Understanding the Causes of Trigger Finger
Trigger finger, also known as stenosing tenosynovitis, affects the tendons in the fingers, “locking” the affected finger into a bent position.
“When the patient tries to straighten the finger, it locks or catches before popping back into a straight position, and it can be painful,” said Dr. Chris Miskovsky, MD, orthopedic hand surgeon on the medical staff at Texas Health Center for Diagnostics and Surgery. “But the good news is, with treatment or surgery, almost all patients obtain lasting relief.”
What Goes Wrong
Flexor tendons control the movements of the fingers and thumb. As the fingers flex and extend, each tendon slides through a snug tunnel called the tendon sheath, which keeps each tendon in place next to the bones of the hand.
“If a flexor tendon becomes irritated, it may thicken and form nodules, so that it’s more difficult for the tendon to slide through the tunnel easily,” said Dr. Miskovsky. “Or, the tendon sheath may thicken, causing the tunnel to become smaller.”
Trigger finger usually affects the middle finger or ring finger, or occasionally the thumb. In addition to the locking sensation, some patients may experience swelling, a tender lump in the palm, or pain when bending or straightening the finger, which worsens after inactivity, such as upon waking in the morning. In severe cases, the patient may be unable to straighten the finger, even with help.
The cause of this problem is usually unknown, although repetitive motion -- gripping and grasping – can be a factor. Trigger finger is more common in women than in in men, among people ages 40-60, and in those with diabetes, gout, kidney disease or rheumatoid arthritis.
Diagnosis and Treatment
Your doctor can usually diagnose trigger finger with an examination. X-rays may be ordered to determine if you have another condition; patients with rheumatoid arthritis may follow a different course of treatment.
Rest may resolve the problem if your condition is mild. Your doctor may recommend a splint to keep the finger in a neutral position. Over-the-counter pain medications, such as ibuprofen or acetaminophen, can help with the pain.
If those measures don’t work, the next option is an injection of a corticosteroid into the affected tendon sheath.
“If one or two injections don’t resolve the problem, it’s time to consider surgery,” said Dr. Miskovsky. “Trigger finger is not a dangerous condition, but if the symptoms are severe, surgery can provide relief and a return to function.”
Surgery
Surgery widens the opening of the “tunnel” formed by the tendon sheath. The procedure typically takes about 30 minutes and is usually done on an outpatient basis, with local anesthesia and IV sedation.
A small incision is made in the palm and the tendon sheath tunnel is cut. When it heals, the sheath is looser and the tendon can glide more easily through it. Patients may have some swelling and soreness in the palm, usually for just a few weeks; full recovery may take up to six months. Depending on the stiffness of the finger before surgery, some physical therapy or finger exercises may be recommended.
“We move and test the finger during the surgery, to ensure there is no residual triggering,” said Dr. Miskovsky. “Most of our patients get relief and a return to full range of motion, shortly after surgery.”
Patients are advised to continue moving the fingers after surgery to prevent the buildup of scar tissue. Many return to work within 48 hours and may perform more strenuous manual tasks within two to three weeks.