Osteitis deformans in diseases classified elsewhere

This code represents Paget's disease of bone (osteitis deformans) when it is a manifestation or complication of another underlying condition. It signifies a chronic bone disorder characterized by abnormal bone remodeling, leading to enlarged, misshapen, and weakened bones, but specifically when this bone pathology is secondary to another disease process.

Use this code when documentation clearly indicates Paget's disease of bone that is directly attributed to or arises from another primary diagnosis. This might include cases where metabolic disorders or other systemic diseases are identified as the cause of the osteitis deformans. The medical record should specify the underlying condition.

• Always sequence the underlying causative disease first, followed by this code for the manifestation.
• Do not use this code for idiopathic or primary Paget's disease of bone; a different code would be appropriate for those cases.
• Ensure documentation explicitly links the osteitis deformans to another classified disease, rather than simply stating "Paget's disease."