Type II odontoid fracture in elderly patients treated conservatively: is fracture healing the goal?

PURPOSE

Analysis of functional outcome of elderly patients with type II odontoid fractures treated conservatively in relation to their radiological outcome.

METHODS

A total of 50 geriatric patients with type II odontoid fractures were treated with Aspen/Vista collars. On admission, each patient was assessed assigning ASA score, modified Rankin Scale (mRS-pre) and Charlson Comorbidity Index (CCI). From 12-15 months after treatment, functional evaluations were performed employing a second modified Rankin Scale (mRS-post) together with Neck Disability Index (NDI) and Smiley-Webster pain scale (SWPS). Radiological outcome was evaluated through dynamic cervical spine X-rays at 3 months and cervical spine CT scans 6 months after treatment. Three different conditions were identified: stable union, stable non-union and unstable non-union. Surgery was preferred whenever a fracture gap > 2 mm, an antero-posterior displacement > 5 mm, an odontoid angulation > 11° or neurological deficits occurred.

RESULTS

Among the 50 patients, 24 reached a stable union, while 26 a stable non-union. Comparing the two groups, no differences in ASA (p = 0.60), CCI (p = 0.85) and mRS-pre (p = 0.14) were noted. Similarly, no differences in mRS-post (p = 0.96), SWPS (p = 0.85) and NDI (p = 0.51) were observed between patients who reached an osseous fusion and those with a stable fibrous non-union. No effects of age, sex, ASA, mRS-pre, fracture dislocation and radiological outcome were discovered on functional outcome. At logistic regression analysis, female sex and high values of CCI emerged associated with worse NDI.

CONCLUSIONS

In geriatric type II odontoid fractures, pre-injury clinical status and comorbidities overcome imaging in determining post-treatment level of function. Hard collar immobilization led to a favourable functional outcome with mRS-post, NDI and SWPS values diffusely encouraging whatever a bony union or a fibrous non-union was obtained. These slides can be retrieved under Electronic Supplementary Material.