Stenosing tenosynovitis, commonly known as a trigger finger, involves the tendons and pulleys of the flexor tendons of the fingers. The tendons function as long cords from the muscles in the forearm and through a tunnel, bone base and roof of fibrous tissue, until they reach the toes. Inside the tunnel the tendons are wrapped in a film that allows easy sliding inside the sheath and pulleys.
Trigger finger happens when the tendon develops a lump or edema of the surrounding film. When the tendon swells, it swells, and it has to brush against the entrance to the tunnel (flexor tendon sheath), which causes pain, bump, and a pinched sensation in the finger. When the tendon rubs against the sheath, more inflammation and edema occur. This causes a vicious cycle between trigger, inflammation and edema, which in some cases leads to a blockage, and it is not possible to bend or stretch the involved finger.
The causes for trigger finger onset are not fully understood. A trauma to the palm may cause irritation of the flexor tendons. Some diseases such as rheumatoid arthritis, gout and diabetes are associated with trigger finger.
Signals and symptons
The trigger finger may start as a slight discomfort felt at the base of the finger. A thickening can be felt in this zone. When the finger begins to become blocked and causes a bounce or trigger, the problem may appear in the proximal interphalangeal joint of the finger.
Non Surgical Treatment
The purpose of trigger finger treatment is to eliminate bounce or arrest and allow full finger movement without pain or discomfort. The edema around the flexor tendon and sheath should be reduced to allow smooth sliding of the tendon. The use of a splint or taking oral or injected anti-inflammatory drugs around the tendon may be indicated to decrease edema. Treatment may also involve a change in activity to lessen direct trauma.
If non-surgical forms of treatment do not improve symptoms, surgery may be indicated. This surgery will be performed on an outpatient basis, and anesthesia may be local, locoregional (where only the arm is anesthetized) or general.
The treatment consists of opening the proximal pulley and tendon sheath and eventually partial longitudinal excision of one of the flexor tendons, usually the superficial one.
Active mobilization of the finger usually begins in the immediate postoperative period and normal use of the finger may resume as soon as no complaints allow.