Fusion vs. replacement of the thumb base joint
Hand surgeon Caringbah Sutherland Shire Sydney
Arthritis can potentially occur in any joint. In the hands, a common location is in the joint at the base of the thumb, where it joins the wrist. Technically known as the first carpometacarpal (CMC1) joint, this joint involves the bone at the bottom of the thumb that’s located in the hand itself, along with one of the carpal bones, which are the small wrist bones.
Arthritis in the thumb base joint can have a huge impact on a person’s ability to function in their daily lives. That’s because this joint is very important for gripping. When this joint isn’t functioning well, people generally lose grip strength. We need grip strength for common activities like twisting the top off of a jar or bottle, opening a doorknob, or doing up buttons. In severe cases, this can even make it difficult to live independently.
For people with thumb base joint arthritis, there are a few nonsurgical options for treatment, including hand therapy, wearing a brace on the joint, and anti-inflammatory medications that are either taken orally or injected into the joint. If these methods aren’t enough to relieve pain and improve function, then surgery may be considered. There are two main options: fusion or replacement of the joint. What is each option like? When might each one be preferred?
Fusion of the thumb base joint
During fusion surgery, the surgeon reshapes the bones of the thumb base joint, so that they fit closely together. The two bones are then held tightly together with wires, pins, or plates and screws. If the surgery is successful, then there will be no further movement of the joint at all.
Thumb base joint fusion is often very effective at relieving pain. Some of the damaged joint tissues are removed, and the surgery also completely prevents movement of the remaining joint tissues, so there’s no longer a reason for pain. If pain is the primary concern, then fusion may be a good option. In addition, if fusion surgery is successful, then the results are permanent. There’s rarely any need for a follow-up surgery later on.
However, the downside of fusion is that movement at the joint is completely prevented. Most people have good enough grip strength after fusion to be able to perform daily tasks like opening jars and turning doorknobs, but they’ll lose some abilities to do finer tasks, because of the restricted motion of the thumb.
Replacement of the thumb base joint
Another option is to replace the joint with an artificial one. The main advantage of choosing joint replacement over fusion is that it maintains movement at the joint. This allows the hand to be more functional, especially for finer movements. When the joint is fused, there’s generally good grip strength, but much less fine control over the movements of the thumb. Joint replacement maintains good mobility at the base of the thumb.
The main disadvantage is that artificial joints don’t last forever. Eventually, the joint may wear out and need to be replaced. Those who do a lot of heavy manual labor (such as people who work in a field like construction) may find that their artificial thumb base joints tend to wear out more quickly, because using a strong grip puts quite a bit of stress on the joint. Some people may prefer fusion, so that they don’t ever have to think about replacing a worn-out artificial joint. Others may prefer to maintain mobility, even though they might need to replace the joint again in the future.
There are a few different options for the specific replacement joint. Currently, Dr. Sungaran generally recommends the BioPro Modular Thumb Implant. To place this implant, a stem is placed in the metacarpal bone at the base of the thumb, and a round head is placed on the end of this. A socket is created in the carpal bone, and the head of the implant fits into this. There are multiple different sizes of each component available to allow a good fit for each person’s hand, and the components are durable, which helps the artificial joint to last longer. This joint is also bioengineered to function as much like the natural joint as possible.
Dr. Sungaran is excited about a new type of artificial joint for this area, known as the KeriMedical Touch. Biomedical engineers have designed this device to be highly personalizable, with many different options to fit different people’s hands. It also allows a high degree of motion, leading to good hand function afterwards.
With the KeriMedical Touch device, it’s easy to replace certain components of the device, which can facilitate any revision surgery that’s needed. This is part of why this new artificial joint is a game-changer for thumb base joint replacement – with separate components being easy to switch out, revision surgery becomes much easier.
This new artificial joint has recently been approved in the US. While it’s not yet approved in Australia, he’ll begin offering it as soon as it’s available here.
Hand surgeon Caringbah Sutherland Shire Sydney
If you’re experiencing pain or dysfunction at the base of your thumb, then you have several different treatment options that may help. Your next step is to talk with an expert in treating conditions of the hand. After examining you and learning more about your concerns as well as your goals for your hand function, they’ll be able to advise you on the best next steps to help get you back to feeling and functioning well.
Dr. Sungaran has extensive training and experience in treating conditions of the hand, including performing surgical procedures on this delicate area. These procedures are challenging, without a lot of room for error, so it’s important to choose someone who’s highly experienced. He also stays up-to-date with the latest developments in the field to ensure the highest-quality treatment for every patient. To schedule your appointment for a consultation with Dr. Sungaran, simply contact our office.
