S82.866C Nondisplaced Maisonneuve's fracture of unspecified leg, initial encounter for open fracture type IIIA, IIIB, or IIIC

Name of the Condition

• Nondisplaced Maisonneuve's fracture of unspecified leg, initial encounter for open fracture type IIIA, IIIB, or IIIC
• ICD-10 Code: S82.866C

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 "open fracture type IIIA, IIIB, or IIIC" designation indicates that the fracture is open (exposing bone or tissue) with varying degrees of soft tissue damage and contamination, requiring specific management considerations.

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. Open fractures occur when the force is severe enough to break the skin, exposing the fracture site.

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.
• Traumatic events with significant force, increasing the likelihood of open fractures.

Symptoms

• Severe pain and swelling localized to the proximal fibula and ankle.
• Difficulty bearing weight on the affected leg.
• Visible wound or open fracture site with possible bone exposure.
• Bruising or tenderness along the lower leg.
• Instability or a feeling of the ankle "giving way."

Diagnosis

Diagnosis involves a physical examination to assess ankle stability, tenderness, and swelling, with careful evaluation of the open wound for contamination or tissue damage. Imaging, typically X-rays, is used to identify the proximal fibula fracture and associated injuries. Additional imaging, such as CT scans, may be required to assess the extent of soft tissue damage or bone involvement. The open fracture type (IIIA, IIIB, or IIIC) is determined based on the severity of soft tissue injury, contamination, and vascular compromise.

Treatment Options

Treatment focuses on stabilizing the fracture, managing the open wound, and preventing infection. Initial care includes wound irrigation, debridement, and administration of antibiotics. Surgical intervention may be necessary to realign and fix the fracture, often using plates or screws. The open wound is treated with appropriate dressings or coverage techniques. Postoperative care involves immobilization, pain management, and physical therapy to restore function.

Prognosis and Follow-Up

Prognosis depends on the severity of the fracture, the success of surgical intervention, and the extent of soft tissue damage. Most patients recover with proper treatment, though open fractures carry a higher risk of infection or delayed healing. Follow-up appointments are essential to monitor healing, assess for complications, and guide rehabilitation. Physical therapy is often recommended to restore strength and mobility.

Complications

• Infection at the open fracture site.
• Delayed union or nonunion of the fracture.
• Chronic ankle instability or pain.
• Nerve or vascular damage from the initial trauma or surgery.
• Post-traumatic arthritis due to joint damage.

Lifestyle & Prevention

• Wear appropriate protective footwear during high-risk activities.
• Maintain good ankle strength and flexibility through exercise.
• Avoid uneven or slippery surfaces to reduce fall risk.
• Seek prompt treatment for ankle injuries to prevent worsening damage.

When to Seek Professional Help

Seek immediate medical attention if you experience severe ankle pain, swelling, or an open wound after trauma. Signs of infection, such as increased redness, pus, or fever, also require urgent care. Persistent instability or difficulty bearing weight after an injury should be evaluated by a healthcare provider.

Tips for Medical Coders

Document the specific open fracture type (IIIA, IIIB, or IIIC) and confirm the fracture is nondisplaced and involves the proximal fibula with associated syndesmotic ligament injury. Ensure the encounter is coded as initial for open fractures, and note any associated injuries (e.g., medial malleolus, deltoid ligament) to support the diagnosis. Verify that the leg is unspecified, as the code does not require laterality.