A ganglion is a protrusion of an articular capsule or a tendon sheath. It is generally filled with synovial fluid and forms a cyst. It is a benign swelling, which can appear in any joint and often varies in size. Ganglia most frequently develop on the dorsum of the wrist where swelling is distinctly obvious. Sometimes a wrist ganglion is too small to be seen or felt on the outside. But still this kind of "occult" ganglion can cause wrist pain.
In many cases the exact cause of the ganglion remains unclear. Possible factors are prior joint trauma, wear and tear of a joint (arthritis) or diseases, which lead to weakening of the joint capsule, as well as increased production of joint fluid (e.g. due to rheumatic diseases.
Aside from swelling a ganglion depending on its size and localization, can cause pain and/or impair the mobility of the affected joint. It is characteristic for a ganglion to change size. If a ganglion appears near the distal finger joint, it can exert pressure on the nail root and lead to nail deformities.
Typically, a tight elastic swelling at a characteristic location lead to the diagnosis. Ultrasound examination can confirm the presence of a fluid-filled cyst.
If joint wear is suspected to cause the ganglion an X-ray can be taken. If the diagnosis is unclear, or an occult ganglion is suspected, an MRI scan may occasionally be necessary.
The treatment is based on patient complaints. If there is no pain, observation may be appropriate since ganglia often resolve spontaneously. If there is pain involved, temporary immobilization may help.
Puncturing with simultaneous cortisone injection, can sometimes lead to healing of the ganglion. However, there is frequently a recurrence (relapse). The operative excision of the complete cyst through a skin incision directly above the swelling is the quickest way to definitive healing. However, even after full surgical removal a relapse can occur. The operation is performed under local or regional anesthesia usually in the ambulatory setting.
Follow up care
Normally after the operation only a dressing is applied, so that the joint can be moved immediately as far as pain allows to. However, sometimes a splint is applied especially at the wrist to minimize postoperative pain.
Supportive mobilization with hand therapy can be useful since there can be temporary limitations of flexion, especially after ganglion excision at the dorsum of the wrist. It takes usually four to six weeks until function of the affected joint is fully restored.