Francois J Duminy



A Ganglion presents as a painful swelling near a joint - often the wrist, but other joints can also be involved.

It is thought to be caused by a minor injury in the capsule of the joint which then becomes a weak spot in the capsule.

Due to varying pressures in the joint fluid, a little bubble can blow through this weak spot.

With continued movement and "pressure pulses" the bubble becomes more and more inflated.

The bubble or "Ganglion" can press on other structures and also excite an inflammatory response that can cause pain in the area.

The patient notices a lump that pains at times and that can also ache for long periods.


The Ganglion is usually filled with crystal clear joint fluid and this clear fluid conducts light very well, so a diagnostic indicator is that when a small torch is placed against the skin over the ganglion, the transillumination flare is much brighter than in normal tissues. You will need to be in a darkened place to see this clearly.

A traditional treatment was "a good smack with the family bible" This would rip the capsule of the ganglion allowing the fluid to escape into the surrounding tissues and to be reabsorbed, thus flattening the ganglion.

Ganglia have long been treated by excision of the sac (bubble), but recurrence rates are high.

For the past 24 years we have been treating them in a very conservative manner by injecting some local anaesthetic, and then using a large needle to make holes/tears in the capsule, remove the joint fluid and instil a small amount of locally active steroid to slow the healing of the holes.

This simple treatment subsequently allows continuous internal leaking from the ganglion, preventing re-inflation. It works in 70% of cases and is safely repeated in the remaining 30% of cases!