Successful Nonsurgical Management of a Traumatic Dens Fracture in a Cat with Clinical and Radiographic Resolution

ABSTRACT An adult domestic shorthair presented with obtundation, vestibular ataxia, head tilt, and visible evidence of facial injury following motor vehicle trauma. Plain radiographs and computed tomography imaging revealed a complete minimally displaced transverse fracture of the caudal aspect of the dens of the C2 vertebra and multiple minimally displaced cranial fractures. The dens fracture was managed with 8 wk of strict rest, followed by 4 wk of supervised activity at home. No external immobilization was performed. Neurological examinations at 8 days, 10 wk, and 9 mo following initial presentation were normal. Repeat radiographic and computed tomography examinations at 10 wk and 9 mo following the traumatic event demonstrated progressive and eventual complete osseous union of the fractured dens. To the authors’ knowledge, this is the first report of successful nonsurgical management of a traumatic dens fracture in an adult cat with documented radiographic and clinical resolution. This report suggests that nonsurgical management can be considered in such cats and that complete resolution with osseous union is feasible.

Incomplete ossification of the atlas in cats: seven cases detected on computed tomography

Defects of the ventral arch of the atlas were detected on computed tomography in nine cats aged 3…12 months with signs of upper cervical injury including paina and ataxia. Seven cats have an ambulatory tetraparesis, and two cats have a nonambulatory tetraparesis. The bone defects were consistent with the normal location of the ventral arch growth areas of the atlas. In all observed cats, the pattern of ossification abnormalities was similar — the lateral portion of the arch was completely absent in seven cats on the left and in two cats on the right. The structure of the ventral tubercle was traceable in 8 of 9 cats. Also, in 8 of 9 cases an isolated bone fragment was observed lateral to the dens of the axis, the exact origin of which was not determined. This fragment was observed in 6 cases on the right, in two cases on the left, and only in two cases it corresponded to the side of the undeveloped arch. In 7 out of 9 cats, the dorsal arch was not fused; in 2 cats with complete fusion, the dorsal arch was deformed. An dens fracture was visualized in 3 cases, no hypoplasia of the dens was visualized, and one cat have atlantoaxial subluxation. Seven cats received conservative treatment and 2 cats received surgical treatment. Clinical improvement was observed in all cats. Disorder the ossification of the ventral arch of the atlas should be considered as the differential diagnosis in young cats with suspected atlanto-axial instability and trauma of the cervical spine. The authors were unable to find publications describing this atlas developmental abnormality in cats, so the authors believe that this is the first mention of incomplete ossification of the atlas in cats.

Association between Cervical Spine Degeneration and the Presence of Dens Fractures

Purpose Results of a small case series indicate an increased risk of dens fractures in patients with osteoarthritis. The purpose of this retrospective cohort study was to analyze the relative risks associated with degeneration of the cervical spine in the occurrence of dens fractures in older patients. Methods We performed a retrospective CT study of 1,794 patients > 55 years of age with and without dens fractures for signs of osteoarthritis (OA). Results OA of the atlanto-dens interval (AdI) was present in 75.9% of fracture patients, whereas 63.5% of non-fracture patients had OA of the AdI (p = 0.04). In cases of osteoarthritis of the facet joints, we did find a significant increase (p < 0.05) in the dens fracture risk in patients with OA. Conclusions This study indicates an association between OA of the cervical spine and the risk of sustaining a dens fracture. OA can lead to a reduction in the range of motion of the cervical spine. As a consequence, a relatively low-energy trauma can induce a forced sagittal motion, which will produce a torque at the base of the odontoid process resulting in a fracture.