Arthritis of the thumb
Richard Baker Blog
What is arthritis of the thumb?
Arthritis at the base of the thumb is very common particularly, in women over the age of 40 years old. It’s probably caused by weakening of the ligaments over the years through exposure to estrogen which is the female hormone. Weakening of the ligament means the thumb partially dislocates from its joint on the hand leading to wear and tear of the cartilage which is essentially what arthritis is. It leads to new bone formation, causing spikes of bone which can dig into the surrounding flesh and causing inflammation of the tissues around the joint. This leads to pain but also to deformity of the joint and reduced range of motion, strength and function. In many patients it’s painful for a few years and then burns it’s self out. In other patients, it’s persistently painful and these patients require treatment. The main treatment is avoiding activities that cause pain but also wearing splints at times of exacerbation of pain, taking pain killers, both tablets but also creams and gels which can be applied to the skin, steroid injections where the steroid is injected directly into the joint under a local anaesthetic, sometimes it’s necessary to use ultrasound on an x-ray machine to ensure the needles are in the right place, very often this can be administered in clinic. Often the joint is more painful after a steroid injection for a day or two and it can take several days for the steroid to kick in and can last up to six months. Steroid injections can be repeated over time and tend to last for shorter and shorter periods. We’re not quite sure why steroid injections work but steroids dampen down inflammation and inflamed tissue is painful.
In some patients, steroid injections and other treatments are not sufficient in controlling the pain and we have to consider surgery. The options begin with denervation, which is where the small nerves that go to the joint are cut and this stops the joint transmitting pain to the brain and so the arthritis goes on, the patient can’t feel the pain. I like to perform this operation in patients who are young, still working and whose joints are not particularly damaged on the x-ray. This is because of the recovery is much quicker and leaves open the possibility of doing other operations. The next option is trapeziectomy which means removing the arthritic piece of bone, which is called the trapezium, and in some patients reinforcing it with nearby tendons to stabilise the thumb. This is a good operation for people whose arthritis is quite advanced and who want a definitive solution. The recovery can take several months and it is quite painful afterwards. However, the pain relief is often permanent.
The last option is a joint replacement and I like to use the operation in people whose arthritis is only moderately advanced. It has the advantage in the recovery is quicker than in a trapeziectomy and the length of the thumb is maintained with a good range of motion. However, joint replacements aren’t strong, so I’d be cautious about using this in a man particularly in a manual worker. All of these operations would require some time off work. For denervation, I’d recommend around two weeks off work, for trapeziectomy, I’d recommend six weeks off work and for a joint replacement something like four weeks.
All of these operations involve a scar about an inch long on the base of the thumb. Other risks include infection, swelling, stiffness and incomplete pain relief or problems with ongoing pain caused by things such as damage to nearby nerves.