[mmglobal]

Our own Steve55 is the proud owner of 3 brand new ProDic-C Novas. This new model has some very key improvements over the current version.

They changed the keel configuration to minimize the risk of adjacent keels in multi-level procedures becoming 'stress risers'. Instead of central keels on both the upper and lower plates, the new Nova version has a central keel on the upper plate and 2 smaller keels on the lower plate.

Most importantly, the new Nova is MRI compatible because instead of the metal components are primarily titanium instead of cobalt chrome. Titanium does not have the durability of cobalt chrome, so Synthes did it right and retained the cobalt chrome where it's needed. The wear partner in the joint are still UHMW Polyethylene and cobalt chrome, while the major portion of the metal is titanium to make the prosthesis much, much more MRI compatible.

While the stress riser issue is not a problem unless the surgeon did not pay attention in class and makes a rookie mistake in the surgery, the new Nova will be more tolerant of this mistake. (the screw holes for the parallel distractor should be well off midline or else it - in conjunction with the keels becomes a stress riser.) I wonder if the smaller keels will provide the same level of 'primary fixation' that reduces the incidence of migration. If it doesn't we'll be trading higher risk of migration for lower risk of fracture. However, I believe that like the fracture issue, migration problems come from poor implantation rather than device or patient problems. So, with the new device, just like the old device, we protect ourselves from problems by getting the best implantation possible.

I'll write more as I hear it!

All the best,

Mark