Pathology
Ganglion cysts are the most frequent cause of swelling or masses found at the wrist level. Ganglion cysts are like a little balloon made out of the joint capsule, filled with a clear, colorless, gelatinous fluid coming from the joint itself. Ganglions usually present with a single cavity but may contain multiple chambers. They remain filled because they have a one-way valve mechanism allowing for fluid to easily come in but difficult to return into the joint.
Ganglion cysts occur most frequently in women. 70% of cases occur in patients between 20 and 40 years old. In older patients, they may be associated with arthritis. Ganglions are rarely seen in children. 60-70% of ganglions occur on the back of the wrist over the scapholunate ligament and about 20% are found in the palmar side over the scaphotrapezoid joint.
Patients complain of localized wrist pain aggravated with activity and weakness during repeated use of the hand. Characteristics of a Ganglion Cyst:
- Slow growing
- Firm
- Smooth
- Rubbery
- Rounded
- Slightly fluctuant mass that initially comes and goes and in time becomes both permanent and tender
Dorsal ganglions become more obvious with wrist flexion. Cysts on exam can transmit the light of a flashlight when in the dark. This is a technique used to confirm the diagnosis.
On occasions, patients will present with pain at maximal wrist extension but no obvious mass is noted on palpation over the scapholunate joint during the physical exam. This may represent an occult ganglion cyst and an MRI may be necessary to confirm the diagnosis.
Treatment
Non-operative treatment consists of aspiration of the cyst with or without steroid injections, followed by wrist splinting. Only 30 to 50 % of cases are successfully treated this way and this technique is commonly only a temporary solution.
Technically, it is very challenging to aspirate the fluid, even with a large needle. The larger the needle, the higher the risk of tendon injury during the procedure. It is also difficult because the cyst may collapse and the needle tip become blocked before the fluid is completely removed. Aspirations are rarely recommended or performed at ROC.
The most reliable procedure for a cyst is surgical excision. This can be done through a small transverse incision over the mass. The incision is cosmetic and in certain cases, removal can be done arthroscopically through small incisions. Both procedures provide comparable outcomes for resolution of symptoms, return to full activities, and recurrence rate. Recurrence after excision is 5-10% of cases.