Anderson type II odontoid fractures are reported to be the most common injury of the odontoid process in patients over the age of 65. However, atraumatic occult Anderson type III odontoid fractures have been rarely described and remain a diagnostic challenge. In the present report, we illustrate a 78-year-old female with osteoporosis-associated marked thoracic kyphotic deformity who developed atraumatic Anderson type III occult odontoid fracture and raise awareness of this condition. Anteroposterior and lateral standard radiographs of cervical spine failed to disclose odontoid fracture. Magnetic resonance imaging demonstrated intensity changes of the axis. Subsequent computed tomography clearly demonstrated Anderson type III odontoid fracture. Conservative treatment achieved complete bone union without neurological deteriorations. At 3-year follow-up, the patient was doing well without neurological and radiological deteriorations. Even if the patients have no traumatic event, we have to keep odontoid fractures in our mind as one of the differential diagnoses when we encounter elderly patients with neck pain, especially in patients with osteoporosis-associated marked thoracic kyphotic deformity.
Odontoid fractures are caused by minor trauma like falls from standing or seated height in elderly individuals [
In the present report, we illustrate a unique case of elderly female patients with occult Anderson type III odontoid fracture without any traumatic event. We emphasize the importance of an awareness of this condition and discuss the likely mechanism of the injury in the present case.
A 78-year-old female experienced sudden severe neck pain when she looked up the refrigerator (her cervical spine was extended) to open its door and visited our institution. She had a mild occasional neck pain before this event; however she reported no traumatic event just before the onset of this symptom or in the past. Physical examination revealed the absence of neurological compromise. In turn, anteroposterior and lateral standard radiographs of cervical spine revealed cervical degenerative spondylosis, but we could not detect apparent fracture (Figures
Anteroposterior (a) and lateral (b) standard radiographs of cervical spine revealed degenerative spondylosis but failed to reveal apparent fracture in cervical spine. Lateral standard radiographs of thoracolumbar spine revealed marked thoracic kyphotic deformity due to multiple compression fractures (c).
She complained about persistent severe diffuse neck pain. Four days later, magnetic resonance (MR) imaging was performed to rule out latent fresh compression fracture and overt intensity changes of axis, which was low intensity on both T1- and T2-weighted images but high intensity on STIR image, were found (Figures
Magnetic resonance imaging demonstrated overt intensity changes of C2, which was low intensity on both (a) T1- and (b) T2-weighted images but high intensity on STIR (c) images. Spinal cord involvement was not evident.
Sagittal (a, c) and coronal (b, d) reconstruction images of computed tomography (CT). (a, b) Anderson type III odontoid fracture was confirmed at the time of initial diagnosis. (c, d) Follow-up CT obtained after 6-month conservative treatment clearly revealed complete bone union.
After the careful explanation of the risk of nonunion/malunion and neurological deteriorations, the patient refused surgical treatment as well as Halo-vest fixation. Conservative treatment with Philadelphia type cervical caller was indicated. Two-month conservative treatment with cervical caller achieved good pain relief. Follow-up CT after 6 months from the initial treatment revealed significant bone union (Figures
Anderson and D’Alonzo classified odontoid fractures into 3 types based on the localization of the fracture line passed through [
Several studies revealed that, compared with patients younger than 65 years, elderly patients require lower energy, that is, fall from standing or seated height, to fracture their cervical spines [
Odontoid fractures are mostly induced by nonphysiological flexion, extension, or rotation force of the upper cervical spine; however exact mechanism is not fully determined [
The precise mechanism of odontoid fracture in the present case remains unknown; however significant osteoporosis might play a pivotal role on our case. In addition to significant osteoporosis, we advocate the possible influence of sagittal malalignment of the spine on odontoid fracture in this case. Namely, a compensatory hyperlordosis of cervical spine due to marked thoracic kyphotic deformity might yield routine hyperextension stress to the cervical spine. In turn, senescent degenerative changes make the mid- to lower cervical spine stiffer and shift the motion segment to the upper cervical spine [
Standard radiographs are routinely used as a screening tool for evaluating cervical spine injuries; however they could not always detect them [
The optimal management of odontoid fractures in the elderly population remains unsettled and management of this group of patients is complicated by multiple comorbidities [
In conclusion, even if the patients have no traumatic event, we have to keep odontoid fractures in our mind as one of the differential diagnoses when we encounter elderly patients with neck pain, especially in patients with osteoporosis-associated marked thoracic kyphotic deformity.
The authors declare no conflict of interests.