child occupants were utilized to study pediatric neck and head injury potential. We hypothesized that inertial loading provides a greater risk of injury to the cervical spine than to the head. METHODS: Full-scale automotive crash tests (n = 131) and deceleration sled tests (n = 32) utilizing forward-facing 3-year-old surrogates with head accelerometers and cervical force sensors were analyzed. One hundred sixty-seven full-scale vehicle and 33 sled test runs were assessed in the context of published injury assessment reference values (IARVs) for closed head injury (head injury criterion 15 [HIC15]) and cervical tensile strength in the 3-year-old model. RESULTS: One hundred sixty-one (96%) child surrogates in full-scale crash tests exceeded the cervical peak tension IARV, while only 37 (22%) surpassed the HIC15 IARV. Similarly, in sled testing runs, 27 (82%) pediatric surrogates exceeded cervical tension IARVs, while 1 (3%) surpassed the HIC15 IARV. In both full-scale and sled tests, all surrogates surpassing the HIC15 IARV also exceeded the cervical tension IARV. Positive linear correlations were observed between HIC15 and cervical tensile forces in both full-scale vehicle (R2 = 0.15) and sled testing runs (R2 = 0.54). CONCLUSIONS: These data support the hypothesis that inertial loading of the head provides a greater injury risk to the cervical spine than to closed-head injury.

Chiari I malformation with acute neurological deficit after craniocervical trauma: Case report, imaging, and anatomic considerations.

BACKGROUND: In patients with Chiari I malformation (CMI), the occurrence of acute neurologic deficit after craniocervical trauma is rare. However, the pathologic potential of exacerbating anatomic overcrowding of the posterior fossa has immense clinical consequences and prompt recognition is essential. CASE DESCRIPTION: This case study describes a 41-year-old male who sustained a single blow to the face, fell, and struck the occiput. On admission, neurological examination revealed a profound paraparesis, upper extremity diplegia, a C4 sensory level and apnea that required intubation. On arrival, computerized axial tomography of the head showed a small amount of contrecoup left frontal traumatic subarachnoid hemorrhage. Magnetic resonance imaging (MRI) performed 19 h after admission was negative except for the presence of a CMI. He acutely declined on post injury day 2, prompting emergent decompression of the posterior fossa where anatomic overcrowding was observed. At 19 weeks post injury, his motor function had significantly improved. CONCLUSION: The constellation of severe neurologic deficit in patients with CMI after relatively minor craniocervical trauma has been previously described. In our patient, neurologic deficit disproportionate to the mechanism of injury was observed and likely in part attributed to the presence of a Chiari malformation. Unfortunately, MRI has not yet been able to clearly define the underlying pathoanatomy, help understand the mechanism of injury, and delineate when operative intervention is indicated in these patients. Here, we review similar cases from the literature, examine findings on MRI, and evaluate mechanisms of injury following craniocervical trauma in patients with CMI to help clarify these questions.

Hematoma epidural pós-traumático na junção crânio-cervical: relato de caso e revisão de literatura / Post-traumatic epidural hematoma in the craniocervical junction: case report and review of the literature

Os autores relatam um caso raro de hematoma epidural pós-traumático na região da junção crâniocervical.Paciente de 63 anos, após grave acidente automobilístico, evoluiu com dor cervical intensa,refratária ao tratamento clínico. A ressonância magnética demonstrou um hematoma epidural desde ajunção crânio-cervical até C1-C2, de localização póstero-lateral direita, sem alterações de partes ósseas.Optado pelo tratamento cirúrgico imediato, foi realizada laminectomia com retirada do hematoma. Houvedesaparecimento da dor e resolução completa do hematoma, comprovado pela ressonância magnética.É feita revisão da literatura sobre o tema.

The authors report a rare case of post-traumatic epidural hematoma in the craniocervical junction ina 63 y.o. male patient, following a car accident. He presented with intense cervical pain refractory tothe clinical treatment. The magnetic resonance imaging demonstrated an epidural hematoma fromthe craniocervical junction down to C1-C2 level, on the right posterior-lateral region, without any bonealterations. An immediate laminectomy for drainage of the hematoma was carried through. The patientpresented alleviation of the pain and complete resolution of the hematoma, as proven by the magneticresonance imaging. Revision of literature on the subject is made.