Wrist Synovial Cyst
Definition
This is a swelling of joint synovial fluid that may be located either on the top of the wrist (dorsal side) or on the underside (palmar side).
What are the causes?
Causes are not always identified. Sometimes they may be associated with ligament injuries of the wrist (ligaments connecting the wrist bones to each other), and these will be investigated.
What are the symptoms?
The complaint can be aesthetic if the cyst is very visible, but is also and especially functional, ranging from simple discomfort during wrist mobilization to pain when the cyst is under tension, regardless of the size of the cyst. Pain may fluctuate over time and often appears after a period of significant wrist use.
What tests may be requested?
An ultrasound is the test of choice to confirm the diagnosis. A standard and dynamic radiographic assessment will also be requested. An MRI may also be requested in some cases.
How is this condition treated?
The spontaneous evolution of the cyst is unpredictable: its size most often fluctuates over time and it can sometimes regress completely. In case of a bothersome cyst, a cortisone puncture-infiltration may be offered, but with a high risk of recurrence (about 50%). Therefore, surgical treatment may be offered immediately and consists of removing the entire swelling as well as its connecting collar with the joint. If a ligament injury is identified, it will be treated at the same time.
What are the risks of the procedure?
Risks inherent to any surgery:
complex regional pain syndrome (formerly known as «algoneurodystrophic syndrome»): the hand becomes red, warm, swollen, and painful with persistent «electric» pain. This syndrome can last several months.
soft tissue and osteoarticular infection
hematoma, which may resolve spontaneously or require surgical revision depending on its size.
An injury to the radial artery in case of palmar cyst remains exceptional.
Recurrence (10%), although significantly lower than with cortisone puncture-infiltrations.