M84.752K Incomplete atypical femoral fracture, left leg, subsequent encounter for fracture with nonunion

Name of the Condition

• Incomplete Atypical Femoral Fracture, Left Leg, Subsequent Encounter for Fracture with Nonunion (ICD-10-CM: M84.752K)

Summary

An incomplete atypical femoral fracture is a specific type of femoral fracture that occurs with minimal or no trauma, typically involving the subtrochanteric or diaphyseal region of the femur. This condition is often associated with underlying bone fragility, such as from long-term bisphosphonate use, and may present with prodromal symptoms like thigh or groin pain before a complete fracture occurs. The "incomplete" designation indicates the fracture does not fully traverse the bone, while "left leg" specifies the anatomical location. The "subsequent encounter for fracture with nonunion" modifier indicates this is a follow-up visit for a fracture that has failed to heal properly.

Causes

Incomplete atypical femoral fractures result from a combination of mechanical stress and impaired bone quality. Prolonged use of antiresorptive medications (e.g., bisphosphonates) is a well-documented cause, as these drugs may alter bone remodeling. Other contributing factors include metabolic bone disorders, vitamin D deficiency, or conditions that weaken bone structure, even in the absence of significant trauma.

Risk Factors

• Long-term use of antiresorptive or antiangiogenic medications.
• History of low-trauma fractures or osteoporosis.
• Vitamin D deficiency or calcium insufficiency.
• Chronic kidney disease or other metabolic disorders affecting bone health.
• Female gender, particularly postmenopausal individuals.

Symptoms

• Persistent, dull, or aching pain in the thigh or groin, often preceding the fracture.
• Sudden, severe pain if the fracture occurs.
• Difficulty bearing weight on the affected leg.
• Possible swelling or bruising around the fracture site.

Diagnosis

Diagnosis typically involves a combination of clinical evaluation and imaging studies. A thorough patient history, including medication use and trauma history, is essential. Imaging modalities such as X-rays, MRI, or CT scans are used to confirm the fracture and assess for nonunion. Bone density tests may also be performed to evaluate underlying bone health.

Treatment Options

Treatment depends on the severity of the fracture and the presence of nonunion. Options may include conservative management with pain relief and activity modification, or surgical intervention such as internal fixation or bone grafting to promote healing. Long-term monitoring of bone health and medication adjustments may be necessary.

Prognosis and Follow-Up

Prognosis varies based on the fracture's response to treatment and the underlying bone health. Nonunion may require additional interventions, and recovery can be prolonged. Regular follow-up with imaging and clinical assessments is important to monitor healing and adjust treatment as needed.

Complications

• Delayed or failed healing (nonunion).
• Progression to a complete fracture.
• Chronic pain or functional impairment.
• Potential for future fractures due to underlying bone fragility.

Lifestyle & Prevention

• Maintain adequate calcium and vitamin D intake.
• Engage in weight-bearing exercises to support bone health.
• Avoid high-impact activities that may increase fracture risk.
• Discuss medication risks with a healthcare provider if on long-term antiresorptive therapy.

When to Seek Professional Help

Seek immediate medical attention if experiencing sudden, severe thigh or groin pain, inability to bear weight, or worsening symptoms. Persistent pain or swelling after a known fracture also warrants evaluation.

Tips for Medical Coders

Document the encounter type (subsequent) and the presence of nonunion clearly in the medical record. Ensure the left leg and incomplete nature of the fracture are specified. Code M84.752K is appropriate for follow-up visits where the fracture has not healed, and nonunion is confirmed.