Hip Dysplasia – Symptoms and Causes
Overview
Hip dysplasia occurs when the hip socket doesn’t completely cover the ball of the upper thighbone. This can allow the joint to become partially or fully dislocated.
Most cases are present at birth. Healthcare providers routinely screen newborns for this condition during initial examinations and subsequent well-baby visits.
When diagnosed in infancy, treatment typically involves a soft brace that can effectively correct the problem. However, mild cases might remain undetected until adolescence or early adulthood.
Symptoms
Symptoms of hip dysplasia differ across age groups. For babies, parents might notice one leg appears longer than the other. When children start walking, they may develop a noticeable limp.
Parents might also observe that one hip has less flexibility during diaper changes.
Teenagers and young adults experience different symptoms. They might develop:
- Groin pain during physical activities
- Feeling of hip instability
- Hip joint discomfort
- Complications like osteoarthritis
- Hip labral tears
These symptoms often worsen with activity and can limit daily movement or sports participation.
Causes
Before birth, the hip joint consists of soft cartilage that later turns into bone. Proper development requires the ball and socket to fit correctly, as they shape each other.
When the ball isn’t positioned correctly in the socket, the socket becomes too shallow.
During the final month of pregnancy, limited space in the womb can force the hip’s ball joint out of position. This displacement leads to incomplete socket formation.
Several factors can reduce womb space and increase the risk:
- First-Time Pregnancies: The mother’s abdominal muscles tend to be tighter.
- Large Babies: More body mass takes up additional space.
- Breech Position: When the baby is positioned feet-first rather than head-first.
The pressure from these conditions can affect how the hip joint develops before birth.
Risk Factors
Several factors can increase a baby’s chance of developing hip dysplasia:
- Family History: The condition often runs in families.
- Gender: Girls have a higher risk than boys.
- Birth Position: Babies born in the breech position face an increased risk.
- Swaddling Practices: Tight swaddling that keeps hips and knees straight can contribute to the problem.
Complications
Hip dysplasia may lead to several serious problems over time. The labrum, a soft cartilage rim around the hip socket, can tear due to abnormal joint mechanics. This condition is known as a hip labral tear.
The risk of osteoarthritis increases significantly with hip dysplasia. This happens because the misaligned joint creates higher pressure on a smaller surface area of the socket.
The uneven pressure distribution gradually damages the smooth cartilage covering the bones. As this protective layer wears away, the bones can no longer move smoothly against each other during movement.
