What is Trigger Finger?
Trigger finger (medically known as stenosing tenosynovitis) is a painful condition of the tendon and pulley system of the hand. Triggering can cause a finger to catch or lock in either a bent or extended position. When a triggering finger is forcibly flexed or extended a “snap” is sometimes felt. This condition is best explained by understanding the anatomy of the hand.
The tendons connect the muscles of the forearm with the bones of the fingers and thumb. The tendons are held close against the bone of the fingers by a pulley system thereby increasing the mechanical advantage to finger movement. The pulleys are a series of rings that form a tunnel through which the tendons glide. The gliding is aided by a slick lining or coating called tenosynovium.
Trigger finger occurs when: the pulley at the base of the finger becomes too thick and constricting around the tendon, making it difficult for the tendon to move through the pulley, or the tendon develops a nodule or swelling of its lining (tenosynovium). This creates a discrepancy between the size of the tendon and the size of the entrance to the tendon sheath. An increased resistance to the gliding of the tendon through the pulley system often results in pain, popping or catching in the finger. When the tendon catches, it produces inflammation and swelling, leading to a vicious cycle of triggering, inflammation, and swelling. On occasion, this will lead to joint stiffness or contracture.
What causes trigger finger?
The causes of trigger finger are unclear and usually occur as an isolated condition. Some trigger fingers are associated with underlying medical conditions that cause changes in tissue such as rheumatoid arthritis, diabetes and gout. Trigger finger is more common in women than in men and tends to occur most frequently in people who are between 40 and 60 years of age. It is common for patients to develop triggering in more than one finger. Episodes of heavily repetitive use can sometimes exacerbate symptoms.
What are the symptoms of trigger finger?
One of the first symptoms of trigger finger is often a soreness or discomfort at the base of the digit. A nodule may be felt in this area. The most common symptom is pain and a clicking or grating sensation when the finger is bent and straightened. In some cases, the affected finger locks in a flexed or extended position because the nodule becomes stuck at the edge of the pulley and cannot move through the tunnel. Manipulation of the finger with the other hand may be the only method to fully flex or extend the digit. In some cases the joint is completely frozen or contracted.
How is trigger finger diagnosed?
Trigger finger is diagnosed by physical examination and a complete patient history. The affected finger may be swollen and there may be nodule or bump felt in the palm of the hand. Usually a palpable click can be felt as the nodule snaps under the first finger pulley. The finger may also be locked in a flexed or extended position. Additional testing such as X-rays, MRI or ultrasound is usually not necessary to confirm the diagnosis.
What is the treatment for trigger finger?
The goal of treatment is to eliminate the catching or locking and allow full movement of the finger without discomfort. This may be accomplished by non-surgical interventions such as:
- wearing a splint
- reducing activities that cause pain
- oral steroids
- steroid injection into the area around the tendon and pulley to reduce the inflammation
If non-surgical forms of treatment do not relieve the symptoms, surgery may be recommended. The goal of surgery is to widen the opening of the tunnel so the tendon can glide through it more easily. The surgery can be performed as an outpatient in most cases. Anesthesia can be: Local, Regional (arm block) or General. Various surgical techniques involving scissors, needles, and endoscopes all have the common approach designed to release the first annular pulley and allow full unrestricted use of the finger.
Newer devices such as the Advansor TF enable the surgeon to safely and effectively perform the procedure percutaneously in his/her office or outpatient setting with minimal soft tissue trauma, often requiring no stitches. If the surgeon and patient elect to perform the procedure in the office, this leads to lower cost for the patient, less time involved in treatment and no return office visit for suture removal. Following the procedure, the hand is wrapped in a bulky, compressive dressing to aid in swelling reduction and minimize bleeding.
What is the rehabilitation following percutaneous surgery?
Movement of the fingers should begin immediately after surgery. Normal use of the hand can usually be resumed when comfort permits. The patient will experience pain, discomfort and swelling about the area of the surgery for the first 24 — 48 hours. The dressing should remain on until 48 hours after surgery. The hand should be kept dry until a scab forms over the incision area, then it can be treated normally. The middle joint of the finger may have occasional soreness for several months following the procedure.
What are the possible complications of a trigger finger release?
Trigger finger release surgery is very safe and effective; however, there are possible complications. The trigger finger could return if there is an incomplete release of the tendon sheath. As with any surgery, infection could occur. Other possible complications include stiffness of the finger, damage to the tendon or nerves and development of scar tissue.