Ultrasound-assisted injection of the centrodistal joint in the horse.

BACKGROUND Injection of the centrodistal (CD) joint in the horse is a commonly performed procedure for both diagnostic and therapeutic purposes. This procedure can be technically challenging, and while radiographic guidance has been previously used, ultrasound localised injection of the CD joint has not been described. OBJECTIVES The purpose of this study was to explore the feasibility of using ultrasound localisation to increase the accuracy of CD joint injection. STUDY DESIGN Experimental method assessment. METHODS One operator performed the ultrasound and injection of 24 CD joints in 12 sedated horses. The joints were injected with iohexol (2 ml), sterile saline (1.5 ml), and amikacin (0.5 ml). Dorsoplantar and dorsomedial plantarolateral radiographic projections were obtained immediately after injection to evaluate the presence of contrast material in the CD joint. RESULTS The CD joint was successfully injected in 17/24 joints, representing a 70.8% accuracy. MAIN LIMITATIONS The horses used in this study were from the University research herd, and not clinical cases. One investigator performed all the ultrasonography and CD joint injections. CONCLUSIONS The use of ultrasound localisation could improve success of CD joint injection as well as improve the learning curve of less experienced practitioners learning this procedure.