Avanta CMC implant is a “ball and socket” design used to
treat basal joint arthritis of the thumb. The prosthesis is offered
in various sizes to accommodate anthropomorphic variations in trapezio-metacarpal
sizes. The metacarpal component is titanium and is
designed to fit the medullary canal of the thumb metacarpal. The
implant is fixed in the metacarpal using a mantle of bone cement.
The stem has a conical shape to resist impaction stresses and a
highly polished ball for engagement with the trapezial component.
The trapezial component is made from ultra-high molecular weight
polyethylene (UHMWPe) and has a proximal stem for insertion into
the prepared trapezium. A mantle of bone cement is used to facilitate
fixation to the trapezium bone. The trapezial component has a congruous
cup corresponding to the polished ball on the metacarpal component.
The components are coupled together using a snap fit. The “ball
and socket” design allows for 90° of conical articulation that permits
radial circumduction of the CMC joint. The implant is provided with
instrumentation to aid in bone preparation and proper size determination.
MKT 10280 Rev. A