M93.031 Acute on chronic slipped upper femoral epiphysis (nontraumatic), right hip

Name of the Condition

• Acute on chronic slipped upper femoral epiphysis (nontraumatic), right hip

Summary

Acute on chronic slipped upper femoral epiphysis (SUFE) is a condition where the femoral head (ball of the hip joint) shifts from its normal position on the femoral neck due to a fracture through the growth plate. This nontraumatic form occurs without a specific injury and presents as an acute worsening of a chronic, pre-existing slip. The condition primarily affects adolescents during growth spurts and can lead to hip pain, stiffness, or gait changes. Prompt evaluation is important to prevent complications.

Causes

The exact cause of acute on chronic SUFE is not fully understood, but it is thought to result from mechanical stress on the growth plate combined with hormonal influences during puberty. Reduced blood flow to the growth plate may weaken the bone, allowing the femoral head to slip. Obesity is also considered a contributing factor due to increased mechanical load on the hip. The acute presentation suggests a sudden displacement, possibly due to cumulative stress or a minor, unrecognized event.

Risk Factors

• Age: Most common in adolescents aged 10-16 years, particularly during rapid growth spurts.
• Gender: Males are more frequently affected than females.
• Obesity: Higher body weight increases stress on the hip joint.
• Endocrine disorders: Conditions like hypothyroidism or growth hormone abnormalities may elevate risk.
• Prior chronic slip: A pre-existing, undiagnosed or untreated chronic slip increases the risk of acute progression.

Symptoms

• Hip, thigh, or knee pain (pain may be referred to the knee).
• Limp or altered gait (e.g., walking with a limp or toe-out stance).
• Reduced range of motion in the hip, especially internal rotation.
• Sudden worsening of symptoms in a patient with a known or suspected chronic slip.
• Pain worsened by activity or weight-bearing.

Diagnosis

Diagnosis involves a physical exam to assess hip range of motion, gait, and pain. Imaging studies, such as X-rays or MRI, are used to confirm the slip and differentiate between acute, chronic, or acute on chronic presentations. The right hip is specifically evaluated in this code.

Treatment Options

Treatment typically involves surgical stabilization to realign the femoral head and prevent further displacement. The approach may depend on the severity of the slip and the patient’s age. Postoperative care includes activity modification and follow-up imaging to monitor healing.

Prognosis and Follow-Up

Prognosis depends on the timing of diagnosis and treatment. Early intervention reduces the risk of complications like avascular necrosis or arthritis. Follow-up care includes regular monitoring of hip function and imaging to assess for long-term effects.

Complications

• Avascular necrosis (loss of blood supply to the femoral head).
• Premature osteoarthritis of the hip.
• Gait abnormalities or leg length discrepancy.
• Chronic pain or reduced mobility.

Lifestyle & Prevention

Maintaining a healthy weight may reduce stress on the hip joint. Regular physical activity and prompt evaluation of hip pain in adolescents can help identify issues early. Avoid high-impact activities that strain the hip until cleared by a healthcare provider.

When to Seek Professional Help

Seek immediate medical attention if there is sudden, severe hip pain, inability to bear weight, or a noticeable change in gait. Early diagnosis is critical to prevent complications.

Tips for Medical Coders

Document the acute exacerbation of a chronic slip and specify the right hip. Include details on the clinical presentation, imaging findings, and treatment to support code assignment. Ensure documentation differentiates this from acute or chronic slips alone.