Thumb arthritis is osteoarthritis of the basal joint, where the thumb meets the wrist. It causes pain gripping and pinching, weakness opening jars, and eventually a bony bump at the base of the thumb. A custom night splint significantly reduces pain over twelve months, exercises and grip changes carry most of the rest, and surgery is a good option that comes later rather than first.
The number worth knowing before anything else: in the trial that established the splint, there was no measurable difference at one month. All of the benefit appeared over the year. That single fact explains why most people give up on the treatment that would have worked.
Which joint is actually the problem
The thumb has more joints than people expect, and thumb arthritis almost always means one of them: the basal joint, also called the carpometacarpal or trapeziometacarpal joint, where the base of the thumb meets a small square wrist bone called the trapezium. Pain in the fingers themselves follows a different map, in which the row of knuckles that hurts tells you which arthritis you have.
That thumb joint is a saddle. It lets the thumb swing across the palm to meet each finger, which is what separates a human hand from a paw. The price of that mobility is stability: the joint relies on a set of ligaments to hold it in place, and the deep one on the palm side, the anterior oblique ligament, is the one that matters most. When it loosens, the joint surfaces start to grind against each other slightly off-centre, and the cartilage wears at the point of highest pressure.
That is why basal joint arthritis is not simply wear from use. It is degeneration in a joint that has lost some of its guidance, and it explains the loss of grip strength that comes with it. It is also why the condition is much more common in women, and much more common after the menopause.
To find it on yourself: fold your other hand’s index finger into the hollow just below the fleshy web between thumb and index. Press in and towards the wrist. If that reproduces your pain, you have found the basal joint. If that spot is comfortable and the pain instead lights up over the tendons on the thumb side of the wrist, that is de Quervain’s tenosynovitis and not arthritis.
The four stages, and why they matter less than the name suggests
| Stage | What the X-ray shows | What it feels like | What is usually offered |
|---|---|---|---|
| 1 | Joint looks near normal, perhaps slightly widened | Ache after use, settles overnight | Night splint, exercises, activity changes |
| 2 | Narrowed joint space, small bone spurs under 2 mm | Pain gripping and pinching, grip strength dropping | The same, plus topical anti-inflammatory gel |
| 3 | Marked narrowing, spurs over 2 mm, the joint drifting | Pain at rest, visible bump at the base of the thumb | Steroid injection, then surgical options discussed |
| 4 | The neighbouring joint involved as well | Constant pain, thumb pulled in towards the palm | Surgery, usually trapeziectomy |
Two points about that table. The staging is radiological, meaning it describes a film rather than a person, and the degree of degeneration on the X-ray correlates poorly with how much someone hurts. And a surgeon deciding whether to operate will ask what you cannot do rather than which stage you are, because a stage 2 thumb in a self-employed joiner is a bigger problem than a stage 4 thumb in someone who has adapted.
The night splint, and why people abandon it
difference in pain between wearing a night splint and usual care at one month. At twelve months the splint group was clearly ahead.
Rannou F. et al., Annals of Internal Medicine, 2009, 112 patients
The Rannou trial is worth understanding because it explains a common failure. 112 patients with base-of-thumb osteoarthritis were randomly assigned either a custom-made splint worn at night or usual care. The primary measurement was pain at one month, and there was no difference.
Had the trial stopped there, the conclusion would have been that splints do not work. It carried on to twelve months.
Night splint against usual care in base-of-thumb osteoarthritis, at 12 months
Two practical instructions come out of it. Wear it at night rather than during the day, because a splint worn all day weakens the muscles you are relying on. And keep wearing it past the point where you have concluded nothing is happening, because in the trial nothing had happened yet at that point either.
A custom splint made by a hand therapist fits better and gets worn more than an off-the-shelf one, which matters more than the material. If you can get a referral to hand therapy, take it.
The exercises, and the grip changes that do more
The muscles at the base of the thumb, the thenar group, do a share of the work of holding that joint together. Keeping them strong takes load off the worn surfaces.
Thumb opposition. Touch the tip of your thumb to each fingertip in turn, then back. 2 rounds, twice a day. Slow, deliberate, no force.
Resisted opposition. A loop of light elastic around thumb and index finger, push the thumb outwards against it, hold 5 seconds. 10 repetitions.
Thumb lift. Hand flat on a table, lift only the thumb, hold 3 seconds. 10 repetitions.
Useful as those are, the changes that reduce day-to-day pain most are usually about how you grip rather than how strong you are.
Widen every handle you can: pen grips, foam tubing on cutlery, a thicker toothbrush. Stop pinching where you can push instead: use the flat of your hand to close a drawer, two hands to lift a full kettle. Buy the tools that exist for this, particularly a jar opener and an electric tin opener, which between them remove two of the three worst daily movements. And use a bag with a shoulder strap rather than one you carry in a pinch grip.
Medicines, injections and what NICE says
The NICE guideline on osteoarthritis, updated in 2022, puts therapeutic exercise and weight management at the centre of treatment, the same first row that governs hand osteoarthritis at every other site, and is explicit about two things not to bother with: it recommends that clinicians do not offer glucosamine, and it does not support chondroitin either. That is worth knowing before you spend money in a health food shop.
For medicines, topical anti-inflammatory gel applied over the joint is the sensible first choice, because it delivers the drug where it is needed with a fraction of the systemic exposure of a tablet. Paracetamol has a modest effect. Oral anti-inflammatories work but carry stomach, kidney and cardiovascular risk on long-term use, which matters in a condition measured in years.
A steroid injection into the basal joint gives useful relief for weeks to months in many people. It is done by a hand specialist, often under ultrasound guidance because the joint is small, and it is best thought of as a way to get through a period rather than a treatment of the disease. Repeated injections into a small joint are not a long-term plan.
