Injecting the coffin joint for navicular

Quick facts

Injecting the coffin joint with triamcinolone acetonide (TA) is a good way to deliver TA to the navicular bursa for horses with navicular syndrome.
No studies have been done to show what level of TA is needed to control pain in the joint or bursa.

Internal anatomy of the horse hoof including coffin joint, coffin bone, hoof wall, navicular bursa and navicular bone. — Internal anatomy of the horse hoof

X ray image of horse hoof showing needle placement in the navicular bursa. — X-rays confirm needle placement in the navicular bursa.

Navicular syndrome commonly causes lameness in horses. Veterinarians often treat this syndrome with a coffin joint injection. This injection usually consists of the following.

Triamcinolone acetonide (TA), a corticosteroid
Sodium hyaluronate (HA)

Injecting the coffin joint relieves lameness in many cases. Some suggest injecting the corticosteroid into the navicular bursa can have better results. This type of injection is harder and requires x-rays to correctly place the needle in the bursa.

Testing injection sites

The goal of the study was to see if injecting TA into the coffin joint is a good treatment for horses with navicular syndrome.

Part one: horses without foot pain or navicular syndrome

Needle being placed to obtain bursal fluid.

The horses tested in the first part had no foot pain or navicular syndrome. One forelimb coffin joint was injected with TA and the other forelimb coffin joint with TA and HA. One hindlimb was a control limb to see if TA passed into the bloodstream. Navicular bursa fluid samples were taken six hours after injection.

Results

TA was present in all bursal samples, while TA levels in the front limbs were much higher than the hind limbs. This means TA did travel through the bloodstream but mainly stayed near the injection site. There wasn’t a difference in TA levels between the front legs despite the presence of HA in one limb.

Part two: horses with navicular syndrome

The horses tested in the second part, had clinical and x-ray signs of navicular syndrome. Both front coffin joints were injected with TA and the same fluid samples were taken as in the first study. X-rays were scored for severity of navicular changes.

Results

TA moved from the coffin joint into the navicular bursa in all of the horses with navicular syndrome. The severity of radiographic changes was not significantly associated with amount of TA found in the front limb bursal fluid samples.

This work was supported by grants from the AQHA, the University of Minnesota Equine Center, College of Veterinary Medicine, and University of Minnesota with funds provided by the Minnesota Racing Commission, Minnesota Agricultural Experimental Station, and contributions from private donors.

Mary Boyce, DVM ACVS Surgeon; Jane Manfredi, DVM formerly with the University of Minnesota; and Erin Malone, DVM

Reviewed in 2018