Arthritis
The base of your thumb is the most common site for arthritis to start in the hand. It causes pain particularly with pinch grip, for example, when turning a key, or opening a jar. The cartilage has worn away, osteophytes form (extra bone which impinges on soft tissue) and the supporting structures around the joint become lax leading to subluxation (the bone slipping out of joint). This leads to increasing pain and weakness.
The other two common areas to be affected by arthritis are the two small finger joints - the end joint (DIP joint) and the middle joint (PIP joint). The PIP joint often develops arthritis following trauma, particularly a fracture that goes into the joint. Arthritis in these joints can cause unsightly lumps and deformity, but despite this, many patients still manage with good hand function. However, when pain and stiffness compromise function, there are many options to improve your symptoms.
Diagnosis
Is based on your pattern of symptoms, clinical examination and xrays. Other conditions may have similar symptoms of pain around the base of the thumb (such as carpal tunnel syndrome, de Quervain’s tenosynovitis, trigger thumb, scapho-trapezio-trapezoidal (STT) arthritis), which need to be ruled out.
Treatment
In the early stages of arthritis, conservative treatment is very successful in managing pain. I will refer you to one of our hand therapists for a supportive splint and to start some stabilising and strengthening exercises. This may significantly improve your symptoms and you may need no further treatment.
However, if symptoms worsen as the arthritis progresses, the next step in treatment is a steroid injection into the affected joint. This can give you good pain relief for many months and can be repeated every six months. If it gets to a point where steroid injections are not controlling the pain, then I will discuss surgical options with you.
Surgery for thumb base arthritis
Surgery involves either a joint replacement, or a trapeziectomy (removing a small bone at the base of the thumb). I will discuss which operation is indicated in your case. If you have a joint replacement, you should maintain reasonably good grip strength and the pain will significantly improve. It may be necessary though in the future to proceed to a trapeziectomy following a joint replacement, or this may be indicated as the first line of treatment. This will improve the pain but will reduce overall grip strength. However, most patients say that before surgery their grip strength is weakened by pain, and after surgery hand function improves overall.
Thumb base joint replacement
Trapeziectomy before and after
Surgery for finger joint arthritis
Surgery involves either a joint replacement or joint fusion. This will depend on the severity of the arthritis and the particular finger and joint involved. Both options significantly reduce pain. A joint replacement maintains some range of movement but this will never return to the range you had when you were younger. A fusion means you lose movement at that particular joint, but it gives greater stability. Generally, overall hand function improves due to the reduction in pain.
DIP joint fusion
Silicone joint replacement
Metal polyethelene joint replacement