Trigger Finger

Question 1

What is trigger finger?

Answer 1

• Finger/thumb click or lock when in flexion
• Preventing return to extension

Question 2

Pathophys of trigger finger

Answer 2

• Preceded by flexor tenosynovitis - often from repetitive movements
• = inflammation of tendon and sheath
• Then there is localised nodal formation on the tendons distal to the pully
• When fingers flex, node moves proximal to the pulley
• But when try to extend the node fails to pass back under pulley = locking

A1 pulley most commonly affected

Question 3

What is the flexor sheath and pulley system?

Answer 3

• Ensures flexor tendons remain in joint axis of motion and prevents ‘bowstringing’
• 3 types of pulley involved in hand

Question 4

What are the three pulleys in the hand?

Answer 4

• Palmar aponeurosis - prom palmar aponeurosis and made up of transverse fascicular bands
• Annular ligaments (5 in total)
• Cruciate ligaments - prevent collapsing and expansion of sheath during movement of digitd

Question 5

Annular ligaments - what does what

Answer 5

• A2 and A4 prevent bowstringing
• A1 - MCPJ
• A3 - PIPJ
• A5 - DIPJ

Question 6

RF for trigger finger

Answer 6

• Occupation/hobby that involves prolonged gripping and use of hand
• Others: RA, diabetes, female, increasing age

Question 7

Clinical features of trigger finger

Answer 7

• Painless clicking/snapping/catching when trying to extend
• Most common middle/ring finger
• Over time can become painful

Question 8

Differentials for trigger finger deformity

Answer 8

• Dupeytrens - flexion is painless, fixed and cannot be passively corrected
• Infection - trauma, red, swollen and tender
• Ganglion
• Acromegaly - swelling in synovium from excess GH, due to increased extracellular volume = limits flexion and extension

Question 9

Management trigger finger - conservative

Answer 9

• Small splint to hold finger extended at night - roughened portion of tendon in tunnel which makes it smoother
• Steroid injections

Question 10

Surgery for trigger finger

Answer 10

• Percutaneous trigger finger release via needle under LA
• Severe - surgical decompression, roof tunnel slit to widen its mouth to release tendon

Problem is can recurr and adhesions can form