S82.865Q Nondisplaced Maisonneuve's fracture of left leg, subsequent encounter for open fracture type I or II with malunion

Name of the Condition

• Nondisplaced Maisonneuve's fracture of left leg, subsequent encounter for open fracture type I or II with malunion

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 "subsequent encounter" designation indicates this is a follow-up visit for an injury that has already received active treatment. "Open fracture type I or II" refers to a break in the skin with minimal contamination or a small wound, respectively, and "malunion" denotes incomplete or abnormal healing of the fracture.

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 broken bone pierces the skin, often due to high-energy trauma or direct impact. Malunion may develop if the fracture does not heal in proper alignment, potentially due to inadequate immobilization or delayed treatment.

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.
• Delayed or inadequate initial treatment of the fracture.

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."
• Visible or palpable deformity if malunion is present.
• Possible signs of prior open fracture, such as scarring or residual wound changes.

Diagnosis

Diagnosis is based on clinical evaluation and imaging studies. A physical examination may reveal tenderness over the proximal fibula, ankle instability, or signs of malunion. X-rays of the ankle and lower leg are typically performed to assess fracture alignment and healing. CT or MRI may be used to evaluate syndesmotic ligament integrity or detect subtle malunion. The history of prior open fracture and current encounter type (subsequent) are critical for accurate coding and treatment planning.

Treatment Options

Treatment focuses on stabilizing the fracture and addressing malunion. Options may include immobilization with a cast or brace, physical therapy to restore function and strength, or surgical intervention to realign and fixate the bone if malunion is significant. Management of the open fracture component may involve wound care or revision surgery. Follow-up imaging is often used to monitor healing and alignment.

Prognosis and Follow-Up

Prognosis depends on the severity of malunion and the effectiveness of treatment. Nondisplaced fractures with proper alignment generally have good outcomes, but malunion may lead to chronic pain, instability, or arthritis. Regular follow-up visits are necessary to assess healing, functional recovery, and address any complications. Long-term monitoring may be required if malunion affects joint mechanics.

Complications

• Chronic ankle pain or instability.
• Post-traumatic arthritis due to malunion.
• Nerve or vascular damage from the initial injury or malunion.
• Infection risk if the open fracture component was not fully resolved.
• Reduced mobility or functional limitations.

Lifestyle & Prevention

• Avoid high-impact activities until cleared by a healthcare provider.
• Use appropriate footwear and supportive devices (e.g., braces) to stabilize the ankle.
• Engage in physical therapy to strengthen surrounding muscles and improve balance.
• Maintain a healthy weight to reduce stress on the ankle joint.
• Follow post-treatment guidelines to prevent re-injury or malunion progression.

When to Seek Professional Help

Seek immediate medical attention if you experience:

• Severe or worsening pain.
• Inability to bear weight on the affected leg.
• Visible deformity or new swelling.
• Signs of infection (e.g., redness, warmth, drainage) at the prior fracture site.
• Sudden loss of function or increased instability.

Tips for Medical Coders

This code (S82.865Q) requires documentation of the following:

• Nondisplaced Maisonneuve's fracture of the left leg.
• Subsequent encounter for care (not initial treatment).
• Open fracture type I or II (minimal contamination or small wound).
• Malunion (abnormal healing) as a current complication.
  Ensure the medical record specifies the fracture type, encounter stage, open fracture details, and malunion to support accurate coding.