Thumb arthritis is very common and it can affect up to seventy-five percent of women who are post-menopausal. The thumb is a joint that moves in many different directions so it’s at great risk for injury in the development of arthritis at an early age. The joint that is affected primarily in thumb arthritis is just below the metacarpal bone, and this is called the carpal-metacarpal joint. This bone and joint are shaped like a saddle, so it has a broad surface that can become affected by arthritis. Patients usually are presented with significant thumb pain after repetitive activities, or when they are trying to squeeze or open jars, which is a common complaint. Doctors usually make the diagnosis based on physical exams and also by looking at patient x-rays. The treatment of thumb arthritis is initially focused on managing the patient’s symptoms and helping them to do activities in a simpler way to place less stress on the thumb.
Doctors usually start treatment by splinting and resting the thumb and administering nonsteroidal (NSAIDs) like Advil in order to control the pain. However, if thumb arthritis advances even with these non-surgical options, doctors may consider injections of either steroids or hyaluronic acid, and only after all of these methods fail, then they may consider surgery. There several different options for surgery. Most common is to entirely remove the trapezium bone. There are several different options of what to put in place of that bone. Some of it may be scar tissue that the body forms. Some surgeons perform a surgery where they place a portion of a tendon within that space. Replacing part of the joint in order to save the bone is the best option. The benefits of preserving the joint may be an increased range of motion, and an improvement in strength by saving the bones that are there.
Many doctors will replace half of the metacarpal bone with a substance called pyrocarbon. Pyrocarbon is a special form of carbon that has an elastic modulus or strength that is equivalent roughly to the outer surface of a normal bone. This half the joint replacement called hemiarthroplasty functions like a ball within a socket within the native trapezium. It allows the thumb to move through an almost normal ark of motion. Surgery normally takes about 30 to 40 minutes. It involves making a small incision over the back of the thumb and then removing the end of the bone. The area of the trapezium that is involved with arthritis is ground down to create a shallow cup, and then the pyrocarbon implant is inserted into the base of the metacarpal and then is placed within the socket in the trapezium. This forms a stable fit. At that point, the soft tissues around the thumb are closed, and the patient is left with an incision that is roughly two centimeters long. The patient is placed into a cast for two weeks. Following that, the cast is removed and the thumb is placed into a soft splint.
Patients can usually begin range motion exercises and rehabbing the thumb after four weeks after surgery. Many patients are able to return to regular activities as soon as six weeks. Doctors have had very good results with this implant, and this procedure has been available to patients for approximately eight years. There are other options that surgeons may offer. In long term outcome studies, all surgeries for the thumb tend to have the same outcome and produce good results in most patients.
The Mayo Clinic has been an innovated leader in thumb arthritis treatment. You may want to consider calling them or visiting their website at mayoclinic.com.