Steroid Injections for Arthritis of the Thumb

Osteoarthritis of the thumb is a common condition which causes pain with gripping and lifting tasks of the hand. Arthritis comes in 2 main types; “Osteo” and “Rheumatoid”. Rheumatoid arthritis is an autoimmune disease meaning it is widespread in the body and it is your immune system that attacks the joints and damages the joint surfaces. This will present with multiple joints inflamed and painful at the same time.

Osteoarthritis is different as it is a gradual deterioration of joint cartilage with time and wear. It most commonly affects joints under repetitive load or following previous trauma to the joint surfaces. This type of arthritis is most likely to occur as we age and may only involve 1 joint on 1 side of the body.

The most common thumb joint to develop arthritis is the joint at the base of the thumb called the carpo-metacarpal joint (CMC joint).

Osteoarthritis will tend to affect us all at some point in life but there are many things you can do to prevent it causing any pain or disability.

Symptoms of Arthritis of The Thumb

The most common symptoms of arthritis of the thumb joints are;

• Pain and or stiffness at the base of the thumb

• Pain with gripping or tasks that involve pinching with the thumb eg opening door handles or turning keys

• Redness and swelling at the base of the thumb close to the wrist.

Causes of Thumb Arthritis

Most causes of arthritis are due to wear and tear with time. However there is often a genetic element which seems to bias some individuals to getting arthritis in certain joints.

If there has been previous injury to the thumb like a fracture, this may predispose you to developing arthritis later in life.

Risk factors include:

• Female
• Age. Over 40 years of age is when you are more likely to develop arthritis
• Obesity
• Previous joint injury like fracture, hypermobility or sprain
• Being involved in job or activity that involves a lot of heavy loads through the thumb eg Manual labour

As the joint surfaces rub together with time, the smooth cartilage that covers the ends of the bone which allows a smooth gliding surface starts to wear and become rough. This gradual deterioration will lead to irritation of the bone ends and joint capsule. The joint space will gradually reduce and bony spurs called osteophytes will start to form on either side of the joint due to the joint rubbing.

Anatomy

The Thumb is made up of 2 Phalanges (distal finger bones) and 1 metacarpal bone (more proximal long bone at the base). This joins onto the wrist carpal bone the Trapezium. This is know as the carpometacarpal joint or CMC joint. It is at this joint where we see most arthritis develop. This saddle type joint needs enough flexibility to allow opposition of the thumb and fingers for gripping  but enough stability to open jars, turn door handles and turn keys in locks. If there is pain in the location of this joint with what looks like swelling or an enlargement of the joint then it may me arthritis of the CMC joint. 

How to diagnose

The Physiotherapist will be able to carry out a physical examination to look for specific weakness of muscles in the hand and wrist. They will assess range of motion in the joints and perform joint glides to work out the specific joint or tendon that is causing the pain.

An ultrasound scan of the wrist and hand can be useful to assess any swelling or inflammation in the joint and tendons and can be sensitive for assessing for bone spurs. An Xray is gold standard for most joint arthritis but is not always needed if you have a diagnosis confirmed on ultrasound scan.

Physiotherapy Treatment

Physiotherapy treatment is very successful in treating CMC and surrounding finger arthritic joints (Spies et al, 2018). The mainstay of management should be strengthening the hand and wrist muscles (Østerås et al,2017) and promoting flexibility with certain finger and thumb movements. Your Physiotherapist will give you exercises to perform regularly which may involve some resistance bands. These can easily be performed independently but occasionally we may also need to get you to wear a splint to off load the joint for certain tasks. Using a splint has been show to be successful in reducing pain in the treatment of this condition (Kjeken et al, 2011).

Thumb Arthritis Injection Therapy

Unfortunately there can occasionally be “flares” of pain and swelling. If this persists and it won’t settle down with conservative treatment of icing, NSAIDs (anti-inflammatory medication topical or oral), splinting and rest, it may be worthwhile considering a corticosteroid injection into the joint.

Steroid injections for thumb arthritis are common when the pain is limiting your abilities to perform activities of daily living and hasn’t settled after several weeks of Physiotherapy. It involves putting a strong anti-inflammatory medication into the joint to reduce the pain and swelling. This has a good short term outcome but there lacks significant evidence to conclude a better long term outcome than other treatments or surgery (Spies et al 2018).

Hyaluronic acid injections for arthritis have become increasingly popular alternatives to steroid injections. This involves putting a lubricant into the joint that is not a drug and can have good results for reducing pain over longer periods of time. It is suitable if someone prefers to avoid steroids but it does not have as powerful anti-inflammatory effect as a steroid so is better suited to mild to moderate artistic pain. Hyaluronic acid injections into the small joints in the thumb usually requires 2-3 injections spaced out over a 3 week period.

You can read more about these injections here.