S79.129A Salter-Harris Type II physeal fracture of lower end of unspecified femur, initial encounter for closed fracture

Name of the Condition

Salter-Harris Type II physeal fracture of lower end of unspecified femur, initial encounter for closed fracture

Summary

A Salter-Harris Type II physeal fracture of the lower end of the unspecified femur is an injury involving the growth plate (physis) at the distal femur, typically occurring in children or adolescents. This fracture disrupts the physis, which is the area of developing bone responsible for longitudinal growth. The injury specifically involves a separation of the growth plate with a fracture through the metaphysis, as defined by the Salter-Harris classification system. The fracture line extends from the physis into the metaphysis, distinguishing it from Type I fractures. This code is used for the initial encounter of a closed fracture, meaning the skin is intact and there is no communication with the external environment.

Causes

Salter-Harris Type II physeal fractures of the lower femur are usually caused by acute trauma, such as falls, sports-related injuries, or direct blows to the knee or thigh. The force transmitted across the growth plate can cause it to separate from the adjacent bone, with the fracture extending into the metaphysis. In some cases, repetitive stress or overuse may contribute to the injury, particularly in active children or adolescents.

Risk Factors

• Age: Most common in children and adolescents, as growth plates are weaker than surrounding bone.
• Activity level: Participation in high-impact sports or activities with a risk of falls (e.g., gymnastics, soccer, skateboarding).
• Growth spurts: Periods of rapid growth may temporarily weaken the physis, increasing susceptibility to injury.
• Anatomical factors: Variation in bone density or growth plate structure may influence risk.

Symptoms

Symptoms typically include pain, swelling, and tenderness at the site of injury, often around the knee or thigh. The affected limb may appear deformed or shortened, and the patient may have difficulty bearing weight or moving the joint. Bruising or discoloration may also be present. In some cases, a visible deformity or abnormal positioning of the limb may be observed.

Diagnosis

Diagnosis is based on clinical evaluation and imaging studies. A physical examination will assess for pain, swelling, deformity, and range of motion limitations. Imaging, such as X-rays, is essential to confirm the fracture type and location. X-rays can show the characteristic fracture line extending from the physis into the metaphysis, consistent with a Salter-Harris Type II injury. In some cases, additional imaging (e.g., MRI) may be used to evaluate soft tissue damage or assess the extent of the injury.

Treatment Options

Treatment depends on the severity and displacement of the fracture. Nondisplaced fractures may be managed with immobilization, such as a cast or splint, to allow healing. Displaced fractures often require closed reduction (realignment of the bone) under anesthesia, followed by immobilization. Surgical intervention may be necessary for severely displaced or unstable fractures to ensure proper alignment and healing. Physical therapy is typically recommended during recovery to restore strength and mobility.

Prognosis and Follow-Up

Prognosis is generally good with appropriate treatment, especially for nondisplaced or minimally displaced fractures. Most patients recover fully without long-term complications. Follow-up care includes regular monitoring of healing through clinical exams and imaging. Physical therapy may be recommended to restore function. Long-term follow-up is important to assess for potential growth disturbances or angular deformities, particularly if the fracture was significantly displaced or required surgical intervention.

Complications

Potential complications include growth plate damage leading to limb length discrepancy or angular deformity, especially if the fracture is severe or improperly aligned. Infection is rare but possible with surgical intervention. Other risks include stiffness or limited range of motion in the affected joint, which may require ongoing therapy. In some cases, premature closure of the growth plate can occur, affecting future growth.

Lifestyle & Prevention

Preventive measures include using appropriate protective gear during high-impact activities (e.g., helmets, pads) and ensuring proper training techniques to reduce injury risk. Maintaining overall bone health through a balanced diet rich in calcium and vitamin D may support bone strength. Supervision during activities with a risk of falls, such as playground use or sports, can help minimize trauma. Gradual progression in physical activity and avoiding overuse can also reduce stress on the growth plate.

When to Seek Professional Help

Seek immediate medical attention if there is severe pain, visible deformity, inability to bear weight, or signs of nerve or vascular compromise (e.g., numbness, coldness, discoloration). Prompt evaluation is critical to ensure proper diagnosis and treatment, especially if the injury is suspected to involve the growth plate. Delayed or improper treatment may increase the risk of complications.

Tips for Medical Coders

When coding for S79.129A, ensure the documentation specifies the fracture as Salter-Harris Type II, involving the lower end of the femur, and indicates it is an initial encounter for a closed fracture. The term "unspecified femur" should be used when the side (right or left) is not documented. Verify that the encounter is classified as initial (not subsequent or sequela) and that the fracture is closed (no open wound or communication with the external environment). Accurate documentation of the fracture type, location, and encounter status is essential for correct coding.