What is Perthes Disease? What Are Its Symptoms? How is It Diagnosed and Treated?

If you have noticed that your child is walking with a limp or experiencing hip pain, the cause may be Perthes disease. This condition is particularly seen in children between the ages of 4 and 10 and occurs 4 times more frequently in boys than in girls. The disease develops as a result of a temporary loss of blood flow to the hip, and the treatment process can take approximately 2 to 2.5 years. In this article, you will find clear answers to questions such as what Perthes disease is, what its symptoms are, and how it is diagnosed and treated.

What is Perthes Disease?

Definition of the Disease

Perthes disease occurs as a result of the temporary cessation of blood flow to the upper part of the thigh bone, which forms the hip joint. Termed Legg-Calvé-Perthes disease or Perthes syndrome in the medical literature, this condition leads to an insufficient supply of oxygen and nutrients to the region called the femoral head. Under normal conditions, this region has a very active blood circulation, and this circulation is of vital importance for the healthy development of bone tissue in growing children.

The disease begins with the disruption of blood flow due to unknown causes, and this situation triggers a process of bone death called avascular necrosis in the femoral head. Affecting 1 in every 10,000 children, this disorder involves a single hip in the vast majority of cases. However, bilateral involvement can also be seen at a rate of 10-15%, and in this case, the course of the disease is more severe.

Changes Occurring in the Femoral Head

When blood flow stops, the bone of the femoral head begins to lose its viability. In the initial stage, damage occurs at the microscopic level, and the bone tissue weakens over time. The body recognizes this dead bone tissue and initiates new bone formation by removing it. During this remodeling process, the bone becomes softer and weaker than normal.

Therefore, fractures and collapses can be seen in the femoral head during activities such as jumping, leaping, or falling. As the bone reshapes, it gains a form according to the pressure it receives. The femoral head may lose its round structure and become unable to move smoothly within the hip joint. Especially during periods of rapid growth, this deformity carries the risk of becoming permanent.

Course of the Disease

Perthes disease progresses in four main stages, and these stages are extremely important in terms of the treatment plan. The process of the disease lasts about 2 to 2.5 years. In the first stage, generally no symptoms are observed, and the disease can only be detected during imaging performed for a different purpose. Towards the end of the third stage, bone death in the femoral head is clearly observed.

The clinical course of the disease depends on the child's age and the amount of involvement. Under the age of 6, the course of the disease is quite favorable. In contrast, in children over 8 years of age, the disease is more severe. While a significant portion of patients recover without sequelae, a small portion exhibits shortening, a limp, and deformity in the femoral head.

Causes and Risk Factors of Perthes Disease

Reasons for the Cessation of Blood Flow

The exact cause of Perthes disease is not yet fully understood. Although many studies have been conducted on the development of the disease, the real cause has not been clarified. The main hypothesis is that it is a multifactorial disease involving mechanical, genetic, and systemic conditions.

The most widely accepted theory is that the disruption of normal blood flow in the femoral head due to repetitive mechanical stress is the main cause. Without adequate blood, the bone weakens and breaks easily. The reason for the temporary decrease in blood flow to the femoral head remains unknown.

In some cases, the reason for the interruption of blood flow remains unclear. There is very little evidence regarding genetic predisposition. Since it is not seen together in twin children, it is thought that it may be related to environmental factors.

Which Children Are at Risk?

The most emphasized definition in the development of the disease is the "susceptible child". The definition of the susceptible child includes the following factors:

Abnormal growth and development

Nutritional deficiency

Hip joint trauma

Hyperactivity and attention deficit

Environmental factors

Exposure to cigarette smoke

Petite body structure

Low birth weight

Hormonal disorders

In children diagnosed with Perthes disease, a delay in bone age compared to their peers may be observed. Hereditary factors, disruption of blood circulation, or the role of environmental influences can also be effective in the development of the disease.

Impaired blood supply to the femoral head can also be observed in children with blood diseases such as sickle cell anemia and thalassemia. Additionally, it can be seen in leukemia, lymphoma, idiopathic thrombocytopenic purpura, and hemophilia. There are studies showing that the risk of Perthes also increases in clotting abnormalities such as Protein C and Protein S deficiency, Factor V Leiden mutation, and prothrombin mutation.

It is seen more frequently in the Caucasian population compared to African and Asian populations. It has been reported that the incidence is higher among individuals living in countries with a lower socio-economic level.

Incidence Rate in Boys

In the disease, which is seen 4 times more frequently in boys compared to girls, a limp during walking is generally observed. The frequency of occurrence is higher in boys. The probability of developing this disorder is higher in white-skinned children than in other races.

According to research, the incidence of the disease varies between 0.2 and 19.1 per 100,000. Although the disease is frequently seen in children between the ages of 4-10, it can occur at any age throughout skeletal development. It is most frequently seen in children aged 4-9.

Generally occurring in a single hip joint, it is seen bilaterally in approximately 10% of cases. Bilateral involvement occurs at a rate of approximately 10%. In this case, the course and treatment of the disease can be more challenging.

What Are the Symptoms of Perthes Disease?

Early Stage Symptoms

Perthes disease symptoms follow a very mild course at the beginning. Children or parents mostly disregard these early signs. While it may sometimes cause no symptoms, it can sometimes manifest itself in the form of mild knee and hip pain. In some cases, the disease shows no symptoms at all and may be discovered incidentally if an x-ray is taken due to an injury or fall.

Symptoms usually start slowly and can intensify over time. Symptoms seen during the disease process can intensify and lighten from time to time. It is observed that families mostly mention past trauma in their history and state that the pain passes after rest.

Limping and Walking Disorders

The first complaint is usually limping noticed by the family. Although the child does not feel a difference at this point, the difference in walking can be seen when observed from the outside. Limping increases with physical activity and regresses with rest.

Especially after long walks or intense physical activities, the limp becomes more pronounced. Children with the disease may develop a walking disorder by restricting the movement of their hips. Examination reveals a mild limp and a decreased range of motion in the inward rotation of the hip.

Pain Complaints

The second most common complaint is pain. Pain is felt in the hip region, groin, knee, and thigh. The pain radiates from the hip joint towards the groin and thigh area. Diseases occurring in the hip joint can sometimes cause pain only in the knee area.

Pain increases with physical activity and reaches its peak especially in evening hours. Night pain is also common. Pain that worsens with activity and improves with rest is a characteristic feature. The child may feel pain when performing hip movements, and the pain may be greater especially when moving it.

Advanced Stage Symptoms

As the disease progresses, a decrease in movement and stiffness occur in the hip joint. Joint movements are limited, and the child may complain of pain during joint movements. Difficulty is observed in movements of opening the hip sideways, bending, or rotating.

In advanced cases, thinning and shortening of the leg diameter can be observed. Thinning in the leg and leg shortening may develop. The affected leg may appear shorter than the other leg. Weakness and thinning in the muscles around the hip and leg can be noticed. Swelling seen in the legs and irritation and inflammation in the hip region may also emerge.

How is Perthes Disease Diagnosed?

Physical Examination and Anamnesis

For the diagnosis of Perthes disease, the doctor first listens to the child's history and performs a physical examination. The orthopedic specialist observes the child's walking and checks hip movements. Limitation in the outward opening and inward rotation movements of the hip in particular are the most important findings.

Inward rotation limitation is best detected when the hip is in a flat position. For this, while the child lies face down, the knees are bent and hip rotations are evaluated. Leg length discrepancy or muscle weakness may also be seen during the examination. Progressive decrease in hip range of motion is a sign of a poor course.

Age, gender, and duration of findings are evaluated in an effort to differentiate it from other hip disorders showing similar symptoms. The starting age of the disease plays an important role in treatment selection.

X-Ray Examination

Most of the time, a bilateral hip X-ray is sufficient for the diagnosis of Perthes disease. X-ray examination is the primary imaging method of the disease. Deformations, collapse, or density changes in the femoral head are seen on the X-ray.

However, in the early stages of the disease, X-ray findings may not have appeared yet. X-rays may appear normal in early phases. X-ray findings are as important for diagnosis as they are guiding for the treatment plan. X-ray findings are guiding in making the decision for surgical treatment and classifying the disease.

MRI and Advanced Imaging Methods

In the diagnosis of Perthes disease, MRI or tomography is not needed in the vast majority of cases. On the other hand, MRI examination can enable diagnosis in the early stages of the disease. MRI is very helpful in early periods when X-rays do not provide sufficient information.

In the event that radiological findings are normal and limping does not pass within a period of 1 to 10 days, an MRI examination may be needed. MRI details the blood circulation disorder in the femoral head and the degeneration in the bone tissue. In addition, MRI provides good images to evaluate the shape of the femoral head cartilage, lateral subluxation, and soft tissues around the joint.

Bone scintigraphy has high sensitivity and specificity in evaluating changes in bone perfusion. Therefore, a skeletal scan can provide an earlier diagnosis compared to an X-ray examination.

Determination of the Stages of the Disease

To evaluate the severity of the disease, the Herring lateral pillar classification and Catterall classification are used. These classifications help determine the treatment plan. Radiological findings show which stage it is in and enable a decision on whether surgery is required.

Waldenstrom described the chronology of the radiological course of the disease. This classification provides information about the stage of the disease. In the initial period, the femoral head shrinks and its density increases. In the fragmentation phase, necrotic parts are resorbed and flattening is seen in the femoral head. In the reossification phase, new bone formation begins. In the remodeling phase, the ossification of the femoral head is completed.

How is Perthes Disease Treated?

Perthes disease treatment varies according to the child's age and the stage of the disease. The primary goal of treatment is to ensure compatibility between the femoral head and the hip joint socket. As long as the femoral head remains inside the socket, it is thought to maintain its roundness during remodeling.

Conservative Treatment Methods

In mild cases, doctors monitor the progression of the disease with regular check-ups. During this process, the child's growth and development process is closely followed. In the early periods of the disease, it is recommended not to weight-bear on the joint. Since the disease can last for 2 to 5 years, crutches should be used during periods when pain and limping increase.

