What is De Quervain Tenosynovitis?
This is a condition that causes pain at the base of the thumb around the wrist. The pain arises from the inflamed and thickened tendons of the thumb.
The tendons that extend (straighten) the thumb originated from the forearm and attached to the thumb. At the back of the wrist, both tendons pass through a tunnel that formed by the radius bone (which made up the floor of the tunnel) and thick fibrous tissue called extensor retinaculum (which made up the roof). The tendons are lined with a slippery coating called tenosynovium that allows the two tendons to glide easily within the tunnel. In de Quervain tenosynovitis, the tenosynovium is inflammed and thickened resulting in constriction of the two tendons within the tunnel.
What are the causes?
In most cases, there is no obvious cause. Majority may be due to repetitive thumb and wrist motion over a long period of time leading to chronic inflammation and thickening of the tenosynovium. Some may present after an episode of acute trauma. This condition is also commonly seen in diabetic patients and in pregnancy as well as in mother after delivery.
What are the symptoms?
The most common presentation is pain over wrist just above the base of the thumb. The pain is aggravated by thumb or wrist movement, and may spread up to the forearm. Sometimes, a ‘click’ can be felt during thumb movement. Grasping objects with the thumb may become difficult especially when the wrist is bent inwards.
How to diagnose?
Diagnosis is usually made based on patient’s symptoms and physical examination.
Imaging is usually not needed. Occasionally X-ray of the wrist is taken to exclude any arthritis of the wrist or base of thumb which may mimic the pain of de Quervain tenosynovitis. Occasionally a cystic swelling develops over the tunnel and this can be visualized with an ultrasound.
What is the treatment?
Non-operative treatment includes resting the wrist and thumb in a splint to allow the inflammation of the tendons to resolve. Avoidance of any activities of the thumb and wrist that cause pain helps. Some anti-inflammatory medication can help to control the inflammation and swelling of the tenosynovium and also ease the pain.
Steroid injection into the tight tunnel will effectively reduces the swelling and inflammation of the tenosynovium and relieves the symptoms. However, recurrence may occur after few months.
If all non-operative treatments fail or the symptoms are severe, surgery is indicated. In this surgery, the roof of the tunnel is divided to relieve the constriction. Thickened tenosynovium of the tendons may need to be excised. Relieve of pain after the surgery occurs early.
Complications of surgery are uncommon. Infection is rare. Injury to the nearby superficial radial nerve is uncommon and can be avoided with careful dissection under loupe magnifications. Tendon subluxation may occur after surgery.