Subacute osteomyelitis, right tibia and fibula

This code signifies an inflammatory condition of the bone and bone marrow, specifically affecting the right tibia and fibula, that has progressed beyond the acute phase but has not yet become chronic. It indicates an infection that has been present for weeks to a few months, often characterized by less severe symptoms than acute osteomyelitis.

Use this code when documentation clearly states "subacute osteomyelitis" involving both the right tibia and fibula. This diagnosis is typically supported by imaging studies (e.g., X-ray, MRI) showing bone changes consistent with subacute infection, along with clinical signs and symptoms such as localized pain, swelling, and possibly low-grade fever, persisting for an extended period.

• Ensure laterality (right) and specific bones (tibia and fibula) are explicitly documented.
• Differentiate carefully between acute (M86.1-) and chronic (M86.3-) osteomyelitis based on the duration and clinical presentation of the infection.
• Always look for documentation of the causative organism (e.g., Staphylococcus aureus) to assign an additional code from B95-B97, if known.