Trigger thumb in children is seen between 8-30 months of age, with an incidence of about 3/1000 births. It presents as a lump on the flexor pollicis longus tendon and can be graded based on the ability to flex and extend the thumb interphalangeal joint. While some cases may resolve spontaneously, splinting and surgery can effectively treat trigger thumb when it does not resolve on its own. Surgery involves dividing the A1 pulley to release the tendon, avoiding damage to other pulleys, and long term follow up shows it is an effective treatment with low risk of complications and normal pinch strength.

1. Trigger thumb in children
It is not congenital
10,000 neonates examined by a hand surgeon1,2. Trigger thumb was not seen
 Trigger thumb seen between about 8 and about 30 months of age with an incidence
of about 3/1000 birth (this is difficult to assess with wildly different estimates)
 Observed in mono-zygomatic twins and some hereditary predisposition
 Occasional bilaterality
A single lump on the flexor pollicis longus: Notta’s nodule
Grading: Watanabe et al classified trigger thumb from stage 0 to stage 33
0-mass palpable at the MCP joint with no restriction of movement
1-the thumb IP joint can be actively flexed or extended with snapping
2-the thumb IP joint can be passively flexed or extended with snapping
3-the flexed IP joint can neither be passively nor actively flexed or extended
Does it is resolve spontaneously?
 20 trigger thumbs < 15 y’rs age, average 39 months follow up – none resolved4
 35 trigger thumbs, average of 5 months follow up 12 thumbs resolved2
 26 trigger thumbs, average 12 months follow up, 8 resolved spontaneously5
Can splinting help?
 thermoplastic splint, 40 thumbs and 3 digits. 24 recovered at 10 months of splinting6
 26 locked thumbs, treated with a coil splint (S), 38 with observation (O): S= 92 %
resolution at 22 months, O= 62 % resolution at 59 months7
Is surgery effective ?
• thumbs at reviewed after surgery at an average of 15 years of age. No recurrence, 3
less IP extension, 2 less IP flexion. 7 patients with longitudinal incisions had scar
concerns, no nerve injuries, normal pinch strength8
Surgery - Divide A1 pulley, avoid damage to oblique pulley.
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Am31, 541-543, doi:10.1016/j.jhsa.2005.12.024 (2006).
2 Moon, W. N.,Suh,S. W. & Kim,I. C. Triggerdigitsinchildren. JHand Surg Br26, 11-12,
doi:10.1054/jhsb.2000.0417 (2001).
3 Watanabe,H., Hamada,Y. & Toshima,T.Conservative managementof infantile trigger
thumb:indicationsandlimitations. Tech Hand Up ExtremSurg 7, 37-42,
doi:10.1097/00130911-200303000-00008 (2003).
4 Skov,O.,Bach, A. & Hammer,A.Trigger thumbsinchildren:afollow-upstudyof 37 children
below15 yearsof age. J Hand Surg Br 15, 466-467, doi:10.1016/0266-7681(90)90092-i
(1990).
5 Dinham,J.M. & Meggitt,B. F. Triggerthumbsinchildren.A review of the natural historyand
indicationsfortreatmentin105 patients. JBoneJoint Surg Br 56, 153-155 (1974).
6 Nemoto,K.,Nemoto,T.,Terada,N.,Amako,M. & Kawaguchi,M.Splinttherapyfortrigger
thumband fingerinchildren. JHand Surg Br21, 416-418, doi:10.1016/s0266-
7681(05)80221-9 (1996).
7 Koh,S.,Horii,E., Hattori,T., Hiroishi,M.& Otsuka,J. Pediatrictriggerthumbwithlocked
interphalangeal joint:canobservationorsplintingbe atreatmentoption? JPediatrOrthop
32, 724-726, doi:10.1097/BPO.0b013e318264484c (2012).
8 McAdams,T. R.,Moneim,M. S. & Omer,G. E., Jr. Long-termfollow-upof surgical release of
the A(1) pulley inchildhoodtriggerthumb. JPediatrOrthop 22, 41-43 (2002).