A waiver of informed consent was granted by the IRB-03 chairman at University of Florida Health Jacksonville to retrospectively evaluate the imaging and clinical findings of patients who suffered a TM injury. Sixteen patients (ten adult and six pediatric) with confirmed TM injury on cervical MRI were identified retrospectively by a keyword search of radiology reports using Nuance mPower software between January 2012 and July 2018 using the keywords ‘tectorial membrane’ ‘craniocervical ligament tear/injury,’ and ‘atlanto-occipital disassociation.’ Electronic patient records were reviewed for the following: 1) age and sex of patient,
2) mechanism of trauma,
3) management (eg,
surgery,
external fixation),
and 4) clinical outcome (eg,
ambulatory,
wheelchair,
paretic).
CT and MRI exams were performed using the standard departmental protocols.
CT images were generated with 0.625 mm slice thickness and reconstructed using multiplanar bone and soft tissue algorithms (GE medical systems).
MRI studies were perfomed on a 1.5 Tesla magnet with a head and neck coil (Avanto,
Siemens).
Slice thickness was 3 mm and sagittal T1,
T2,
and STIR as well as axial T2,
and T2 MEDIC sequences were obtained.
All CT and MRI exams were reviewed by two experienced CAQ certified neuroradiologists in consensus.
The tectorial membrane was considered injured when the normal thin T2 hypointense band was fully or partially disrupted,
demonstrated increased T2 signal and a “stretched” appearance,
or was stripped from the posterior clivus. Furthermore,
the location of TM injury was evaluated and divided into “subclival” if the location of injury was located inferior to the clivus,
or “retroclival” if the injury was located posterior to the clivus. The subclival tears were further subdivided by whether the tear occurred nearer the clivus versus the odontoid tip.
The presence or absence of a retroclival epidural hematoma (REH) was recorded.
The size of the REH,
if present,
was measured in greatest anteroposterior dimension perpendicular to the long axis of the clivus.
A thorough analysis of the integrity of the apical ligament,
alar ligaments,
transverse ligament of C2,
and anterior and posterior atlantooccipital membranes was obtained.
Additionally,
the anterior and posterior longitudinal ligament,
ligamentum flavum,
and interspinous ligaments from C2-C6 were evaluated for injury.
Any fractures of the occipital condyles or cervical spine were documented.
The presence of intracranial trauma,
including shear injury,
hemorrhagic or non-hemorrhagic contusion,
and extra-axial hemorrhage (including epidural,
subdural,
and subarachnoid hemorrhage) was documented along with the presence of cervical cord contusion. Patient age and sex,
mechanism of injury,
management,
and outcome were analyzed.
The patients were grouped by age into adult and pediatric (less than 14 years) groups and statistical analysis was performed.