The joint at the base of the thumb wears out more often than any other joint in the hand except the fingertip joints. Many people have it on an X-ray and never notice. For others it makes pinching, gripping and turning painful. This guide explains what thumb-base arthritis is, what helps, and what surgery can and cannot do.

What is thumb-base arthritis?

The base of your thumb sits on a small wrist bone called the . The two bones meet in a saddle-shaped joint. This shape lets the thumb swing across the palm and turn to meet the fingers. It also makes the joint easy to wear. Sixteen small ligaments steady the trapezium and the joint. Two of them do most of the work, and one probably acts as a pivot that lets the thumb rotate1.
is wear of the smooth cartilage in this joint. As the cartilage thins, the bones rub and the joint becomes painful and stiff. Surgeons grade the wear on X-rays, mainly on the side view. In early disease the joint is loose and painful but the cartilage is still there. In late disease the joint is stiff and the wear spreads to the joints around the trapezium2.

How common is it?

It is very common. In a review of 16 studies, about 6 to 7 in 100 people had X-ray signs at age 50 and 33 to 39 in 100 at age 80, with women at the higher end of each range3. In a large Finnish survey, 7 in 100 men and 15 in 100 women over 30 had it on X-ray. Being heavier raised the risk. A history of heavy physical work did not4. Among people over 55 in Rotterdam, more than a third had it on X-ray5.
X-ray changes and pain do not always go together. In one study of women after the menopause, only 28 in 100 with wear confined to the thumb-base joint had thumb pain, and 55 in 100 when the next joint was also worn6. In a UK community study, about 1 in 5 adults over 50 had painful thumb-base arthritis7.

What are the symptoms?

The usual symptom is an ache or a sharp pain at the base of the thumb. It comes on with pinching and twisting: turning a key, opening a jar, wringing a cloth, writing. The joint is tender to press. It may look swollen or bony. Movement of the thumb may be reduced4.
Over years the thumb can change shape. The base slips outwards and the thumb pulls in towards the palm. The middle thumb joint then bends back to make up for it. This gives a zigzag look and a weaker pinch. Before joint replacement in one series, nearly half of the thumbs had this bent-back middle joint and about 1 in 4 had the full zigzag8.

How is it diagnosed?

Your surgeon will ask about your pain and examine your thumb. Two simple tests are good at finding the arthritis. In one, you hold the thumb against the side of the hand while the examiner pushes it. In the other, you lift the thumb up while the examiner pushes it down. Each picks up 94 in 100 cases and is rarely positive in people without arthritis9. The older "grind test", where the thumb is pressed and twisted, misses about half of cases910.
An X-ray confirms the diagnosis and shows the stage2. It does not show how much pain you will have. The link between the X-ray and the pain is loose5. Treatment is guided by your symptoms, not by the picture.

Will it get worse?

Slowly, and not always. In a review of studies that followed people with hand and thumb-base arthritis for about 10 years, average pain changed little. Hand function and grip tended to decline. About 1 in 4 people reported worse pain over that time11. No treatment has been shown to slow the changes on X-ray12. Treatment aims at pain and function.

Treatment without surgery

Most people start here, and many never need more. European, American and British guidelines all put self-management, exercise and a splint before medicines and injections131415.

Learning to protect the joint

A hand therapist can show you how to pinch and lift in ways that load the joint less. Wider handles, jar openers and key turners help. Guidelines recommend this first13.

Exercises

Simple exercises for the thumb muscles give a small benefit. In a review of trials for hand arthritis, exercise lowered pain by about half a point on a 10-point scale. The gain faded by 6 to 12 months. Side effects were few and mild16. In trials of thumb-base arthritis alone, exercises improved grip strength in the short term17.

A thumb splint

A supports the base of the thumb. In a trial of 112 people, a custom splint worn at night made no difference after 1 month. After 12 months the splint group had less pain and less disability. Most people were still wearing it more than 5 nights a week, and there were no side effects18. A rigid splint that holds both thumb joints was the only treatment with a clear benefit for pain and function at 3 to 12 months in a review of 22 trials17. The British guideline adds a splint when self-management alone is not enough15.

Medicines

Anti-inflammatory gels rubbed on the joint work as well as and cause fewer side effects12. Tablets are for short courses13. Paracetamol has not shown a clear benefit12. In a large review of drug trials, no medicine beat a dummy treatment when only thumb-base trials were counted19.

Injections

A into the joint can ease pain for a while. The benefit is mostly in the first 1 to 3 months20. Trials against a dummy injection are sobering. In one, the steroid gave no benefit at 24 weeks21. In another, both the steroid and the dummy injection helped at 4 weeks and the effect was gone by 12 weeks22. A review of all the trials found no injection clearly better than a dummy or than another injection, and no trial has compared an injection with no injection23. Steroid was as good as hyaluronic acid or and is cheap and simple, so it is a reasonable first choice if an injection is used24. A single platelet-rich plasma injection did no better than salt water at 6 months in a well-run trial25.
Guidelines place injections after self-management and a splint have failed15. No injection changes the course of the arthritis12.

When is surgery considered?

Surgery is for pain that limits your daily life despite the steps above15. There has never been a trial that compared surgery with continuing non-surgical care26. The decision rests on how much the thumb troubles you, what you need your hand for, and how you weigh the recovery against the likely gain.

