Legg-Calve-Perthes disease

Right now, you probably have lots of questions: How serious is Legg-Calvé-Perthes disease? What’s the best treatment? What do we do next? We’ve provided some answers to your questions on this site, and our experts at Children’s Hospital Boston can explain your child’s condition fully when you meet with us.

Background: the normal hip joint

The hip joint is one of the body's most reliable structures, providing most people with movement and support without pain or problems for a lifetime. The hip’s simple ball-and-socket anatomy—with the ball-shaped femoral head rotating inside a cup-shaped socket called the acetabulum—usually works well with amazingly little friction, and little or no wear.

The well-fitting surfaces of the femoral head and acetabulum, which face each other, are lined with a layer of cartilage, lubricated by a thin film of fluid. Friction inside a normal hip is less than one-tenth that of ice gliding on ice.

What is Legg-Calvé-Perthes disease?
Legg-Calvé-Perthes disease (also known as LCP or Perthes disease) is a temporary condition in children in which the ball-shaped head of the thigh bone (femoral head) loses its blood supply. As a result, the head of the thigh bone collapses, and the area becomes inflamed and irritated.

As the condition runs its course, the body will absorb the dead bone cells and replace them with new bone cells. The new bone cells will eventually reshape the head of the thigh bone, but the result can be a deformation that can cause arthritis later on.

What are the stages of Perthes?
Legg-Calvé-Perthes disease goes through four phases of changes that affect the head of the thigh bone: 

• Phase 1, necrosis:The blood supply to the head (ball) of the thigh bone is interrupted, so the hip joint becomes inflamed, stiff and painful. Portions of the bone turn into dead tissue (avascular necrosis). The ball of the thigh bone becomes less round in appearance on x-rays. This phase can last from several months up to one year.
   
• Phase 2, fragmentation:The body “cleans up” the dead bone cells and replaces them with new, healthier bone cells. The head of the thigh bone begins to remodel into a round shape again. The joint is still irritated and painful. This phase can last from one to three years.
   
• Phase 3, reossification:The head of the thigh bone continues to model itself back into a round shape with new bone. This phase lasts for one to three years.
   
• Phase 4, remodeling:Normal bone cells replace the new bone cells and the remodeling continues. To complete the healing process, this phase can last a few years.

What causes Legg-Calvé-Perthes disease?
LCP is idiopathic, which means that there is no known cause for the disease.

Who’s affected by/at risk for Perthes?

• Boys are five times more likely to be affected than girls (but girls’ cases can be more severe).
• Affected children are usually:
  • between 4 and 10 years old
  • very physically active
  • small for their age
• The condition tends to be more common in children who’ve been exposed to second-hand smoke.

What are the signs and symptoms of Legg-Calvé-Perthes disease?
Some signs and symptoms can include:

• pain in the hip that’s aggravated during activity
• pain in the thigh or knee area
• walking with a limp (can be a “painless limp”)
• pain that goes away with rest

How common is LCP?

Legg-Calvé-Perthes disease occurs in about one out of every 12,000 children.

How serious is LCP?
Perthes is a self-limiting disease, meaning that it eventually corrects itself by forming new, healthy bone in the place of dead bone. But the condition can leave the hip deformed and vulnerable to arthritis later in life. If the condition develops before a child is 6 years old, the hip’s self-correcting capability is very good. If Perthes develops later (after age 6), the condition can have more serious consequences.

How does a doctor diagnose Perthes?

In addition to a complete medical history and physical exam, a doctor’s tools for diagnosing LCP may include:

• x-rays (chief diagnostic tool)
• MRI (magnetic resonance imaging) (picks up early stages better than x-ray)
• blood tests (to rule out infection)

How does Children’s treat Legg-Calvé-Perthes disease?
The goals of treatment for LCP are to:

• preserve the roundness of the head of the thigh bone
• prevent deformity while the condition runs its course

Treatment may include:

• rest
• activity restrictions
• non-steroidal pain medication
• bed rest and traction
• casting or bracing
• physical therapy
• crutches or wheelchair (in some cases)
• surgery (osteotomy, osteoplasty)

For details on treatments, see Treatment & Care.

