- Discussion:
- stenosing tenosynovitis of the flexor pollicis longus in childhood is relatively uncommon condition which causes triggering, IP joint
flexion contracture, and a flexor tendon nodule over the metacarpal head level (Notta's nodule);
- although present at birth, dx often not made until 4-6 months of age
- often bilateral, with fixed flexion contractures at presentation;
- in some cases, there will be an associated anomaly;
-
diff dx:
- may be mistaken for a fracture or dislocation of the thumb;
- congenital loss of the extensor tendon;
- in some cases, the diagnosis will be confused with arthrogryposis or CP;
-
prognosis:
- if trigger thumb is present at birth, approximately 30 % of children will recover spontaneously in one year;
- 12 % of the trigger thumbs that develop at the age of six to 30 months recover in six months;
- if trigger thumb develops in a child over three years of age, however, it almost never improves spontaneously;
- therefore, it is wise to operate as soon as acceptable at this age
- a child not seen until after the age of four has a 50 per cent chance of developing a permanent flexion contracture;
- in the report by Moon et al, 7700 newborn children were examined prospectively to determine the congenital incidence
of trigger thumb and finger - no cases were found;
- case histories of 43 trigger digit cases (35 trigger thumbs and 8 trigger fingers) noted in 40 children diagnosed were reviewed;
- of 35 thumb cases, 23 underwent surgical release and all responded satisfactorily to surgical treatment;
- spontaneous recovery was noted in 12 trigger thumb cases and in all eight trigger finger cases;
- trigger finger developed earlier in life than trigger thumb and the spontaneous recovery rate was higher in trigger finger than trigger thumb;
- ref: Trigger Digits in Children. WN Moon. Journal of Hand Surgery (Br) p 11-12, Volume 26B, No 1, Feb 2001
- Exam:
- most often involves the thumb but may involve any digit;
- thumb is often held in fixed, flexed position;
- characteristically, a palpable nodule called Notta's node is present on tendon in the region of the metacarpal head;
- Treatment:
- surgery should be considered if not resolved by 12 months of age;
- most surgical procedures for trigger thumb should be postponed until the age of 2 yrs, but should not be delayed beyond 3 yrs because of possible flexion contractures;
- general anesthesia;
- only potential surgical complication of significance in this anomaly is the severing of one of the digital nerves;
- radial digital nerve is esp at risk;
- both nerves hug the flexor tendon, and one or both can be easily cut by slight deviation of a knife or scissors in either direction as the pulley is opened;
- avoid making incisions directly over MP flexion crease, since there is little or no subQ fat underneath the crease, which leaves nerves unprotected during incision;
- generally only excision of the A1 pulley is required (since Notta's flexion tendon nodule will disapate with time);
-
outcomes:
- in the report by TR McAdams et al 2002, the authors reexamined 21 patients (30 thumbs) who underwent a release procedure,
with an average follow-up of 181.3 months (15.1 years).
- 23 % of patients had a loss of IP motion and 17.6% had metacarpal phalangeal hyperextension, and this was unrelated to age at the time of surgery;
- there were no recurrence of triggering or nodules and no functional deficit;
- all seven patients who had a longitudinal incision had concerns about their scar appearance;
- it is the authors' belief that a transverse skin incision and surgical release of the A1 pulley for trigger thumb in children is a successful procedure even when done
after age 3, but IP motion loss and metacarpal phalangeal hyperextension may occur in the long term;
Congenital trigger digit.
Congenital trigger digit.
Trigger thumbs in children. Dinham, J. M., and Meggitt, B. F.: J. Bone Joint Surg. 56B:153, 1974.
Long-Term Follow-Up of Surgical Release of the A 1 Pulley in Childhood Trigger Thumb Timothy R. McAdams, M.D J Pediatr Orthop 2002 January/February;22(1):41-43
Incidence and Development of Trigger Thumb in Children.
Surgical Treatment of the Pediatric Trigger Finger
The Natural History of Pediatric Trigger Thumb
The treatment outcome of trigger thumb in children. J Pediatric Orthop B 2002;11:256-259.
Acquired thumb flexion contracture in children: Congenital trigger thumb. J Bone Joint Surg Br 1996;78:481-483.
