Trigger thumb is caused by a mismatch between the size of the flexor tendon to the thumb and the tendon sheath (the fibrous band over the tendon) causing difficulties with the gliding motion of the thumb. When the sheath is too tight, the enlarged tendon can lock in one position. This can cause clicking, popping with motion, or a fixed flexed position of the thumb. The child can have pain with forced extension of the thumb and relief when going back into flexion.
Most children will develop a nodule at the base of the thumb.
As high as 63-80+ percent of congenital trigger thumb resolves itself (spontaneous resolution) when it presents in young children without any intervention. Time and growth are necessary for resolution in most cases. Therapy and stretches do not speed the process along.
There is as high as 50% incidence in both thumbs.
Reasons to operate:
- Changes on X-rays
- No improvement or worsening of the thumb contracture over one year
If surgery is necessary, it will require general anesthesia.
- There is a small incision made at the base of the thumb
- The sheath over the tendon is released
- Absorbable sutures are placed
- The child will be placed in a thumb spica cast or soft bandage for about two weeks. The cast or bandage must be kept dry
- At the two-week follow up appointment, the child can start using the thumb
The recurrence rate is less than 3%.