Trabecular metal fixation: A new chemical concoction

Abstract

Secure fixation of metal prosthesis to bone has always been a challenge. Bone cement has been a great help in achieving this goal, but there can be complications, such as cement loosening and breakage. Therefore, it is reasonable to consider types of coating on a metal surface that will allow bone ongrowth or a type of metal (tantalum) that will allow bone ingrowth as it is a porous scaffold. Furthermore the stiffness of tantalum is between subchondral bone and cortical bone, which also promotes ingrowth. This metal can be overlayed on other metal or used by itself as an implant. In primary osteoarthritis of the glenohumeral joint, it can be used for both the humeral and glenoid components allowing for a cementless prosthesis. Thus the complications from the use of bone cement can be avoided. Tantalum can also be used with a reverse prosthesis. It is especially important for the glenoid baseplate component as it will take away stress from the screws that are used for early fixation. Tantalum is also useful in the revision setting where there is bone loss and secure fixation is needed to the remaining bone. Tantalum has been used in the shoulder for more than 5 years successfully and longer in the hip and knee.