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Friday, February 25, 2005

Panel discusses pros and cons of L/MIS

A panel of experts discussed the pros and cons of the latest techniques in joint replacement surgery, the need for accurate methods to measure patient outcomes, best candidates for the procedure and appropriate training for surgeons during a media briefing held on Wednesday.

Less and minimally invasive surgery (L/MIS) for total joint replacement has recently been the subject of much attention in the media. As a result, many patients who need joint replacements are asking their orthopaedic surgeons about the technique.

Traditional open surgery for total joint replacement involves a 6- to 10-inch incision where muscles are cut to allow surgeons to fully visualize and operate on the joint. Minimally invasive, or minimal incision, surgery (MIS) uses a 3- to 4-inch incision. Some surgeons use even smaller incisions (1- to 2.5-inch) for even less minimally invasive surgery or (L/MIS). Both MIS and L/MIS procedures require additional smaller incisions for insertion of surgical instruments to complete the replacement.

Benefits from MIS
"Minimally invasive surgery is a new, comprehensive approach to pain relief and rapid recovery that enables patients to walk independently and return home the same day they have surgery, which is truly remarkable," said Richard A. Berger, MD, of Rush University Medical Center, Chicago. Berger was the first surgeon to perform minimally invasive total hip arthroplasty and minimally invasive total knee arthroplasty as outpatient procedures. "Every patient that has undergone either total hip replacement in the past two years or total knee replacement in the past year at our hospital using this new MIS protocol has been able to go home the day of surgery," he added.

Lawrence D. Dorr, MD, medical director, Dorr Arthritis Institute Centinela-Freeman Hospital System in Inglewood, Calif., said that psychological results from a recent study of patients who had MIS surgery for hip reconstruction indicated that they believed their body was less violated and less injured from this type of procedure. "Patients thought they would function better after the procedure-and they did," said Dr. Dorr. He added that they exuded greater confidence, and a more positive attitude about the outcome and the overall cosmetic effect of the smaller incision.

"Among patients who underwent MIS, 79 percent went home using a cane versus 21 percent of those who underwent traditional hip replacement surgery," said Dr. Dorr. "Six weeks after surgery, patient scores indicated less pain and less pain pill use. The MIS hip reconstruction showed the same quality as with a long incision, suggesting the same anticipated durability."

Alfred J. Tria, Jr., MD, clinical professor of orthopaedic surgery, St. Peter's University Hospital, Robert Wood Johnson Medical School, New Brunswick, N.J., agreed that MIS is a better choice for knee surgery because it allows surgeons to spare cutting into the quadriceps muscle. In using the quadriceps-sparing arthroplasty MIS technique for the knee-a procedure co-designed by Dr. Tria-patients recover three times faster, have about one-third less pain, one-third the length of hospital stay, 30 percent less blood loss and 10 degrees more motion of the knee at the end of the first and second years after the surgery, than those compared to those who underwent standard procedures.

The question of risk
Pre-emptive analgesia and other anesthetic improvements, improved radiographic imaging, intraoperative rehabilitation and patient education have also been major contributors to shorter hospital stays and reduction in post-operative L/MIS recovery time, according to Thomas S. Thornhill, MD, chairman of the department of orthopaedic surgery, Brigham and Women's Hospital, Boston.

Selecting the proper procedure for a patient centers on the question of whether the additional risks of L/MIS surgery are worth the benefits. As with all new procedures, surgeons need to ensure patients are informed of the learning curve involved, explained Dr. Thornhill. "Surgeons also must ensure the length of skin incision and exposure involved with L/MIS do not preclude the basic achievements of arthroplasty, such as soft tissue balance, component position and alignment," he added.

Not all patients are candidates for these types of surgery, depending on the type of injury and the person's health. "I performed 414 total knee surgeries in 2004-35 percent were done with MIS, 30 percent were performed using a 'mini' incision and the remaining 35 percent were performed with the traditional knee incision," said Dr. Tria. "I believe that 40 percent to 50 percent of all total knees will be performed with smaller incisions over the next five years, and that components for the replacements will be redesigned to make the procedure simpler."

But incision size is not the most important aspect of L/MIS surgery, according to Thomas P. Vail, MD, director of both adult reconstructive surgery and the Total Joint Replacement Center, Duke University, Durham, NC. "The procedure is a 'total package,'" he said. "You must focus on all aspects to ensure you get the best outcome from a combination of the right implant and tools, minimal tissue trauma, proper pain management and possibly accelerated rehabilitation."

Computer-assisted surgery
"Using L/MIS techniques for partial and total joint replacements holds the promise to change the way adult reconstructive surgery is performed and may dramatically improve patient outcomes," said Anthony M. DiGioia, III, MD, director of the Institute of Computer Assisted Orthopaedic Surgery, The Western Pennsylvania Hospital, Pittsburgh. "This is not only because of the smaller incisions, but also because of the development of new comprehensive programs addressing the complete care of patients needing total joint replacement."

A new generation of computer-assisted orthopaedic surgical (CAOS) tools that include navigation systems, miniature robots and new intraoperative visualization devices that provide "x-ray vision" without x-rays are enabling these new less invasive techniques for joint replacement and eventually for biologic implants. "These CAOS tools are also being used to train surgeons and measure outcomes in L/MIS," explained Dr. DiGioia. "Together, with improved care pathways, there is potential to improve our patients' outcomes in the short- and long-term."

Beyond all the hype, according to Dr. DiGioia, any new clinical technique or technology must also be critically examined as they relate to patient outcomes in order to see what is working well and what surgeons still need to learn. "However, the goals are to develop new techniques that will permit more procedures to be done less invasively with improved accuracy and precision, but also safely and effectively," said Dr. DiGioia.

Dr. Thornhill concurred about the future adoption of L/MIS among the orthopaedic community. "Surgeons will move towards using L/MIS techniques based on evidence-based data published in peer review journals," he said, "not because of market demand for such surgeries."

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