Just like in dogs, the stifle joint (knee) in cats is made up of 4 ligaments to help movement and prevent excessive rotation of the joint. The 4 ligaments are two collateral ligaments (either side of the joint) and two inside the joint itself called Cruciate ligaments. They are so called because they go over each other forming a cross shape. These ligaments attach the tibia (shin bone) to the femur (thigh bone). And, if damaged, can be torn fully or partially damaged. So, yes, cats can have cruciate ligament injuries, just like dogs. But as for surgery – that’s a little more complex.

In cats, the damage to the cruciate ligament is usually due to trauma, and other reasons are rarely the cause. It could be from jumping and landing awkwardly when outside, so you may not have seen the original injury being caused and may just see the resulting signs. 

Diagnosis

You may have noticed your cat limping on their back leg suddenly and not able to use it properly. There may be some swelling noticeable also. 

Once your cat is seen by your vet, they will perform an examination. This includes feeling the stifle joint and moving the bones of the leg to see if the ligament is damaged. Sometimes it is not clear on examination whether there is damage. And so further investigation may be advised, such as radiographs (x-rays) of the leg, under sedation or general anaesthetic, to assess further. 

Treatment – Medical

Medical treatment can also be called conservative treatment and is usually the first option for cruciate ligament damage in cats. It involves weight management, exercise control, supplements and medications such as non-steroidal anti-inflammatories. Weight management is important if your cat is overweight, as excess weight causes extra pressure on the joints making it harder to move. Weight control is often in the form of a diet food that helps to keep your cat full for longer. 

Non-steroidal anti-inflammatories are a form of pain relief and help to reduce the inflammation inside the joint. They must be given with food as they can cause stomach upset otherwise. Restricting exercise initially, and then gradually increasing it in a controlled way is important; as it helps build up muscle tone which is vital to give support to the bones. 

As cats are small and agile, often medical treatment works well, but in some surgery may be required.

Treatment – Surgical 

Surgery may be needed for any cats that do not respond to medical treatment; or those that have a very unstable leg due to severe trauma. There are a few surgical options, the first being a suture (stitch), almost as a prosthetic ligament, made from strong material such as nylon.

Very few complications are seen with it but, rarely, the suture can break over time and then your cat will become lame as before. However, this is more often seen in larger dogs. 

There are a few different surgeries involving cutting the bone and placing metal plates to stabilise. TPLO (tibial plateau levelling osteotomy) is one surgery that is used commonly in dogs, but less so in cats. It involves changing the angles in the joint, meaning your cat doesn’t have to rely upon the damaged ligament to walk. There are also two other surgeries that are not commonly used for cats but if they are applicable to your cat, your vet will discuss them with you in detail. 

Possible surgical complications

Infection is a complication that can be seen in patients following surgery of any kind. The majority will respond to antibiotics, but a small portion may require removal of the metal at a later date. A very low percentage of cats will get a late injury of the cartilage in the joint (meniscal) (although this is more common in dogs). And this may require just medication or surgery to remove the cartilage. 

Costs

Almost any orthopaedic surgery is expensive, and cruciate repairs are no exception. This is one reason why pet insurance is invaluable. It’s a rare injury, but if it doesn’t respond to conservative medical treatment, surgery is complicated and expensive.

Post operative care

Your cat will go home on pain relief medication and with instructions for you to check the wound daily for any sign of swelling, discharge or heat. Your cat may have a buster collar (plastic cone) around their neck to prevent them from getting to the wound and licking it. You will be instructed to stick to an exercise restriction schedule initially, and then slowly increase the exercise over time. Having a large dog crate to keep your cat confined and prevent them from injuring themselves is also advised. 

Outcome

A good outcome is expected in 90% of cats, so the majority of cats will return to completely normal following treatment. 

If you notice your cat limping or not using their back leg properly then it is important to visit your Vet for a clinical examination and assessment. They will advise you on the appropriate next step for your cat and the sooner treatment is started the sooner your cat will be back to normal. 

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