Child Health

Pediatric Hip Dislocation: Causes, Symptoms, Treatment, and Developmental Dysplasia

By Alex 7 min read

A child can dislocate their hip, though it is a relatively uncommon occurrence, particularly in traumatic scenarios, and distinct from developmental hip issues more prevalent in infants.

Can a Child Dislocate Their Hip?

Yes, a child can dislocate their hip, though it is a relatively uncommon occurrence, particularly in traumatic scenarios, and distinct from developmental hip issues more prevalent in infants.

Understanding Hip Anatomy in Children

The hip joint is a crucial ball-and-socket joint connecting the femur (thigh bone) to the pelvis. In children, this joint shares the fundamental structure of an adult hip but possesses unique developmental characteristics that influence its susceptibility to injury:

  • The Ball-and-Socket Joint: Formed by the head of the femur (the ball) fitting into the acetabulum (the socket) of the pelvis. This design allows for a wide range of motion but relies on strong ligaments and surrounding muscles for stability.
  • Growth Plates and Ligamentous Laxity: Children's bones contain epiphyseal growth plates, which are softer areas of cartilage where bone growth occurs. While these are not directly involved in dislocation, their presence means the surrounding bone structure is still maturing. More significantly, children often exhibit greater ligamentous laxity (looseness) compared to adults, which can, in some contexts, increase range of motion but also alter joint stability under extreme forces. However, the deep socket of the hip generally provides excellent inherent stability.

Yes, But It's Uncommon: The Nature of Pediatric Hip Dislocations

While possible, a true traumatic hip dislocation in a child is considered rare. When it does occur, it typically requires significant force due to the inherent stability of the hip joint. It's crucial to differentiate between:

  • Traumatic Hip Dislocations: These are acute injuries where the femoral head is forcefully displaced from the acetabulum, usually due to high-energy trauma.
  • Non-Traumatic/Developmental Hip Dysplasia (DDH): This is a more common condition, especially in infants, where the hip joint has not formed properly or the socket is too shallow, leading to instability, subluxation (partial dislocation), or frank dislocation without a specific traumatic event. While not a "dislocation" in the acute, traumatic sense, it represents a state of hip instability or displacement.

Causes and Mechanisms of Pediatric Hip Dislocation

The causes vary depending on whether the dislocation is traumatic or developmental:

  • High-Impact Trauma: The most common cause of acute hip dislocation in children.
    • Motor Vehicle Accidents (MVAs): Often involve dashboard injuries where the knee impacts the dashboard, driving the femur posteriorly.
    • Falls from Heights: Significant vertical impact can transmit force up the leg to the hip.
    • Sports Injuries: Less common than in adults but can occur in high-contact sports or activities involving falls (e.g., cycling, gymnastics).
  • Specific Risk Factors for Traumatic Dislocation:
    • Ligamentous Laxity: While the hip is deep, excessive general joint laxity can contribute.
    • Underlying Neuromuscular Conditions: Conditions like cerebral palsy or spina bifida can lead to muscle imbalances and joint instability, increasing the risk of both traumatic and atraumatic dislocations.
  • Developmental Dysplasia of the Hip (DDH):
    • This is a congenital or developmental condition, not an acute injury. It occurs when the hip socket (acetabulum) is too shallow or the femoral head is not positioned correctly.
    • Risk Factors for DDH: Breech presentation, female gender, first-born child, family history of DDH, and oligohydramnios (low amniotic fluid). It can range from mild instability to complete dislocation.

Recognizing the Signs and Symptoms

Identifying a hip dislocation in a child requires careful observation:

  • Acute Traumatic Dislocation:
    • Severe Pain: The child will typically be in significant distress and pain.
    • Inability to Move the Leg: The affected leg will often be held still.
    • Abnormal Leg Position: The leg may appear shortened, internally rotated (most common, posterior dislocation), or externally rotated (less common, anterior dislocation).
    • Swelling and Bruising: May develop around the hip joint.
    • Palpable Deformity: In some cases, a bulge or depression may be felt around the hip.
  • Developmental Dysplasia of the Hip (DDH) - Infants:
    • Asymmetrical Thigh or Gluteal Folds: One side may have more or deeper skin creases.
    • Limited Abduction: Difficulty spreading the legs apart (like opening a book).
    • Leg Length Discrepancy: One leg may appear shorter than the other.
    • Clicking or Clunking Sound: While not always indicative of DDH, a doctor may detect a "clunk" during specific maneuvers (Ortolani or Barlow tests) that signifies the hip dislocating or reducing.
    • Limp or Waddling Gait: In older children with undiagnosed DDH.

