Do people with cerebral palsy have an increased risk of hip dislocation?
Cerebral palsy is a motor disability that is primarily characterized by irregular muscle tone, which can place quite a bit of strain on the joints.
In this article, you’ll discover why so many individuals with cerebral palsy experience hip dislocation, and how to effectively prevent hip problems from negatively influencing quality of life.
Cerebral Palsy Hip Problems
The hip allows the leg to move in many different directions (planes). It can move forward and back (like during walking), side to side (like when walking sideways or crossing the legs), and rotate inward and outward (pigeon toeing or out-toeing). With more movement planes comes less stability. For comparison, the knee joint can only move in one plane (bending and straightening), making it a much more stable joint.
This is why it is much easier for the hip joint to be displaced or even dislocated than a less mobile (and consequently more stable) joint, such as the knee. Additionally, this is part of the reason that hip problems are so common in children with cerebral palsy.
The hips are a ball-and-socket joint. The socket is the concave part of the pelvis called the acetabulum, and the ball is the head of the thigh bone (or femur). Hip dysplasia describes when the ball and socket aren’t a perfect fit.
Subluxation is when the ball is displaced and not secured but still within the socket.
Hip dislocation is when the ball moves out of the socket altogether.
Cerebral palsy related hip problems usually progress from hip dysplasia to subluxation to dislocation.
How is Hip Dislocation Related to Cerebral Palsy?
Children with cerebral palsy typically aren’t born with hip dysplasia.
However, due to rapid growth and spasticity (involuntary muscle contractions), the muscles become tight and pull on the joints. If the legs are affected, this means that the hip joint can commonly be pulled out of place.
The risk of hip displacement progressing to hip dislocation in children with cerebral palsy is about 15-20%.
This scale consists of 5 levels with level 1 being the mildest and level 5 the most severe.
Therefore, the more severe your child’s cerebral palsy is, the more likely they are to experience hip dislocation.
Generally, individuals with non-ambulatory cerebral palsy have a greater risk of hip dysplasia than CP patients that can walk.
Signs of Hip Dislocation in Cerebral Palsy Patients
Hip dysplasia can start as early as age 2 but is most frequent between ages 3-5.
Most hip dislocations in children with cerebral palsy occur before age 7, so spotting signs of hip problems early and getting proper management is crucial.
Individuals with spasticity in the hips may experience:
- Difficulties sitting or performing transfers
- Hip pain
- Restricted range of motion
- Uneven leg lengths
- Abnormal walking patterns or inability to walk
Why is Hip Dislocation So Common in Childhood?
The acetabulum (the hip socket) in young children is covered with cartilage.
Cartilage is slippery, which makes it ideal for allowing the bones to slide against each other.
However, in cases where the ball and socket aren’t a perfect fit, lots of cartilage can actually increase the risk of hip displacement.
As we get older, the cartilage starts to wear down, which can reduce the risk of hip dislocation.
Prevention and Treatment for Hip Dislocation in Individuals with Cerebral Palsy
Hip dysplasia may not bother your child for years, which is why so many people put off getting treatment until it starts becoming painful and restricting their ability to perform everyday tasks.
Don’t wait until symptoms become problematic!
The best way to prevent hip dislocation in individuals with cerebral palsy is to treat the underlying problem: spasticity.
Generally, a combination of the following interventions will result in the most effective outcomes.
Physical therapy for hip subluxation will focus on lengthening tight muscles through stretching, manual therapy, and promoting proper form through exercise.
Lengthening muscles like the hamstrings, hip flexors, and quadriceps will help relieve strain on the hip joints.
Correcting abnormal movement patterns will help ensure that the femoral head remains centered and secure.
Carrying over techniques learned during physical therapy to the child’s everyday life is essential for continued progression and prevention of further problems.
Braces will help gently stretch spastic muscles and provide the structural framework necessary to promote proper bone alignment.
They will also restrict unwanted movements caused by spasticity.
Botox is a nerve blocker that is injected into spastic muscles to temporarily relieve high muscle tone.
It’s important to understand that spasticity will return in about 3-6 months.
The best way to ensure long-term spasticity relief is to take advantage of the reduced muscle tone while using Botox and pursue intensive physical therapy. Great improvements can be made while under the effects of Botox, and these improvements can carry over even once the medication has worn off.
Muscle relaxants like baclofen help alter the chemical balance in the central nervous system so that there are fewer messages being transmitted through the nerves telling the muscles to contract.
Like Botox, they provide temporary spasticity relief. When taken in pill form, muscle relaxants last several hours but may need to be taken multiple times a day.
Your child’s doctor will likely only recommend surgery for your child’s hip problems if all other management interventions prove ineffective.
Soft tissue lengthening surgeries involve manually lengthening tight muscles and tendons so that there is less tension on the bones and joints.
A femoral or pelvic osteotomy is a procedure where the bones are cut, repositioned, and reattached with rods and screws. This ensures that the hip joint is more securely aligned.
Cerebral Palsy and Hip Displacement
Hopefully, this article helped you better understand the link between cerebral palsy and hip dislocations.
Early intervention is essential for preventing hip problems from developing and further restricting mobility. Good luck!
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