Trigger Finger
What is a Trigger Finger?
Trigger finger is a painful, clicking, or locking of the finger or thumb due to thickening of the tendons usually occurring in adults over 40 years. It also occasionally occurs in toddlers where the finger (usually the thumb) is painless but stuck in a bent position.
The tendons are tough, fibrous cords that connect the muscles of the forearm to the bones of the fingers and thumb, so we can bend (flex) and straighten (extend) our fingers. The flexor tendons glide through a tunnel called the tendon sheath. The sheath is lined with a thin membrane called synovium. The synovium produces lubricating fluid that helps reduce friction as the tendons glide through the tendon sheath. The tendon sheath has several thick, fibrous tunnels called pulleys.
What causes trigger finger?
Tendons thicken with age and this results in more friction where they travel through tight tunnels. The tendon becomes irritated with repetitive use and swells more, resulting in nodular thickening of the tendon and catching of the nodule as it moves in and out of the tunnel.
In gout, rheumatoid & psoriatic arthritis, the synovial covering of the sheath becomes inflamed and thickened to several times its normal size. The tendon is no longer able to glide freely, forming a nodular thickening at the point where it tries to pass into the tunnel.
Trigger finger may also be associated with conditions such as diabetes, hypothyroidism & pregnancy which all cause thickening of the sheath or tendons. It can also occur in small children. The cause in children is poorly understood but possibly tendon thickening follows a minor injury.
Conditions associated with trigger finger
Diabetes
Hypothyroidism
Pregnancy
Carpal tunnel syndrome Rheumatoid/Psoriatic Arthritis
Family with trigger finger Injury to the hand.
Gout
What are the signs & symptoms?
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Pain at the base of the finger aggravated by gripping
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Clicking at the finger straightens and bends - painless or painful.
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Locking of the finger in a bent position
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Weakness of grip
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Stiffness of the affected finger
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Mild swelling at the base of the finger
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A flexor sheath ganglion may be present
Treatment Options
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Non-operative treatment
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Trigger finger release surgery
Non-operative treatment
For mild symptoms a combination of splinting and steroid injection is recommended.
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Trigger finger splint - for 4 weeks, removed only for showering and hand washing.
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Cortisone (steroid) injection - may be effective when the symptoms have only been present for 3-4 months.
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Activity modification - avoid repetitive gripping activities (break these tasks into shorter time frames).
Trigger finger release surgery
Trigger finger surgery is usually recommended when the symptoms are causing repeated locking, pain or interfering with daily activities. Trigger finger release surgery is safe and reliable. It is performed as a day surgery procedure under sedation with local anaesthetic or general anaesthetic. procedure takes approximately 45 minutes.
The procedure involves making a 1cm incision at the base of the finger and dividing the A1 pulley of the flexor tendon sheath. This makes the tunnel larger so that the tendon may glide smoothly and is no longer being irritated by friction with movement.
What to expect after surgery
When you go home your finger will be numb for 6-8 hours due to the anaesthetic. This will keep your pain to a minimum. Strong pain relief is usually only needed in the first 48hrs, if at all.
What about recovery?
First 2 days:
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Rest, elevation and pain relief.
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Stretch the finger straight for 5 minutes, 3 times per day.
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Very light use of hand only.
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Keep dry for 2 weeks.
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The finger will be swollen for several weeks.
2-3 days:
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Most people will be able to drive & return to light clerical duties with regular panadol osteo to control discomfort.
2 weeks:
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Stitches will be removed & you can now wash the hand normally.
8 weeks:
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Progress review with the surgeon.
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Normal finger movement.
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All light daily activities should now be pain-free.
3-4 months:
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Heavy manual workers may not return to work for 2-4 weeks and shall be on restricted duties for approximately 8-12 weeks.
What are the risks?
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Recurrence - very rare.
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Infection (1%)
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Nerve injury (0.1%)
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Finger stiffness - if any concerns, you will be referred to a hand therapist.