In this month’s article, Neil Liffen, Clinical Director of East Coast Physio Ltd, focuses on osteoarthritis (OA) of the thumb.

What is osteoarthritis?
A condition which results in destruction of a joint is termed arthritis. Osteoarthritis is the most common type of arthritis and it is often referred to as degenerative joint disease or ‘wear and tear’. Normal joints are lined by cartilage which allows the bones to move smoothly over each other. In OA this layer of cartilage is thinned or absent resulting in joint stiffness, swelling and pain.

Base of the thumb osteoarthritis:
The joint at the base of the thumb is very mobile which enables the thumb to have a large range of movement. Painless movement at this joint is important for normal function as it allows us the ability to use our thumb so effectively that distinguishes us from other animals. This joint allows us to move our thumb so that it can touch the little finger (thumb opposition), something that is unique to humans. The basal thumb joint (also known as the 1st carpometacarpal joint) is ‘saddle’ shaped and formed by a small bone called the trapezium and the thumb metacarpal bone (Figure 1). Arthritis of the base of the thumb is more common in women typically occurring over the age of 40.

Symptoms and signs:
The presence of arthritis does not always cause any symptoms. However, pain at the base of the thumb is typical. Patients often describe a background ache felt at the base of the thumb that is present most of the time. This pain is worse with thumb pinch activities such as opening a jar, turning keys, lifting heavy saucepans or kettles. Loss of movement of the thumb is often present but this is not always noticed by the patient. Some people notice that there is a ‘grinding’ or ‘cracking’ sensation with thumb movement (crepitus). With advancing OA some people develop a bony prominence or bump over the joint (Figure 2).

Diagnosis
Your physiotherapist/GP can often diagnose your condition by history i.e. symptoms, any prior injury, pain patterns, or activities that aggravate the condition, and by objective examination. One of the tests used during the examination involves holding the joint firmly while moving the thumb. If pain or a gritty feeling results, or if a grinding sound (crepitus) can be heard, the bones are rubbing directly against each other. An x-ray is routinely utilised to investigate the joint to show deterioration of the joint as well as any cysts, bone spurs or calcium deposits that have developed (Figure 3).

Treatment
Treatment includes non-surgical and surgical approaches. Many people respond well to non-surgical treatment activity modification, rest, analgesia medication, thumb splint and/or steroid injection into the joint normally is effective. However, in recalcitrant cases referral for surgical opinion maybe warranted. A common surgical procedure is a trapeziectomy, removal of a bone at the base of the thumb, and has high success rates.

We can offer various treatments at all our clinics across Suffolk >>

Figure 1. Osteoarthritis Base of Thumb

Figure 2. Osteoarthritis Base of Thumb

Figure 3. Osteoarthritis Base of Thumb