Trigger Finger stenosing tenosynovitis
Tendons are bands that connect muscles to bones.  As the muscles contract, they pull on the tendons which act like cables and pull on the bones, producing movement.  The tendons that bend the fingers pass through the palm of the hand.  They are known as the flexor tendons.
Trigger finger is diagnosed based on a history and physical exam.  Patients complain of the finger locking up in a flexed (bent) position.  The finger will snap, or trigger, open with effort.  This is usually painful.
During the physical exam, the triggering is usually easy to recognize.  If the finger will not trigger open but remains fixed in a bent position it is probably another condition such as a flexion contracture or Dupuytren’s contracture.  The hand is typically tender over the A1 pulley in the palm at the base of the finger.
Carpal tunnel syndrome cannot be identified on x-rays, but they may be obtained to look for other causes of hand and finger pain.
Non-surgical treatments for trigger finger are anti-inflammatory medications like ibuprofen, splinting, and steroid injections.  These treatments are meant to reduce inflammation and swelling.  They may or may not be effective in relieving triggering.
Non-surgical treatment often fails to relieve symptoms associated with a trigger finger.  If this is the case, a simple and effective surgery is almost always beneficial.  A trigger finger release is performed by cutting the A1 pulley to free the flexor tendon.  The tendon is then free to glide back and forth.  The other pulleys are adequate to keep the tendon from bowstringing.  Strenuous activity with the operative hand must be avoided for a few weeks to allow the incision to heal.
Trigger Finger
flexor tendons
Small ligaments called “pulleys” cross over the tendons and hold them to the bone.  This keeps the tendon from “bowstringing” as the finger flexes.
A1 pulley A2 pulley C1 pulley A3 C2 A4 A5 C3
bowstringing of tendon
If the tendon swells and becomes too thick to fit through the pulley, the finger will “lock” in a flexed position.  This is known as a trigger finger.  With some effort (and usually pain) the finger can be straightened out.  As the thick portion of the tendon passes through the pulley, the finger triggers open.
A1 pulley
Trigger Finger Surgery