Trigger thumb is a condition that causes your thumb to get stuck in a bent (flexed) position. Trigger Thumb generally results from inflammation within a tendon sheath, restricting tendon motion. A bump (nodule) in the tendon also may form. Tendons work to make our thumbs move. They are like strings inside your thumb and are held in place by a tunnel system of ligaments (also known as “pulleys”). These tunnels or ligaments keep the tendon next to the bone and allow it to slide back and forth.
The flexed fixed deformity of the affected thumb causes difficulty with passive extension and this can cause painful triggering or snapping. Pathological findings of this condition are fusiform hypertrophy of the flexor pollicis longus (FPL) tendon producing a nodularity of the FPL tendon (Notta’s node), palmar to the metacarpophalangeal (MP) joint, and flexion deformity at the thumb interphalangeal (IP) joint.
Incidence of Trigger thumb is 3 /1000 live birth, mostly in-between age 1 and 3. Boys and girls have the same risk of developing Trigger thumb. Both thumbs can be affected in up to 30 percent of children and spontaneous improvement in 30% of cases.
Cause – The exact cause is not known. Children are not born with it. It does not occur from overuse, trauma, or injury.
Symptoms of Trigger Thumb –
- Thumb is locked in a bent (Flexed) position.
- A bump or nodule (Notta’s nodule) is present on the palm side, at the base of the thumb.
- There is a sensation of popping, clicking or catching when the thumb is moved.
- Pain and swelling at the base of the thumb, although that is rare.
Wait and watch to see if the flexion contracture goes away on its own. In children younger than one year of age, sometimes disappears without anything being done. Observation for spontaneous resolution up to the age of 12 months.
Stretching and splinting the thumb – the thumb will be kept straight in a splint. Child may need to wear the splint at all times or at specific times, such as when sleeping. Keeping the thumb in a straight position, without allowing movement, can help the swelling go down. Stretching and splinting are not always successful. Movement may be improved but full-motion may not be achieved.
Surgery is done in a Daycare procedure and has few risks. The surgery will be a small cut or incision at the base of the thumb at MCP Joint. The A1 pulley ligament is released either Open or percutaneous USG Guided procedure.
Post-operative protocol – An extensor-type splint was used for immobilization at day/night time in all children for 15 days. Active and passive exercise was started at 1 week after surgery.
Details of Treatment and Result – 3-year female child who presented with deformity of right thumb was treated with Percutaneous Trigger Finger Release. The child has a full correction of deformity and excellent function without any pain or scars. “Post Operative Follow up 6 months”