A hip dislocation occurs when the ball-shaped head of the femur, or thighbone, is forced out of its normal position in the pelvis socket.
This painful injury immobilizes the hip joint, making it difficult or impossible to move the leg. The ligaments, muscles and other surrounding soft tissues are often injured when the hip dislocates, and some people also suffer nerve damage or fractures in the pelvis and legs.
Causes of Hip Dislocation
In normal hip joints, the femoral head is situated deep within the pelvis socket, protected by a ring of cartilage, a fibrous joint capsule and many ligaments and muscles. This anatomical configuration gives the joint significant stability.
Consequently, much force is required to dislocate the hip.
Motor vehicle collisions are the most common cause of traumatic hip dislocations, accounting for two-thirds of these injuries. People who do no wear seatbelts face the greatest risk of dislocation during a crash.
Dislocations also often occur as a result of falls from high places. In a smaller percentage of cases, the injury happens while playing high-impact or contact sports.
Hip Dislocation Diagnosis
Every hip dislocation should be considered a serious medical emergency in need of immediate medical attention.
If the joint dislocation damaged nearby blood vessels and normal blood circulation is not quickly restored, tissue death, or avascular necrosis, can occur. Moving the injured person is not advised; instead, experts recommend calling for emergency assistance.
An orthopedic surgeon may be able to diagnose a dislocation based on a visual examination of the leg, as the knee and foot may be rotated toward or away from the middle of the body.
To confirm the diagnosis — and because other injuries may be present — the doctor may order imaging tests. An X-ray can reveal the exact position of the dislocation as well as any additional fractures.
An MRI also may be ordered to assess damage to the surrounding soft tissues.
Treatments for Hip Dislocation
The orthopedic surgeon may administer an anesthetic or a sedative and immediately perform a reduction procedure, in which the bones are manipulated back into their proper positions. If soft tissue injuries or fractures are present, surgery may be necessary to perform the reduction.
After the procedure, the doctor will likely order another set of X-rays or a CT scan to confirm that the bones are correctly positioned.
To protect the hip after reduction, the orthopedic surgeon may recommend limiting hip movement for several weeks. Most patients must undergo physical therapy and use crutches, walkers or canes during this time.
Healing from a hip dislocation may take as long as a few months, but recovery may take longer if additional injuries or complications are present.