My child’s LCP is mild. Does he still need treatment?
Even for mild cases of Perthes, treatment is usually recommended in order to prevent additional deformity of your child’s joint. If his condition is mild, conservative treatments such as rest, activity restrictions and pain medication may be all that’s needed as the condition runs its course.

If my child needs surgery, what will that entail?

If conservative treatments prove inadequate, your child may need surgery to hold the head of the thigh bone in the hip socket (containment). Surgery involves cutting and reorienting the affected bones (osteotomy), and stabilizing the realignment with screws and plates.

The two most important factors that determine the outcome are the child's age (usually, the younger the better) and how much of the head of the thigh bone is affected by the condition.

Will my child be OK?

The majority of children treated for LCP at Children’s have corrections that enable them to walk, play, grow and live active lives. Diagnosing and treating your child’s Perthes early in its development greatly increase the likelihood of a successful outcome.

The two most important factors that determine the outcome are:

• your child's age at onset (usually, the younger the better)
• how much of the head of the thigh bone is affected by the condition

The more severe his case is, the greater the chance for the child’s hip motion to become limited and for him to have further hip problems in the future.

What new research is Children’s doing regarding developmental hip conditions?

Developmental hip conditions such as Legg-Calvé-Perthes disease, slipped capital femoral epiphysis and hip dysplasia can lead to premature arthritis in young adults with resulting pain and disability. Children’s many research studies focus on understanding the mechanical forces (pathomechanics) that adversely change the hip’s structure and function. With better understanding, we can improve existing therapies and develop new therapies for these conditions.

The clinical and basic science researchers at Children’s Orthopedic Center are recognized throughout the world for their achievements in the field. Our breakthroughs mean that we can provide your child with the most innovative care available.

For more on Children’s extensive orthopedic research, see Research & Innovation.

FAQ

Q: What is Legg-Calvé-Perthes disease?
A: Legg-Calvé-Perthes disease (also called LCP or Perthes) is a temporary condition in children in which the ball-shaped head of the thighbone, referred to as the femoral head, loses its blood supply. As a result, the head of the thigh bone collapses, and the area becomes inflamed and irritated.

As the condition runs its course, the body will absorb the dead bone cells and replace them with new bone cells. The new bone cells will eventually reshape the head of the thigh bone, but the result can be a deformation that can cause arthritis later on.

Q: If my child has LCP, will he be OK?
A: The majority of children treated for Perthes at Children’s have corrections that enable them to walk, play, grow and live active lives. Diagnosing and treating your child’s condition early in its development greatly increase the likelihood of a successful outcome.

The two most critical factors that determine the outcome are the child's age at onset (usually, the younger the better) and how much of the head of the thigh bone is affected by the condition. The more severe his case is, the greater the chance for the child’s hip motion to become limited and for him to have further hip problems in the future.

If my child needs surgery, what will that entail?

If conservative treatments prove inadequate, your child may need surgery to hold the head of the thigh bone in the hip socket (containment). Surgery involves cutting and reorienting the affected bones (osteotomy), and stabilizing the realignment with screws and plates.

The two most important factors that determine the outcome are the child's age (usually, the younger the better) and how much of the head of the thigh bone is affected by the condition.

Q: How long will it take for my child to heal?

After surgery, your child will need to limit his weight-bearing by using crutches or a walker for about six to eight weeks. Physical therapy will help him restore his muscle strength.

Q: What are the signs and symptoms of Legg-Calvé-Perthes disease?
A: Some signs and symptoms, which usually appear between the ages of 4 and 10, can include:

• pain in the hip that’s aggravated during activity
• pain in the thigh or knee area
• walking with a limp (can be a “painless limp”)
• pain that goes away with rest

Q: How does Children’s treat Perthes?
A: Treatment may include:

• rest
• activity restrictions
• non-steroidal pain medication
• bed rest and traction
• casting or bracing
• physical therapy
• crutches or wheelchair (in some cases)
• surgery (osteotomy, osteoplasty)

For details on treatments, see Treatment & Care.

