Major osseous defect, unspecified forearm

This code signifies a significant structural deficiency or loss of bone tissue within an unspecified forearm. It indicates a substantial gap or absence in the bony architecture, often resulting from trauma, infection, tumor resection, or congenital anomaly. The defect is large enough to compromise the structural integrity and function of the forearm.

Use this code when documentation clearly indicates a major osseous defect in the forearm, but the specific bone (radius or ulna) is not specified. This applies to situations where imaging reports or operative notes describe a large bone void without further anatomical precision. Supporting documentation includes radiology reports (X-ray, CT, MRI) or surgical notes detailing the size and location of the defect.

• Do not use this code if the specific forearm bone (radius or ulna) is documented; instead, select a more specific code from the M89.73- series.
• Ensure the documentation explicitly states "major" or describes a defect of significant size to warrant this code, rather than a minor cortical defect.
• Consider sequencing this code with external cause codes (V, W, X, Y) if the defect is due to trauma.