Epiphysiolysis

Epiphysiolysis is a type of fracture that occurs in the growth plates of children’s bones, where the rounded end of the bone separates or slips from the main bone shaft, often affecting active youngsters during their growing years.

Table of contents

• What is epiphysiolysis?
• Growth plate anatomy
• Who is affected?
• What causes epiphysiolysis?
• Signs and symptoms
• How is it diagnosed?
• Classification of epiphysiolysis
• Treatment approaches
• Potential complications

What is epiphysiolysis?

Epiphysiolysis, also known as a growth plate fracture, occurs when the growth plate at the end of a child’s bone separates^[14]. These fractures are among the most common injuries in growing children and adolescents. The growth plate is a crucial area responsible for bone growth, and any disruption in this area can lead to problems with bone development^[14].

The condition commonly affects growing children and adolescents due to the vulnerability of their developing bones^[14]. Among pediatric fractures, epiphysiolysis accounts for between 15% and 30% of all cases^[13].

growth plate fracture, physeal fracture, slipped epiphysis

Growth plate anatomy

The growth plate, also called the physis, is the rounded end part of the bone. In children, it generates new bone, which makes the bone grow^[9]. These plates are located near the ends of long bones and allow the bones to elongate^[13].

The growth plate consists of 4 regions that progress from cartilage to bone formation^[13]. Growth plates are located between the widened part of the shaft of the bone (called the metaphysis) and the end of the bone (called the epiphysis)^[3].

The blood circulation of the epiphysis is poor and injuries can damage the small vessels that feed the growth area^[13]. The most common injury occurs in the hypertrophic region due to its structural weakness^[13].

Who is affected?

Growth plate injuries are most common in the wrist and ankle^[13]. One specific type of epiphysiolysis, called slipped capital femoral epiphysis or SCFE, is the most common hip disorder in adolescents^[3]. This condition most commonly occurs between the ages of 12 and 16 years in boys, and the ages of 10 and 14 years in girls^[3].

The single most significant risk factor for certain types of epiphysiolysis is obesity^[4]. Other risk factors include male sex, periods of rapid growth, prior radiation therapy, and specific anatomical factors that increase mechanical stress across the growth plate^[4].

What causes epiphysiolysis?

The main cause of epiphysiolysis is usually related to sudden or repetitive stress on the growth plate during activities such as sports or accidents^[14]. Most cases are idiopathic, meaning there is often no history of trauma or injury before the onset of symptoms^[4].

Young athletes who specialize in a single sport, or who throw or pitch often without proper rest, may develop this condition^[17]. The condition results from repeated stress to the growth plate region. Normally the body responds to pulling and stretching forces by healing any stressed tissue during times of rest in between periods of activity^[17].

An association has been reported between the development of epiphysiolysis and patients with endocrine disorders (including hypothyroidism, hyperthyroidism, and growth hormone deficiency), kidney disorders, and Down syndrome^[4]. Hypothyroidism is the most common cause of non-idiopathic cases^[4].

If epiphysiolysis is seen in children below walking age, child abuse should be suspected^[2].

Signs and symptoms

Epiphysiolysis can cause symptoms such as pain, swelling, and difficulty bearing weight on the affected limb^[14]. Children may experience a sudden onset of pain during physical activity or after an injury^[14].

Common examination findings after an epiphyseal injury include^[13]:

• Deformity
• Pain
• Swelling
• Increased pain with touch

When the hip is affected, specific symptoms may include^[14]:

• Pain in the hip or groin area, often worsening with activity
• Limping or difficulty bearing weight on the affected leg
• Limited range of motion in the hip joint, making activities like walking or sitting uncomfortable
• The affected leg may appear shorter than the other, causing an uneven walk
• In some cases, the leg may turn outward while walking or standing

The affected limb may appear shorter than the other, and there could be limited range of motion^[14]. Questioning the injury mechanism in detail will provide valuable information in the diagnosis^[13].

How is it diagnosed?

