Pseudarthrosis after fusion or arthrodesis

This code identifies a failed surgical fusion or arthrodesis procedure, resulting in the formation of a false joint (pseudarthrosis) at the surgical site. This indicates a lack of bony union following an attempt to permanently join two bones. It represents a complication of a previous orthopedic surgery.

Assign this code when documentation clearly states pseudarthrosis as a complication following a prior fusion or arthrodesis. This typically occurs when the bone graft fails to integrate, leading to persistent motion and pain at the intended fusion site. Supporting documentation includes operative reports, imaging studies (e.g., X-rays, CT scans) confirming non-union, and physician notes describing the failed fusion.

• Always sequence this code after the primary reason for the patient's encounter, if applicable (e.g., pain, instability).
• Do not confuse with nonunion (M84.2-) or malunion (M84.3-) of a fracture, which are distinct conditions.
• Specify the anatomical site of the pseudarthrosis using an additional code from categories such as M96.01-M96.09.