GANGLION OF WRIST
A ganglion is a cystic lesion that is found closely associated with a joint capsule or tendon sheath. It is often seen in young adults but rarely in children; most frequently, it forms in the hand and wrist and less often in the ankle, foot, and knee. The most common site is the dorsum of the wrist just lateral to the common extensor tendons of the fingers. A ganglion usually occurs singly and may be multilocular; it consists of an outer fibrous coat and an inner synovial lining and contains a clear, colorless, gelatinous fluid.
Although the cause is uncertain, perhaps the most accepted theory is that a ganglion results from cystic degeneration of connective tissue near joints or tendon sheaths. Repeated trauma appears to be a causative factor in about 50% of cases.
The only finding may be a slowly growing, localized swelling, but most patients report intermittent aching and mild weakness. Commonly, the patient will describe the mass waxing and waning in size and may have short-term resolution after “bumping” the mass inadvertently.
On examination, the cyst is firm, smooth, rubbery, rounded, slightly fluctuant, and, at times, tender. It is usually fixed but may be slightly movable if it involves a tendon sheath. Shining a light (pen light) through the mass confirms the fluid-filled cyst and aids in the correct diagnosis (transillumination). Clinical examination should also focus on evaluating for any carpal instability. Commonly, tears of the scapholunate interosseous ligament can lead to a dorsal ganglion cyst.
Some ganglia disappear spontaneously. Treatments such as traumatic rupture, aspiration, and injections are associated with a high recurrence rate. Complete surgical excision of the ganglion and the ligamentous tissue at its base is the treatment of choice and usually prevents recurrence. Removal of the stalk and under- lying swath of capsular tissue is critical to diminish recurrence. Arthroscopic techniques for removal of ganglia are gaining favor with the goals of removing the cyst with less tissue trauma and more expedient recovery.