In vitro evaluation of a medial approach for intra-articular injection of the tarsometatarsal joints of horses.

This research report provides an evaluation of a new method for injecting the joint of the tarsometatarsal (TMT) in horses using a medial approach, assessing reliability, effectiveness, and potential risks. The team used radiography and CT scans to track the dispersion of the contrast medium, comparing it to a lateral approach with consistent results across professionals and students, and noted possible increased injury risk to veterinarians.

Objective of the Study

• The main aim of this study was to develop a reliable way of injecting the tarsometatarsal (TMT) joint of horses via a medial approach.
• This approach was also tested to evaluate its anatomical characteristics with the aid of computed tomography (CT).

Methods Used

• Thirteen pairs of freshly obtained equine cadaver tarsi were used in this experiment.
• The authors first assessed the TMT joints with radiography and CT.
• Twelve pairs of TMT joints were then chosen for injection with a contrast medium via a medial or a lateral approach. These injections were performed by an experienced veterinarian and a veterinary student.
• Post-injection, each TMT joint was reassessed with radiography and CT to evaluate the distribution of the contrast medium.
• The authors also compared the number of attempts it took to accomplish the injection for both the lateral and medial approaches, as well as between the two injectors.

Results and Conclusion

• The researchers found that all 24 TMT joints were successfully injected with the contrast medium, as confirmed through radiography and CT scans.
• They found no significant difference in the number of attempts it took to inject the contrast medium, whether it was done medially or laterally. The level of experience of the injector also didn’t make a significant difference.
• The distribution of the contrast medium in each synovial recess remained consistent regardless of whether the medial or lateral approach was used.
• The researchers thus concluded that this medial approach for injecting the TMT joint of horses is reliable, offering an alternative method that might be useful in clinical practice, though there might be an increased risk of injury to the veterinarian.