Thumb Base Arthritis

Thumb basal joint arthritis, also known as joint arthritis (CMC arthritis), also sometimes referred to as trapeziometacarpal joint arthritis (TMC arthritis), has even more options for treatment!

Despite the confusing name terminology, the condition we are talking about is arthritis of the thumb base.

1) What does it feel like?

Often, people describe a throbbing or aching sensation (though sometimes it can be very intense and sharp) at the bottom of the thumb where the thumb meets the wrist:

This pain can be aggravated by pinching of the thumb or twisting of the wrist (opening door knobs, using a can opener, turning a key).

2) Why did I get it?

This is a joint prone to arthritis because of how many directions the joint moves. Over time, normal use of the thumb can result in wearing of the smooth cartilage joint surface that eventually turns into cartilage loss. The rubbing of this worn and exposed bone can be painful and is what we call osteoarthritis or just arthritis.

3) How can I make the pain better?

Currently, we don't have the technology to reverse arthritis. We do, however, have several treatment options for this incredibly common condition.

When I counsel patients who have never seen anyone for arthritis before, I offer them the most conservative measures:

a) Diclofenac 1% topically - this is available over the counter. I often send a prescription anyway in case it's covered by my patient's insurance plan. It is recommended 4 times daily, and the evidence suggests it provides a noticeable difference within 2 weeks of consistent use.

b) Oral NSAIDs - over-the-counter anti-inflammatories like ibuprofen or naproxen work great, but are sometimes not tolerated due to stomach irritation or interactions with other medications like blood thinners.

c) Tylenol - works very well for some, and for others, not as much.

d) Splinting - Our office recommends a Comfort Cool® splint, which tends to work well and provides support for the joint. Many people find it comfortable to wear during all sorts of activities, but I don't advise wearing it around the clock in order to prevent stiffness and weakening of the hand muscles.

e) Hand Therapy - can be effective in reducing hand pain and delaying the need for surgery.

f) Turmeric - the recommended dose is 1 gram (1/4 teaspoon of the spice) daily. It's generally well tolerated; however, some people don't like the taste and prefer to take a pill. Evidence suggests it works as an anti-inflammatory in a way different from an NSAID (safe to take together) and can work as effectively.

g) Topical CBD/THC - I usually suggest this as an option as many of my patients anecdotally have found it helpful. They can sometimes be expensive, and there is limited data to support use. You should know that the topical THC formulations of products can show up on drug screening, so use with caution. I conducted a personal survey of dispensaries in Massachusetts to see what vendors noticed patients repeatedly purchasing, and the broad-spectrum topical products frequently came up as an option.

If my patient has already done all this and we are ready to move to another step, I offer them an in-office steroid injection (cortisone shot). Patients can expect the joint to hurt worse for the first couple of days before it gets better—usually by a week. The effect can last several months; I've had a few patients say it lasted a year. There isn't an official set number of injections a person can have in the joint, but I will check the skin to make sure it isn't thinning excessively in the area of the injection, which is a known side effect. There is always a risk for infection with the injection, and we do know that it may increase the rate of cartilage wear, but usually the cat is out of the bag when we reach this point.

If we have "graduated" from steroid injections, we should discuss surgical options. If you look up treatment of thumb base arthritis, you will find several described surgical techniques. Generally, there are three categories of surgery:

a) Denervation: This type of surgery is the least invasive and involves selectively cutting nerves that transmit the pain sensation of the joint to the brain. This works for the majority of patients and has about a 2-week downtime, which is why I tend to recommend it as a first choice in treatment. It takes anywhere between 2 weeks and 3 months to notice a difference in pain. There is no splinting with this operation and no hand therapy required afterward. The other advantage of this operation is that it can provide an improvement in pinch strength, which is a major advantage over trapeziectomy, which I'll discuss below. If the operation doesn't succeed in providing pain relief, we can always move forward with trapeziectomy.

b) Trapeziectomy: This is the classic operation for thumb arthritis and involves the removal of one of the two bones responsible for thumb base arthritis pain. Once the bone is removed, there are several varieties of ways surgeons try to support the thumb while the space where the bone used to sit fills with scar tissue and creates a softer pad for the thumb to rest on. My preferred technique is to use a large suture to create a hammock between tendons that sit where the bone used to live. The reason I like it is because it doesn't involve surgery anywhere else on the hand, wrist, or forearm, and according to the available evidence, provides equivalent pain relief, stability, strength, and durability compared to other options. Downtime is about 4 weeks before the splint from surgery comes off and hand therapy begins, which usually continues for 8 more weeks.

c) Joint replacement: Historically, joint replacements of the thumb haven't done very well for patients due to issues of hardware failure and inflammation. Currently, there are newer implants that exist, and I do have colleagues who have had good success with them. I am personally waiting for more information on the longevity of success and a clear advantage over trapeziectomy alone before offering this option to my patients.

Thumb arthritis is extremely common. It's also very interesting to note that there seems to be a poor correlation between the changes noted on x-ray and severity of symptoms. When I'm talking with patients about what to do for their arthritis, I follow a stepwise approach that takes risks and goals all in consideration.