Arthroscopic approach and intra-articular anatomy of the equine atlanto-occipital joint.

The research article explores arthroscopic methods to study the atlanto-occipital (A-O, the joint connecting the head and the spine) in horses, both in dissection studies and a clinical case. The paper highlights that digital imagery plays a crucial role in diagnosing joint pathologies and performing surgical interventions.

Method

• The study was performed on ten horse joint cadavers and one clinical case of a two-week-old foal suffering from septic arthritis.
• Arthrograms were conducted on eight A-O joints using CT scan technology to establish the suitable location for an arthroscopic portal.
• Arthroscopy was carried out through either dorsal (back) or ventral (front) approaches, i.e., dorsal or ventral to the large spine muscle – longissimus capitis tendon.
• A portion of accessible cartilage was eliminated in three cadaver joints.
• The researchers gauged the feasibility and potential risks by reviewing arthroscopic images, carrying out postoperative necropsy, and using computed tomography (CT).

Results

• The researchers found out dorsal and ventral pouches of the A-O joint with the help of CT scan technology.
• The dorsal pouch arthroscopy provided access to roughly 50% of the dorsal cranial occipital condyle and 15% of the dorsal cranial atlas articular surfaces.
• Distension of the joint caused the displacement of the dura, the protective membrane covering the brain and spinal cord.
• In two of five joints, the researchers observed a blind dorsal approach caused perforation of the dura.
• No perforation occurred when using ultrasound-guided approaches.
• A successfully executed arthroscopic debridement (removal of damaged tissue) of septic arthritis and osteomyelitis was carried out in the clinical case.

Conclusions

• Based on CT examinations, researchers developed approaches to the A-O joint.
• The dorsal pouch of A-O joint, specifically its cranial aspect, was accessible via arthroscopic triangulation in all the horses in the study.
• Using ultrasound guidance while accessing the joint helped in preventing perforation of important structures, including the spinal canal.
• Employing advanced imaging techniques greatly assists in diagnosing pathologies of the A-O joint. The paper’s provided descriptions of arthroscopic anatomy and accessibility offer imperative data for surgical intervention.