Navicular bursa injections can both help and hurt. The help they offer with diagnosing problems with this cushion between the navicular bone and the deep digital flexor tendon, and treating pain in the same area is offset by a risk for damage and infection. Colorado State University (CSU) researchers have been examining whether there’s a better way to conduct this important procedure.

Alexander Daniel, MRCVS, and CSU colleagues described disadvantages posed by the traditional, or palmar, approach and made recommendations for an alternative at the 2013 American Association of Equine Practitioners’ Convention, held Dec. 7-11 in Nashville, Tenn.

The main drawback to the palmar method, he explained, in which the veterinarian accesses the bursa from the back of the pastern—is that the needle must penetrate the deep digital flexor tendon (DDFT). This risks damaging the tendon, especially if the injection is repeated on several occasions.

Problems can also arise if the veterinarian needs to aspirate bursal fluid to check for infection: He or she could inadvertently cause infection if entering the structure through an infected or contaminated wound.

Daniel used radiographs (X rays) and MRI to identify a way to bypass the DDFT and other critical structures on the way to the bursa. He found that by injecting the bursa through the lateral aspect (outside) of the limb using radiographs to guide the needle placement, veterinarians can avoid DDFT puncture while still accessing the bursa. He also noted that the team determined they could aspirate bursal fluid more consistently with the new approach than when the bursa is approached from