Q: If my child has LCP, what should I ask my Children’s doctor?
A: Some of the questions you may want to ask include:

• Could you describe what’s wrong with my child’s hip joint? How serious is his case?
• Are other tests needed to confirm this diagnosis?
• Is there, or could there be, damage to his tissues or blood vessels?
• Does my child need treatment? Does he need surgery?
• Will LCP affect his growth plate and/or the normal growth of his leg?
• How long will it take for him to heal?
• Will he need to use crutches? If so, when, and for how long?
• Will he need rehab or physical therapy?
• Will there be restrictions on my child’s activities? If so, for how long?
• Could there be long-term effects? Pain? Arthritis?
• For how long should my child be followed by his care team?
• What can we do at home?

Q: How is Perthes usually diagnosed?
A: In addition to a complete medical history and physical exam, the doctor’s tools for diagnosing LCP may include:

• x-rays (chief diagnostic tool)
• MRI (magnetic resonance imaging) (picks up early stages better than x-ray)
• blood tests (to rule out infection)

Q: If my child has LCP in one hip, will he develop it in the other hip, too?
A: For the majority of children with LCP, only one hip is ever affected; in 10 to12 percent of children with the condition, both hips are affected, but not usually at the same time.

Q: What are the causes and risk factors for Legg-Calvé-Perthes disease?
A: LCP is idiopathic, which means that there is no known cause for the disease. What we do know is that:

• Boys are five times more likely to be affected than girls (but girls’ cases can be more severe).
• Affected children are usually:
  • between 4 and 10 years old
  • very physically active
  • small for their age
• The condition tends to be more common in children who’ve been exposed to second-hand smoke.

Q: What’s the long-term outlook for a child who has LCP?
A: The majority of children treated for Legg-Calvé-Perthes disease at Children’s have corrections that enable them to walk, play, grow and live active lives. Diagnosing and treating your child’s LCP early in its development greatly increase the likelihood of a successful outcome.

The two most critical factors that determine the outcome are the child's age at onset (usually, the younger the better) and how much of the head of the thigh bone is affected by the condition. The more severe his case is, the greater the chance for the child’s hip motion to become limited and for him to have further hip problems in the future.

Q: What is Children’s experience treating hip problems in children?
A: At Children’s, we’re known for our clinical innovations, breakthrough research and leadership in treatment for Perthes and other hip problems. We offer the most advanced diagnostics and treatments—several of which were pioneered and developed by Children’s own researchers and clinicians.

Causes

LCP is idiopathic, which means that there is no known cause for the disease. But we do know that:

• Boys are five times more likely to be affected than girls (but girls’ cases can be more severe).
• Affected children are usually:
  • between 4 and 10 years old
  • very physically active
  • small for their age
• The condition tends to be more common in children who’ve been exposed to second-hand smoke.

Signs and symptoms

Some signs and symptoms of Legg-Calvé-Perthes disease can include:

• pain in the hip that’s aggravated during activity
• pain in the thigh or knee area
• walking with a limp (can be a “painless limp”)
• pain that goes away with rest

When to seek medical advice

Contact your child’s doctor if your child:

• has pain in his hip that’s aggravated during activity
• has pain in the thigh or knee area
• is walking with a limp (can be a “painless limp”)
• has pain that goes away with rest

Questions to ask your doctor

If your child is diagnosed with Legg-Calvé-Perthes disease, you may feel a bit overwhelmed. It can be easy to lose track of the questions that occur to you. Lots of parents find it helpful to jot down questions as they arise—that way, when you talk to your child’s doctors, you can be sure that all your concerns get addressed.

Some of the questions you may want to ask include:

• Could you describe what’s wrong with my child’s hip joint? How serious is his case?
• Are other tests needed to confirm this diagnosis?
• Is there, or could there be, damage to his tissues or blood vessels?
• Does my child need treatment? Does he need surgery?
• Will LCP affect his growth plate and/or the normal growth of his leg?
• How long will it take for him to heal?
• Will he need to use crutches? If so, when, and for how long?
• Will he need rehab or physical therapy?
• Will there be restrictions on my child’s activities? If so, for how long?
• Could there be long-term effects? Pain? Arthritis?
• For how long should my child be followed by his care team?
• What can we do at home?

