Trigger finger, unspecified middle finger

This code describes a stenosing tenosynovitis affecting the flexor tendon of the middle finger, characterized by a catching or locking sensation during finger flexion and extension. It results from a disparity in size between the flexor tendon and its surrounding sheath, often leading to pain and impaired digital movement. The "unspecified" nature indicates that the laterality (right or left) of the affected middle finger is not documented.

Use this code when the medical record clearly diagnoses trigger finger of the middle finger, but the documentation does not specify whether it affects the right or left hand. This is appropriate for initial evaluations or follow-up visits where laterality is not explicitly stated. Supporting documentation includes physician notes detailing symptoms like locking, catching, or pain in the middle finger, without specifying the side.

• Ensure the documentation explicitly identifies the middle finger; avoid using for other digits.
• If laterality is documented (right or left middle finger), use the more specific codes M65.331 or M65.332.
• This code should be sequenced as a primary diagnosis when trigger finger is the main reason for the encounter.