This article is more than 5 years old. Information may no longer be current.
CAOS navigation users make predictions, see expansion in the coming years
Market for computer-assisted surgery continues to grow as patients request less invasive procedures.
More orthopedic surgeons in the United States today are considering navigation equipment as guides to perform joint replacement, spine, ACL or trauma surgeries, even though many hospitals still can not afford the equipment.
Perhaps the primary factor behind this swell in interest is the mounting demand for minimally invasive orthopedic procedures. As more patients request procedures that involve smaller incisions, orthopedic surgeons are forced to consider different ways to operate within a much more restricted surgical field.
And the minimally invasive field is growing. According to a recent report by the Millennium Research Group, minimally invasive orthopedic procedures will generate in excess of $170 million in revenue by 2010. Likewise, the U.S. navigation market — consisting of image-based and kinematic navigation systems used for spine, hip, knee, ACL, neurology, and ear, nose and throat procedures — was valued at more than $115 million in 2005 … and the numbers continue to escalate, according to the report.
Totals for installed orthopedic navigation equipment alone will increase annually more than 25% over the next 5 years, according to Millennium researchers.
This phenomenon is not restricted to the United States. Last year, more than 500 navigation systems were sold in Europe, with navigation sales volumes increasing in all European regions and across all specialties, according to the Millennium report. In Japan, more than 60 navigation systems were sold in 2005, with navigation sales volumes increasing in all surgical specialties.
What can surgeons expect?
Some surgeons who have already implemented computer-assisted orthopedic surgery (CAOS) tools into their practice predict that the number of “converts” to navigation could increase significantly in the next year or two.
“I think we should expect navigation to become more easily accessible, affordable and user-friendly,” said Tyler D. Goldberg, MD, an orthopedic surgeon at the Austin Diagnostic Clinic in Texas. “Navigation will no longer be just for the passionate few, but for every surgeon interested in improving outcomes for his or her patients. The technology will become more interactive with the surgeon, allowing the flow of surgery to remain smooth, while still maintaining the accuracy, dependability and reproducibility.”
Specifically, the technology may serve a greater role in knee revisions.
“Thus far, CAOS systems have only been used [with any consistency] in primary knee replacement. However, CAOS may be even more useful in the revision setting, when landmarks are either not present or distorted by previous surgery,” Goldberg said.
Tracking will improve
Anthony M. DiGioia III, MD, clinical associate professor of orthopedic surgery at the University of Pittsburgh School of Medicine and chairman of the annual MIS Meets CAOS Symposium, also believes that the current navigation instruments will become easier to use and more streamlined in terms of “fitting into the flow of surgery.”
“On the technology side, we’ll see improved tracking systems that are less surgically intrusive and less disruptive to the operating room, as well as new ‘plug-in’ tools that combine the best of navigation and the best of robotic tools, while keeping the surgeon in the loop,” DiGioia told Orthopedics Today.
Likewise, in the next few years, “There will be systems that take advantage of all the different imaging modalities,” such as X-rays with MRIs, and ultrasound with CT scans, he said.
DiGioia also believes the future may bring “X-ray vision”-type display devices, as well as higher fidelity surgical trainers and computer-based simulators, combined with greater portability.
Best areas of application
DiGioia and Goldberg agree that navigation is suited for all areas of orthopedic surgery that requires accuracy and reproducibility.
“I find it especially useful in joint replacement, as the computer often ‘sees’ angles and distances that my own eye often cannot,” Goldberg said. “For example, I am usually able to see coronal and sagittal plane alignment within 2° to 3°. However, the computer can accurately detect subtle changes of even 0.5°.”
Also, “Intraoperative errors such as malrotation, femoral notching and ligamentous imbalance are virtually eliminated,” he added.
T. Bradley Edwards, MD, believes navigation is very helpful for joint replacement — especially in the shoulder.
“Navigation is useful for correcting glenoid osseous wear,” said Edwards, an orthopedic surgeon at the Fondren Orthopaedic Group in Houston. “Without navigation, any correction of glenoid version is qualitative and largely dependent on surgeon experience. With navigation, glenoid reaming and version correction becomes quantitative and more easily controlled, even by surgeons with less experience.”
Edwards believes orthopedic surgeons will come to rely on navigation more to perform prosthetic positioning in hemiarthroplasty cases performed in the treatment of proximal humeral fractures.
“We are already using navigation for shoulder arthroplasty performed for nontraumatic etiologies,” so this is just a natural extension, he told Orthopedics Today.
Too much information?
|
Despite the abundance of tracking and placement information orthopedists can glean from using IGS, DiGioia hopes future navigation systems actually streamline the information surgeons receive. The first navigation instruments often inundated surgical teams with tracking data, much of which they never used, he said.
“We also hope we can use [future] navigation systems to measure and document surgical techniques so that we can relate surgical technique to patient outcomes in a more direct way,” he said.
Using navigation instruments has had a dramatic effect on how DiGioia views some procedures he performs.
“We need to re-examine what the ‘correct numbers’ (ie, measurements) are [in some of our procedures],” he told Orthopedics Today. “Now that we are measuring what we do, we are finding out that the ‘numbers’ that we thought were correct in the past are not. We need to provide guidance to surgeons on what is ‘correct.’”
As part of this process, orthopedics surgeons will hopefully learn to use patient kinematics instead of “numbers” to determine what is correct for each individual, DiGioia said.
Challenges: costs and software
Despite the technical breakthroughs, orthopedic surgeons will not widely embrace navigation instruments until the costs come down. That has to happen, DiGioia said, “in order to permit every surgeon and hospital to use these systems on a more routine basis.”
Goldberg added that one of the biggest challenges for manufacturers of navigation equipment is making the software more user-friendly and easier to understand, especially for surgeons “who are slow to embrace CAOS techniques.”
On the plus side, “The instrumentation itself will continue to evolve to be smaller and more precise, thus satisfying those surgeons who wish to utilize minimally invasive techniques,” Goldberg added.
He also hopes new or improved navigation products will allow surgeons to obtain information about patellofemoral kinematics both pre- and postresection.
“Current systems provide excellent precision in the placement of femoral and tibial components. However, patella complications are the current leading cause of failure in TKA, and the current CAOS technology does not address the patella,” he said.
For more information:
- Dr. DiGioia is the designer of the HipNav system (The Robotics Institute).
- Dr. Edwards is a paid consultant to Kinamed.
- Dr. Goldberg is a paid consultant for Plus Orthopedics.
- Millennium Research Group Inc. U.S. markets for image-guided surgery: 2005.