As tendons cross over the wrist joint, they pass through fibrous tunnels which hold them in the 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.
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.
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 a 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.
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.
Kienböck's disease refers to the death of the lunate, one of the eight carpal bones that form the wrist joint. The blood supply to the lunate is disrupted, leading to the death, fragmentation, and collapse of the bone. The cause of the blood supply disruption is a topic of some debate and there is no consensus opinion. Several factors have been associated with Kienböck's disease, including increased length and tilt of the distal radius relative to the ulna, blood-clotting abnormalities, and certain systemic diseases. None of them have been shown to be the single causative factor.
Patients with Kienböck's disease typically complain of wrist pain localized centrally on the back of the wrist/hand. Pain intensity varies from mild to severe and increases with wrist motion and lifting. Depending on the severity of the disease, wrist motion may be decreased when compared to the uninvolved wrist.
X-rays of the wrist will demonstrate sclerosis, fracture, and/or collapse of the lunate associated with Kienböck's disease. Both MRI and CT scans of the wrist can provide helpful information regarding the extent to which the lunate is diseased.
Treatment of Kienböck's disease is guided by both the severity of symptoms and the radiographic appearance of the lunate and wrist. Surgery is often necessary, particularly in the more advanced cases.
The goal of treatment is to halt the progression of the disease by improving the blood supply to the lunate. This may be accomplished through several different procedures including decreasing the pressure on the lunate through a radial shortening osteotomy or removing a portion of the dead bone and replacing it with bone graft. If the lunate has completely collapsed with resultant severe wrist arthritis, excision of wrist bones or a wrist fusion may be necessary.