A trigger finger is the name given to a catching of fingers or thumb when moving from bent to straight. It is commonest in ring finger and thumb, but occur in any digit. The cause is catching on the flexor tendon on a tight entrance to the flexor tendon sheath or cover.
A common time for the finger to be stuck is first thing in the morning. Other times include when gripping, such as knife or fork.
Mostly it starts for no obvious reason, but is occasionally seen after minor injuries or a burst of heavy hand use. People with established Diabetes are more commonly affected by trigger digits.
Sometimes an ultrasound can show the thickened first part of the flexor tendon sheath if the diagnosis is uncertain.
Many triggers will be cured by a cortisone/ steroid injection.
Those that don't can be treated surgically. Through a small incision in the palm the flexor sheath is divided for about a centimetre. This can be preformed with local anaesthetic and sedation for most people.
After the operation, a couple of sutures are removed at 10 days.
A simple stretch is essential to get the finger out straight, using a pen or pencil. This picture shows the stretch for the ring finger.