Comminuted Fractures in Cats

While common in all animals, comminuted fractures are seen more often in cats since their bones tend to be weaker compared to other animals. There are no breed, sex, or age predispositions for comminuted fractures.

Comminuted fractures occur when a bone fractures in three or more places, with the fracture lines connecting or intersecting at a point. These types of fractures are typically associated with severe trauma, such as falling from a significant height or getting hit by a car. Comminuted fractures are considered more difficult to treat than other fractures, since they destabilize the bone. 

Fractured limbs, particularly comminuted fractures, can cause tremendous pain and stress for your cat. In some cases, they may be life-threatening as fractures in certain locations can cause internal hemorrhaging. Seek immediate veterinary attention if you notice any of the following symptoms:

• Limping or lameness
• Holding up the fractured limb
• Swelling
• Signs of pain
• Changes in behavior
• Hiding
• Shock
• Fever

Other symptoms associated with hemorrhaging may also be present, such as:

• Pale gums 
• Weakness
• Difficulty breathing
• Enlarged abdomen

The primary cause of comminuted fractures in cats is trauma, especially severe trauma. Comminuted fractures are classified as complete fractures, in which the entire bone has broken into separate pieces. Accidents are usually responsible for these kinds of breaks, although cats have a higher chance of experiencing comminuted fractures than other animals due to their brittle bones.

Your vet will be able to make a tentative diagnosis based on a thorough physical exam and presentation of symptoms. Be sure to inform your vet of your cat’s current medications, any previous bone fractures or injuries, and any recent traumatic events that you know of.

Your vet will make a tentative diagnosis by taking an x-ray of the affected limb or area. Your vet may administer an oral pain medication – or, in some cases, a mild sedative – to soothe the pet during the x-ray. During this time, your vet will also ensure that the break has not caused any internal hemorrhaging or other damage. Additional diagnostic methods may include blood tests, chest x-rays, and ultrasounds.

Treatment will vary based on the location and type of fracture as well as the cat’s age and overall health. Comminuted fractures may be open or closed; an open fracture is one in which the broken bone has punctured the skin or soft tissue, while closed fractures do not pierce the skin or muscles. Treatment methods for open and closed fractures differ. Closed fractures are more straightforward. These should be treated within two to four days with an externally placed splint or cast, but may also be repaired using internal fixation.

Treatment for open fractures is more invasive as there is a risk for bone contamination due to its exposure to the environment. Open fractures are generally treated with two surgical methods. The first is done within eight hours of the initial visit in order to clean the bone. During this time, your cat will be anesthetized and the wound will be flushed and may be treated with antibiotics to eradicate infection. The final surgery to repair the fracture may take place up to 48 hours later.

Simple open fractures – e.g. those that do not cause muscle or tissue damage after the initial surgery – may be treated by internal fixation. This will involve surgically restructuring the bone internally using fixative devices such as plates and screws. Complex open fractures that cause muscle damage or cannot be restructured may be treated with external skeletal fixation. During this procedure, your vet will externally apply a metal bar affixed with pins that thread through the fracture. The most severe cases of comminuted fracture may require amputation.

Please note that these treatment methods may vary depending on the veterinarian, the severity of the fracture, and your financial preferences. Your vet will be able to advise you on a treatment method based on your cat’s situation.

Recovery and prognosis are generally good following treatment. Always follow your vet’s post-treatment and/or post-operative instructions carefully. On the return home, ensure your cat has a warm, safe place to rest. It may be a good idea to confine them to a small space in order to restrict movement and promote healing. Never allow your cat to irritate the surgery site.

The veterinary surgeon may place a bandage on the surgery site for three to four days following surgery. It is imperative that you do not remove the bandage until instructed to do so by your vet; cats have a high chance of experiencing post-operative swelling, which can cause further complications. After the bandage is safe to remove, you may be able to help to relieve swelling by gently massaging the area. However, you’ll want to ask your vet if this is appropriate for your cat’s specific fracture and treatment method.

Your vet will schedule follow-up appointments every four to six weeks. During these appointments, your vet will take x-rays to monitor healing and evaluate stability. If you notice any swelling, signs of infection, or other complications following surgery, contact your vet immediately.