Abscess of tendon sheath, unspecified site

This code signifies an infection within the synovial sheath surrounding a tendon, characterized by the formation of pus, where the specific anatomical location of the abscess is not documented. It indicates an inflammatory process affecting the tendon's protective covering, leading to localized purulent collection.

Apply this code when documentation explicitly states "abscess of tendon sheath" but does not specify the affected tendon or body region. This is appropriate for cases where the physician notes the presence of a tendon sheath abscess but omits laterality or anatomical detail.

• Avoid using this code if a more specific anatomical site (e.g., hand, foot) is documented; instead, use the appropriate M65.0- subcategory.
• Ensure the documentation clearly indicates an "abscess" and not just tenosynovitis without pus formation.
• Consider sequencing this code after a code for the underlying cause of the infection, if known and documented.