33rd Annual Scientific Meeting proceedings

Introduction
Surgeons use manipulation of a physis known as the neurocentral synchondrosis (NCS) in pigs as a model of scoliosis in children. Transphyseal bridging of the NCS results in scoliosis and narrowing of the spinal canal/stenosis. Spontaneous growth disturbances of the NCS may therefore also be relevant to equine wobbler syndrome. The aim was to describe the computed tomographic (CT) closure times for all physes in the equine cervical spine. 

Materials and Methods
The cervical spine of 34 foetuses and foals from 270 days gestation to 438 days old was examined postmortem using CT. The mid-dorsal physis, left and right NCS, cranial and caudal vertebral body physes were scored on a scale from 6: fully open to 0: fully closed. 

Results
The NCS of C2-C7 was closed in foals ≥93 days old, whereas the NCS of C1 was closed at ≥115 days. The mid-dorsal physis closed earlier and the cranial and caudal vertebral physes closed later than the NCS. Vertebral growth closed in the following order: C7, C6, C4, C3, C5, C2, C1. 

Discussion/Conclusions
This study represents the first systematic description of the NCS in horses. In pigs, the NCS is responsible for growth of the dorsal third of the vertebral body and the spinal canal, including the cervical articular process joints. Growth disturbances in the NCS have the potential to explain both spinal stenosis and articular process joint arthropathy implicated in wobbler syndrome. Further knowledge of the NCS could lead to future interventions during active growth, limiting stenosis development.