Trigger finger (thumb) is a condition associated with clicking and pain of the digit during movement. Affected finger often gets locked so that one needs to pull it with the other hand. Condition is due to peculiarities of hand anatomy and/or repetitive forces imposed onto the finger.
Finger tendons run within the tight tunnels in the hand. Tunnels are held in place, almost anchored onto the bones, by a series of ligaments called pulleys. The tendons are wrapped in a slippery coating called tenosynovium which reduces friction and allows the flexor tendons to glide through the tunnel smoothly. The constant irritation of the tendon by repetitive sliding within the tunnel can cause the tendon to swell either along its all length, or more commonly, within its small segment. The later presents with a rounded swelling (nodule) embedded in the tendon which often gets caught against tight pulleys causing jerky movement (triggering) (Picture 1). This is why trigger finger is also known as a stenosing tenosynovitis. The pulley ligament itself may thicken as well. Rheumatoid arthritis, partial tendon lacerations, repeated trauma from gripping tools/objects/steering wheel, can cause triggering.
The symptoms of trigger finger or thumb include pain and a funny clicking sensation when the finger or thumb is bent. Tenderness usually occurs in the mid palm long the axis of the digit. The clicking sensation occurs when the nodule becomes large enough that it may pass under the ligament during finger flexion (bending), but it gets stuck as you try to straighten the digit. The nodule cannot move back through the tunnel, and the finger becomes locked in flexed position. This happens because extensor tendons (at he back of the hand) are weaker then the flexor (finger bending) tendons.
The diagnosis of trigger finger is usually quite obvious on physical examination. A palpable and visible click can be felt as the nodule snaps under the first pulley. If the condition is allowed to progress, the nodule may swell to the point where it gets caught and the finger is locked in a flexed position. No special tests or X-rays are required.
Treatments provided by a physical or occupational therapist may be effective when triggering has been present for less than few months. Therapists often build a splint to hold and rest the inflamed area. Special exercises are used to encourage normal gliding of the tendon. You might be shown ways to change your activities to prevent triggering and to give the inflamed area a chance to heal. If you wear a splint, the nodule may shrink temporarily, but patients often end up needing surgery for this problem.
A cortisone injection into the tendon sheath is often the first line of treatment and in approximately 30-40% of patients, this is all that is required. Steroid predictably helps alleviating triggering and pain by decreasing tendon inflammation. Patients can expect to have resolution after one week. Sometimes, injections are administered as a temporary measure only, and as an adjunct to the forthcoming surgery, but this is an exception rather then a norm in a treatment planning. In my personal experience, further intervention (repeated injection or surgery) is required in 40-60% of cases.
The most predictable solution for trigger digit is surgery. In trained hands, it is a very straightforward undertaking whereby a tight pulley is divided (incised) allowing underlying tendon more space during gliding. There are no long term functional consequences of leaving pulley open. It will reform reasonably quickly, in less obstructing fashion.
The surgery takes 15-20 minutes and is done under the local anesthesia on a day care basis. Local anaesthetic is injected around the area of incision. Injection itself is uncomfortable for just few seconds, but bearable by almost everybody. It is a reliable method of analgesia and works very quickly. Surgery is only started when the whole area becomes numb. Sensation of touch and temperature remains preserved, as local anaesthetic selectively numbs pain nerves only. Please rest assured that you will feel no pain during intervention.
Once the tendon pulley has been cut and free tendon gliding is ensured, the skin is sewn together with fine stitches (absorbable or non-dissolvable). Picture 2 illustrates the length and location of the wound in the palm and future scar which is hardly identifiable several months after surgery. A small plaster that covers the wound is left undisturbed until review in the clinic, usually 2 weeks later. Hand is bandaged for 2 days (Picture 3), but finger movements are encouraged straight away.
Bandage provides gentle compression and reduce bleeding and swelling that occurs immediately after surgery. You should begin gentle finger motion straight after the surgery. No formal rehabilitation program is required.
Wound will heal in up to 2 weeks and should be kept dry for the first 3-4 days only. You may undertake usual activities of daily living almost straight away, but vigorous sport activities should be avoided for 2 weeks.
If you have any concerns following your surgery please contact:
Ashtead 01372 221 442; St Anthony’s 020 8337 6691; Parkside 020 8971 8000
|Hospital stay||Day care|
|Surgery time||15-20 min|
|Wound healing||10-12 days|
|Hand therapy||not required|
|Washing||from week 1|
|Time off work||n/a|
|Sports and exercise||from week 2|
|Full recovery||10 days|
Picture 1: patophysiology of trigger finger
Picture 2: wound at the end of the procedure
Picture 3: Bandage for the first 2-3 days