X-rays can help us see what’s inside the foot!
Motion Equine Podiatry Consulting
X-rays are not a new technology. They have been around since the late 1800’s. The concepts are the same, however as the world has become more digitalised, x-rays have become an important part of veterinary practice. Instead of taking an x-ray and driving back to the clinic to process, the x-ray is displayed instantly on a computer screen. From there we can examine many different parts of the horses anatomy. When it comes to foot related lameness, x-rays and the measurements that can be performed are very helpful for both the vet and farrier. X-rays also help the horse owner to see what is beneath the hoof capsule.
What can foot x-rays tell us?
X-rays are great at imaging bone and the hoof capsule, not so great for soft tissue such as tendons and ligaments. The bones within the foot are; the pedal bone, the navicular bone and the short pastern bone. We can take different views of the foot to highlight each of these bones. Some bone related conditions that we can see on x-ray include fractures, changes associated with osteoarthritis of the coffin joint and damage to the surface of the pedal bone from disease processes such as laminitis.
The hoof capsule can also be easily seen on x-ray. Importantly, the pedal bone can be seen in relation to the hoof capsule. This gives us the understanding of how the foot is growing and the overall conformation of the foot. This is particularly important in cases of mis-matched foot conformation and laminitis. Mis-matched foot conformation is when a horse has one upright or club foot and one flat or long toe low heel foot. Every horse has a mis-matched foot conformation. That means every foot is slightly different from the opposite foot, however the degree of difference varies.
In the case of laminitis, x-rays are invaluable. It allows us to determine how close the pedal bone is to the ground surface and how the hoof is growing. We can see how much the lamellar attachment has been damaged. These findings are really important when discussing the ongoing management plan and the overall prognosis for the case.
Hoof measurements brought to life
The above video demonstrates some of the measurements we can perform when examining foot x-rays. These measurements include;
- Solar depth – the distance from the bottom of the pedal bone to the shoe or ground surface (if barefoot)
- Hoof wall width – distance from the front of the pedal bone to the outer limit of the hoof wall. This is particularly important for measuring lamellar damage in laminitis cases
- Coronary band to extensor process – measuring from the coronary band to the top of pedal bone. Is this important when taking x-rays of the foot on consecutive days in early stage laminitis
- Centre of rotation of coffin joint – used to determine where the hoof capsule is in relation to the coffin joint. This is important in cases of coffin and pastern osteoarthritis (high and low ringbone)
- Toe to heel length ratio – important when discussing changes in break-over of the hoof capsule
- Hoof wall angle – used to help determine differences in hoof conformation, important in cases of mis-matched hoof conformation
- Boney column alignment – can be described as aligned, broken forward or broken back. Broken forward occurs in moderate to severe club feet, whereas broken back typically occurs in horses with an upright pastern conformation
- Palmar angle – the angle of the bottom of the pedal bone in relation to the shoe or ground surface. The palmar angle is linked to the solar depth. It can be described as zero, positive or negative.
Start the conversation
Chat to your vet and farrier about x-raying your horse, especially if it has a foot related lameness. Foot x-rays can also be performed on a routine basis to monitor how the hoof grows over the shoeing or trimming cycle. This is also useful in finding early changes before they become an issue.
To help in the process of interpreting foot x-rays in relation to the history of the horse, Dr Luke Wells-Smith provides an online consultation service. Luke will look through all the information provided and x-rays, as you can see, give him a lot of information about the case. From there, Luke can recommend an ongoing management plan. If you have a case, please contact us today.