Orthosis treatments have an important place among conservative methods. Special orthopedic devices such as hip braces support joint alignment. However, in cases where head involvement is widespread, brace treatment can lead to poor results. In younger patients and those with less widespread head involvement, better results can be achieved with brace treatment.

Painkillers and anti-inflammatory drugs are used to keep pain and inflammation under control. These drugs ensure the child's comfort and support the treatment process.

Physical Therapy and Rest

The main goal of the physical therapy program is to preserve the range of joint motion and increase muscle strength. With stretching exercises, the flexibility of the hip and thigh muscles is increased, preserving the range of joint motion. Thanks to strengthening exercises, muscle groups around the hip are strengthened to ensure better support of the joint.

Hydrotherapy is extremely effective in the treatment of Perthes. The buoyancy of water eliminates body weight and reduces the load on the hip joint by up to 90%. Children cannot participate in sports activities, but activity restriction covers movements that put a load on the hip, such as jumping and running.

Surgical Treatment Options

In case of disease progression, surgical treatment may be required. Surgery ensures proper alignment of the femoral head. Screws, plates, or pins can be placed to keep the hip stable.

With osteotomy, the thigh bone or hip socket is surgically cut and reshaped. Femoral osteotomy allows the femoral head to sit more correctly into the joint socket. Pelvic osteotomy, on the other hand, reshapes the structure of the hip socket to ensure the femoral head remains in the correct position within the socket.

Treatment Process and Follow-up

After surgery, the child may need to be casted for six to eight weeks. Physical therapy is often required to accelerate the post-operative recovery process. The treatment process usually takes years, and regular follow-up is important to protect hip health.

Treatment Approaches According to Age

Surgical treatment is rarely required in children under 6 years of age. In the early phase, especially in children younger than 6 years old, the femoral head has the potential to remodel itself. In contrast, surgical intervention is required more frequently in children over 8 years of age.

Frequently Asked Questions About Perthes Disease

Does Perthes disease completely go away?

With early diagnosis and correct treatment management, the vast majority of children have a painless and functional hip in adulthood. The quality of recovery of the disease is directly dependent on the age of diagnosis, the stage of the disease, and the treatment methods applied.

With early diagnosis and appropriate treatment, the femoral head can be reshaped and permanent damage can be prevented. Over time, if blood flow continues, the femoral head renews itself, but deteriorations may occur. While some patients recover, deformity is seen in the femoral head in some patients, and this condition causes a limp and a gait disturbance.

If left untreated or delayed, the femoral head can permanently flatten or take an irregular shape. This condition can result in hip osteoarthritis, chronic pain, and limited movement in adult life.

In which age group is treatment more successful?

The success of treatment depends on the age at which the disease is diagnosed and how much of the femoral head is affected. When the disease is seen under the age of six, the recovery process is faster. In children diagnosed at a young age, especially under 6 years old, the bone regeneration capacity is higher, so the results are generally more gratifying.

In contrast, in children older than 6 years, in children with a severe course of the disease, and in females compared to males, the results are slightly poorer. The risk of early osteoarthritis increases at an advanced age and with widespread involvement. Children with an onset age of less than 8 years have a better prognosis than children older than 8 years.

How long does the treatment process take?

The treatment process can vary depending on the patient's condition. The course of the disease usually ends within 2 to 3 years. Complete recovery, re-hardening, and final shaping of the femoral head take between 2 and 4 years.

Although the treatment process changes depending on the child's age and the stage of the disease, it usually lasts between 1 and 3 years. Physiotherapy and doctor follow-up continue throughout this period. Regular check-up appointments track the healing process in the hip joint and detect possible complications at an early stage.

Why does the disease occur?

The main cause of the disease is insufficient blood reaching the femoral head. When blood circulation is cut off, the oxygen and nutrients necessary for the bone cannot be transported, and this leads to the weakening of the bone tissue. Although the exact cause of the disease is unknown, genetic predisposition may play a role in some cases.

In some children, Perthes disease can be seen more frequently due to genetic predisposition. However, it is definitely not contagious. Although it is thought that there may be a genetic predisposition, it is not a hereditary disease passed directly from mother and father to child.

The disease usually appears during periods of rapid growth. During this period, there may be an incompatibility between blood circulation and bone development. In addition, the risk increases in children exposed to passive cigarette smoke because nicotine disrupts vascular structure and reduces the blood supply to bone tissue.

In Summary, Perthes Disease

Perthes disease can cause concern in your child, but it can be managed successfully with the right approach. Early diagnosis is extremely important, and when you notice limping or hip pain in your child, you should immediately consult an orthopedic specialist. Treatment results are quite favorable, especially in children under 6 years of age.

The treatment process can last 2 to 3 years, so you must be patient and not neglect doctor follow-ups. Conservative methods are sufficient in most cases, but surgical intervention may be required in some cases. By adhering to regular check-ups and the physical therapy program, you can protect your child's hip health and ensure a long-term, pain-free quality of life.