Surgical Management of Traumatic Atlanto‐Occipital Instability in a Dog

Abstract

An unusual case of atlanto‐occipital instability resulted from traumatic disruption of the lateral atlanto‐occipital ligament and fracture dislocation of the dens in a 13‐month‐old male Basset Hound. Initial treatment was traction‐immobilization splintage followed by decompressive dorsal laminectomy of the atlas. Wiring the wing of the atlas to the base of the occipital condyle provided lateral, rotational and dorsoventral stability of the atlanto‐occipital articulation.

Dorsal surgical stabilisation using tension bands for treatment of traumatic atlanto‐occipital instability in a cat

“…To the authors’ knowledge, traumatic AO luxation with survival has been reported in only eight dogs and one cat . The most common cause of dislocation is road traffic trauma, which was the cause in the case of the cat reported previously.…”

“…AO luxation usually results in significant neurological injury with non‐specific clinical signs. In previous reported cases, gait dysfunction was present: ataxia, hemiparesis, tetraparesis and tetraplegia . Spinal reflexes were always increased.…”

“…Anisocoria, transient nystagmus and lingual paresis were also reported. In the human literature, it is reported that trauma causing AO luxation can consequently cause brainstem lesions that result in cranial nerve deficits …”

“…Surgical decompression by enlargement of the foramen magnum of the occipital bone was performed before applying the cervical splint in one case . Multiple surgical options have been proposed: decompressive dorsal laminectomy of the atlas and wiring a wing of the atlas to the base of an occipital condyle; ventral AO arthrodesis performed with a transarticular lag screw associated with a dorsal band between the occipital protuberance and the spinous process of the axis . In the present case we performed dorsal reduction of the AOI using two divergent tension bands between the nuchal crests of the occipital bone and the spinous process of the axis without AO arthrodesis.…”

Tetraparesis, Hemiparesis, and Ataxia

“…[266][267][268][269][270] The luxations can be managed with conservative therapy in which the luxation is manual reduced and a cast with the neck in flexion is applied or with surgical stabilization. Traumatic luxations of the occipitoatlantal articulation are rare.…”