Osteolysis, unspecified lower leg

This code represents the pathological destruction or dissolution of bone tissue in the lower leg, where the specific cause or type of osteolysis is not documented. It indicates a generalized bone loss or breakdown process affecting the tibia or fibula without further specification.

Use this code when documentation clearly states "osteolysis of the lower leg" but lacks details regarding the etiology (e.g., infectious, neoplastic, post-traumatic, inflammatory) or specific type of osteolysis. This code is appropriate when the physician has not identified the underlying cause of the bone resorption.

• Avoid using this code if the underlying cause of osteolysis is known and documented; instead, code the specific type of osteolysis (e.g., M89.50-M89.59).
• Always query the provider for more specific information regarding the cause or type of osteolysis if not clearly documented, to allow for more precise coding.
• This code is for the lower leg (tibia/fibula); ensure the documentation specifies this anatomical site.