Ankylosis of ear ossicles, left ear

This code signifies the pathological fusion or stiffening of the small bones (malleus, incus, stapes) within the middle ear, specifically affecting the left ear. This ankylosis impairs the normal transmission of sound vibrations from the eardrum to the inner ear, leading to conductive hearing loss.

Use this code when documentation clearly indicates ankylosis of the ossicles in the left ear, often identified during otoscopic examination, audiometry showing conductive hearing loss, or surgical exploration. It is appropriate for primary or secondary diagnoses when this condition is being treated or investigated.

• Ensure laterality is precisely documented (left ear). If bilateral, a different code (H74.313) would be appropriate.
• Distinguish from otosclerosis (H80.-), which is a specific bone remodeling disease that can cause ossicular fixation, but is coded separately.
• Look for documentation of associated hearing loss (e.g., H90.02, H90.12) to code concurrently, if present.