What is Trigger finger/thumb?
Trigger finger is a condition when one or more fingers of the hand click, catch or get locked when you bend them. The affected finger may bend or straighten just like a trigger is released or pulled. When the condition involves thumb, then it is known as Trigger thumb. Medically, trigger finger or thumb is termed as stenosing tenosynovitis. It is basically inflammation of the pulleys and tendon sheath of tendons that helps in the movement of finger or thumb. Pulleys are bands of tissue that hold the tendons to the bones of the finger. In this condition, pulleys could get thickened like a nodule in the palm and will be tender to touch. The inflamed tendon gets trapped in the pulleys leading to locking of finger/thumb. Ring finger and thumb is commonly affected by this condition.
The exact cause of trigger finger is not known. Forceful and repetitive use, prolonged strong gripping, injury, diabetes (up to 10%), carpal tunnel syndrome, De Quervain’s disease, rheumatoid arthritis, hypothyroidism, amyloidosis and gout can trigger them. Women above the age 40 years are more commonly affected by this condition. Its peak incidence occurs in the age below 8 years and age of 50-70 years. 2.6% of the general population have the lifetime risk to develop this condition.
What are the symptoms of Trigger finger/thumb?
Pain and presence of a nodule (bump) at the base of the thumb or finger are the most common symptoms of the condition. Pain is worse when the fingers are bent or straighten. You will feel a locking, popping or catching sensation with each movement of the finger. You will feel stiffness in the fingers in the morning especially after a long period of inactivity. More than one finger can be affected by this condition at a time. In severe cases, the affected fingers may get locked in the bent position. In patients with trigger thumb/finger the symptoms could sometimes be localised in the joint (proximal Inter phalangeal) with a flexion deformity. In severe cases the affected finger is bent and locked in to the palm.
How is it diagnosed?
Your surgeon will diagnose trigger finger by evaluation of your symptoms, complete medical history and examination of your affected finger. He will examine your affected finger, and assess your tenderness, thickening, and swelling of the sheath when you bend your affected finger. In selected cases your surgeon may ask for ultrasound scan.
What happens if nothing is done?
If trigger finger/ thumb is left untreated, the affected finger or thumb may get permanently locked in the bent position. You will feel difficulty in performing day-to-day activities.
How is it treated?
The treatment depends on the severity of the symptoms and around 70% of them could be treated without surgery. Non-operative treatment includes rest, splint, anti-inflammatory medicines, steroid injections and hand therapy.
Surgery is indicated in
- Failure of the conservative treatment
- Locked finger
- Contraindication to steroid injection
- Unresolved congenital trigger thumb
What are the non-operative treatments?
Non- operative treatment is the first line of treatment in trigger finger. It includes
- Rest- you should rest your hand and avoid those activities that provoke pain.
- Splint- your therapist will give you a splint which is to be worn at night to hold the involved finger straight while sleeping.
- Medicines– anti-inflammatory drugs such as aspirin and ibuprofen can be taken to control inflammation and pain.
- Steriod injections– cortisone (an inflammatory agent) is directly injected into the tendon sheath/A1Pulley at the base of the involved finger. Some cases require two steroid injections to resolve the problem. If the problem is persistent after two injections, then surgery may be considered.
- Hand therapy– gentle exercises including massage of the nodule could help with the symptoms in early stages. It helps to improve the range of motion in the affected finger.
What does the operation involve?
.The operation is conducted as a day case with local anaesthetic into the palm of your hand and a small 1cm cut is made in the palm over the nodule (A1Pulley).
- The tight tunnel of the pulley and tendon sheath is released, to allow free movement of tendons again.
- The skin is then closed with stitches and is kept covered with a light bandage for a few days. The operation ends in 20 minutes and most patients are discharged on the same day.
What happens after surgery?
- The local anaesthetic wears off in 4 to 12 hours after surgery. Patients are given painkillers before the pain starts i.e. on return to home. It is continued for at least 48 hours after the first dose. Thus, most of our patients report little or any pain.
- You will have a bulky bandage when you wake up, that usually needs to be reduced in 24-48 hrs. You will have spare dressings to take home and have to keep the wound dry and clean for 2 weeks
- You have to keep your hand and wrist elevated (above the level of your heart) and keep moving your fingers, elbow and shoulder to maintain the flexibility and prevent stiffness of its joints.
- You are reviewed again after the period of two weeks to check the wound and in some patients hand therapy is advised for rehabilitation.
- The wound should be massaged (typically after 2 weeks) using moisturising cream by the patient 3 times a day for 3 months once the wound is well healed. This reduces the scar sensitivity and scar-related complications (tenderness; helps scar to mature).
- Physical therapy of hand is needed in some patients to restore the range of motion, normal function and strength of the hand.
Are there any risks?
- Damage to nerves, vessels and tendons
- Temporary swelling or soreness at the site of the surgery
- CRPS (Complex Regional Pain Syndrome)
- Persistent locking
- Scar tenderness
- Inadequate release
- Digital nerve injury
- Bowstringing of tendons
What are the results of the operation?
The results of the operation are excellent with a success rate of > 97% and few complications. The results are more predictable under the author’s experiences.
When can I return to driving and work?
You can get back to work in few days if you have a desk job, however might take 2-4 weeks if your job involves physical work. You should be able to resume driving in 1- 2 weeks. The above time line could vary based on the severity of problem and the treatment modality. Your surgeon can give you the correct estimation for this.
In early stages the finger clicks with movement and could lock in later stages.
The image on the right shows the locked finger that appears like a trigger
The tenosynovium is inflamed/swollen (Red) around A1 pulley and once the inflamed synovium passes proximal to the pulley (on flexion of the finger) the finger locks.