S79.139 Salter-Harris Type III physeal fracture of lower end of unspecified femur

Name of the Condition

Salter-Harris Type III physeal fracture of lower end of unspecified femur

Summary

A Salter-Harris Type III 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 and extends through the epiphysis, as defined by the Salter-Harris classification system. The injury involves a fracture line that passes through the growth plate and into the epiphyseal bone, potentially affecting joint stability and future growth.

Causes

Salter-Harris Type III 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 and extend into the epiphysis. 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: Variations in bone structure or alignment may predispose to injury.

Symptoms

Symptoms may include pain, swelling, and tenderness at the fracture site, often with visible deformity or inability to bear weight. The affected limb may appear shortened or misaligned, and movement of the knee joint may be restricted. Bruising or discoloration around the injury area is common.

Diagnosis

Diagnosis typically involves a physical examination to assess pain, swelling, and range of motion, followed by imaging studies such as X-rays or MRI to visualize the fracture pattern and extent of damage. The Salter-Harris classification is used to determine the fracture type, and additional tests may be ordered to rule out associated injuries.

Treatment Options

Treatment depends on the severity and displacement of the fracture. Nondisplaced fractures may be managed with immobilization (e.g., casting) and activity restriction. Displaced fractures often require surgical intervention to realign the bone and stabilize the growth plate, followed by postoperative immobilization and physical therapy to restore function.

Prognosis and Follow-Up

Prognosis varies based on the accuracy of reduction and the extent of growth plate involvement. Early intervention and proper alignment generally yield better outcomes. Follow-up care includes regular monitoring of growth and joint function, with imaging to assess for potential growth disturbances or long-term complications.

Complications

Potential complications include growth plate arrest, limb length discrepancy, joint stiffness, or arthritis. Malunion or nonunion of the fracture may also occur, particularly if treatment is delayed or inadequate. In rare cases, avascular necrosis of the epiphysis may develop.

Lifestyle & Prevention

Preventive measures include using appropriate protective gear during sports, ensuring proper training techniques, and avoiding high-risk activities without supervision. Maintaining bone health through adequate nutrition (e.g., calcium and vitamin D) and avoiding overuse injuries can reduce fracture risk.

When to Seek Professional Help

Seek immediate medical attention if there is severe pain, inability to move the limb, visible deformity, or signs of infection (e.g., fever, redness, drainage). Prompt evaluation is critical to prevent complications and ensure proper healing.

Tips for Medical Coders

When coding for S79.139, ensure the documentation specifies the fracture as Salter-Harris Type III and involves the lower end of the femur without specifying laterality. Verify that the injury is clearly described as a physeal fracture to support accurate code assignment. Documentation should include details of the fracture pattern, treatment, and any associated complications to support comprehensive coding.