Computer aided surgery (CAS) has broken new ground for orthopaedic total joint replacement surgery because the system allows surgeons to precisely track both the bones and surgical tools during surgery, making the surgery more accurate and consistent.

"In our study we compared the computer aided surgery (CAS) measurement against a CT scan measurement and discovered that the computer navigation system is accurate within ~2 degrees," said Dr. Bargar. "This is exceptionally accurate. There's no question in my mind that this technology is a real asset for my patients undergoing total hip replacement."

Computer aided surgery is the most recent technological upgrade in total joint replacement surgery for total hip and knee replacement. This computer navigation system has evolved over the past 20 years and is now used in neurological, ENT, oral, abdominal and heart surgery as well as orthopaedic surgery.

"Precision in placing a joint implant is a tremendous asset to the patient," said Dr. Bargar. "We are always striving for more precision because it means better mechanics and performance for our patients."

In this study, Dr. Bargar performed total hip replacement surgery on 25 patients using CAS (the ci System™, DePuy/BrainLab). He recorded the final measurement that the computer provided for the orientation of the implant relative to the pelvis. After the hip replacement surgery he then asked that each patient undergo a CT scan, using the CT as the "gold standard of measurement." Using the images from the CT scan, the hip implant was measured to ascertain how accurately it had been placed.

The study determined that orthopaedic surgeons can rely on the computer navigation system to help them be more accurate and consistent in placing hip implants in patients undergoing hip replacement surgery.

Computer aided surgery can assist with minimally invasive techniques where the surgeon has a more limited view through the small incision, and accurate surgery is more difficult.

CAS begins at the start of surgery, when temporary "pins" are placed into the bones in areas around the hip joint. Attached to these pins are tiny balls that are tracked by an infrared stereo camera attached to a computer. The surgeon then touches known points on the bones with a special tracking wand, and the computer creates a 3-dimensional model of the bones on the computer screen. The surgical tools have tracking devices on them as well, so the surgeon can visualize the position of the tools on the computer screen relative to the bones. By watching the computer screen, the surgeon guides the tools and the implants into the exact desired position.

According to Dr. Bargar, several prior studies have shown that when using manual instruments to align the socket even the best surgeons only get alignment within the 'safe zone' just 80 percent of the time. “This study justifies our use of CAS," Dr. Bargar said. "Not all surgeons currently use CAS but these study results certainly suggest that they should."

During his 28 years of practice, Dr. Bargar, has performed over 4,000 total hip and knee replacements. He has two degrees in engineering in addition to his medical degree and residency in orthoaedic surgery, with a fellowship in joint replacement surgery. His passion is to bring the precise and accurate processes from the engineering world into the field of joint replacement. He has pioneered the development of custom-made implants for patients using Computerized Tomography (CT) and CAD/CAM manufacturing; invented the first active surgical robot called ROBODOC™; and has helped develop many technological advancements such as CAS for hip and knee replacement surgery.

This recent study confirms just how much computer navigation technology helps Dr. Bargar customize the surgery and implant selection for each patient, enabling him to provide the best possible treatment and care for his total joint replacement patients. "When we can get precision in placing the hip and knee implants, there is less chance of complications," he said. "The result is a better functioning joint that we expect will last longer."