Immediate Actions and Medical Intervention

If a hip dislocation is suspected, prompt medical attention is critical:

  • Do Not Attempt to Reduce: Never try to manipulate or "pop" the hip back into place. This can cause further damage to nerves, blood vessels, and the joint itself.
  • Seek Emergency Medical Care: Call emergency services immediately. Keep the child as still and comfortable as possible.
  • Diagnosis and Treatment:
    • Imaging: X-rays are typically used to confirm the dislocation and its direction. MRI or CT scans may be used to assess soft tissue damage or for more complex cases.
    • Reduction: The hip must be reduced (put back into place) as soon as possible, ideally within a few hours, to minimize complications. This is usually done under sedation or general anesthesia in a controlled medical setting.
    • Immobilization and Rehabilitation: After reduction, the child will likely require a period of immobilization (e.g., traction, spica cast, brace) to allow soft tissues to heal. Physical therapy will follow to restore strength and range of motion.
    • DDH Treatment: For DDH, treatment varies by age and severity, ranging from harnesses (Pavlik harness for infants) to casts, and in some cases, surgery.

Potential Complications

Pediatric hip dislocations, especially traumatic ones, carry a risk of serious complications:

  • Avascular Necrosis (AVN) of the Femoral Head: This is the most feared complication. The blood supply to the femoral head can be disrupted during dislocation, leading to the death of bone tissue. The risk increases with the duration of dislocation before reduction. It can result in long-term pain, arthritis, and joint collapse.
  • Sciatic Nerve Injury: The sciatic nerve can be stretched or compressed during dislocation, leading to weakness or numbness in the leg and foot.
  • Recurrent Dislocation: While rare after a primary traumatic dislocation, it can occur, particularly if there's significant ligamentous damage or an underlying predisposition.
  • Post-Traumatic Arthritis: Long-term damage to the articular cartilage can lead to premature arthritis.
  • Growth Plate Injuries: Though less common for hip dislocations themselves, any significant trauma can affect growth plates in the vicinity, potentially leading to growth disturbances.

Prevention and Awareness

While not all dislocations are preventable, certain measures can reduce the risk:

  • Safety Measures:
    • Car Seat Safety: Ensure children are properly secured in age- and size-appropriate car seats or booster seats.
    • Supervision: Closely supervise children during play, especially on playgrounds or near heights.
    • Sports Safety: Ensure proper coaching, equipment, and adherence to rules in organized sports.
  • Early Screening for DDH:
    • Regular Pediatric Check-ups: Crucial for infants and young children, as pediatricians routinely screen for DDH during well-child visits.
    • Ultrasound Screening: May be recommended for infants with risk factors (e.g., breech presentation, family history).
  • Educating Parents and Caregivers: Awareness of the signs and symptoms of both traumatic hip injury and developmental hip issues is vital for prompt intervention.

In conclusion, while a child's hip is remarkably stable, it is not immune to dislocation. Understanding the distinct causes, recognizing the signs, and seeking immediate medical attention are paramount to ensuring the best possible outcomes and minimizing long-term complications.

Key Takeaways

  • Traumatic hip dislocations in children are rare, requiring significant force, and differ from developmental hip dysplasia (DDH).
  • High-impact trauma like motor vehicle accidents or falls are primary causes of acute dislocations, while DDH is a congenital condition of improper hip formation.
  • Signs of acute dislocation include severe pain and an abnormally positioned leg; DDH in infants may show asymmetrical thigh folds or limited leg abduction.
  • Immediate medical attention is crucial for suspected hip dislocation, with reduction performed under sedation to prevent severe complications like avascular necrosis.
  • Prevention involves ensuring child safety in vehicles and during play, alongside early screening for DDH during routine pediatric check-ups.

Frequently Asked Questions

Is it common for children to dislocate their hips?

No, traumatic hip dislocations in children are relatively uncommon and typically require significant force due to the inherent stability of the hip joint.

What are the main causes of hip dislocation in children?

Traumatic dislocations are usually caused by high-impact trauma such as motor vehicle accidents, falls from heights, or sports injuries, while developmental dysplasia of the hip (DDH) is a congenital condition.

What should I do if I suspect my child has dislocated their hip?

Seek emergency medical care immediately and never attempt to manipulate or "pop" the hip back into place yourself, as this can cause further damage.

What are the potential long-term complications of a hip dislocation in a child?

The most feared complication is avascular necrosis (AVN) of the femoral head, which can lead to bone tissue death, long-term pain, arthritis, and joint collapse. Other risks include nerve injury and recurrent dislocation.

How can developmental dysplasia of the hip (DDH) be prevented or detected early?

DDH is screened for during regular pediatric check-ups, and ultrasound screening may be recommended for infants with risk factors like breech presentation or a family history.