A condition causing pain and difficulty moving a finger. Also known as stenosing tenosynovitis
Flexor tendon pass through synovial sheaths
Trigger finger - thickening of the tendon or thickening of this sheath
Consequence = Tendon prevented from moving smoothly through sheath when finger is flexed and extended = Sx
The most commonly affected part of the sheath is the first annular pulley (A1) at the metacarpophalangeal (MCP) joint.
There may be a nodule on the tendon. When the finger is flexed, the nodule is outside the A1 pulley. As the finger is extended from a flexed position, the tendon nodule can get stuck at the entrance to the A1 pulley. This causes the finger to lock or get stuck in the bent position. It may release suddenly with a painful pop or click.
Risk factors: