Perthes disease in children causes complications and treatment

If you notice that your child suddenly starts limping or complaining of hip or knee pain without a clear reason, the issue may not be as simple as it seems. In some cases, this could be a sign of Perthes disease in children, a condition that affects the hip joint due to a temporary loss of blood supply to the head of the femur. Over time, this can weaken the bone and change its shape.Although the name may sound alarming, Perthes disease is not the end of the road. Most children improve significantly with early diagnosis and proper treatment, whether through physical therapy, medications, or sometimes surgery in more severe cases.In this article by Dleli Medical, we will explore Perthes disease in children, including its causes, symptoms, diagnostic methods, and the latest treatment options, so you can feel reassured and know how to respond from the very first warning sign.

What Is Perthes Disease?

Perthes disease, also known as Legg-Calvé-Perthes disease, is a condition that affects the hip joint in children. It occurs when the blood supply to the head of the femur (the ball-shaped part that fits into the hip socket) is temporarily reduced or completely interrupted.

A healthy blood supply is essential for bones because it delivers oxygen and nutrients needed to maintain bone strength. When this blood flow decreases, the bone cells begin to die, a condition known as avascular necrosis.

As the lack of blood supply continues, the rounded head of the femur may gradually weaken, collapse, or change shape. Once blood flow returns, the bone starts rebuilding and strengthening itself again, but in some cases, the shape of the bone may remain permanently altered.

Is Perthes Disease Serious?

The severity of Perthes disease varies from one child to another. Some cases are mild, while others may be more complicated. However, early diagnosis and proper treatment play a major role in protecting the hip joint and reducing the risk of long-term complications.

Can Perthes Disease Be Cured?

Yes, many children recover well over time because the body gradually rebuilds the femoral head. The degree of recovery depends on several factors, including the child’s age, the severity of the condition, and how early treatment begins.

How Long Does Treatment Take?

Treatment usually lasts between one and two years in mild to moderate cases. In more severe cases, recovery may take longer depending on the severity of the disease, the child’s age, and their response to treatment.

Can Perthes Disease Cause Disability?

In most cases, Perthes disease does not lead to permanent disability, and many children are able to return to normal daily activities after treatment. However, advanced or untreated cases may lead to complications such as:

A mild limp while walking
Stiffness in the hip joint
An increased risk of early hip arthritis later in life

Do All Children Need Surgery?

No, not every child with Perthes disease requires surgery. Many cases can be treated conservatively through:

Physical therapy
Reducing intense physical activities
Regular medical follow-up

Surgery is usually considered only in moderate to severe cases or when the hip joint does not respond well to conservative treatment.

Can a Child Walk During the Disease?

That depends on the severity of the condition. Some children can walk relatively normally, while others may need:

Crutches
Reduced weight-bearing on the affected leg
Periods of rest to reduce pressure on the hip joint

Are Sports Restricted?

Not all sports are prohibited, but high-impact activities are usually avoided temporarily, such as:

Football (soccer)
Running
Jumping

On the other hand, lighter activities such as swimming are often recommended because they help strengthen the muscles without putting pressure on the hip joint.

Does Perthes Disease Affect Adults?

Perthes disease mainly affects children, but some of its long-term effects may continue into adulthood, including:

Hip osteoarthritis
Limited hip movement in some cases

Is Perthes Disease Hereditary?

The exact cause of Perthes disease is still unknown. However, it appears more frequently in some families, suggesting that there may be a genetic factor that increases susceptibility, although it is not considered a directly inherited disease.

Can Perthes Disease Affect Leg Length?

Yes, in some cases Perthes disease may cause a slight difference in leg length, especially if the condition significantly affects the growth of the femur. Usually, the difference is minor and does not cause major problems, but doctors monitor the child’s growth regularly to ensure healthy bone and joint development.

Is the Pain Limited to the Hip Area?

No, the pain is not always limited to the hip. Some children may complain of pain in the:

Knee
Thigh
Leg

This can sometimes delay diagnosis because the underlying problem is actually in the hip joint, even though the pain appears elsewhere.

Can Perthes Disease Return After Recovery?

