Picture of a lady with arthritic thumb bases, note the deformity and swelling at the base of the thumb.

Advanced osteoarthritis. X-Rays show loss of the joint space, bony fragments and thickening of the bone around the joint (sclerosis).

Trapeziectomy involves removing all the trapezium bone and filling the space with a cuff of tissue.

Arthritis of the thumb base, treated with a fusion using a plate and screws

A Joint Replacement for thumb base arthritis

What is it?
The trapezium is one of the eight carpal bones and lies at the base of your thumb. Arthritis in this joint is very common. It is a progressive condition that leads to increasing stiffness and deformity in the thumb. Pain is common especially in ladies over the age of 50yrs. This arthritis often runs in families.

What can be done?
The methods for relieving discomfort in any arthritic joint, whether it is the hip, knee, shoulder or base of the thumb are the same. I call this the therapeutic ladder. Start at the bottom with the simplest treatment and work up the ladder as symptoms require:-

(i) activity modification, (ii) pain-killers, (iii) splints, (iv) steroid injections and (v) surgery.

Surgery is the only definitive treatment for persistent symptoms. The usual indication is pain and consequent functional difficulties. There are several options available and some controversy as to which is best. I will discuss all with you before a decision is made.

1. Joint stabilisation using a tendon is only suitable for a minority of patients who have an unstable joint but little damage to the joint surfaces. This would be in younger patients with little or no evidence of arthritis on an X-Ray.
2. Trapeziectomy involves the complete removal of the trapezium bone. It is mandatory if the joints both above and below the trapezium are arthritic. This is my preferred treatment in most patients. I stabilise the base of the thumb with a cuff of tissue.
3. Trapeziectomy with ligament reconstruction is performed by some surgeons. There is no evidence that this improves outcome.
4. Arthrodesis (fusion) is reserved for younger patients who are involved in heavy manual jobs, or in advanced cases with very deformed thumbs. It has the disadvantage of stiffening the thumb and is contraindicated if there is any wear beneath the trapezium.
5. Joint Replacement. This is used more rarely. The ends of the bones which are rubbing are removed. The gap is replaced with a prosthetic joint. The long-term results of this procedure is not known. It however may be of use in a younger patient with significant arthritis. If the replacement fails at a later stage there is a good salvage option of a Trapeziectomy.

Post-operative care
My standard procedure is a simple trapeziectomy and stabilisation. The operation is carried out either under a peripheral block or a general anaesthetic supplemented by local anaesthetic. You may stay in hospital for one night after the operation.

Hand elevation is important to prevent swelling and stiffness of the fingers. Your hand will be placed in a bulky dressing, which includes a plaster to protect the operation. Movement of the hand and thumb-tip should be continued and you should perform normal light activities after the operation.
Between one and two weeks after the operation your plaster will be changed to a lighter splint. Physiotherapy rehabilitation will start at this stage. Sutures are usually dissolvable. 6 weeks after surgery, you will be able to take off your splint during the day but it is worth wearing it for protection at night for a further two weeks or so.

Possible complications are as follows:

Scar
You will have a scar on the back of the thumb. This will be somewhat firm to touch and tender for 6-8 weeks. Massaging it firmly with moisturizing cream can help this.

Infection
This can occur after any operation and would be treated by antibiotics.

Stiffness
All patients will have some stiffness after surgery. This will be treated by the therapists during your rehabilitation. About 5% (1 in 20) of people are sensitive to hand surgery and their hand may become swollen, painful and stiff after any operation (Complex Regional Pain Syndrome). This problem cannot be predicted but will be watched for afterwards and treated with physiotherapy.

Neuroma
A small nerve running in the region can occasionally be damaged during the surgery and either cause numbness on the back of the thumb or form a painful spot in the scar (neuroma). The latter complication may require a further operation to correct it.

Pain
Pain is not uncommon after surgery, but would normally settle over the first week or two. Occasionally this can be prolonged and can be due to inflammation around a tendon in the wrist. This will usually settle, a steroid injection may help.

Function Recovery from this operation can be slow and it can often be 6 months before you can resume heavy activities. You will probably be able to drive a car after 8-12 weeks as long as you are comfortable and you have regained full finger movements. Timing of your return to work is variable according to your occupation and you should discuss this. Success rate from a Trapeziectomy is in the order of 70-80%.