S92.313K Displaced fracture of first metatarsal bone, unspecified foot, subsequent encounter for fracture with nonunion

Name of the Condition

• Displaced fracture of first metatarsal bone, unspecified foot, subsequent encounter for fracture with nonunion
• ICD-10 Code: S92.313K

Summary

This condition refers to a displaced fracture of the first metatarsal bone in an unspecified foot, where the fracture has failed to heal properly (nonunion) during a subsequent encounter. The first metatarsal, the largest and most weight-bearing bone in the foot, is prone to displacement due to trauma. Nonunion indicates the bone fragments have not fused after an initial injury, requiring ongoing medical attention. This code is used for encounters following the initial treatment phase when healing has not progressed as expected.

Causes

Direct trauma to the foot, such as a fall, sports injury, or crush injury, is the primary cause of the initial fracture. Nonunion may result from inadequate immobilization, poor blood supply to the bone, infection, or excessive movement during healing. High-energy impacts or delayed treatment can increase the risk of the fracture not healing properly.

Risk Factors

• Participation in high-impact activities (e.g., running, jumping)
• Wearing ill-fitting or non-supportive footwear
• Conditions that impair bone healing, such as diabetes or smoking
• Advanced age, which may reduce bone density and healing capacity
• Previous fractures or bone disorders (e.g., osteoporosis)

Symptoms

• Persistent pain at the fracture site, often worsening with activity
• Swelling or tenderness that does not resolve over time
• Difficulty bearing weight or walking on the affected foot
• Possible visible deformity or instability in the foot

Diagnosis

Diagnosis involves a physical examination to assess pain, swelling, and mobility. Imaging tests, such as X-rays or CT scans, are used to confirm nonunion by showing a persistent gap between bone fragments or lack of callus formation. Additional tests may evaluate blood flow or infection if suspected.

Treatment Options

Treatment focuses on promoting bone healing and may include surgical intervention, such as bone grafting or internal fixation, to stabilize the fracture. Immobilization with a cast or brace may be necessary, along with physical therapy to restore function. Pain management and addressing underlying risk factors (e.g., smoking cessation) are also key components.

Prognosis and Follow-Up

Prognosis depends on the severity of the nonunion and response to treatment. With proper intervention, many fractures can heal, but recovery may be prolonged. Regular follow-up appointments and imaging are essential to monitor progress. Long-term outcomes may include residual pain or limited mobility if healing is incomplete.

Complications

• Chronic pain or arthritis in the affected joint
• Persistent instability or deformity of the foot
• Infection, particularly if surgical intervention is required
• Reduced mobility or difficulty with weight-bearing activities

Lifestyle & Prevention

• Wear supportive, properly fitted footwear to reduce injury risk.
• Avoid high-impact activities that strain the foot until fully healed.
• Maintain a healthy diet rich in calcium and vitamin D to support bone health.
• Follow post-injury care instructions strictly to minimize nonunion risk.

When to Seek Professional Help

Seek medical attention if pain persists or worsens, swelling increases, or you experience difficulty walking. Signs of infection, such as redness, warmth, or fever, also require prompt evaluation. Early intervention can improve outcomes for nonunion fractures.

Tips for Medical Coders

This code is specific to a subsequent encounter for a displaced first metatarsal fracture with nonunion. Document the encounter type (subsequent) and confirm the presence of nonunion through clinical notes or imaging. Ensure the foot is documented as "unspecified" if the side is not recorded. Code accurately to reflect the ongoing nature of the fracture and healing status.