The first imaging method used is X-ray. Most of the time, it provides sufficient information in diagnosis and treatment. When necessary, the image of the healthy side should be taken and compared^[13].

When X-ray is not sufficient to identify complex, intra-articular, or displaced fractures, computed tomography (CT) can be used by adjusting the dose^[13]. MRI can detect hidden fractures in patients with normal X-rays. It can show structures such as periosteum, ligaments and tendons that may prevent proper healing^[13].

It is essential to seek medical attention if symptoms occur to prevent complications and ensure proper treatment^[14].

Classification of epiphysiolysis

The most commonly used classification for growth plate injuries is the Salter-Harris Classification^[13]. Complication rates generally increase in advanced stages as the injury approaches the growth-producing region^[13].

Salter-Harris Type I fractures are physeal injuries without epiphyseal or metaphyseal extension. Undisplaced fractures are common, not visible on an X-ray, and diagnosed clinically by local tenderness^[5].

Salter-Harris Type II fractures are the most common type of growth plate injury^[13]. These are physeal injuries with metaphyseal extension. The metaphyseal component is known as the Thurstan Holland fragment and remains attached to the epiphysis^[5]. The Salter-Harris II fracture is the most common pattern of injury involving growth plates in various bones, including the distal femur and distal fibula^[2][5].

It should be kept in mind that in type 4 injuries, the articular surface is damaged. All layers are affected. In case of separation, fusion can be seen in the bone tissues separated by the growth plate^[13].

Treatment approaches

Child fractures heal faster than adults and require a shorter cast. Joint stiffness is less common. Angular or length difference improvement over time, which is defined as remodeling, in children is much higher than in adults^[13].

Very commonly, growth plate fractures can be treated without surgery. Salter-Harris Type I and Type II injuries usually can be managed adequately with closed manipulation and reduction^[10]. Upon reduction, these injuries are typically stable, and casting is sufficient^[10].

In these injuries, cast treatment with closed intervention (manipulation) is usually applied first. If the control images obtained later meet the follow-up criteria, the patient is followed up closely. It should be checked at short intervals^[13]. If unsuitable, repetitive manipulations should be avoided. Repeated manipulations can damage the growth plate, causing growth arrest^[13].

Especially in unstable fractures, if the decision to follow-up with cast is taken, imaging follow-up should be performed at short intervals in the early period. If a loss of position in the cast is noticed after 7-10 days, further interventions may result in growth arrest^[13].

After surgery, children need to be encouraged to walk and move their limbs as much as they can. It is important not to stop doing this as it can get stiff and make their limb more painful^[9]. The child may not need a walking aid if they can hold their own weight by themselves. It will be uncomfortable, but with pain relief it will be eased^[9].

Salter-Harris Type III and Type IV injuries represent disruption of the physis and the epiphysis, as well as intra-articular fracture. Proper management requires anatomic reduction and internal fixation to restore anatomic alignment of the joint surfaces and proper alignment of growth plate surfaces^[10].

For specific hip conditions involving epiphysiolysis, treatment involves surgery to stop the head of the femur from slipping any further^[3]. To achieve the best outcome, it is important to be diagnosed as quickly as possible^[3].

Potential complications

Growth plate injuries can lead to many complications such as limb length inequalities, growth retardation, improper healing, angular deformities, and bone bridge formation in the growth plate^[13]. The complication rate is between 5% and 10%^[13].

The earlier the injury occurs, the higher the risk of complications^[13]. Salter-Harris Type V and Type VI injuries often result in partial or complete growth arrest, which means bone bridge formation in the growth plate. As a result, surgical procedures may be necessary to prevent or correct deformity^[10].

Without early detection and proper treatment, certain types of epiphysiolysis can lead to potentially serious complications, including rapid deterioration of the bone end and painful arthritis in the joint^[3].

A delay in the diagnosis is associated with higher rates of complications, including bone death (osteonecrosis)^[4]. Therefore, medical providers must always consider the diagnosis of epiphysiolysis when children and adolescents present with limb pain^[4].