What is it?
Patients with osteoarthritis of the thumb carpometacarpal joint, or base of the thumb, commonly seek help for their symptoms. Arthritis at the base of the thumb causes functional disability and pain, particularly with “pinching” actions.
A hand with arthritic changes. Image source: Cicadas, a Creative Commons license.
How common is osteoarthritis of the thumb?
The prevalence of this condition increases with age and is greatest in postmenopausal women. It ranges between 15% prevalence in adults in Finland and a 33% prevalence in postmenopausal women. This is likely to increase as populations age and people stay active for longer.
How to diagnose it?
Pain reproduced on the axial grind test localizes pathology to the base of the thumb.
Trapeziometacarpal and scaphotrapeziotrapezoid joints should be assessed with plain radiographs (X-rays) that typically show degenerative changes. However, X-rays may underestimate the extent of the disease.
What to do?
Non-operative treatments can ameliorate symptoms and delay surgery in most patients with osteoarthritis of the thumb:
- behaviour modification
- pain relief
- corticosteroid injections
No single operative procedure has been shown to be superior:
- simple trapeziectomy has the lowest complication rate
- arthrodesis may be the best option for patients who value pain relief and reliable strength and stability more than mobility (such as younger manual workers)
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Osteoarthritis at the base of the thumb. BMJ, 2011.