Capital Physeal Dysplasia
Hi! Thanks for reading! Today we are going to discuss a condition called Capital Physeal Dysplasia – a cause of hip injury in cats. Let’s break that name down, since it is certainly quite a mouthful.
- Capital: this comes from the Latin caput for “head.” This refers to the head of the femur.
- Physeal: this comes from Greek for “to grow.” This refers to the growth plate near the head of the femur.
- Dysplasia: this is a compound word with Greek roots meaning “abnormal growth or development.”
So, Capital Physeal Dysplasia means that there is abnormal development of the growth plate of the head of the femur.
What does it look like?
Capital physeal dysplasia most commonly affects neutered male cats, around 1.5 to 2 years of age. This population of cats has the slowest growth plate closure, meaning that they are at risk for growth plate injury for a longer time than other cats. As they continue to grow in size (often these cats are obese too!) their growth plates are subjected to forces higher than they can withstand. Even normal activity like playing around home can cause injury. This injury is in fact a fracture of the growth plate of the femur. Radiographs (“x-rays”) can show the fracture, although it may require extra views and most cats will need sedation to get good radiographs.
Many cats can still walk despite this injury, but they will have a definite limp or lameness. If both hips are affected at the same time, it can be challenging to see a lameness sometimes. But you may notice that your cat is less willing to jump, or is crankier than normal, or seems uncomfortable when you handle him. Check out the resources tab for Pain Scales for Cats. Or head over to the lesson on Signs of Pain.
How is it diagnosed?
Diagnosis is based on signalment (age, sex, reproductive status), history, and radiographs. As mentioned above, this condition may require sedation to get good radiographs because the necessary x-ray images may be painful to obtain.
Can it be treated?
If you read the last lesson on hip dysplasia in dogs, you remember a short description of a surgery called Femoral Head Ostectomy. This is the most common treatment for capital physeal dysplasia. In this surgery, the head and neck of the femur are removed – thus removing the instability and bone-on-bone contact that leads to pain. The muscles of the pelvis and thigh take over the duties of the hip joint. Cats do great with this surgery, as long as they are assisted through the rehabilitation process. As you can imagine, physical rehabilitation with a cat can be challenging but veterinarians certified in rehabilitation like Dr Rushing can help create a plan that maximizes your cat’s recovery.
Another surgical option is the placement of pins across the fracture to stabilize the growth plate until it heals. This options is not as commonly performed because it works best when performed within 3-4 days after the injury. Cats, being the trixy creatures that they are, often don’t make it apparent when they are injured and thus days or weeks can pass before the injury is diagnosed.
What does recovery look like? How do you keep a cat still after surgery???
Recovery from a Femoral Head Ostectomy (FHO) is actually much easier than after most orthopedic surgeries. The goal of FHO recovery is: GET THEM MOVING. Because the muscles are taking on the duties of the hip joint, it is important to keep them stretched and strong. If rehabilitation is not undertaken immediately in the days following the procedure, the muscles can tighten – reducing your pet’s range of motion and making activities like climbing or jumping much more difficult.
In the first few days after surgery, your cat should be encouraged to walk around the home. This can be done by encouraging with food, toys, or affection. As your cat becomes more comfortable with walking, challenges can be added in the form of less stable surfaces (cushions, dog beds, mattresses, etc) and obstacles (toys, boxes, other things the cat must walk over or around.) Once these challenges are mastered, you can start having more fun with jumping, stretching high to reach things, and playing with laser or chase toys. Before you know it, your dear kitty can be back to his pre-injury activities.
What happens if you don’t do anything? Or what if you adopt a cat that had this injury a long time ago?
Ideally this injury is treated as soon as possible. Unfortunately, it is not uncommon that a cat can compensate well enough that the injury is not identified for an extended period. With enough time, the fractured growth plates may heal on their own. However, there is significant pain during the healing process and likely there will be chronic pain associated with arthritis. During the healing process, there is often significant loss of muscle mass in the hind end as well, which can have a big effect on a cat’s mobility.
Don’t despair! Even with an old injury, there are ways to help. Radiographs can help determine if surgery can help decrease discomfort. Pain medication, acupuncture, laser, and rehabilitation can help decrease discomfort and increase strength.