Abstract
Objective The aim of this study was to describe the anatomy of the nerves supplying the cervical
articular process joint and to identify relevant anatomical landmarks that could aid
in the ultrasound-guided location and injection of these nerves for diagnostic and
therapeutic purposes.
Study Design Twelve cadaveric equine necks were used. Five necks were dissected to study the anatomy
of the medial branch of the dorsal ramus of the cervical spinal nerves 3 to 7. Relevant
anatomical findings detected during dissections were combined with ultrasonographic
images obtained in one other neck. Six additional necks were used to assess the accuracy
of ultrasound-guided injections of the medial branch with blue dye.
Results Each examined cervical articular process joint, except for C2 to C3, presented a
dual nerve supply. The articular process joints were found to be in close anatomical
relationship with the medial branch of the dorsal ramus of the cervical spinal nerve
exiting from the intervertebral foramen at the same level, and with the medial branch
of the dorsal ramus of the cervical spinal nerve exiting from the intervertebral foramen
one level cranial to the articular process joint of interest. A total of 55 nerves
were injected under ultrasonographic guidance, 51 of which were successfully stained.
Conclusion The current study provided new detailed information regarding the innervation of
the cervical articular process joint. The medial branches of the dorsal rami of the
cervical spinal nerves were injected with an accuracy that would be of clinical value.
Our study offers the foundations to develop new diagnostic and therapeutic techniques
for pain management in cervical articular process joint arthropathy in horses.
Keywords equine - medial branch block - articular process joint - neck osteoarthritis - perineural
injection
