Innervation and nerve injections of the lumbar spine of the horse: a cadaveric study.

This study provides a detailed exploration of the anatomical structure of the lumbar spine in horses, with a specific focus on its innervation. With this, the researchers aim to improve our understanding of back pain in horses and enhance the accuracy of ultrasound guided injections, for diagnosing and treating such conditions.

Objective and Methodology

• The ultimate objective of this research is to obtain a better comprehension of the innervation of the lumbar spine in horses. The researchers intend to use their findings to establish key anatomical features that could act as reference points for diagnostic or therapeutic injections under ultrasound guidance.
• As part of their methodology, the spinal structures of 8 mature horses were dissected. The researchers traced the branches of the dorsal rami (groups of nerve fibres) and recorded their anatomical relationship with certain structures, such as articular facets, interspinous structures, and muscles.
• They also sectioned the spines of three other horses transversely, performing dissections that would allow for identification of ultrasonographic landmarks for the nerves.
• On six other spines, the researchers tested the accuracy of ultrasound guided injections of the nerves using blue dye.

Findings and Conclusions

• Gross dissections provided confirmation of the dual segmental innervation of the articular facets. An articular facet is a small, smooth, flat area on a bone, typically for a joint or connecting two bones. The facets between pairs of lumbar vertebrae were each found to be innervated not only by the medial branch of the dorsal ramus located between the two vertebrae, but also by the branch stemming from the dorsal ramus above it.
• The research team observed that the medial branch split into two nerves before exiting the intertransverse space. They found discernable anatomical landmarks which could be identified using ultrasound.
• The technique of ultrasound guided injections, as tested by the researchers, was found to possess an accuracy level that would be beneficial in a clinical setting.
• The research concludes that the anatomical features of the medial branch of the dorsal ramus, as discovered in this study, can be leveraged as landmarks for reliable ultrasound-guided injections.
• Summarily, the value of the study lies in its potential applications for the development of diagnostic and therapeutic injection techniques in treating lumbar spine conditions in horses.