Fibrous dysplasia (monostotic), left ankle and foot

This code signifies the presence of fibrous dysplasia affecting a single bone (monostotic form) specifically located in the left ankle or foot. Fibrous dysplasia is a non-hereditary developmental anomaly where normal bone is replaced by fibrous tissue and immature woven bone, leading to weakened bone structure.

Apply this code when documentation clearly indicates a diagnosis of monostotic fibrous dysplasia localized to the left ankle or foot. This diagnosis is typically confirmed through imaging studies (X-ray, MRI, CT) and potentially biopsy. Use this code for patients presenting with pain, swelling, or pathological fractures in the specified anatomical region due to this condition.

• Ensure documentation specifies "monostotic" and clearly identifies the left ankle or foot as the affected site.
• Do not use this code for polyostotic fibrous dysplasia; a different code would be required.
• Consider sequencing this code as a primary diagnosis if it is the reason for the encounter, or as a secondary diagnosis if it's an underlying condition impacting treatment.