Myositis ossificans progressiva, unspecified foot

This code describes a rare, progressive genetic disorder characterized by the formation of heterotopic bone in muscles, tendons, ligaments, and other connective tissues, specifically affecting an unspecified foot. The condition leads to progressive immobility and skeletal deformities as soft tissues ossify.

Use this code for patients diagnosed with myositis ossificans progressiva where the ossification is documented as present in the foot, but the specific laterality (right or left) is not specified. Documentation should clearly indicate the diagnosis of myositis ossificans progressiva and involvement of the foot.

• Ensure documentation specifies "unspecified foot" or lacks laterality for foot involvement.
• If laterality is known, use the more specific codes M61.171 (right foot) or M61.172 (left foot).
• Code also any associated complications or manifestations of the disease.