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Less pain for outpatient knee replacement
New technique does not cut the quadriceps muscle
Although technological advances are responsible for the movement of many surgical procedures from the inpatient to the outpatient setting, sometimes the switch relies more upon the surgeon’s technique rather than the actual equipment.
"The main reason knee replacement patients experienced a great deal of pain and a slow recovery in a traditional knee replacement is that the quadriceps muscle is cut to give the surgeon access to the knee," says Richard Berger, MD, an orthopedic surgeon in Chicago who is performing knee replacements on a same-day surgery basis. "There was a need for instruments that enable minimally invasive surgery in knees, but the major change is the surgeon’s approach," he says.
As with most procedures that move to the outpatient setting, the difference in recovery time between a traditional knee replacement and a minimally invasive knee replacement is substantial, points out Berger. Recovery from traditional knee surgery requires three to five days in the hospital and another five to seven days in a secondary care facility such as a rehabilitation center or a nursing home before the patient goes home, he says.
Although the cost of the implants and the tools is comparable to those used in traditional surgery, the shortened length of stay and the reduced need for lengthy therapy decreases the overall cost of the procedure, he adds. Recovery of function also is significantly faster, Berger notes. "Once a patient can go up and down stairs, get in and out of bed on his or her own, and get in and out of a chair, the patient is sent home.
At this time, all of his outpatient knee replacement procedures are scheduled as first case of the day, so the patient spends a few hours in recovery, has lunch, goes to physical therapy, and then is discharged to home in the afternoon using crutches or a cane for support. "Within three to four days, they are walking on their own," Berger says. Patients undergoing traditional knee replacement surgery reach this point in three to four weeks after going home, he adds.
Patients undergoing the minimally invasive surgery are 90% recovered in three weeks, as compared to traditional surgery recovery time of three to four months, Berger adds. Because the patient doesn’t experience the same level of pain with the minimally invasive surgery, most patients are able to drive in six to seven days because they no longer need pain medication, he says.
Alfred J. Tria, MD, an orthopedic surgeon at The Institute for Advanced Orthopaedic Study, a division of The Orthopaedic Center of New Jersey in Somerset, pioneered the minimally invasive method but does keep his patients in the hospital for one night. "At the present time, only about 30% of my patients can undergo the procedure," he says. "I limit it to patients less than 80 years of age, under 225 pounds, with minimal deformity of the knee, with osteoarthritis, and with no previous major open-knee operations."
While there only are a few surgeons performing minimally invasive knee replacement at this time, Tria expects the popularity of the procedure to grow. "We believe the minimally invasive technique will account for 40% of all total knee replacements in the next five years," Tria explains. "The technique has no disadvantages, as long as surgeons are properly trained to avoid complications."
Berger contends credentialing for this procedure should require procedure-specific training. "This is not a simple procedure for a surgeon and does require special instruction," he says.
Zimmer, the Warsaw, IN-based manufacturer of the instruments, offers a two-day course at which the surgeons can practice on a cadaveric knee, he says. (For contact information, see the resource at the end of this article.) In addition to the course, surgeons must scrub with one of the surgeons involved in the design of the equipment before Zimmer will release the instruments to them, adds Tria.
The minimally invasive knee replacement was not discussed by the National Institutes of Health Consensus Panel on Total Knee Replacement because the approach is too new to assess its effectiveness, says E. Anthony Rankin, MD, chief of orthopaedic surgery at Providence Hospital in Washington, DC, and chair of the consensus panel. In addition to the need for additional training, there also is a disadvantage due to the lack of a track record regarding longevity of the results and the short length of time in which surgeons have had to evaluate patient-based outcomes, he adds.
However, "there is an appeal for this technique, both for surgeons and patients, based on its newness and promise of shorter recovery time," he adds.
Sources and resource
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For information on minimally invasive instruments and training for total knee replacement contact: