How Do You Know If Your Baby Has Hip Dysplasia? Signs & Symptoms

Hip dysplasia in babies is also known as developmental dysplasia of the hip (DDH). It occurs when the socket-like structure that forms the baby’s hip joint (also known as acetabulum) is too shallow to cover the head of the thigh bone (femoral head) adequately. This results in an unstable joint, in which some babies develop minor looseness in one or both of their hip joints. 

For some babies, the ball that forms the upper part of the thigh bone easily and completely comes out of the socket (dislocatable DDH). Dislocatable DDH occurs when the head of the femur lies within the acetabulum but can be easily pushed out of the socket during a physical examination. 

Subluxatable DDH is a mild case of DDH in which the head of the femur is simply loose in the socket. The bone can be moved within the socket, but will not dislocate.

Although the exact cause of this condition is unknown, doctors believe several factors increase a child’s risk of developing hip dysplasia:

• Family history of developmental dysplasia of the hip
• Oligohydramnios in the mother (less volume of amniotic fluid around the fetus)
• Female gender (girls are 2-4 times more likely to have the condition than boys)
• First-born babies, who fit in the uterus more tightly than in later babies
• Breech babies (often have both legs extended in a partially straight position, which can prevent the hip socket from developing properly)
• Tight swaddling with the legs extended 
• Babywearing with infants in the M-position (very rare)

According to the American Academy of Pediatrics, swaddling can be an effective technique to promote sleep in infants when done correctly. However, if you plan to swaddle your infant, you need to follow a few guidelines to make sure you are doing it safely:

• Spread the blanket out flat, with one corner folded down.
• Lay the baby face-up on the blanket with their head above the folded corner.
• Straighten one arm, wrap the corner of the blanket on that side over their body and tuck it between their other arm and the other side of the body.
• For example, if you tuck down the right arm, fold the right corner of the blanket over their body and under their left side.
• Fold or twist the bottom of the blanket loosely and tuck it under one side of the baby.

If diagnosed early and treated successfully, most children recover completely and develop normal hip joints. The later the treatment is initiated, the greater the risks of residual stiffness and onset of hip osteoarthritis by early adulthood. If treatment begins after 2 years, hip deformity may persist, and osteoarthritis may develop later in life.

• When the problem is found during the first 6 months of life, the doctor will provide a harness to keep the legs apart (frog-leg position). This will hold the hip joint in place as the child grows. 
• Children who do not improve or who are diagnosed after 6 months often need surgery. After surgery, the surgeon will place a cast on the child's leg for a prolonged period of time to keep the hip position such that the hip dysplasia is corrected.
• From ages 6 months to 2 years, either a closed reduction procedure (manual fixing of the ball within the socket and applying plaster) or an open surgery is necessary. During this procedure, the surgeon makes an incision at the baby's hip that allows them to clearly see the bones and soft tissues. 
• In some cases, the thigh bone is shortened to properly fit the bone into the socket, and the child is placed in a spica cast to maintain the proper hip position. The cast may be needed for many months to correct the deformity.

It is advised to seek professional help for DDH because the condition can cause substantial pain, hip stiffness, and early onset arthritis if left untreated.