Thursday, August 19, 2010
COW: Navicular Bursa Injection
Here is an interesting radiograph from the other day. This x-ray shows the proper placement of a spinal needle into the navicular bursa. Because the target area is so deep within the foot, it is best (though not always necessary) to confirm proper placement with a radiograph. The navicular bursa is a little sack of fluid around the deep digital flexor tendon at the level of the navicular bone. It serves to lubricate the tendon as it glides over the navicular bone. This is the area of discomfort in horses with navicular disease. Other structures associated with this bursa, aside from the navicular bone, could also be a source of lameness.
Navicular bursa injections are not our first choice for treatment of navicular disease, but in cases that are refractive to other treatments, this can be a highly effective method of delivering anti-inflammatory medication directly to the source of discomfort.
The most significant potential complication with navicular bursa injections is the risk of infection. We go to great measures to do this under sterile conditions, however, anytime we stick a needle in to something the risk for infection is present. The problem with the navicular bursa is that, if it gets infected, it is much more difficult to treat then a regular joint, because of where it is anatomically within the hoof capsule. The other risks are damage to the deep flexor tendon. Because of those risks, it is not something we jump right to, but in certain situations, it can be the best option.