In most cases, Perthes disease does not return in the same hip after complete recovery, especially with proper treatment and follow-up. However, regular medical monitoring during growth remains important to ensure the hip joint develops normally and to detect any future complications early.

Stages of Perthes Disease

Perthes disease, medically known as Legg–Calvé–Perthes disease, progresses through several distinct stages. Each stage reflects the development of reduced blood supply to the femoral head and its effect on the hip joint.

1. Initial Stage (Early Stage)

At this stage, the blood supply to the femoral head begins to decrease.

Symptoms are usually mild, such as a slight limp or occasional pain
X-rays may appear normal or show only very subtle changes
The child may still walk normally at first without obvious signs of a problem

2. Avascular Necrosis Stage

During this stage, the blood supply becomes significantly reduced.

Bone cells gradually begin to die
Pain increases, especially during movement or running
The child becomes less active and tries to protect the affected leg

3. Fragmentation Stage

This is considered one of the most important and noticeable stages of the disease.

The femoral head weakens and starts breaking into small fragments
Limping becomes more obvious while walking
Hip joint movement becomes more limited
In some cases, a slight difference in leg length may appear

4. Reossification Stage

At this stage, the body gradually begins repairing the damaged bone.

The weakened bone slowly becomes stronger again
Pain decreases noticeably
Hip movement gradually improves over time

5. Healed Stage

In this final stage, the condition becomes stable.

The hip joint reaches a stable condition
The femoral head may return to a near-normal shape, or some deformity may remain depending on the severity of the disease
The final outcome depends on the child’s age, early diagnosis, and timely treatment

Causes of Perthes Disease

Perthes disease, or Legg–Calvé–Perthes disease, is a condition affecting the hip joint in children. It occurs when blood flow to the femoral head decreases, causing the bone to weaken and change shape over time.

Main Causes and Risk Factors

Temporary Loss of Blood Supply

This is the primary cause. Insufficient blood reaches the femoral head, leading to gradual damage and weakening of bone cells.

Genetic Factors

Some children may have a family history of the condition, suggesting a possible inherited susceptibility.

Abnormal Blood Vessel Development

Certain children may have weak or abnormal blood vessels supplying the hip joint.

Repeated Minor Injuries

Not usually one major injury, but repeated minor trauma to the hip may contribute to the disease in susceptible children.

Growth-Related Factors

The disease commonly appears between the ages of 4 and 10 years, a period of rapid growth that may be linked to its development.

Passive Smoking (Indirect Factor)

Some studies suggest that exposure to cigarette smoke may affect blood circulation, although it is not considered a confirmed direct cause.

Symptoms of Perthes Disease

Symptoms of Perthes disease usually develop gradually and most commonly affect children between 4 and 10 years old.

Common Symptoms

Limping While Walking

This is often the first and most noticeable symptom. The child may begin walking abnormally or limping without a clear reason.

Hip Pain

Pain may occur in the hip or thigh area. In some cases, the pain appears in the knee instead of the hip, which can delay diagnosis.

Reduced Physical Activity

The child may avoid running or playing and become less active than usual.

Hip Joint Stiffness

There may be difficulty moving the leg or turning it outward, especially in younger children.

Weakness of the Leg Muscles

Parents may notice that the affected leg looks thinner or weaker than the other leg.

Increased Pain with Activity

Pain often worsens during running or prolonged walking and improves with rest.

Diagnosis of Perthes Disease

The diagnosis of Perthes disease, or Legg–Calvé–Perthes disease, depends mainly on physical examination and imaging tests because its symptoms may resemble other hip or knee conditions.

1. Clinical Examination

The doctor evaluates the child by:

Observing walking and checking for limping
Examining hip joint movement
Testing for pain during leg movement
Looking for stiffness or weakness in the joint

Sometimes the child may complain only of knee pain, which can delay the diagnosis because the actual problem is in the hip.

2. X-rays

X-rays are one of the most important diagnostic tools.

They can show:

Changes in the shape of the femoral head
Flattening or fragmentation of the bone
Progression of the disease stages

However, in very early stages, X-rays may appear normal.

