M84.750 Atypical femoral fracture, unspecified

Name of the Condition

• Atypical Femoral Fracture, Unspecified (ICD-10-CM: M84.750)

Summary

This condition refers to a specific type of femoral fracture that occurs with minimal or no trauma, often associated with long-term bisphosphonate use or other risk factors. It typically involves the subtrochanteric or diaphyseal region of the femur and may present with prodromal symptoms before a complete fracture.

Causes

Atypical femoral fractures are thought to result from impaired bone remodeling, often linked to prolonged bisphosphonate therapy, though other factors like glucocorticoid use, vitamin D deficiency, or metabolic bone disorders may contribute. The exact mechanism involves reduced bone turnover leading to increased brittleness.

Risk Factors

• Long-term bisphosphonate therapy (e.g., alendronate, risedronate)
• Advanced age
• Low vitamin D levels or calcium deficiency
• History of prior femoral stress fractures
• Chronic glucocorticoid use
• Asian ethnicity (higher reported incidence)

Symptoms

• Groin or thigh pain, often bilateral and insidious in onset
• Pain that worsens with weight-bearing or activity
• Possible prodromal symptoms like dull aching before fracture
• Sudden severe pain if a complete fracture occurs
• May present with a visible deformity or inability to bear weight

Diagnosis

Diagnosis requires a combination of clinical evaluation and imaging. Plain radiographs typically show a transverse or short oblique fracture with cortical thickening or a "beaking" appearance. MRI or bone scans may be used to detect early or incomplete fractures. Patient history, including medication use, is critical for correlation.

Treatment Options

• Immediate immobilization and non-weight-bearing status
• Surgical fixation (intramedullary nailing or plate fixation) for displaced fractures
• Discontinuation of inciting medications (e.g., bisphosphonates) under medical guidance
• Calcium and vitamin D supplementation to support bone health
• Physical therapy for rehabilitation post-surgery

Prognosis and Follow-Up

Prognosis depends on fracture severity and treatment timing. Early diagnosis and intervention improve outcomes. Follow-up includes monitoring for healing via imaging and assessing for contralateral limb involvement. Long-term surveillance for bone health is recommended.

Complications

• Delayed or nonunion of the fracture
• Contralateral femoral fracture
• Surgical complications (infection, hardware failure)
• Chronic pain or functional impairment
• Increased risk of future fractures due to underlying bone fragility

Lifestyle & Prevention

• Maintain adequate calcium and vitamin D intake
• Engage in weight-bearing exercise to support bone density
• Avoid smoking and excessive alcohol, which weaken bones
• Discuss medication risks with providers if on long-term bisphosphonates
• Use protective measures during high-impact activities

When to Seek Professional Help

Seek immediate care if you experience sudden, severe thigh or groin pain, especially if you have a history of bisphosphonate use or prior femoral issues. Persistent, unexplained thigh pain warrants evaluation to rule out early fracture.

Tips for Medical Coders

Document the fracture location (subtrochanteric/diaphyseal), trauma history, and associated risk factors (e.g., bisphosphonate use) to support coding. Ensure the unspecified nature of the fracture is clearly noted, as this code is used when details are not documented. Correlate with imaging and clinical findings to confirm atypical characteristics.