Who’s at risk

While the exact cause of Legg-Calvé-Perthes disease is unknown (idiopathic), we do know that certain factors increase the risk for this condition:

• Boys are five times more likely to be affected than girls (but girls’ cases can be more severe).
• Affected children are usually:
  • between 4 and 10 years old
  • very physically active
  • small for their age
• The condition tends to be more common in children who’ve been exposed to second-hand smoke.

Complications

The vast majority of surgical treatments for Legg-Calvé-Perthes disease at Children’s occur without major complications. But patients who’ve had surgery for LCP are at a very small risk for infection, bleeding or poor bone healing (malunion).

Long-term outlook

Children’s extensive research into bone problems means that we can provide your child with the most innovative care available. As a result, the majority of children treated for Legg-Calvé-Perthes disease at Children’s have corrections that enable them to walk, play, grow and live active lives.

Diagnosing and treating your child’s LCP early in its development greatly increase the likelihood of a successful outcome.

The two most critical factors that determine the outcome are the child's age at onset (usually, the younger the better) and how much of the head of the thigh bone is affected by the condition. The more severe his case is, the greater the chance for your child’s hip motion to become limited and for him to have further hip problems in the future, including premature arthritis.

Legg-Calvé-Perthes disease glossary

• acetabulum: hip socket; a part of the pelvis
• arthritis (osteoarthritis): joint damage, resulting in pain, swelling, stiffness and limited movement. Arthritis can occur when a joint’s cushioning cartilage wears away.
• arthrogram (MRI arthrogram): a two-part imaging study that’s useful for studying the non-bony structures of the joint
• avascular necrosis (osteonecrosis): a condition in which poor blood supply to a bone leads to bone death; the head of the femur is a common site of this condition
• The Center for Families at Children’s: dedicated to helping families find the information, services and resources they need to understand their child’s medical condition and take part in their care
• cartilage: smooth, rubbery tissue that cushions the bones of a joint and other areas; allows the bones to move easily without pain
• containment: in orthopedics, surgery to hold the head of the thigh bone in the hip socket
• diagnosis, diagnostics: identifying disease or injury through examination, testing and observation
• femoral head: round-headed top of the thigh bone (femur)
• femur: the thigh bone, the longest and strongest of your child’s bones. The rounded top of the femur (femoral head) joins the hip socket (acetabulum) to form the hip joint.
• Legg-Calvé-Perthes disease (LCP, Perthes): a temporary condition in children in which the ball-shaped head of the thigh bone (femoral head) loses its blood supply. As a result, the head of the thigh bone collapses, and the area becomes inflamed and irritated.

As the condition runs its course, the body will absorb the dead bone cells and replace them with new bone cells. The new bone cells will eventually reshape the head of the thigh bone, but the result can be a deformation that can cause arthritis later on.

• malunion: poor bone healing after surgery that involves cutting a bone
• MRI (magnetic resonance imaging): a diagnostic procedure that uses a combination of large magnets, radio frequencies, and a computer to produce detailed images of organs and structures within the body
• onset (of signs or symptoms): the first appearance of signs or symptoms
• open reduction surgery: a procedure in which the doctor repositions the hip bone into the socket through an incision in the patient’s body (see osteoplasty below)
• orthopedic surgeon, orthopedist: a doctor who specializes in surgical and non-surgical treatment of the skeletal system, spine and associated muscles, joints and ligaments
• orthopedics: the medical specialty concerned with diagnosing, treating, rehabilitating and preventing disorders and injuries to the spine, skeletal system and associated muscles, joints and ligaments
• osteonecrosis (avascular necrosis): the death of a bone due to loss of blood supply
• osteoplasty, osteotomy: surgical procedures that involve cutting and reshaping bone
• physical therapy: a rehabilitative health specialty that uses therapeutic exercises and equipment to help patients improve or regain muscle strength, mobility and other physical capabilities
• thigh bone: common term for the femur, the longest and strongest bone in the body
• x-rays: a diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones and organs onto film.
  

  Unique expertise in problems of the adolescent hip
  Many teens and young adults with hip problems need diagnostic and surgical techniques that are significantly different from what’s indicated for younger children. Children’s Child and Adult Hip Preservation Program is dedicated to finding better ways to care for adolescents and young adults with hip problems.