S82.864K Nondisplaced Maisonneuve's fracture of right leg, subsequent encounter for closed fracture with nonunion

Name of the Condition

• Nondisplaced Maisonneuve's fracture of right leg, subsequent encounter for closed fracture with nonunion

Summary

A Maisonneuve's fracture is a specific type of ankle injury involving a fracture of the proximal fibula (upper portion of the smaller lower leg bone) combined with a tear of the syndesmotic ligaments and often an associated injury to the medial malleolus or deltoid ligament. The term "nondisplaced" indicates that the fractured bone fragments remain in their normal alignment. This injury typically results from rotational forces applied to the ankle, commonly seen in trauma such as falls or sports injuries. The "subsequent encounter for closed fracture with nonunion" specifies this is a follow-up visit for a fracture that has not healed properly, with no open wound present.

Causes

The fracture is caused by external rotational forces applied to the ankle, often during activities that involve twisting or turning. Common scenarios include falls, motor vehicle accidents, or sports-related impacts where the foot is planted and the body rotates forcefully. The mechanism typically involves the talus rotating outward, stressing the syndesmotic ligaments and causing the proximal fibula to fracture. Nonunion may occur due to inadequate immobilization, poor blood supply to the fracture site, or excessive movement before healing.

Risk Factors

• Participation in activities with high rotational stress on the ankle, such as soccer or basketball.
• Previous ankle injuries or ligamentous instability.
• Improper footwear or uneven terrain increasing fall risk.
• Age-related factors that may affect bone density or ligament integrity.
• Smoking or other factors that impair bone healing.
• Inadequate initial treatment or noncompliance with immobilization protocols.

Symptoms

• Persistent pain and swelling localized to the proximal fibula and ankle.
• Difficulty bearing weight on the affected leg.
• Instability or a feeling of the ankle "giving way."
• Possible visible deformity if displacement occurs (though nondisplaced by definition).
• Prolonged healing time or lack of improvement with standard treatment.

Diagnosis

Diagnosis typically involves a physical examination to assess pain, swelling, and stability of the ankle. Imaging studies, such as X-rays, are used to confirm the fracture and assess alignment. Additional tests like CT scans or MRIs may be ordered to evaluate the syndesmotic ligaments or check for nonunion. The "subsequent encounter" designation implies prior documentation of the fracture, and the "nonunion" finding is confirmed by imaging showing no bridging bone across the fracture site after an appropriate healing period.

Treatment Options

Treatment focuses on promoting healing of the nonunion and restoring ankle stability. Options may include prolonged immobilization with a cast or brace, surgical intervention to fix the fracture (e.g., internal fixation with screws or plates), and physical therapy to regain strength and mobility. Pain management and activity modification are also part of the plan. The choice of treatment depends on the severity of the nonunion and the patient's overall health.

Prognosis and Follow-Up

Prognosis varies based on the success of treatment and the patient's adherence to rehabilitation. With proper intervention, many patients achieve union and improved function, though some may experience long-term ankle instability or arthritis. Follow-up visits are necessary to monitor healing, adjust treatment, and address any complications. Regular imaging may be used to assess progress toward union.

Complications

• Persistent nonunion or delayed healing.
• Chronic ankle pain or instability.
• Post-traumatic arthritis in the ankle joint.
• Nerve or blood vessel damage (rare).
• Infection (if surgical intervention is required).

Lifestyle & Prevention

• Avoid high-impact activities until cleared by a healthcare provider.
• Use proper footwear and avoid uneven surfaces to reduce fall risk.
• Engage in exercises to strengthen the ankle and lower leg muscles.
• Follow rehabilitation protocols closely to support healing.
• Maintain a healthy lifestyle, including adequate nutrition and avoiding smoking, to promote bone health.

When to Seek Professional Help

Seek immediate medical attention if you experience severe pain, inability to bear weight, visible deformity, or signs of infection (e.g., redness, warmth, fever) after a fracture. For follow-up, consult a healthcare provider if symptoms worsen, or if you notice persistent swelling, instability, or lack of improvement during recovery.

Tips for Medical Coders

Document the encounter as a "subsequent" visit for a closed fracture with nonunion. Ensure the record specifies the fracture type (Maisonneuve's), location (right leg), and the presence of nonunion. Include details on treatment provided, imaging results, and any modifications to the care plan. The code S82.864K requires clear documentation of the nonunion status and the closed nature of the fracture to support accurate coding.