When two bones meet in a joint, their smooth ends are usually covered with cartilage that lets them slide against each other without any pain or difficulty. If the cartilage wears out and the ends of the bones rub together when moved, the resulting condition is called osteoarthritis or degenerative arthritis.
The basal joint, at the base of the thumb, develops osteoarthritis more often than any joint in the hand except the wrist, and is one of the more complex joints in the body. It's made exists between a small bone in the wrist and one in the thumb, and has a special saddle shape that enables the thumb to have a wide range of movement.
Women over forty are most likely to develop arthritis at the base of the thumb. If arthritis shows up in younger individuals, it is often a result of an earlier injury to the joint such as a bad sprain or fracture.
Symptoms of Arthritis
Those who suffer from arthritis in the thumb's basal joint very often experience deep and aching pain at the base of the thumb. When opening jars, turning door knobs or keys, or doing other things that use pinching actions, the pain worsens. Pinching strength is often reduced as the disease worsens, as is overall grip strength, and the joint may be painful even when not in use.
If the disease grows still worse, the joint further degenerates. The alignment of the two bones worsens and a small bump can show up at the base of the thumb. This repositioning narrows the space between the thumb and the index finger and restricts the thumb's movements, which further weakens and reduces pinching. To make up for this, the next joint up, in the middle of the thumb, may hyper-extend.
Diagnosis of your Thumb
Your hand surgeon will examine the hand and note how the thumb looks and where there is pain. This helps determine if the joint at the base of the thumb is arthritic. To reproduce the symptoms, the thumb may be moved back-and-forth. X-rays may be taken, however the appearance of the joint does not typically reflect the severity of the pain and related symptoms.
Non-Surgical & Surgical Treatments
Surgery isn't always used to treat this type of arthritis and usually isn't needed in milder cases or when it is caught early enough. In such instances, treatment in the form of medication, creams and balms, and even a shot or two of cortisone can help with the pain. Splints, used under the care and direction of your hand surgeon, can help support the thumb during activities that are known to be painful.
If the arthritis isn't helped by the aforementioned treatments, or is too far along to be relieved by them, surgery to reconstruct the joint is available. Your hand surgeon can discuss a number of surgeries that can reduce or get rid of the pain and get the thumb back to its original position and uses.
A common surgery involves removing the bad and damaged bone from the site of the arthritis and reconstructing the joint in a procedure called joint arthroplasty. Other common surgeries include bone fusion and, sometimes, arthroscopic procedures. Your hand surgeon will discuss the possibilities with you, along with what should be expected regarding potential benefits and side-effects.