BASE OF THUMB ARTHRITIS
- Very common condition in the hand
- More common in women than men, but is seen in both sexes
- Patients usually present with pain at the base of the thumb, the carpo-metacarpal (CMC joint). The most common joint to be involved is the 1st carpo-metacarpal joint (1st CMC J), also called the trapeziometacarpal joint. The Triscaphoid or scaphoid-trapezium-trapezoid joint (STTJ) can also be involved.
- A spectrum of pain and disability seen but patients may present early on in the disease process
- Pain worse with activities such as gripping, pinching, wringing out a cloth
- May present with a changed appearance at the base of the thumb with shouldering, or hyperextension at the metacarpo-phalangeal (MCP) joint
- On examination – pain at the thumb base (CMC joint) with tenderness that can extend from dorsal around into the palmar side of the hand, into the thenar eminence
- Pain on grind testing: combined axial compression of the thumb with circumduction
- X-Rays will show reduced joint space with presence of osteophytes, which can sometimes be subtle. Sclerosis and degenerative cysts may be seen within the CMC joint. There may be associated arthritic change at the Scapho-trapezial-trapezoid (STT) joint.
Natural history
Base of thumb arthritis is a generally benign condition. Patients may experience pain that can vary in severity over time, but as the joint becomes stiffer, the pain tends to “burn out”
The vast majority of patients will not require any specific treatment for their base of thumb arthritis.
The hand team have developed a package of thumb base pain education resources so that patients can understand their pathology and self -manage their symptoms. This includes a video with Hand therapy (physiotherapy) exercises and treatment methods.
Differential Diagnosis:
- De Quervain’s disease
- Pain more proximal at the radial styloid
- Younger demographic
- Provocative tests – Finklestein’s manoeuvre, Eichoff manoeuvre
- Wrist Osteoarthritis
- Usually secondary to previous injury: scaphoid fracture or scapho-lunate ligament injury
- Usually male patient complaining of radial sided wrist pain with reduced range of movement
- Wartenberg’s syndrome (Cheiralgia paraesthetica)
- Compression of the superficial radial nerve by scissoring action of brachioradialis and ECRL tendons in the distal forearm
- Patient complains of burning sensation/numbness in dorso-radial hand
- On examination – positive Tinel’s sign over superficial radial nerve
Options for treatment of base of thumb arthritis include:
- Physiotherapy (hand therapy) and splintage – this can be helpful for early symptoms. Further information, for patients to self manage is available in Base of Thumb Arthritis resource pack through your practice (found under the Resources and Links tab).
- Steroid injections – which are usually performed under radiological control. They do not cure the disease process, but may offer some relief of pain if non-interventional measures have failed. Steroid injections do carry risks of transient increase of pain, failure to improve symptoms, theoretical risk of infection, cosmetic issues such as altered pigmentation of the skin or fat atrophy local to the site of injection.
- Steroid injections were initially withdrawn from use at the beginning of the COVID-19 pandemic due to concerns of their effect on the immune system. However, we are offering them after verbal consent and information has been given to the patients
- Surgery – generally in the form of a trapeziectomy (excision of the trapezium), surgery is the last resort of treatment. The procedure creates a gap between the base of the thumb metacarpal and the scaphoid, meaning that there is no articulation at the arthritic area. This operation does offer pain relief, but not necessarily improved function of the hand or thumb. It is not likely to improve grip or pinch strength around the thumb.
- For the young patient with base of thumb arthritis a fusion of the CMC joint may be more appropriate
Thumb base replacement is not currently offered in NHS Lothian
Who to refer:
- Those patients in whom a diagnosis of base of thumb arthritis has been made (clinical AND radiological), who have tried non-operative measures for at least three months but still have significant pain. These patients will have already been provided with and tried the information in the Base of Thumb Arthritis resource pack through your practice (found under the Resources and Links tab). For example a patient who has pain on activities (and possibly at rest), not relieved by painkillers and splints, thus affecting sufficiently that they would consider further treatment (injections or surgery).
Who not to refer:
- Patients who have not tried self-management of the condition after the diagnosis has been made and explained to them
- Please provide the information in the Base of Thumb Arthritis resource pack to the patients (to be found under the Resources and Links tab).
How to refer:
- As routine patient to the hand service at St John’s Hospital via SCI Gateway through the thumb base arthritis pathway. Please note that an x-ray needs to have been completed before referral and please not the results in your referral letter. This pathway is for patients with a clinical AND radiological diagnosis of base of thumb OA, who have failed self-care management
- Please highlight if the patient has already been given Base of Thumb Arthritis resource pack and whether they have tried these treatments and appropriate thumb base splints for 3 months. We will then triage these patients to a F2F clinic
- Patients who have not tried non-interventional management will be assessed in a virtual clinic and sent the education pack
Investigations:
- X-Ray of thumb to confirm presence of osteoarthritis
Primary Care Treatment:
- Education: Base of thumb arthritis education pack (see resources and link section)
- Analgesia: oral +/- topical
- Splints: see resources and link section
- Activity modification
Base of thumb arthritis education pack:
- Base of thumb arthritis introduction letter
- Splints for thumb base arthritis – Splints for Thumb Base Arthritis V0 3 PIL review.pdf
- BSSH thumb base arthritis information sheet
