M86.352 Chronic multifocal osteomyelitis, left femur

Name of the Condition

• Chronic multifocal osteomyelitis, left femur

Summary

Chronic multifocal osteomyelitis (CMO) is a condition marked by persistent inflammation of the bone, affecting multiple sites, with the left femur being the specified location. It is characterized by recurrent episodes of bone pain and swelling, typically without a clear infectious cause. The condition may involve any bone but commonly affects long bones like the femur.

Causes

The exact causes of CMO are not fully understood. It is thought to be an autoimmune or autoinflammatory disorder, where the body’s immune system mistakenly attacks bone tissue. Unlike other forms of osteomyelitis, bacterial or fungal infections are rarely the primary cause.

Risk Factors

• Family history of autoimmune or inflammatory disorders
• Certain genetic mutations linked to immune system function
• Age, with children and adolescents more commonly affected
• Prior history of inflammatory conditions

Symptoms

• Persistent bone pain in the left femur, often worsening at night
• Swelling and tenderness over the affected area
• Reduced mobility or stiffness in the hip or knee joint
• Fatigue or general malaise during flare-ups

Diagnosis

Diagnosis involves a combination of clinical evaluation, imaging studies (such as X-rays, MRI, or CT scans), and laboratory tests to assess inflammatory markers. A bone biopsy may be performed to rule out infection or other conditions.

Treatment Options

• Nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation
• Corticosteroids for severe inflammation
• Biological therapies or disease-modifying anti-rheumatic drugs (DMARDs) in refractory cases
• Physical therapy to maintain mobility and function

Prognosis and Follow-Up

Prognosis varies, with some patients experiencing long-term remission and others having recurrent episodes. Regular follow-up with imaging and clinical assessments is important to monitor disease activity and adjust treatment as needed.

Complications

• Chronic pain and functional impairment
• Joint stiffness or deformity
• Potential for growth disturbances in children
• Rarely, progression to more severe bone damage

Lifestyle & Prevention

• Maintain a healthy weight to reduce stress on the femur
• Engage in low-impact exercises to preserve mobility
• Avoid activities that exacerbate pain or swelling
• Follow prescribed treatment plans consistently

When to Seek Professional Help

Seek medical attention if you experience persistent bone pain, unexplained swelling, or reduced mobility in the left femur, especially if symptoms worsen or do not improve with initial care.

Tips for Medical Coders

Document the specific site (left femur) and confirm the chronic, multifocal nature of the osteomyelitis. Ensure clinical notes support the absence of acute infection to justify the chronic classification. Code M86.352 is appropriate when the left femur is the documented site of involvement.