Hip Dysplasia
What is hip dysplasia?
The bones of the hip joint are the head of the femur (the ball) and the acetabulum of the hip (the socket). Hip dysplasia occurs when the acetabulum is not as deep as expected. In other words, the socket is shallow compared to the ball and it’s easier for the ball to slip out. If it’s hard to imagine how the shape of the hip joint and the likelihood of the bone slipping out of place are related, imagine you have 2 bowls and 2 balls that fit just inside the rims of the bowls. Your first bowl is deep, perfect for cereal & milk. You poke the ball from the side, then push it harder and harder, trying to knock it out of the bowl. You’ll probably end up knocking over the bowl by the time the ball comes out. Your other bowl is wide and shallow, the kind you might use for salad so you can get a nice, even spread of dressing. You poke the ball a bit and it wiggles. You push it a few times and the ball eventually pops up and out of the bowl, leaving the bowl unharmed. A hip with dysplasia is like ball and bowl #2, with the force of daily activities acting as the force from the pokes or pushes. A hip with dysplasia is more likely to dislocate with activities like jumping, running, or even walking in more severe cases. The hip helps hold you up, so it’s super important to make sure this joint is stable!
Image A is closer to what is usually expected for normal hip development. Image B demonstrates what a hip with dysplasia might look like. Try to imagine jumping with each of these hips and how the force of landing might push a ball out of its socket or how a socket might hold its ball in. Image C is a rough representation of hip subluxation, when the ball starts coming out of the socket. Image D shows a hip dislocation, when the ball is completely out of the socket.
"File:Hip dysplasia - schematic.jpg" by Original uploader was Londenp at nl.wikipedia is marked with CC BY-SA 3.0.
How does physical therapy help?
PT can come into the picture in a couple of ways here. First, PTs can often treat people with mild hip dysplasia by helping them develop an excercise plan that focuses on strengthening the muscles that help hold the head of the femur in the acetabulum. This can be achieved in a variety of ways and a PT will help determine which exercises should be the safest and most effective. A physical therapist can also advise individuals on how different extracurricular activities or movements might be impacted by their hip dysplasia. For example, a high schooler interested in sports may be less likely to experience a dislocation with one kind of sport over another. Or an older adult may experience symptoms less frequently by changing the way they hold their body when walking up and down the stairs.
If someone has moderate to severe hip dysplasia, they should work with their primary care provider to determine the best course of action. This might involve a hip brace, hip cast, or surgery, among other options. It depends a lot on the age of the person, their medical history, their desired level of activity, their financial or social situation, and many other things.
"Child laughing" by cheriejoyful is marked with CC BY 2.0.
So why is this post in pediatrics?
While it is not uncommon for adults to have hip dysplasia, more severe cases tend to be caught during routine check-ups in a child’s first year of life. People with mild cases can live out their entire lives not even knowing because their actvities and movements are not impacted. Mostly because of these factors, treatment for hip dysplasia frequently begins during childhood.
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