Trapeziectomy: removing the small bone

The standard operation is a . The trapezium is removed, so the worn joint no longer exists. The space fills with scar tissue and the thumb settles a little. Surgeons have added many extras over the years, such as . A 2026 review of the trials found low-quality evidence that adding a tendon sling makes little or no difference to pain, function or complications26. The British guideline says the same15.

What to expect

In a long trial that followed 153 thumbs for 5 to 18 years, 78 in 100 had good pain relief whichever version was done. Grip strength gains lasted. Pinch strength faded over the years27. Pinch after a trapeziectomy usually does not return to normal.

Risks

In the pooled trials, about 10 in 100 people had a complication after a simple trapeziectomy and about 19 in 100 after the version with a tendon sling2826. Most are minor: a tender scar, tingling from the small nerve that runs over the joint, or a slow return of strength. Further surgery is rare: about 1 in 100 in a review of more than 13,000 thumbs29.

Recovery

In a pooled analysis, pinch strength took about 6 months to get back to where it was before the operation30. Return to work took about 8 weeks in the large review29. Moving the thumb early is as safe as 6 weeks in a rigid splint31. You can drive when you are out of any rigid splint, off strong painkillers and can grip the wheel and brake without pain, usually four to six weeks after a trapeziectomy. I perform a trapeziectomy only occasionally: most people who choose surgery with me have a joint replacement, so the recovery figures above are the published ones rather than my own.

Joint replacement

The alternative is a . A small ball-and-socket implant replaces the worn joint and keeps the thumb at its full length32. The implant I use is a dual-mobility ball-and-socket prosthesis. The operation is done as a day case, usually under a nerve block of the arm.

What the trials show

In a randomised trial of 62 women, replacement was no better than trapeziectomy on the hand-function score at 1 year. The replaced thumbs were stronger and moved more33. At 5 years it was still no better on that score. , satisfaction and the wish to have the same operation again favoured replacement. Re-operation rates were not significantly different34. A review of 21 trials found similar pain relief with both operations. Pinch was about 0.9 kg stronger after replacement, the only difference large enough to matter. There were no long-term data, and the authors say that until there are, its widespread use cannot be recommended35.

How long it lasts

In 130 replacements with one modern dual-mobility implant, 96 in 100 were still in place at 2 years. Among those followed up, rest pain scores fell from 5 to 0 and pinch strength rose from 4.5 to 7.0 kg36. In 61 replacements followed for 5 to 8 years, one needed revision, and everyone was satisfied8. There are no long-term results for this design yet37. Across all designs, between 3 and 20 in 100 implants failed depending on the implant, with modern designs at the lower end38. Across the older literature, implants failed at about 2.4 per 100 thumb-years, against 0.5 for trapeziectomy39.

Risks

In a review of 1,421 modern implants, 13 in 100 had a complication and fewer than 1 in 100 dislocated37. The common problems are irritation of the tendons on the thumb side of the wrist, a trigger thumb, and tingling from the small nerve over the joint3640. The implant can loosen or wear. If it fails, it is changed or converted to a trapeziectomy4032. The trapezium can crack during the operation. If it does, the surgeon may switch to a trapeziectomy, or protect the bone for longer afterwards.

Recovery

This is the main practical difference. Pinch strength was back to its starting level about 1.5 months after replacement, against 6 months after trapeziectomy, although the studies were of low quality and the difference was not statistically certain30. Working patients returned to work after 52 days on average, against 84 days after trapeziectomy with a tendon sling, in a Swiss study41. After a replacement I use a plaster back-slab for 3 to 5 days, then a removable thumb splint for 4 weeks. You move the thumb out of the splint from day 5. No forceful pinch or lifting over 1 kg for 6 weeks. Most people drive from 4 weeks, return to desk work in 2 to 3 weeks and to manual work in 6 to 8 weeks.

Other operations

Fusing the joint gives a stiff, strong thumb. In a trial against trapeziectomy with a tendon sling, it caused so many more complications that the trial was stopped early42. The bones fail to join in 8 to 21 in 100 cases43. Cutting the small nerves that carry pain from the joint is a less common option. The studies are small and there is no randomised trial4426.

Which operation?

There is no single right answer. A trapeziectomy has a long record, few re-operations and a slower recovery. A replacement recovers faster and keeps a stronger pinch, has a small risk of implant problems, and does not yet have long-term results. Both relieve pain in most people. Your work, your hobbies, your age and how you feel about a slower recovery all matter. In a group of women who had one operation in each hand, 10 of 14 would choose the implant again, 1 the trapeziectomy, and 3 were undecided45.
In New Zealand, ACC does not usually cover wear-and-tear arthritis. Arthritis that follows an injury may be covered.

When to seek help

Contact the clinic or your GP if you have:
  • a fever, or spreading redness, warmth or discharge at the wound;
  • pain that gets worse instead of better after the first days;
  • numbness or tingling that does not settle;
  • fingers that turn cold, pale or blue;
  • after a replacement, a sudden clunk with loss of movement or a change in the shape of the thumb.
is an uncommon but recognised reaction after any hand operation, including thumb-base surgery40. It causes pain, swelling and stiffness that seem out of proportion. Tell your surgeon early.

Summary

Thumb-base arthritis is common and often mild. Most people manage with joint protection, exercises, a splint and pain relief. Injections give short-term relief at best. Surgery helps most people who need it. Removing the trapezium is the standard operation. A joint replacement gets people back faster and stronger, at the cost of a small risk of implant problems and without long-term results yet. The choice is yours to make with your surgeon.