A ganglion cyst of the wrist is a fluid-filled sack usually located under the skin on the back of the wrist or hand.
A ganglion cyst is a benign formation that is more often present at the wrist and occasionally at the finger joints. A ganglion develops in proximity of the joint capsule, which is a multitude of ligaments enclosing the joint. The capsule contains a viscous synovial fluid to facilitate the movement of the bones within the joint.
Ganglions are mostly located to the dorsal side of the wrist or hand. They can be protruding and visible or occult, when forming in the deeper tissues. Usually over time they grow in size but reduce with rest. In fingers, ganglion cysts are more often located at the end of the finger joint. Ganglions may interfere with function of the fingers and cause pain; however, they may also be asymptomatic.
Ganglion cysts are frequently observed in younger individuals between 15 and 40 years of age and more often in elderly women. The cause of ganglion cyst formation is unknown. Hypotheses suggest that it can develop:
Following minor, repetitive injuries particularly during prolonged sport activities
Consequence of damage to the joint capsule causing the synovial fluid to leak outside the capsule and become enclosed in a cyst
Due to phalangeal joint arthritis at the finger extremities in older adults
These are some recognised risk factors leading to ganglion cyst formation:
Micro-injuries to the wrist capsule related to prolonged sports
Tenosynovitis (De Quervain's tenosynovitis, volar flexor tenosynovitis in trigger finger)
The most evident symptom of a ganglion cyst is the typical swelling with a round and smooth shape which varies in size from a pea to a larger protuberance. Due to its close connection to the median or ulnar nerves at the wrist, a ganglion may cause pain but also be completely pain-free. This can cause limitations in wrist function. Spontaneous leakage of the synovial fluid can occur. When located in deep tissues, a ganglion cyst may not manifest as clearly but reveals itself with pain during wrist movement.
Diagnosis of a wrist ganglion only requires medical examination. No tests are necessary. Patient history and arising symptoms are discussed with the patient. Ultrasound is useful to confirm the diagnosis and determine the best treatment options. Occasionally a MRI can assist in complex cases where ganglion cyst is linked to other pathologies (lipomas and vascular lesions).
Gangliography is another method used in conjunction with needle aspiration of the synovial fluid. It consists in the injection of a dye opaque to X- rays, followed by radiological imaging. This allows to determine the exact location and size of the ganglion. The strength of the wrist under grip and pinch can be undertaken to measure changes in function.
Up to 50% of ganglion cysts do not require any treatment and recede spontaneously. Conservative management of a ganglion cyst can vary and include:
A traditional method consisting in smashing a heavy book (Bible) on the cyst, causing the cyst to burst and gradual absorption of the synovial fluid
Immobilisation of the wrist with a brace or splint to reduce pain and monitor whether the ganglion will reduce in size
Needle aspiration of the synovial fluid from the cyst and followed by steroid injection into the cavity. This approach is used particularly in dorsal cysts and may have limited success requiring repetitive aspirations or ultimate surgical removal.
When conservative treatment or needle aspiration fail and the ganglion cyst does not recede, surgical removal is necessary, especially when associated with discomfort and pain. With position of the ganglion in the palmar (volar) side of the wrist, needle aspiration is not recommended due to the potential damage to local vessels and nerves. Surgery remains the standard treatment for this type of ganglions. This however can be complicated by the proximity or attachment of the ganglion to the radial artery. In this procedure the fibrotic tissue forming the cyst capsule including the area of the tendon sheath where the ganglion is attached is removed. The latter is considered the ganglion root. This is a simple day surgery in outpatient clinic under local anaesthesia. Normal wrist function can begin a few weeks after surgery.
Although surgery has higher success rate compared to other treatments, there is a small chance of recidivism. Complications after surgery include:
Recurrence of the ganglion
Reduced wrist motion and instability
Nerve and blood vessel damage
Regardless of conservative treatment (use of a splint) or surgery, rehabilitation therapy for ganglion cyst includes:
Manual massage delivering pressure in the region to direct the synovial fluid out of the ganglion
Passive range of movement to mobilise the wrist
Tendon gliding exercises with wrist flexion/finger extension and wrist flexion/finger flexion
Wrist stretching to extend the scar post-surgery
There are no specific guidelines to prevent the formation of ganglion cysts. However, it is recommended to reducing or modifying those daily or sport activities that put strain on the wrist. These may cause wear of the capsule thus increasing the risk of developing ganglion cysts.