Successful closed reduction of an atlantoaxial luxation in a Dutch Warmblood gelding with long-term follow-up

Introduction: Atlantoaxial luxation is a rare condition in horses, due to a congenital malformation of the dens of C2 or due to trauma. Successful reduction has only rarely been reported. In this report we will present an approach, which has been successful in our case. Material and Methods: A 4-year-old Dutch Warmblood gelding was presented to the clinic with a painful stiff neck and an abnormal head-neck positioning after a traumatic ridding event. General clinical, neurological and radiographic examinations were performed. A closed reduction using a combination of traction and manual manipulation (in hyperextention) was initiated. And follow up radiographs were made after 1 day, 1 week, 2 months, 6 months, 1,5 years and 5 years. Results: The horse had a normal clinical and neurological exam. Radiographs showed a malalignment at the level of C1-C2, with the axis of C2 being displaced ventrally and a dorsal rotation of C1. After reduction a normal alignment of C1-C2 and a correct positioning of the dens were radiographically confirmed. Follow up radiographs show an increasing mineralisation cranio-dorsally of the dens. The horse has not shown clinical problems related to the atlantoaxial luxation and has been competing in 2* eventing competitions. Conclusions: The technique used in this case has not been described in literature. The manual manipulation in hyperextention allows reducing the linear traction needed to be able to reposition the dens of C2 in its normal position. Although no controls are available, this technique appears to be less traumatic for the spinal cord and the surrounding structures