Radiographic analysis of type II odontoid fractures in a geriatric patient population: description and pathomechanism of the "Geier"-deformity

Abstract

Introduction: Type II odontoid fractures are one among the most common cervical spine fractures in the elders. We reviewed a consecutive series of patients, aged 65 years and older, presenting to our institution with type II odontoid fractures. Our analysis focused on the radiographic outcome, union rate and the development of cervical spine postural deformity.

Patients/methods: Indications for surgical treatment (OP) included displaced or unstable injuries. Stable, non-displaced injuries or patients with significant co-morbidities were treated nonoperatively (non-op).

Results: Ninety patients (50 f, 40 m) with an average age of 83 years (65-101) were identified. 31 (34.4%) patients were received OP and 57 (63.3%) were received non-op treatments. The hospital length of stay was significantly longer after OP (mean 10 days vs. 6 days non-op) treatment (p = 0.007). At follow-up, higher union rates were noted in the OP (76.2%) than in the non-op group (58.3%).

Conclusion: We observed a characteristic cervical spine deformity in geriatric patients with type II odontoid fractures, and have termed this the "Geier-deformity". Clinical findings of the deformity include sagittal imbalance and kyphosis of the lower cervical spine.

Fig. 1

Measurement of the neural canal balance defined by a the displacement/distance between opisthion and spinolaminar line at midvertebral height of C7 (mm) [anterior, posterior], b angulation (°) between McCrae’s line (connecting line between basion and opisthion) and tangent to the lower endplate of C7

Fig. 2

Type II odontoid fracture subgroup frequencies clockwise from left upper corner: (1) transverse fracture (n = 33, 36.3%), (2) oblique anterior (n = 1.1%), (3) oblique posterior (n = 48, 52.7%), and (4) comminuted (n = 1, 1.1%) fracture pattern (other n = 7, 7.7%, missing n = 1, 1.1%)

Fig. 3

a Frequency of image modalities available for assessment on admission, discharge, and FU in percent (n_total = 90). b Patient position during image acquisition on admission, discharge and FU

Fig. 4

Statistically significant correlation (−0.275, p = 0.011) between osteoporosis classification and average pixel statistics as seen in a boxedregion of interest (ROI) at the body of the axis with a decreasing pixel average from categories mild (mean 247), moderate (mean 213) to severe (mean 177)

Fig. 5

Comparison of patient numbers and union rates following OP (n_total = 16, 76.2%) and non-op (n_total = 14, 58.3%) treatment

Fig. 6

A Clinical picture, naming, and lateral cervical spine X-ray, a clinical picture with patient wearing a Miami-J collar presenting at FU with a “stooped” forward position, b naming of the pathology according to the distinct features of a vulture’s neck called "Geier-deformity", c corresponding lateral radiograph of the cervical spine showing the loss of the physiologic profile with loss of lordosis at in the subaxial cervical spine and increased kyphosis of the cervico-thoracic junction to compensate for the posterior oblique odontoid fracture. Hypothesis and possible explanation for the Geier-deformity, d equilibrium of load and muscle forces in the intact situation, e oblique posterior fracture line with corresponding force vectors in an upright position causing posterior displacement, f compensatory mechanism to counteract the posterior displacement by stooping/bending forward. B Case sample No 2 left sagittal reconstruction of CT scan obtained at the time of injury of a 73yrs old male patient presenting with posterior oblique diffuse idiopathic skeletal hyperostosis of the subaxial cervical spine, middle lateral xray of patient in upright position at discharge wearing a Miami-J-collar, right lateral X-ray obtained during FU in an stooped forward position and findings of the Geier-deformity as outlined in the text following non-operative treatment

Fig. 7

Case sample of an 81-year-old male patient who sustained a fall in his bedroom and had posterior oblique odontoid fracture and severe degenerative changes of the subaxial cervical spine. Left CT scan at the time of injury; middle upright lateral X-ray at discharge with some posterior displacement; right “Geier-deformity” with lateral cervical spine radiograph obtained at follow-up with stooped forward position (neural canal outlined in yellow, red line to highlight fracture line, and green arrow indicating force vector in the stooped forward position; see also Fig. 6)