Thumb Arthritis: Pain at the Base of the Thumb

Thumb arthritis is wear in the small joint at the base of your thumb, where it meets the wrist. It aches when you pinch, grip, open a jar or turn a key. Most people do well without surgery. A splint, hand therapy and a guided injection come first, and PRP or a fat graft is the next step when steroid shots stop lasting.

Why does the base of my thumb hurt so much?

The joint at the base of the thumb is called the CMC joint. It is shaped like a saddle. That shape lets your thumb swing across the palm and touch each finger. The price of all that motion is a loose joint. Every pinch pushes the thumb bone against a small wrist bone, and the force there is several times the force at your fingertips.

Over the years the ligaments that hold the joint in place stretch. The thumb starts to slide a little with each pinch. Cartilage wears where the sliding happens. Bone spurs grow at the edge. In time a bump shows at the base of the thumb, and the thumb may fold in toward the palm.

Women are hit harder than men, most often after menopause, when ligaments lose some of their hold. But hormones are only part of it. High blood sugar coats cartilage and tendon with sugar-bound proteins that make them stiff and brittle. Belly fat sends out inflammatory signals that reach every joint, which is why hand arthritis tracks with weight even though your hands carry none of it.

Then there is the work. Around Bridgeton and North County, a lot of people scan, sort, stock, cut hair, wrap, or turn wrenches for a living. The thumb that pays the rent is the same thumb that is wearing out. Telling someone to rest it for three months is not advice. It is a pay cut.

See every joint and tendon we treat with PRP, bone marrow or fat on our PRP injections in St. Louis page.

How do I know it is thumb arthritis and not something else?

Several problems live within an inch of each other, and many people have two at once. Here is how they usually differ:

• Thumb arthritis: a deep ache at the base of the thumb, worse with pinch and grip, sometimes with grinding.
• De Quervain’s tenosynovitis: pain along the thumb side of the wrist, a little higher up, worse when you lift with the wrist bent.
• Carpal tunnel syndrome: numbness and tingling in the thumb, index and middle fingers, often at night.
• Trigger thumb: a catch or click on the palm side when you bend and straighten the thumb.
• A pinched nerve in the neck: the C6 nerve can send pain or numbness into the thumb. See cervical radiculopathy.

We press on the joint, move it, and grind it gently while it is loaded. An X-ray shows how far the wear has gone. The X-ray grade and the pain often do not match, though. Some people with a bad-looking film work all day. Others with a mild film cannot hold a coffee cup. We treat the person, not the picture.

What helps thumb arthritis without surgery?

• A splint. A short thumb splint at night, and during heavy tasks, rests the joint in a good position.
• Hand therapy. Strong muscles at the web of the thumb hold the joint centered so it slides less. That work is done in our physical therapy program.
• Tool changes. Fat-grip pens, a key turner, a jar opener and lever door handles take hundreds of hard pinches out of a day.
• A guided injection. A steroid shot placed with imaging can calm a flare fast. See joint injection.

A steroid shot is a good bridge. It is a poor habit. Steroid quiets inflammation for weeks or months, but it does nothing to repair tissue. Trials of repeated steroid shots in arthritic joints show the benefit fades with each round. By one to two years, repeated steroid did no better than salt water.

Can PRP or a fat graft help thumb arthritis?

Yes, for many people, and the details matter. PRP is platelet-rich plasma. We draw your blood, spin it, and concentrate the platelets, which carry signals that tell injured tissue to repair. Microfragmented fat is a small amount of your own fat, taken with a thin needle from the belly and washed. It acts as a cushion and a source of repair signals.

Here is what the thumb research shows. A trial of 95 people in Austria compared fat, PRP, fat plus PRP, and salt water. Over two years, fat plus PRP clearly beat salt water for pain and hand use. A review of eight studies found that PRP and fat gave longer pain relief than steroid.

Our reading is simple. One shot dropped into a joint, with nothing around it, is not a plan. What we do is place the injection with imaging so it lands inside that tiny joint. We choose the product and the platelet dose for your stage. Then we put a splint, hand therapy and work changes around it, and we look at the blood sugar and inflammation that keep wearing the joint down.

Over 90% of our accepted case-study patients see significant improvement. These are practice-reported figures from our own population, not trial outcomes, and individual results vary.

The procedure is done awake, with local numbing medicine. Most people drive themselves home. Expect soreness for about 48 hours. How many injections you need depends on how your thumb responds, not on a preset series. Orthobiologic care is not covered by insurance, and HSA and FSA funds can generally be used. The procedure is done at our regenerative clinic, 4477 Woodson Rd in St. Louis.

When is surgery the right call?

When the joint has collapsed, the thumb has folded into the palm, and nothing holds for more than a few weeks, surgery is a fair answer. The usual operation removes one small wrist bone. It works, and recovery takes months. If that is where you are, we will say so plainly. Most people we see are not there yet.

Frequently asked questions

Is thumb arthritis the same as rheumatoid arthritis?

No. Thumb arthritis is wear and tear in one joint. Rheumatoid arthritis is an immune disease that usually hits many small joints on both hands, with morning stiffness that lasts an hour or more. If your pattern points that way, we check blood tests before anything else.

Should I wear a thumb brace all day?

Usually not. Wear it at night and for heavy or repeated tasks. Wearing it all day can weaken the muscles that protect the joint. Hand therapy builds those muscles back.

Will a cortisone shot wear out my thumb joint?

One shot for a bad flare is reasonable. Shot after shot is the problem. Repeated steroid does less each time and does nothing to repair the joint. When shots stop lasting, it is time to talk about other options.

How long does PRP take to work in the thumb?

PRP is not a painkiller. Most people notice change over four to eight weeks as the tissue responds. The first two days can be sore. Keep up the splint and therapy while you wait.

Can I keep working with thumb arthritis?

Most people can. Small changes to grip size, tools and task order make a big difference. If you need work notes or limits for a while, we write them.

Sources

• Winter R et al. Minimally Invasive Treatment of Trapeziometacarpal Osteoarthritis: Results of a Blinded Randomized Controlled Trial. Plastic and reconstructive surgery, 2023. PubMed 37039525
• Winter R et al. Autologous Fat and Platelet-Rich Plasma Injections in Trapeziometacarpal Osteoarthritis: A Systematic Review and Meta-Analysis. Plastic and reconstructive surgery, 2022. PubMed 36219860
• Donovan RL et al. Effects of recurrent intra-articular corticosteroid injections for osteoarthritis at 3 months and beyond: a systematic review and meta-analysis in comparison to other injectables. Osteoarthritis and cartilage, 2022. PubMed 36108937