Thumb Base Osteoarthritis (Thumb Arthritis)
Thumb base osteoarthritis, often simply called thumb arthritis, is a common cause of pain around the base of the thumb where it meets the wrist.
It announces itself in small, infuriating ways. A jar that will not open. A key that will not turn. Scissors, secateurs, a kettle, a seatbelt buckle. None of it is dramatic, and all of it adds up, because the thumb is involved in almost everything the hand does.
The joint most commonly affected is the carpometacarpal, or CMC, joint, where the first metacarpal bone of the thumb meets a small wrist bone called the trapezium. It is a small joint with a demanding role: it lets the thumb move across the hand, and it provides the stability behind every grip and pinch.
What does thumb base osteoarthritis feel like?
Pain is usually felt around the base of the thumb, where the thumb meets the wrist.
People commonly notice pain or weakness when:
- opening jars or bottles
- turning a key
- using scissors
- gripping or carrying objects
- pinching between the thumb and fingers
- gardening or using tools
- writing, or using the hand for long periods
As the osteoarthritis progresses the joint may stiffen, and the shape or position of the thumb can gradually change.
The amount of arthritis on an X-ray does not reliably predict how much pain someone has. People with marked changes can manage well, and people with modest changes can struggle.
How is thumb arthritis diagnosed?
Thumb base osteoarthritis can often be identified from the history and the clinical examination alone. Not everybody with thumb pain needs imaging.
An X-ray is usually the most useful investigation where confirmation is needed, or where the extent of the arthritis matters to the decision ahead.
Diagnostic ultrasound adds information about the joint and the soft tissues around it. It is particularly useful where another condition may be contributing to pain in the same small area — De Quervain’s tenosynovitis being the usual candidate.
Is all pain at the base of the thumb arthritis?
No.
Several conditions produce pain around the thumb and wrist. The most common alternative is De Quervain’s tenosynovitis, which affects the tendons running along the thumb side of the wrist. Pain can also come from other wrist joints, from tendons, or occasionally from a nerve.
These are treated differently, so establishing which one you have — or whether more than one is present — is the first job of the assessment.
Hand therapy and rehabilitation
Treatment usually starts conservatively.
Hand therapy or physiotherapy helps maintain movement and improve the strength and function of the muscles supporting the thumb. It also covers how to modify the activities that repeatedly overload the joint, and how to do the painful tasks differently.
The aim is not to stop using your hand. It is to take unnecessary stress off a painful joint while keeping the strength and function you have.
Thumb splints and supports
A thumb support or splint helps a great many people.
The point is to support the painful CMC joint while still allowing useful movement of the hand and fingers. A splint is often worn for the activities that aggravate things rather than continuously.
There are several types, and which suits you depends on your symptoms and what you need your hand to do.
Steroid injection for thumb base osteoarthritis
Where pain remains significant despite appropriate conservative treatment, a steroid injection, sometimes called a cortisone injection, into the thumb CMC joint may be considered.
The aim is to reduce pain and inflammation within the joint, making everyday activities more comfortable and allowing rehabilitation to progress.
How much it helps, and for how long, varies between individuals. It does not reverse the osteoarthritis, and repeated injections are not appropriate for everyone.
The CMC joint is small, which is where ultrasound guidance earns its place. The joint is visualised and the needle guided accurately into it, rather than the injection being placed by feel into a space a few millimetres across.
The clinician who assesses your hand and scans it is the same one who gives the injection and then manages the rehabilitation that follows, so the procedure sits inside a plan rather than standing alone.
When should I see a hand surgeon?
Most people with thumb base osteoarthritis are managed without surgery.
Referral to a hand surgeon may be appropriate where pain and loss of function remain significant despite appropriate non-surgical treatment, and are substantially interfering with everyday life.
Surgery is not decided by the X-ray. The decision takes account of how severe your symptoms are, how the hand functions, what treatment you have already had, your general health, and what you need to be able to do. Several surgical procedures exist for this joint, and a hand surgeon can discuss which, if any, suits you.
What does it cost?
Every appointment lasts a full hour. Where a diagnostic scan is needed, that appointment is charged at the scan rate, which replaces the standard consultation fee rather than being added to it. Current prices are on our prices page.
Thumb arthritis treatment in Weybridge
Thumb base osteoarthritis is a long-term condition, but arthritis on an X-ray does not mean surgery is inevitable.
Management may include education, activity modification, hand therapy or physiotherapy, a thumb support or splint, medication and, where appropriate, an ultrasound-guided steroid injection. Where symptoms remain significantly disabling despite all of that, a specialist hand-surgery opinion is the right next step.
Meyer Physio assesses and treats hand and wrist problems at its clinic on Baker Street in Weybridge, Surrey. You can come to us directly — no GP referral is needed to book, and there is no waiting list.
The first question is always whether the thumb CMC joint is genuinely responsible for your symptoms. The second is where you are in the treatment journey, and what the sensible next step is from there.
Written by Suegnet Meyer, Advanced Practice Musculoskeletal Physiotherapist and MSK Sonographer. HCPC registered [PH55635]. Chartered Society of Physiotherapy member [66175]. Last reviewed: 29 October 2026.