What is it?
As tendons cross over the wrist joint, they pass through fibrous tunnels which hold them in proper position. There are six of these tunnels, called extensor compartments, on the back of the wrist. Movement of the tendons through these tunnels can occasionally lead to irritation and inflammation. The tendons of the first extensor compartment are most commonly involved with this type of inflammation. Located along the thumb-side of the wrist, this compartment contains two tendons, both of which assist in moving the thumb and wrist. Irritation of these tendons as they move through their compartment is known as deQuervain's tendonitis.
What are the symptoms?
Pain along the thumb-side of the wrist, which increases with thumb and wrist motion, is the most common symptom of deQuervain's tendonitis. In addition, some people will have swelling of the compartment, creating a painful bump along this portion of the wrist. Occasionally, small cysts may be present. Not infrequently, deQuervain's tendonitis occurs in new mothers. Repeated lifting of their infant requires the use of the muscle/tendon units of the first extensor compartment, leading to inflammation of the tendons secondary to overuse.
How is it evaluated?
The diagnosis is made through the classic patient complaints of thumb-sided wrist pain coupled with positive physical exam findings. A Finkelstein test, performed by having the patient close their fist around their thumb and deviate the wrist in the direction of the small finger, will put stretch on the involved tendons, eliciting pain. The first extensor compartment will be tender on palpation and a bump or cyst may be noted. While x-rays may show small calcifications in the area of the compartment, they are not necessary to make the diagnosis. An MRI or CT scan is not indicated.
How is it treated?
The goal of treatment is to reduce the inflammation around the involved tendons. There are several ways to do this. Activities that require the use of these tendons and elicit pain should be avoided. This is often not possible as these muscle/tendon units are involved in most daily activities, particularly lifting. An injection of corticosteroid, an anti-inflammatory medication, directly into the compartment can be performed at the time of the initial visit to the doctor. This injection, coupled with a splint that immobilizes the wrist and thumb, are successful in up to 80% of patients. Sometimes, more than one injection is necessary to achieve lasting pain relief.
If injections are not successful, surgical release of the tendons from their compartment is indicated. This is an outpatient procedure performed in the operating room. Often times this procedure can be performed under a local anesthetic. A common finding during surgical release is a septum dividing the compartment into two tunnels, each containing one of the two tendons. This arrangement occurs in approximately 30% of people. It is believed that this division of the first compartment into two tunnels is associated with failure to respond to corticosteroid injections. Unfortunately, there is no reliable way to tell if a patient has this septum except to visualize it at surgery. Over 90% of patients who require surgery for deQuervain's tendonitis have the septum creating two tunnels.