Trigger fingers, De Quervain syndrome, and intersection syndrome are the topic of this review article. These three conditions have one thing in common: they all cause painful forearm, wrist, and/or hand symptoms. Although these problems all fall under the category of tenosynovitis (inflammation of the synovial lining around the tendons), they aren't all really inflammatory conditions.
How do we know this? Scientists have examined cells taken from painful tendons, tendon sheaths, the synovial lining, and other supportive soft tissue structures. By looking at them under a microscope, they have been able to see that very few (sometimes no) inflammatory cells are even present. So what's going on?
It's more likely that repetitive motions (using the finger or hand over and over) have caused the lining around the tendon (called the tendon sheath) to form extra fibers and then start to thicken. Thickening of the tendon sheath is referred to as hypertrophy.
The fingers and hand are delicate structures and carefully put together. Every layer of tissue (tendon, sheath, synovium) and each layer of space between have just the right amount of room for smooth sliding and gliding of the tendons. Even a small amount of thickening can cause a problem called stenosis. Stenosis is a narrowing of the normal space allowed for the tendons to move through the tendon sheath.
Over time, with thickening and stenosis, the tendon gets "stuck" while trying to move through the narrow space available in the tunnels created for them. As the tendon passes over boney bumps normally there to help fulcrum them (acting like a pulley system), tendon gliding is restricted. That's when the patient feels like the finger is catching or locking up on them -- a perfect description of trigger finger.
Trigger fingers may be painful but just as often there may be no pain -- just the locking or catching sensation. Locking is more common as the patient tries to extend or straighten the affected finger but triggering can occur with flexion (bending) the finger, too. Sometimes the patient has to physically use the other hand to "unlock" the finger that is stuck. In chronic cases, the finger gets stuck in the locked position and can't be pulled out of it.
What can be done about this trigger finger condition? Many times a simple treatment formula of rest, change in activity and use of the fingers/hands, and use of ice and ibuprofen does the trick. Symptoms slowly go away and full hand motion and function are restored. Studies show that the most successful treatment may be the use of steroid injection. Finger and hand splints have also been used with good results.
But steroid injections have complications of their own so physicians are studying patient factors to see who might be the best candidates for this type of treatment. Studies are also being done to compare type of injection given (e.g., dexamethasone, triamcinolone) and location (e.g., into or around the tendon sheath). So far, they've discovered that it is easier to tell who won't do well with steroid injections rather than who will benefit from them.
Patients with diabetes, a previous history of trigger fingers, more than one finger affected, and a long history of symptoms are not likely to get the desired results with steroid injections. These patients seem to do better with surgical release. The surgeon cuts through fibrotic tissue to release the tendon pulley mechanism. This procedure must be done carefully to avoid cutting into the tendon. It is not advised for trigger thumb or trigger index finger because of the danger of cutting blood vessels and nerves in the area.
In this article, the authors give equal time and focus to De Quervain and intersection syndromes. Both of these conditions occur as a result of overuse of the thumb or wrist. Pain and swelling on the thumb side of the hand with clicking during thumb and wrist movement are the main symptoms. The main differences between these two syndromes are the cause and pain location.
Intersection syndrome is more often seen in athletes such as tennis players (or other racquet sports), weight lifters, and rowers. The painful symptoms are above the wrist (more toward the elbow side rather than down by the thumb where symptoms of De Quervain syndrome occur). De Quervain syndrome is seen more often in older women (40 years old and older), African Americans, and members of the military.
Treatment is the same for both De Quervain and intersection syndromes (and very similar to trigger finger). Rest from aggravating activities, steroid injections, and splinting may be helpful. Steroid injections seem to have the best results for nonoperative care, providing pain relief lasting at least a full year for 78 per cent of patients. There are some studies that show splinting offers no extra help and may not really be needed for De Quervain syndrome. Splinting seems to be more useful for intersection syndrome.
As with trigger fingers, if conservative (nonoperative) care (including one or two steroid injections) doesn't work, then surgery may be needed. An open incision is made and the affected tendon sheath(s) are split from top to bottom. The surgeon makes every effort to avoid cutting the tendon or nearby nerves and blood vessels. The surgeon is more likely to remove tissue during surgery for intersection syndrome, especially when there is active inflammation.
In summary, trigger finger, De Quervain syndrome, and intersection syndrome make up a group of painful conditions referred to as stenosing tenosynovitis of the hand, wrist, and forearm. The surgeon who understands how the individual anatomical parts (tendon, sheath, synovium) are affected will have a better idea how to successfully manage these conditions. Every effort is made to treat the problem conservatively. Surgery is the treatment of choice only after nonoperative care has failed to provide pain relief and/or improve thumb, hand, wrist, or forearm function.
Reference: John S. Taras, MD, and Brandon J. Valentine. Tenosynovitis. In Current Orthopaedic Practice. November/December 2010. Vol. 21. No. 6. Pp. 609-614.