During the 13th Annual Meeting of the International Society for Computer Assisted Surgery, a study presented by Dr. Jan Koenig demonstrated why APEX Robotic Technology™ (OMNIlife science, Inc., East Taunton, MA) continues to be an industry leading solution to achieve post-operative alignment accuracy in total knee arthroplasty (TKA). It is not just effective in routine cases of osteoarthritis but also when managing large pre-operative deformity (“large” in this study is knee alignment of more than 10 degrees from neutral mechanical alignment in the coronal plane). For these more difficult cases Dr. Koenig’s study showed consistent and reproducible mean post-operative alignment of less than 2 degrees in the coronal plane for these large deformity cases with the use of APEX Robotic Technology™.[1]
Achieving post-operative knee alignment less than 3 degrees from neutral alignment is widely recognized as resulting in increased implant survivorship and decreased chance of having a revision of the original surgery.[2] [3] More impressive may be the fact that the average surgery time for these large deformity cases added less than 5 minutes to the average surgery time for the control group which had no significant deformity.
“The fact that we can formulate a virtual surgical plan and then validate that plan’s execution with an average of less than 5 minutes added per case with an extreme level of accuracy demonstrates the effectiveness of real time navigation and robotics for total knee replacement,” notes Dr. Koenig.
One reason OMNI’s APEX Robotic Technology™ (A.R.T.™) system is able to achieve such good post-operative leg alignment is through the precision of its robotic saw guide.[4] In Dr. Corey Ponder’s study presented at the CAOS meeting, he demonstrated how the robotic cutting guide allows him to obtain significantly more accurate and repeatable bone cuts than can be achieved with manual instruments.[5] More accurate bone cuts have a practical value to Dr. Ponder because of a unique “Press Fit” optimization feature he utilizes within the A.R.T.™ software.
In some patients, surgeons select to use knee replacement implants that do not require bone cement. Instead of bone cement these implants use a porous metal backing that allows the bone to grow onto and into the surface of the implant binding it to the patient’s bone. However, the effectiveness of these porous “bone friendly” surfaces is highly dependent on a tight and intimate fit of the implant to the cut surfaces of the bone, hence the term “Press Fit”. The robotic cutting guide allows the surgeon to make adjustments of just fractions of a millimeter to the cuts in real time during the surgery which may help adjust for differences in patients bone quality and achieve the desired component fit. Dr. Ponder stated, “It’s a great benefit to be able to customize the dimensions of your bone cuts so that I can create the tightest fit possible for the implant. A.R.T.™ affords my patients and I that luxury.”
APEX Robotic Technology™ is offered by OMNIlife science, Inc. as part of their computer-assisted total knee replacement platform. The A.R.T. system does not require a preoperative CT or MRI scan like other robotic systems or so called patient-specific instruments, avoiding the expense and radiation associated with these procedures. Instead, it uses a patient-specific computer model of the knee joint, generated through use of the company’s patented Bone Morphing™ technology, to virtually plan all of the required bone cuts in real time during surgery.
