Hip Dislocation
When the thighbone is forced out of the hip socket
Quick Facts
- Type: Orthopedic (joint) injury
- Common cause: High-impact trauma, such as car crashes
- Urgency: Medical emergency
- Treatment: Prompt repositioning of the joint
Overview
A hip dislocation happens when the ball-shaped head of the thighbone (femur) is forced out of the cup-shaped socket of the pelvis. The hip is a strong, deep ball-and-socket joint, so dislocating it usually takes a powerful force, such as a car crash or a fall from a height. This makes a traumatic hip dislocation a serious injury that is often accompanied by other damage.
A dislocated hip is a medical emergency. The longer the joint stays out of place, the higher the risk of lasting damage, including injury to nearby nerves and blood vessels and loss of blood supply to the bone. Prompt treatment to put the joint back in place greatly improves the outlook. (Note: an infant's hip that develops out of the socket is a different condition, hip dysplasia, rather than a traumatic dislocation.)
Symptoms
A hip dislocation causes immediate and obvious symptoms. Seek emergency care right away if you have:
- Severe pain in the hip and inability to move the leg
- The leg held in an abnormal position, often turned inward or outward and appearing shorter
- Inability to bear weight or walk
- Numbness, tingling, or weakness in the leg or foot, which can mean nerve injury
- Visible deformity of the hip area
Because dislocations usually result from major trauma, there may also be other injuries that need urgent attention.
Causes
It takes a strong force to dislocate a healthy hip. Common causes include:
- Motor vehicle crashes: The knee striking the dashboard can drive the femur out of the socket (a "dashboard injury").
- Falls from a height: Landing forces can dislocate the hip.
- Sports injuries: High-impact collisions or falls in contact sports.
- Complications after hip replacement: An artificial hip can dislocate more easily, sometimes with less force.
The direction of the force determines whether the hip dislocates backward (most common) or forward.
Risk Factors
- High-impact activities and contact sports
- Not wearing a seatbelt
- A previous hip replacement
- A previous hip dislocation
- Conditions that weaken bones or connective tissue
- Situations with a high risk of falls or collisions
Diagnosis
Diagnosis is made quickly in an emergency setting:
- Physical examination: The position of the leg and the inability to move the joint strongly suggest a dislocation; nerve and blood flow to the leg are checked.
- X-rays: Confirm the dislocation and show any associated fractures.
- CT scan: Often used to detect small fractures and bone fragments before and after the joint is put back in place.
Treatment
Treatment is urgent and aims to return the joint to its socket as soon as it is safe to do so.
- Reduction: The doctor repositions the ball back into the socket, usually with sedation or anesthesia. Doing this promptly lowers the risk of complications.
- Surgery: Needed if reduction cannot be done in a closed manner, or if there are fractures or trapped bone fragments.
- Treating associated injuries: Fractures, nerve injuries, and other trauma are addressed.
- Recovery: Rest, limited weight-bearing, and physical therapy help restore strength and motion, and follow-up monitors for complications such as loss of blood supply to the bone (avascular necrosis) or later arthritis.
Prevention
- Always wear a seatbelt and use appropriate child restraints in vehicles
- Use protective equipment and proper technique in contact sports
- Reduce fall hazards at home, especially for older adults
- Follow your surgeon's precautions after a hip replacement to avoid positions that risk dislocation
- Strengthen muscles around the hip with appropriate exercise
When to See a Doctor
A hip dislocation is a medical emergency. Call emergency services or go to the nearest emergency department right away if you have:
- Severe hip pain after an injury with an inability to move the leg
- A leg that looks deformed, shortened, or twisted
- Numbness, tingling, or weakness in the leg or foot
- Inability to bear weight after a significant impact
Do not try to force the joint back yourself; prompt professional treatment protects nerves, blood vessels, and the bone.
Frequently Asked Questions
Is a hip dislocation an emergency?
Yes. A dislocated hip is a medical emergency. The longer the joint stays out of place, the higher the risk of nerve injury and loss of blood supply to the bone. Seek emergency care immediately and do not try to reposition it yourself.
What does a dislocated hip feel like?
It causes sudden, severe hip pain, an inability to move or bear weight on the leg, and the leg often appears twisted and shortened. Numbness or weakness in the leg or foot can signal nerve injury and needs urgent care.
How is a dislocated hip put back in place?
A doctor performs a reduction, gently maneuvering the ball back into the socket, usually under sedation or anesthesia. This is done as soon as safely possible. Surgery is needed if reduction is not possible or if there are fractures.
What causes a hip to dislocate?
It usually takes a strong force, such as a car crash (often the knee hitting the dashboard), a fall from a height, or a high-impact sports collision. Artificial hips after a replacement can dislocate more easily.
What are the long-term risks after a hip dislocation?
Possible complications include loss of blood supply to the femoral head (avascular necrosis), nerve injury, and later arthritis of the hip. Prompt repositioning and follow-up care reduce these risks, and physical therapy aids recovery.
References
- American Academy of Orthopaedic Surgeons (AAOS). Hip dislocation.
- MedlinePlus, U.S. National Library of Medicine. Dislocation.
- Mayo Clinic. Dislocation — Symptoms and causes.
- OrthoInfo, American Academy of Orthopaedic Surgeons.