Subluxation of metacarpophalangeal joint of left thumb, init

This diagnosis code signifies a partial dislocation of the joint connecting the thumb's metacarpal bone to its first phalanx on the left hand. This injury involves the joint surfaces losing their normal alignment but remaining in partial contact.

This code is appropriate for documenting an initial presentation of a patient with a left thumb metacarpophalangeal (MCP) joint subluxation. This often occurs due to hyperextension or direct trauma to the thumb. It should be used when the patient is receiving active treatment for the injury.

• Confirm the laterality (left thumb) and the specific joint (MCP) are accurately documented.
• Ensure "initial encounter" is appropriate; subsequent encounters for the same injury will require a different seventh character.
• Look for documentation of mechanism of injury, pain, swelling, and limited range of motion consistent with a subluxation.