Using your thumbs for hand work like crocheting and knitting, can cause the joint where the thumb attaches to the hand to suffer from wear and tear. This joint is called the carpometacarpal or CMC joint. The CMC is the joint that allows you to move your thumb in all sorts of directions while using a crochet hook or knitting needle. The CMC joint is sometimes referred to as a “universal joint” because of the wide range of movements possible.
The place where the CMC joint of the thumb attaches to the wrist is at the trapezium bone. This joint is sometimes referred to as the basal joint of the thumb. The CMC or basal thumb joint suffers a lot of stress over the years. This can lead to the painful osteoarthritis of this joint that you are experiencing.
One of the more successful surgical procedures for CMC joint arthrosis is to remove the trapezium bone completely, a procedure referred to as a trapeziectomy. Taking a bone out of the wrist does leave a space or hole. Surgeons usually put something in that hole to keep the bones from shifting. As you have mentioned, there are several choices. The surgeon may use a tendon graft harvested from you or a synthetic (manmade) spacer.
In recent review, two hand surgeons from Columbia University in New York City provided an update on the use of nonautogenous spacers. Nonautogenous means the material used was not taken from the patient but rather from a tissue bank (a biologic material) or from one of several synthetic products available.
Nonautogenous products have the distinct advantage of no donor site pain, infection, or other problems that can occur from harvesting the patient’s own tissue. Using a nonautogenous source (either synthetic or biologic materials) also reduces surgical time.
But what about the results? How well do they work? Is there an advantage of one type of nonautogenous material over the others? By reviewing the results of studies published in this area, the authors may help answer your question
A human-based product called Graft-Jacket has had some good success. This material is taken from cadavers (human bodies preserved after death for study) and treated in a way to prevent an immune response. This approach works well but there are concerns that there could be disease transmission from the cadaver to the patient. It is also possible that in time the body will find a way to get rid of this tissue.
Surgeons comparing the use of interspacers versus removal of the bone without filling in the gap made a surprising discovery. They found the results were just as good (and often even better) if they just left the gap unfilled. There was less risk of infection, inflammation, and no risk of graft material moving out of the space or spreading disease to the patient.
It is possible that inserting something into the void left by removing the trapezium just isn’t necessary. If this is the case, it would be a cost savings with no risk of foreign body reaction. The authors suggest further studies are needed to take a closer look at this phenomenon. Studies comparing autogenous with nonautogenous grafts would be helpful along with efforts to compare these two approaches with no interspace filling.
Until those studies provide us with the evidence we need to direct and guide treatment, we must rely on the individual surgeon’s experience and expertise. Ask her to review all the pros and cons of each choice with you and offer her opinion. This may help you make the final decision together.