Stenosing tenosynovitis of the thumb, often referred to as trigger thumb, is one of the more common abnormalities of the hand. This condition is associated with painful triggering or locking of the thumb. When the patient tries to straighten the thumb, the nodule jams beneath the pulley proximally. This occurs with a painful snap, much like a trigger being pulled and released, with either flexion or extension of the thumb. Small changes in the tendon’s diameter will have significant effect on the function of the thumb. The nodule is usually pulled proximally to the pulley with active thumb flexion.
Treatment for trigger thumb typically consists of anti-inflammatory medications and injections. Injections will be performed into the sheath- not the tendon. The needle should be placed obliquely towards the tendon and then withdrawn slightly so the physician can inject freely into the sheath. An ultrasound guided injection of the tendon sheath and pulley may be beneficial. The needle is inserted into the sheath above the tendon and the fluid is then injected. If the symptoms persist, surgery will be considered. In surgery, the pulley will need to be released to allow active motion of the thumb without triggering. It is important for the surgeon to be aware of the position of the radial digital nerve which is close to the incision.