By Occupational Therapist Ann Morley, OT
Stenosing Tenosynovitis, commonly known as trigger finger/thumb, involves the pulleys and tendons in the hand that bend the fingers. It most frequently occurs in middle age or older women. Each finger and thumb have flexor tendons that work like long ropes going from the muscles of the forearm and passing through a tunnel of tissue and bone in the hand to reach the fingers and the thumb. The tendons in the tunnel have a smooth, slick lining that allows easy gliding like a pulley.
Trigger finger/thumb happens when the tendon develops a nodule or swelling of its lining. When the tendon swells, it must squeeze through the opening of the tunnel, which causes a popping or catching feeling in the finger or thumb. When the tendon catches, it produces an inflammation and more swelling. Sometimes the finger becomes stuck or locked and is hard to straighten or bend.
Causes: Causes are unclear. Repetitive gripping of objects or injury to the palm may irritate the flexor tendons. The medical conditions of rheumatoid arthritis, gout, and diabetes may cause trigger finger/thumb symptoms.
Signs/Symptoms: Trigger finger/thumb may start with discomfort felt at the base of the finger or thumb. A thickening may be found at this area. When the finger begins to trigger or lock, the problem may seem to be in the middle knuckle of the finger or end knuckle of the thumb.
Treatment: The treatment goal is to eliminate the catching or locking and allow full pain free movement of the finger or thumb. Swelling around the flexor tendon must be reduced to allow smooth gliding of the tendon. Taking anti-inflammatory medication by mouth or injection into the area around the tendon may be recommended to reduce the swelling. Treatment may also include changing activities to reduce repetitive motions in the hand, finger and the thumb. Your Dr. may recommend Occupational Therapy for exercises and splint fitting.
If non-surgical forms of treatment do not improve symptoms, surgery may be recommended. This surgery is generally performed on an outpatient basis. Active motion of the finger/thumb generally begins immediately after surgery. Normal use of the finger/thumb can usually be resumed once comfort permits. Your doctor may also recommend Occupational Therapy for assistance in regaining movement and strength of your fingers/thumb.