3. MRI Scan

MRI helps detect the disease early before changes appear on regular X-rays. It can show:

The size of the affected bone area
The degree of reduced blood flow
The extent of hip joint involvement

4. Blood Tests

Blood tests do not directly diagnose Perthes disease, but they help rule out other conditions such as:

Infections
Rheumatic diseases
Bacterial joint infections

Complications of Perthes Disease

Complications vary depending on the child’s age, the severity of the disease, and how early treatment begins.

1. Deformity of the Femoral Head

The shape of the femoral head may become abnormal during the fragmentation stage, including:

Flattening of the bone
Irregular shape
Enlargement or deformity

This may affect hip joint movement later in life.

2. Early Hip Osteoarthritis

This is one of the most important long-term complications, especially if the femoral head does not heal into its normal shape.

It may increase the risk of developing early arthritis of the hip joint compared to healthy individuals.

3. Slight Leg Length Difference

A small difference in leg length may occur due to the effect of the disease on the growth of the femur on the affected side.

4. Hip Joint Stiffness and Limited Movement

Children may experience:

Difficulty moving the hip
Limited ability to spread the leg outward
Pain during movement or physical activity

5. Persistent Limping

In some severe cases, limping may continue even after the disease has completed its stages.

6. Weakness of the Thigh Muscles

Because of reduced movement over a long period, the child may develop:

Muscle weakness
Decreased muscle size in the affected leg

Do Complications Occur in All Children?

No, not all children develop complications. Recovery is usually better in younger children, especially with:

Early diagnosis
Regular medical follow-up
Commitment to physical therapy and medical instructions

Medications for Perthes Disease

Treatment of Perthes disease, or Legg–Calvé–Perthes disease, with medications mainly focuses on relieving symptoms and improving the child’s comfort rather than directly treating the underlying cause.

The main problem in this disease is the reduced blood supply to the femoral head, so treatment usually depends on a combination of rest, physical therapy, and sometimes braces or surgery.

Goals of Medication Treatment

Relieve pain
Reduce inflammation inside the hip joint
Improve the child’s ability to move
Reduce limping caused by pain
Protect the joint during the healing process

Medications Used for Perthes Disease

1. Pain Relievers and Anti-Inflammatory Medications

These are the most commonly used medications in children.

Common examples include:

Ibuprofen
Paracetamol (Acetaminophen)
Naproxen (in some cases)

Benefits include:

Relieving hip or knee pain
Reducing joint inflammation
Improving daily movement
Reducing limping caused by pain

2. Muscle Relaxants

In some cases, muscle tightness may develop around the hip joint. Doctors may prescribe mild medications to help:

Reduce muscle spasms
Improve comfort during movement

However, their use in children is usually limited and closely supervised by a doctor.

3. Calcium and Vitamin D Supplements

Doctors may sometimes recommend:

Vitamin D supplements
Calcium supplements

This is especially important if the child has nutritional deficiencies or weakened bones.

Is There a Medication That Treats the Main Cause?

Currently, there is no medication that can directly restore blood flow to the femoral head or completely cure Perthes disease. However, ongoing research is exploring treatments that may improve bone nutrition and speed up recovery.

Important Instructions During Medication Treatment

Reducing Pressure on the Joint

The child should avoid:

Running
Jumping
High-impact sports

This helps protect the femoral head from deformity during the weakened stages of the disease.

Importance of Physical Therapy

Physical therapy is an essential part of treatment because it helps:

Maintain hip joint movement
Prevent stiffness
Strengthen the muscles surrounding the joint

When Does the Child Need Additional Treatment?

If the condition becomes advanced or significant bone deformity develops, the doctor may recommend:

Orthopedic braces
Casting
Surgical intervention depending on the severity of the condition

Surgical Treatment of Perthes Disease

Surgical treatment for Perthes disease, or Legg–Calvé–Perthes disease, is usually reserved for moderate to severe cases. The main goal of surgery is to keep the femoral head properly positioned inside the hip socket during healing and to reduce the risk of future deformities and complications.

Surgery is not always the first treatment option, but doctors may consider it when: