Osteoarthritis at the base of the thumb

SUMMARY POINTS Arthritis at the base of the thumb causes functional disability and pain, particularly with "pinching" actions Pain reproduced on the axial grind test localises pathology to the base of the thumb-the trapeziometacarpal and scaphotrapeziotrapezoid joints should be assessed Plain radiographs showing degenerative changes in affected joints are usually diagnostic but may underestimate disease Non-operative treatments such as behaviour modification, pain relief, splinting, and corticosteroid injections can ameliorate symptoms and delay surgery in most patients No single operative procedure has been shown to be superior but 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)