Base of Thumb Arthritis

What is base of thumb arthritis?

Base of thumbarthritis refers to inflammation of where the thumb joins the hand – this is the carpometacarpal (or CMC) joint. This condition involves deterioration of the smooth cartilage covering the surfacesof the joint at the base of the thumb. Without a cartilage cushion in the joint, you basically have bone rubbing on bone.

Arthritis may be due to:

  • wear and tear over time
  • a previous injury or fracture

It is a very common condition among postmenopausal women and women over 50 years of age. Approximately 40% of postmenopausal women have X-ray changes at the base of the thumb. Around 1 out of 10 will seek medical treatment and only 1in 100 is severely affected. It does occur in men, but it’s much less common.

What are the symptoms of base of thumb arthritis?

The symptoms of base of the thumb are:

  • pain when moving or touching the joint at the base of the thumb
  • reduced grip strength
  • swelling at the base of the thumb

The pain and reduced grip strength can limit many daily activities.

What does your doctor look for?

Your doctor will take your medical history and perform a physical examination include looking and feeling (or palpating) your thumb. A Grind Test, where the thumb is pushed along its long axis towards the base of the thumb, can also be specifically tender.Your grip strength will be compared in each hand.

What investigations are needed?

The most common investigation is an X-ray of the thumb, which shows typical features of osteoarthritis, including loss of joint space, osteophytes or bony swelling around the joint

How is base of thumb arthritis treated?

There is no cure for arthritis but there are several very effective treatments. All have the same goals – to control pain and improve the function of the elbow so that you can move better and get on with everyday living.

Treatments include:

  • non-drug therapy (eg rest, seeing a hand therapist for joint protection, thumb splints and exercises)
  • medications (egoral anti-inflammatories or joint injections)
  • surgery

Our specialists at Orthopaedic Clinics Gold Coast will work with you to create the best treatment plan for your particular situation.

Surgery for base of thumb arthritis

Surgery is usually reserved for when non-surgical options fail to relieve symptoms.

Surgery is usually performed under a general anaesthetic as a day procedure. It usually takes 30–40 minutes to complete. A tourniquet is placed above the elbow to ensure a bloodless field then an incision is made over the base of the thumb (palm side). The trapezium bone is removed, creating extra space in the joint. A small portion of one of the wrist tendons is then harvested and used to fill the affected space and stabilise the base of the thumb. The skin is sutured closed and a cast is then applied.

Post-op rehabilitation

You need to keep your hand elevated as much as possible for the first 5 days after surgery. Bending and straightening of the fingers during this time is strongly encouraged. Around 10–14 days after the operation, the wound is reviewed by your hand therapist. At this stage, a thermoplastic splint is fitted, which is worn for 4–6 weeks. Range of motion exercises are usually commenced at this stage under the supervision of the hand therapist.

Most people find that the arthritic pain is gone within 4_8 weeks after surgery. But improvements can continue to be made for 6–12 months after surgery as the thumb strengthens.

Possible complications

More than 95% of patients are happy with the results of the surgery. But complications do occur sometimes.

Some complications specifically related to hand surgery include infection (less than 1% chance); neuroma (less than 1% chance), which is a damaged nerve that becomes painful on reattempts to regenerate; numbness; chronic regional pain syndrome or reflex sympathetic dystrophy (1-2% chance), which is a reaction to surgery that can cause painful or stiff hands.

Complications specific to base of thumb osteoarthritis surgery include failure to completely resolve the symptoms due to arthritis in the adjacent joints. This is rare but may require further surgery. The thumb will be weaker than on the opposite side if this side is unaffected. This will improve with time but may never be fully normal.