MAKO is a system by Stryker which brings the use of robotics into joint replacement procedures (knee and hip). I have never used it nor seen it used, but it would be used intra-operatively to assist and guide the bone cuts of the femur, tibia, and probably the patella, so as to be as exacting and precise as possible allowing for the best possible prosthetic fit and alignment of the joint. Since it is used during the procedure, it would fall into the category of code 20985: Computer Assisted surgical navigation procedure for a Musculoskeletal Procedure, without images. It is “real time” use by the surgeon, but doesn’t rely on X-ray imaging such as fluoroscopy, and this makes it different from other types of combined X-ray and computerized intra-operative guidance systems.
The Code 0055T: Computer assisted surgical navigational orthopedic procedure with image guidance based on CT or MRI images is different in that this applies to the preoperative evaluation and planning for a procedure, usually a TKR. This is not intra-operative imaging or guidance. In this, the CT or MRI studies are used to create “customized” instruments or bone cutting guides to be used in surgery to help with prosthetic fit and alignment. If the preoperative clinical notes document that an MRI or CT was used to design and customize the instruments and guides for the planned procedure, then this code could be used.
I don’t know if the MAKO system is in any way involved, affected, influenced by the preoperative imaging or not, i.e. is the preoperative imaging study “downloaded” into the MAKO computer to help guide the procedure? For what it is worth, they appear to me to be independent of each other. Consequently, if both are done and documented, then both could be coded.

I hope this helps some. This is “new stuff,” particularly the MAKO system/technology.

Respectfully submitted, Alan Pechacek, M.D.