An in vitro study to compare 5 different techniques for injection of the navicular bursa in the horse.

Numerous different techniques for injection of the navicular bursa have been described but there is little conformity between these descriptions. A literature review was performed and techniques for injection of the navicular bursa were categorised into 5 approaches. This study was performed to evaluate the reproducibility of each technique and to assess which technique was consistently most successful. Five inexperienced operators performed each technique on 5 cadaver forelimbs. Once a needle had been placed, a radiograph was taken to confirm placement was in accordance with the description of the technique. Contrast agent was then injected and another radiograph taken to determine whether the navicular bursa had been injected successfully. The position of the navicular bone was highly predictable as a point 1 cm distal to the coronary band and halfway between the most dorsal and most palmar aspect of the coronary band. The use of this point as a landmark for injection of the navicular bursa allowed a high degree of accuracy and reliability of needle placement, irrespective of foot conformation.