Surgery, and when it becomes reasonable
Base-of-thumb arthritis is one of the conditions where surgery has a good reputation among the people who have had it. The standard operation is a trapeziectomy: the trapezium, the small wrist bone that the thumb sits on, is removed, and the space fills with scar tissue that acts as a cushion.
Surgeons have tried for decades to improve on that by adding a ligament reconstruction, threading a tendon slip through to hold the thumb up. Comparative studies have not shown the more complex operation to give better results than the simple one, at the cost of a longer recovery. If a reconstruction is proposed, that is a fair question to ask.
Recovery is three to six months before the hand feels genuinely useful, and grip strength takes longest to come back. That timeline is the reason surgery sits at the end of the road rather than the start, and the reason it is worth giving the splint and the grip changes a proper year first.
In the UK the route is through your GP to a hand surgery service. The British Society for Surgery of the Hand publishes patient information on this condition that is worth reading before an outpatient appointment, if only so that the words trapeziectomy and basal joint are not new to you in the room.
Where a supplement fits
Osteoarthritis is not the purely mechanical wear-and-tear picture it used to be described as. Low-grade inflammation within the joint lining is part of what drives the process and part of what makes it hurt, which is a legitimate target even though it does not regrow cartilage.
Nothing in a capsule reverses a worn basal joint. If you want to support that inflammatory background while the splint and the grip changes do the mechanical work, our osteoarthritis support formulation is built for it, and the absorption problem behind the choice of extracts is explained on the bioavailable natural anti-inflammatory page.
Frequently asked questions
What can be done about arthritis in the thumb?
Three things carry most of the benefit and none of them are surgery. A custom night splint worn every night, which in a randomised trial of 112 patients reduced pain significantly at 12 months. Simple thumb and hand exercises to keep the surrounding muscles doing part of the job. And changing the way you grip: wider handles, two hands on a kettle, a jar opener rather than a stronger squeeze.
What are the first signs of arthritis in the thumb?
Aching at the base of the thumb after a day of gripping, settling overnight. Difficulty opening jars, turning a key or using a tin opener. A grip that feels weaker rather than painful. Later a bony bump appears at the base of the thumb and the web between thumb and index finger starts to narrow. Early symptoms are easy to dismiss, and this is the stage where a splint does most good.
What are the four stages of thumb arthritis?
They come from the X-ray. Stage 1 is a near normal joint. Stage 2 shows narrowing and small bone spurs. Stage 3 shows marked narrowing, larger spurs and the joint starting to drift out of position. Stage 4 means the neighbouring joint is involved too. It is worth knowing because a surgeon will use the terms, but treatment is decided by what your hand can do rather than by the stage.
What can be mistaken for thumb arthritis?
De Quervain’s tenosynovitis above all, and the difference is where it hurts: de Quervain’s is tender over the tendons on the side of the wrist, a couple of centimetres above the thumb base, and it hurts most when you tuck the thumb into a fist and tip the wrist down. Carpal tunnel syndrome causes tingling rather than pain, and a scaphoid problem after a fall can mimic both.
Does thumb arthritis surgery work?
Yes, and it is one of the more reliably satisfying operations in hand surgery, which is why the British Society for Surgery of the Hand describes good outcomes. Trapeziectomy, removing the small wrist bone the thumb sits on, is the commonest procedure. Adding a ligament reconstruction has not been shown to improve results over the simpler operation. Recovery takes three to six months, so it is a decision to make when conservative treatment has genuinely been tried.
Do glucosamine or joint supplements help thumb arthritis?
NICE looked at this for its 2022 osteoarthritis guideline and recommends specifically that clinicians do not offer glucosamine or chondroitin, because the evidence of benefit is not there. That is a useful piece of information to have before spending money. It does not extend to every supplement, and it says nothing about topical treatments, but it does mean the two best-known joint supplements have been assessed and found wanting.
What to take away
Get a splint, wear it at night, and put a note in your calendar for twelve months rather than one. That is the whole of the evidence-based advice, and the timescale is the part people get wrong.
While you wait for it to work, change three grips: buy a jar opener, put foam tubing on your pen, and carry bags on your shoulder instead of pinching the handles. Those cost almost nothing and they take load off the joint every single day, which is more than any tablet on this page will do.
Sources
Rannou F., Dimet J., Boutron I. et al. (2009). Splint for base-of-thumb osteoarthritis: a randomized trial. Annals of Internal Medicine, 150(10), 661-669. DOI: 10.7326/0003-4819-150-10-200905190-00003
Kloppenburg M., Kroon F.P., Blanco F.J. et al. (2019). 2018 update of the EULAR recommendations for the management of hand osteoarthritis. Annals of the Rheumatic Diseases, 78(1), 16-24. DOI: 10.1136/annrheumdis-2018-213826
Wu R., Peng Q., Wang W. et al. (2024). Systematic review and network meta-analysis on the efficacy and safety of pharmacotherapy for hand osteoarthritis. PLOS ONE, 19(4), e0298774. DOI: 10.1371/journal.pone.0298774
Robinson W.H., Lepus C.M., Wang Q. et al. (2016). Low-grade inflammation as a key mediator of the pathogenesis of osteoarthritis. Nature Reviews Rheumatology, 12(10), 580-592. DOI: 10.1038/nrrheum.2016.136
Sanchez-Lopez E., Coras R., Torres A. et al. (2022). Synovial inflammation in osteoarthritis progression. Nature Reviews Rheumatology, 18(5), 258-275. DOI: 10.1038/s41584-022-00749-9
