What is a Trigger finger in hand surgery?
It is one of the most frequent causes of pain and disability. Trigger finger causes painful catching or jumping of the compromised flexor tendon when the patient extends and flexes the finger. It is more common in middle-aged women.
Types of trigger finger
We can distinguish two types of trigger finger:
- Primary trigger finger: In primary trigger finger, the thumb is most often affected, followed by the ring, middle, and little fingers.
- Secondary trigger finger: They are more common in diabetics, patients with gout and rheumatoid arthritis.
Clinic of trigger finger
The patient comes to the office referring pain in the palm of the hand on the distal palmar crease. A nodule can be palpated in this location with or without associated blockage.
In the initial phases, only pain appears at the level of the distal area of the palm. Subsequently, a nodule appears in the A1 pulley blocking passive movement and then active movement.
The last stage is when a flexed attitude appears with rigidity.
Pathophysiology of trigger finger
Classification of trigger finger
- Grade I (Pre trigger finger): pain, history of entrapment not evident at the time of examination with pain on palpation of the A1 pulley.
- Grade II (Active): actively demonstrable entrapment.
- Grade III (Passive): Demonstrable entrapment requiring passive extension or inability to actively flex.
- Grade IV: Fixed contracture in proximal interphalangeal joint flexion.
Diagnosis of trigger finger
The diagnosis is basically clinical and confirmed with an ultrasound study.
Treatment of trigger finger
Conservative treatment of trigger finger
The initial treatment of trigger finger is conservative, through exercises, NSAIDs, splints and changes in activity. When they do not improve, it can be infiltrated using ultrasound guidance, with 70% symptom relief in long fingers and 90% in the first finger.
Ultrasound-guided infiltration of trigger finger
It is important to carry out an ultrasound study to confirm the diagnosis, and to verify that the projection occurs under the A1 pulley in the long fingers and under the T1 pulley in the thumb.
Trigger finger infiltrations, if performed with ultrasound guidance, are safer and more effective, and in a high percentage of patients, they do not require surgery.
When infiltrations fail, surgical intervention can be performed.
Trigger finger surgery
This can be through open surgery or percutaneous ultrasound-guided surgery.
Ultra minimally invasive ultrasound-guided surgery
It is done under local anesthesia, without hand ischemia and without incision. It is a safe and precise technique when performed using an ultrasound technique. With the ultrasound we can control the vessels and nerves and release the pulley without anesthetizing the hand.
The patient can always move the fingers and hand, so it is easy to check if the trigger has been resolved or if the finger is still blocked.
Open trigger finger surgery
It is based on the opening of the A1 pulley in the long fingers and the T1 pulley in the thumb through a 1 cm skin incision. It is important to identify the neurovascular bundles and open pulley A1 in the case of long fingers or T1 in the case of the thumb.
Care must be taken not to open pulley A2 to avoid bowstrings from the flexor tendons. The results are usually satisfactory.
Complications that may arise include scar pain, infection (more common in diabetics), and neurovascular injury.
Conclusions of trigger finger
- Trigger finger is the most frequent pathology in hand surgery.
- It is important to make a good clinical diagnosis supported by ultrasound.
- In my opinion, as a hand surgeon, I believe that ultrasound-guided infiltration is an effective treatment prior to a possible surgical intervention.
- The ultrasound-guided percutaneous polectomy obtains immediate results.
- Ultrasound-guided percutaneous polectomy can be done in the office and without preoperative studies.