S82.866B Nondisplaced Maisonneuve's fracture of unspecified leg, initial encounter for open fracture type I or II

Name of the Condition

• Nondisplaced Maisonneuve's fracture of unspecified leg, initial encounter for open fracture type I or II
• ICD-10 Code: S82.866B

Summary

A Maisonneuve's fracture is a specific type of ankle injury involving a proximal fibula fracture combined with a tear of the tibiofibular syndesmosis and often an associated medial malleolus or deltoid ligament injury. 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, leading to instability in the ankle joint. The "open fracture type I or II" designation refers to a fracture where the skin is breached, with type I involving a wound less than 1 cm and type II involving a wound 1–10 cm without extensive soft tissue damage or contamination.

Causes

The fracture is usually caused by external rotation of the foot, which can occur during activities like twisting the ankle, falls, or sports-related injuries. The rotational force disrupts the syndesmotic ligaments and may cause additional damage to the medial structures of the ankle. Open fractures occur when the force is sufficient to penetrate the skin, often due to high-energy trauma or a sharp bone fragment piercing the tissue.

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.
• Traumatic events involving significant rotational forces or direct impact to the leg.

Symptoms

• 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."
• Bruising or tenderness along the lower leg.
• Visible wound or laceration at the fracture site (for open fractures).

Diagnosis

Diagnosis involves a physical examination to assess ankle stability, tenderness, and swelling. Imaging, typically X-rays, is used to identify the proximal fibula fracture and associated injuries. Additional imaging, such as CT or MRI, may be required to evaluate soft tissue damage or syndesmotic ligament tears. For open fractures, the wound is assessed for size, contamination, and depth to determine the fracture type.

Treatment Options

Treatment depends on the severity of the fracture and soft tissue damage. Nondisplaced fractures may be managed with immobilization (e.g., casting or bracing) and weight-bearing restrictions. Open fractures require prompt wound care, irrigation, and debridement to reduce infection risk, followed by stabilization (e.g., casting or surgical fixation). Surgical intervention may be necessary for unstable fractures or significant ligament damage. Physical therapy is often recommended during recovery to restore strength and mobility.

Prognosis and Follow-Up

Prognosis is generally favorable with appropriate treatment, though recovery time varies based on fracture severity and soft tissue involvement. Nondisplaced fractures typically heal within 6–8 weeks, while open fractures may require longer healing periods due to infection risk. Follow-up appointments are necessary to monitor healing, assess for complications (e.g., infection or malunion), and guide rehabilitation. Long-term outcomes depend on adherence to treatment and rehabilitation protocols.

Complications

• Infection (more common in open fractures).
• Delayed union or nonunion of the fracture.
• Chronic ankle instability or arthritis.
• Nerve or vascular damage from the initial injury or surgical intervention.
• Skin necrosis or wound healing issues in open fractures.

Lifestyle & Prevention

• Wear appropriate footwear for activities, especially those with high rotational stress.
• Use ankle braces or supports during sports or on uneven terrain.
• Maintain strength and flexibility in the ankle through regular exercise.
• Avoid activities that increase fall risk, such as walking on slippery surfaces.
• Seek prompt treatment for ankle injuries to prevent progression to more severe fractures.

When to Seek Professional Help

• Severe pain, swelling, or inability to bear weight on the leg.
• Visible wound or laceration at the injury site.
• Numbness, tingling, or coldness in the foot (signs of nerve or vascular damage).
• Worsening symptoms despite initial care (e.g., increased pain, redness, or drainage from a wound).
• Suspected open fracture or signs of infection (e.g., fever, pus, or red streaks).

Tips for Medical Coders

Document the fracture location (proximal fibula), displacement status (nondisplaced), leg (unspecified), encounter type (initial), and open fracture type (I or II) clearly. Specify the mechanism of injury (e.g., rotational force) and any associated injuries (e.g., medial malleolus or deltoid ligament damage) to support code assignment. Ensure wound characteristics (size, contamination) are documented for open fractures to justify the type I or II designation.