Basal Thumb Arthritis

The carpometarpal joint (basal thumb)  is the most commonly used joint in the hand that can become arthritic. It is especially common in middle aged women and presents with pain at the base of the thumb, difficuting opening tight jar lids, pain on wringing out a cloth and difficulty holding objects such as a kettle.LENOVO-PC - 1

The condition is confirmed on examination – pain and crepitus on grinding or axially loading the thumb. As the disease progresses the hand can adopt a characteristic appearance as the basal thumb joint gradually subluxes and the thumb adducts with secondary compensatory hyperextension at the metacarpophalangeal joint resulting in a Z thumb deformity in advanced cases.

X-rays will usually confirm the diagnosis.

Treatment is tailored to the severity of disease. In mild cases lifestyle modification, simple analgesia and possible splintage may suffice. In others, a steroid injection into the basal thumb joint can be helpful. In fact the majority of patients who get as far as presenting to a hand surgeon will probably have a steroid injection as most will have already tried the simpler treatments. The risks of steroid injections are post-steroid flare, depigmentation and skin atrophy. Your surgeon will discuss these with you.

In advanced cases, surgery is offered when other treatments have failed. The gold standard operation remains a trapeziectomy – excision of the arthritic bone at the base of the thumb. The market has been flooded with various arthroplasties (artificial thumb base joints) and many have been withdrawn over time. Some implants have shown good survivorship beyond 10 yrs however the overall published evidence does not support their use over a trapeziectomy. After trapeziectomy, you will require a splint and some hand therapy. Your surgeon will discuss this with you.

Occasionally, the X-rays will show arthritis affecting the joint below (the scaphotrapeziotrapezoidal joint, STTJ ). The X-ray below shows a fusion of the STTJ – this is a rather unusual operation and most patients respond to a steroid injection under X-ray guidance thus not requiring the fusion.FullSizeRender - Copy (2)