Dr Stuart Myers

Osteoarthritis Thumb CMC joint




- A very common problem particularly in middle aged women.

There may be a family history of osteoarthritis.

It may complicate previous thumb fractures. 


1. Pain in the base of the thumb
- simple activities that involve the thumb
- removing the lid from a jar
- turning a key in a lock or opening a door.
2. Clumsiness or pain when handling small objects
3. Stiffness - making it difficult to grasp larger objects.
4. Weakness of grasp

5. Deformity - the MCP joint of the thumb stretches to make up for the loss of CMC joint movement and
this can cause secondary arthritis at the MCP joint



- Rest

- Activity restriction

- Anti inflammatories  or Paracetamol taken intermittently or regularly.
- Tablets - Beware stomach upset.
- Always take with Food
- Creams - eg Voltaren Gel

- Splints:

              Thermoplastic                                                  Neoprene                                           Combination of plastic & Neoprene

1. Thermoplastic splints are rigid and therefore somewhat restrictive but provides support for the thumb when doing heavy activities.

        The are removable and are custom made  by a Hand Therapist.

2. Neoprene splints can be be obtained from Hand therapist or Chemist.

        They are made from wet suit material ( Neoprene)  and are less supportive but will keep the thumb warm but are also less cumbersome.

Often having both types of splints or a combination of both can be of benefit.

Splints only work when they are being worn and so some people find them a nuisance after a while.

Cortisone Injections:

- Often provide good relief of pain for a variable period of time.
- If one obtains 6 months relief the injection can be repeated over and over
- If injection only lasts for 1 month then other treatments may be required.

- Very rarely it is difficult to enter the joint due to spurs from the arthritis. Under these circumstances the injection can
be inserted under Xray or ultrasound control. There is no documented benefit giving injections under ultrasound control and they may be more painful.  ( Research Ye & Myers 2015)
- Once the anaesthetic wears off, it is common for the thumb to ache for 1-2 days after the injection due to stretching of
the joint capsule. Take some Panadeine after the injection

- At times one may experience pain from both the Basal Thumb joint and also the nearby STT joint. An injection of cortisone can be used as a test to try and determine how much of the pain is coming from each joint.


- Surgery:


F.C.R. Interposition Arthroplasty involves:
- Excision of all or part of the trapezium
- Replacement of this bone with a tendon in the forearm.
- Only one half of the FCR ( Flexor Carpi Radialis) tendon is used.
- This removes the area of arthritis and the tendon acts as a cushion between the remaining bones
- Avoids use of artificial materials eg Silicone which can cause long-term problems in the body
- Hospital stay Overnight
- General Anaesthetic or Regional anaesthetic or commonly both.


- Problems: - Rare - 90% patients very satisfied with the pain relief & restored use of the thumb
- Nerve irritation in the scar
- Prolonged recovery of pinch strength

- Operation Technique

Other thumb joints may also require corrective surgery, which can be done at the same time without prolonging the recovery time

 Recovery Period - Prolonged:

1. Plaster slab for 1 week then removal of sutures.
2. Neoprene & plastic splint for 2 weeks. See Hand Therapist to have this fitted.
3. Neoprene Removable splint for a further 3 weeks. This splint can be removed to allow gentle range of motion exercises under the supervision of a hand therapist
- Strenuous activity is avoided for 2 - 3 months following the surgery.

- Total recovery may take from 6 - 12 months- with a steady increase in strength & motion & comfort.



              Plaster slab 1 week   then   Neoprene/Plastic 2 weeks    then      Neoprene 3 weeks

Other thumb joints may also require corrective surgery, which can be done at the same time without prolonging the recovery time.

If the M.C.P. joint (2nd joint in the thumb) bends back >30* this will require stabilisation. 




If the S.T.T. joint is severely involved the Trazezoid can be partly resected. It takes a lot longer to recover from this procedure.


Arthritis Foundation:

13 Harold St,
North Parramatta NSW 2151
Ph: 02 9683 1622
Fax 02 9683 1633