Navicular Bone
Fracture of the navicular bone
Fractures of the navicular bone cause a sudden, severe lameness that improves rapidly after a couple of weeks box rest. The cause is usually external trauma.
Diagnosis
Radiographs are required for diagnosis.
Treatment
The only way for the fracture to heal is by surgical fixation, however, long-term box rest can occasionally result in soundness. In some cases the palmer digital nerves are cut to relieve the pain.
Navicular syndrome
Navicular syndrome is the most commonly diagnosed chronic forelimb lameness and can involve many structures in the region of the navicular bone. These are th navicular bone, the coffin joint, the navicular bursa, the deep digital flexor tendon and associated ligaments.
Signs
Navicular syndrome is most commonly seen in 6-12 year olds and affected horses show a reluctance to do hard work and a short strided gait. Horses have an intermittent lameness, often only seen initially in one limb, which is worse on the hard ground. X-ray of a navicular bone
Diagnosis
Nerve blocks, radiographs and in some cases MRI are required to diagnose navicular syndrome.
Treatment
There is usually no cure for navicular syndrome, however, there are many options to help manage the condition. Corrective farriery can be of great help by either shoeing with a rolled toe and raised heal or using an egg bar shoe. Pain relief such as phenylbutazone (‘bute’) is often used as required to keep horses comfortable. There are surgical procedures available to either desensitize the area, palmer digital nerve neurectomy, or reduce the forces applied to the area, check ligament or suspensory ligament desmotomy.