ARTHRITIS AT THE BASE OF THE THUMB

GENERAL

• A common problem
• Often no cause is found
• Middle-aged women
• Previous thumb fractures
• Family history of arthritis

SYMPTOMS

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.

TREATMENT

• Rest
  
• Activity restriction
  
• Anti-inflammatories
    - Tablets - beware stomach upset
    - Always take with food
    - Creams - e.g. Voltaren Gel

SPLINTS

1. Thermoplastic

• Removable splint made by a Hand Therapist.
  
• Rigid and therefore somewhat restrictive but provides support for the thumb when doing heavy activities.

2. Thermoskin

• Obtain from Hand Therapist or Chemist.
• Wet suit material (Neoprene).
• Less supportive but will keep the thumb warm.
• Less cumbersome.

Often having both types of splints 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.
  
• Occasionally it is difficult to enter the joint due to spurs from the arthritis. Under these circumstances the injection can be inserted under x-ray control.
  
• 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 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.

Incisions...

PROBLEMS

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

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

RECOVERY PERIOD

• Plaster 6 weeks - the thumb is rested in a fibreglass cast for 6 weeks.
  
• Removable splint for a further 4 - 6 weeks.
  
• Strenuous activity is avoided for 3 months following the surgery.
  
• Total recovery may take from 6 - 12 months following surgery, with a steady increase in strength, motion and comfort.

  

         Cast                    Splint