May also be called: Dislocated Hip
A dislocation is when the bones in a joint slip out of their normal position. A hip dislocation is an injury that happens when the ball of the thighbone moves out of the socket of the hipbone.
The hip is a ball-and-socket joint made up of the thighbone (femur) and hipbone (pelvis). The ball-shaped head of the femur fits into a hollow in the pelvis and is held in place by ligaments and cartilage. This structure makes the hip very stable, but a lot of force applied to the leg can pop the head of the femur out of its socket, or dislocate it.
Most hip dislocations are the result of motor vehicle accidents, but severe falls (such as from a ladder) or injuries due to sports like football, rugby, skiing, and snowboarding also can generate enough force to dislocate a hip. Some children are born with a congenital defect called developmental dysplasia of the hip that makes hips unstable and can cause them to become dislocated.
In about 90% of dislocated hips, the thighbone is pushed backward, which causes the hip to bend and the leg to twist in toward the middle of the body. In other cases, the thighbone is pushed forward, which results in less bending of the hip and a leg that is twisted out away from the middle of the body.
Hip dislocations usually cause severe pain in the hip that can spread to the legs and back, and they can make the affected leg appear deformed or shorter than the other leg. Treatment involves resetting the head of the thighbone in the socket of the hipbone. This can be done manually by a trained doctor or through a surgical operation.
Hip dislocations are relatively rare, but they are serious injuries that need immediate medical attention. With treatment, a dislocated hip should heal in 2 to 3 months. Any additional injuries — such as hip fractures — can make the hip take longer to heal completely.
All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.
