Arthritis at the Base of the Thumb
What is it?
Arthritis at the base of the thumb is a common problem that may affect anyone at anytime. Previous thumb fractures, certain types of inflammatory arthritis such as rheumatoid arthritis or gout, and occasionally infection are believed to cause some of the cases. In most cases, however, osteoarthritis is the cause, coming on usually after the age of 40 years.
What are the symptoms?
The most common symptom is pain at the base of the thumb, especially when performing simple activities that involve the thumb, such as removing the lid from a jar, turning a key in a lock, opening a door, or using a knife or fork. Clumsiness or pain when handling small objects may also occur.
How is it diagnosed?
The clinical consultation with the aid of an x-ray examination of the thumb will normally reveal the diagnosis and extent of the problem and enable the best treatment to be determined for you.
What is the treatment for it?
Initial treatment includes rest, avoidance of painful activities and the use of painkillers to relieve pain. Occasionally a small thumb splint may be used to reduce pain by limiting movement at the base of the thumb. The splint often enables the patient to perform daily activities adequately. However, whilst the splint always reduces pain, it can limit the use of the thumb and hand in some cases.
Often an injection of local anaesthetic and steroid into the joint can provide lasting benefit. Because the joint at the base of the thumb is very small, these injections are usually performed with the help of an X-ray machine to confirm correct placement of the injection into the joint at the base of the thumb.
If these measures do not relieve discomfort adequately, surgery may be necessary. The type of surgery depends on the condition of the joint at the base of the thumb, the age of the patient, and the needs of the patient.
If the arthritis is in an early stage, reconstruction of the thumb ligaments may be the best option. Fusion is another method to treat arthritis at the base of the thumb. The trapezium and thumb metacarpal are permanently fused together. This provides good relief of pain without loss of strength. However, some decrease in motion of the thumb will likely result.
If the arthritis is more severe part or all of the trapezium bone is removed. This may be combined with inserting a small spacer (Pyrodisk) in the gap left by removing all or part of the trapezium and sometimes with reconstruction of the thumb ligaments. I always discuss which of these options is best for the individual patient with them.
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| Picture 1: Pyrodisk implant for Trapezium replacement in Picture 2 | Picture 2: shows insertion of Joint implant following partial resection of Trapezium |
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What type of anaesthetic will I have?
All of the surgical options require either a general anaesthetic, where the patient is put to sleep during the surgery, or a regional anaesthetic (block) where the whole arm is numbed during the surgery but the patient remains awake. If the patient remains awake they do not see the surgery taking place and they do not feel anything in their arm or hand.
How long will I be in hospital?
This depends on a number of factors. The majority of patients can be admitted and discharged home the same day (Day Case Surgery). A small number of patients require an overnight admission.
What is the treatment after surgery?
A cast or splint is worn after the surgery for four to six weeks. During this time the patient returns to have their stitches removed, usually between ten and fourteen days after surgery. Once the cast is removed physiotherapy is started and this may continue for several months. A removable splint is worn for a few more weeks once physiotherapy starts.
What are the risks of surgery?
All of the surgical methods involve similar risks including infection, stiffness, nerve injury and increased sensitivity of the skin. Occasionally, when bones are fused together they do not unite (knit) to each other and this may require further surgery. These problems can usually be managed successfully but occasionally they may result in long-term problems.
How successful is the surgery?
The success rate of surgery is good with about 90 % of patients being satisfied with the pain relief and restored use of the thumb. Occasionally other joints near the base of the thumb develop arthritis requiring another operation.
How long is the recovery period?
Once the cast or splint is removed and physiotherapy is started, there is a steady increase in strength and motion and decrease in discomfort. Total recovery may take six months to a year following surgery.