Computer Assistance Increases Precision of Component Placement in Total Knee Arthroplasty with Articular Deformity

Computer Navigation is a valuable tool that surgeons use to accurately position components for Knee and Hip replacement surgery. Computer navigation is embraced by patients – it is common sense that technology is helping medicine to evolve and improve. However, there continues to be push back to the adoption of this technology. Not surprisingly, health insurance companies continue to deny payment to surgeons who believe this valuable technology improves joint replacement surgery. Traditional “old guard” joint surgeons refuse to adopt emerging technologies. Insurance claim payment for navigation is denied is based on ” experimental or not necessary” reasoning. However, a large body of medical literature supports the use of computer navigation to aid joint replacement surgeons.

The next wave of technology will combine navigation with robotics which will further revolutionize joint replacement surgery. Look for this technology to be minimized and deprecated by health insurance companies and old guard surgeons.

This is the abstract of a scientific paper demonstrating the value of computer navigation in total knee replacement surgery.

Methods

Results

Conclusions

Each author certifies that his or her institution approved the human protocol for this investigation, that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained.

This study belongs to a project promoted by the Health Research Institute (Carlos III Health Institute) of the Spanish National Healthcare System.

Computer-Assisted Surgery More Accurate for Total Knee Replacement

Medical articles on new technologies are often times conflicting. The the old guard designs research protocols to verify that time tested procedures are the standard. The forward thinking innovators design studies supporting the benefits new technologies represent. Computer Navigated Knee (and Hip) replacement surgery is in the middle of a technological revolution and this is being carried out in the press, the medical literature and in operating rooms across the world. Here is a compelling study citing both the effectiveness and safety of computer assisted Knee Replacement Surgery.According to data presented at the AAOS 2010 Annual Meeting, total knee arthroplasty (TKA) conducted with computer assistance is more accurate than conventional surgery. The authors based their data on the results of 1,000 computer-assisted TKAs conducted at a single center between February 2005 and January 2010. They found that alignment within 3 degrees was achieved in 100 percent of the patients, with an average final, post-surgical alignment of 0.8 degrees. In addition, none of the knees failed early or have required revision secondary to misalignment, instability, or aseptic loosening. In other words, a study of 1,000 consecutive Computer-Assisted Robotic Total Knee Replacements performed over a five year period at Mercy Medical Center in Rockville Centre, NY demonstrates that the computer-assisted procedures result in far better leg alignment, much less likelihood of complicating infection, and a far lower early failure rate than surgeries performed using conventional techniques.

Scientific Article Questions Routine Use of Computer Navigation for Knee Replacement Surgery

A Mayo Clinic 15 year study confirms accurate placement of Total Knee Components does not improve long term results.

One long-held tenet of total knee arthroplasty is that implant durability is maximized when postoperative limb alignment is corrected to 0° ± 3° relative to the mechanical axis. Recently, substantial health-care resources have been devoted to computer navigation systems that allow surgeons to more often achieve that alignment. Better long-term survival of total knee arthroplasty in accurately aligned implants was similar to the group of alignment outliers. 398 Knees were studied.

Results At the time of the latest follow-up, forty-five (15.4%) of the 292 implants in the mechanically aligned group had been revised for any reason, compared with fourteen (13%) of the 106 implants in the outlier group. Revision for specific reasons thought to be related to initial position showed the following: seventeen (5.8%) of the 292 implants in the mechanically aligned group had been revised because of aseptic loosening, mechanical failure, or wear, compared with four (3.8%) of the 106 implants in the outlier group (p = 0.49).

Conclusions A postoperative mechanical axis of 0° ± 3° did not improve the fifteen-year implant survival rate following these 398 modern total knee arthroplasties. We believe that describing alignment as a dichotomous variable (aligned versus malaligned) on the basis of a mechanical axis goal of 0° ± 3° is of little practical value for predicting the durability of modern total knee arthroplasty implants.

This report suggests that for traditional knee replacement surgery with standard instrumentation aligns the knee well enough for an 85 % good result rate fifteen years after surgery. This report suggests that “perfect axial alignment” is not an important variable toward improving the long term result after total knee replacement. The author’s initial bias was to discount the benefit of accurate alignment using the current technology of computer navigation, which the data confirms. Computer navigation use to prevent implant alignment errors in minimally invasive surgery or in the case of unusual leg deformities as a result of trauma or congenital variation is still considered valuable in my opinion. Also, the combination of computer assisted surgery with robotics might be the next “great” advancement in joint replacement surgery. More on robotics and computers later.