Acquired clawhand, unspecified hand

This code signifies an acquired deformity of the hand characterized by hyperextension of the metacarpophalangeal joints and flexion of the interphalangeal joints, giving the hand a claw-like appearance. It is not present at birth but develops due to various underlying conditions affecting nerve or muscle function.

Use this code when documentation specifies an acquired clawhand deformity without further detail regarding the specific hand affected (left or right). This applies when the physician's notes clearly state "acquired clawhand" but do not specify laterality.

• Avoid using this code if laterality (left or right hand) is documented; instead, choose the more specific M21.511 or M21.512.
• Always code the underlying cause of the acquired clawhand (e.g., nerve injury, poliomyelitis) first, if known and documented.
• Ensure documentation explicitly states "acquired" to differentiate from congenital deformities.