Mucous Cysts & Finger Arthritis
Mucous Cysts & Finger Arthritis | Denver, Colorado
A mucous cyst is a common finding in the finger I routinely treat in my hand surgery practice in the Denver metropolitan area. The underlying cause of a mucous cyst is typically arthritis of one of the joints in the finger.
Mucous cysts are small fluid-filled cysts that typically occur in the last finger joint, closest to the fingernail. We call this the distal interphalangeal, or DIP, joint. A mucous cyst is a small pouch of fluid that originates from this joint when it becomes arthritic, and is a result of a small underlying bone spur (osteophyte).
Mucous Cyst Diagnosis & Treatment
Figure 1 - A large mucous cyst overlying the DIP joint of the finger
Diagnosing a mucous cyst is straightforward. They are easily visible fluid-filled cysts that arise just below the fingernail. In severe cases, they can spontaneously pop or drain. They can even become infected. If they have been present for a long period of time, they can result in a nail deformity due to the pressure they exert on the adjacent nailbed. An x-ray is typically useful to confirm the presence of an underlying bone spur and arthritis of the joint. Additional imaging or testing is not necessary.
Treatment of a mucous cyst relies on understanding the original cause. Because these result from arthritis and a bone spur, there is no at-home or nonoperative treatment that will successfully treat a mucous cyst. In fact, whatever you do, do not ever attempt to drain a mucous cyst. This cyst is a direct connection to the joint. Not only will the cyst just come back after draining, but it puts you at risk for a joint infection. This can be devastating, sometimes requiring hospital stays or even amputation.
Mucous Cyst Excision Surgery
Many patients ultimately choose to have their cysts removed, whether for cosmetic or functional reasons.
Surgery to remove a mucous cyst involves a surgical incision slightly larger than the cyst. I will then go all the way down to the joint level where the cyst originates and excise the cyst and the bone spur that caused the cyst in the first place. Without successful excision of the bone spur, a mucous cyst will come back. This is another reason why it’s important to never attempt mucous cyst drainage at home.
Typical recovery from this surgery occurs over 2-3 weeks. I use 3-4 sutures that need to be removed in the office. Light use of the finger is encouraged immediately, taking care to protect the wound during the healing process.
Additional Information
If you’d like more information on mucous cysts or finger arthritis, please continue reading through the frequently asked questions below. You can also access my ‘deep dive’ section to the right of the FAQs where I have links to the longer-form articles I have written about various topics related to mucous cysts and finger arthritis.
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The Basics
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A mucous cyst is a fluid-filled cyst that commonly develops in association with arthritis, particularly at the distal interphalangeal joint (DIP). They arise as the result of an underlying bone spur (or osteophyte) from the joint.
While mucous cysts aren't dangerous, they can be painful, especially if they grow large enough to rise to the skin surface.
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Mucous cysts arise from the DIP joint as a result of an underlying bone spur. Bone spurs are a natural response to developing arthritis in a joint.
These spurs can protrude from the joint, thinning the joint capsule. Joint fluid can then accumulate in this space, leading to the growth of a mucous cyst.
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Aging individuals are more susceptible to developing mucous cysts due to their strong association with arthritis.
Every so often I will see a mucous associated with a bone chip, rather than a bone spur, in a younger person after a finger injury.
Mucous Cyst Symptoms & Diagnosis
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Mucous cysts are not dangerous but are often painful. If the cyst grows too large near the base of the nail, it can cause a noticeable groove in the nail. Unfortunately, this nailbed deformity can be permanent.
A mucous cyst may also spontaneously drain and can even become infected. Please see a hand surgeon right away if you have a draining mucous cyst. And remember. Never ever drain your own mucous cyst (see below for more details).
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A mucous cyst is easily diagnosed by your physician. A fluid-filled cyst adjacent to the DIP joint is almost universally a mucous cyst.
An x-ray revealing underlying arthritis of the DIP joint with bone spurs will seal the diagnosis.
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Beyond a standard x-ray, no additional imaging or testing is needed in the diagnosis or treatment of mucous cysts.
Mucous Cyst Treatment
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Unfortunately, because the underlying cause of a mucous cyst is a bone spur at the level of the joint, there is no at-home treatment that will eliminate the problem. While it is certainly safe to choose to ‘do nothing’ about your cyst, please monitor the cyst and see a hand surgeon right away if it comes to the surface and drains on its own.
I will stress this again. Never drain your own mucous cyst. The cyst represents a direct connection to the joint. If bacteria enter through the cyst, they can access the joint and cause ‘septic arthritis.’ This is a condition that can result in widespread infection, need for prolonged hospital stays, and even a need for finger amputation.
And remember. Even if you drain it safely, it’s only a matter of time before it comes back since you didn’t address the underlying cause.
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As discussed above in the ‘at-home treatment options,’ needle drainage is not effective for a mucous cyst. No doctor, practitioner, or patient should attempt mucous cyst drainage given its high level of risk and high rate of failure.
Mucous Cyst Excision Surgery
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The most reliable treatment for a mucous cyst is surgical excision. In this procedure, an incision just larger than the cyst is made. I will then work all the way down to the joint and cut out the bone spur causing the cyst. The cyst is then completely removed.
I will then close your skin with sutures and place your finger in a soft, sterile dressing.
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Mucous cyst excision surgery is a day surgery typically performed in an outpatient surgery center. In most cases, I offer my patients a choice of anesthesia.
Most patients choose to do the procedure under local anesthesia, which is accomplished by injecting numbing medicine into the finger (like the dentist). Patients will then remain wide awake for the 20-minute procedure.
If this makes you uncomfortable or squeamish, you can choose to have an anesthesiologist administer a ‘twilight’ sedation (similar to a wisdom tooth extraction or colonoscopy procedure). With this anesthesia, you will feel asleep but will be breathing on your own without the need for a breathing tube.
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Following mucous cyst excision surgery, you will be placed into a soft, sterile dressing. I encourage light to moderate use of the hand right away, taking care to avoid anything that would strain the healing wound.
I will then meet with you approximately two weeks after surgery to evaluate your healing process. Your stitches will be removed at this visit.
The next stage of healing involves gentle progressive range of motion exercises and resumption of all activities. The majority of patients feel 80-90% recovered by 6 weeks.
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Restrictions are fairly simple after mucous cyst excision surgery. The surgical dressing must stay on and dry for five days following surgery. Finger movement and light to moderate use of the hand is allowed and encouraged, beginning on the day of surgery. Please do not engage in any activities that would stress the wound or ‘pop’ the stitches. This restriction remains in place until about one week following suture removal, or about three weeks after the procedure.
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All surgeries have risks, many of which are generic to surgery itself. I go over these in detail with you before surgery as part of the informed consent process. Examples include bleeding, infection, damage to surrounding tendons/nerves/vessels, anesthesia risks, or failure of the procedure.
The most common risk of mucous cyst excision surgery is finger stiffness. Because some of the surgical work is done at the level of the joint, the joint capsule is involved in the healing process after the cyst is removed. As it heals, the tissues contract and naturally cause some stiffness. Most patients work through this over the first 4-6 weeks after surgery. Occasionally, it can take even longer.
The other important risk to understand with this surgery is recurrence of the cyst. Please see below for additional information about this risk.
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An important risk to understand following mucous cyst excision is recurrence.
Mucous cysts can recur after surgery about 5-10% of the time. This reality is important to consider prior to electing for surgery.
If your cyst recurs, you could require a second surgery to remove the cyst again.
