Computer Navigation Knee Replacement

Some of the latest technology in joint replacement includes not only implant material advances, but also advances in how we place the components during the reconstructive surgery. As other articles on this site discuss, there are different surgical approaches in knee replacement that can make significant differences in early and late outcomes. Another technology that is attempting to improve early and late outcomes by making implant placement more accurate is computer aided surgery or CAS.

Currently all primary knee replacements at Muir Orthopaedic Specialists are being done utilizing computer guidance for implant placement. I’ve used this technology since July 2007 for knee replacement. Nearly all patients are candidates for CAS except the very morbidly obese. The technology itself has been available in limited markets for a few years and mainly in knee replacement. Recent software developments have expanded the technology to hip replacement.

The goals for CAS are simple; to improve implant placement, ligament balance and leg length control in an effort to customize each joint replacement with the patient’s anatomy, thereby minimizing implantation related complications. The potential complications of interest are ligament imbalance, component malrotation and angular malalignment.

Thus far CAS has been very successful in achieving the above goals. In the knee, ligament balance and overall joint motion has been significantly improved by allowing the computer to aid in component size and rotational alignment.

It is important to understand that CAS is not robotic surgery. The surgeon obtains highly accurate information from the computer, but the surgeon ultimately has complete control and must apply the information correctly. The information obtained is highly precise but could be inaccurate if input information into the computer is incorrect.

There are very few downsides using CAS. Four additional 5mm wounds are made to place pins in the femur. There has been very little pain from these wounds reported by patients In my experience, there have only been improvements using CAS. No reconstructions have been adversely affected in my hands with this technology. Again, CAS is an additional tool not the only tool used to properly reconstruct knees.

At this point I have no reason to return to non-navigated replacements. Both in the knee and the hip CAS is another check in an effort to make every joint replacement as close to perfect as possible. Individual patient considerations at times force certain limitations in replacement surgery, but with proper pre-operative planning and additional intra-operative information from technologies such as CAS, surprises during and after surgery can be minimized.

For general information regarding knee replacement surgery or further details regarding the minimal anterior approach contact our office.