Innovative technology and orthopaedic expertise allow Baylor to keep patients moving.

This is not the orthopaedics program of even 10 years ago, says Jay Mabrey, MD, chief of orthopaedic surgery and member of the medical staff at Baylor University Medical Center at Dallas.

More than 1,500 joints a year are replaced at the medical center, making Baylor one of the busiest total joint replacement center in Dallas, he says.

Surgeons on the medical staff at Baylor are increasingly turning to a surgical computer system to assist them in creating perfect alignments of the bones in total knee replacements, says Mabrey. Surgical navigation systems used in the operating room allow the surgeon to make precise alignments using computer guidance, he says.

In addition to proper alignment, the navigational system may have other health advantages over the more established methods of total knee replacement.

"Using the navigational system adds about 10 minutes of time to the surgery, but basically gets proper alignment every single time," Mabrey says.

Another new technological advancement in orthopaedics at Baylor is the use of the Birmingham hip resurfacing system. Several surgeons on the medical staff an Baylor Dallas have traveled to the McMinn Centre in Birmingham, England, in the past year to receive training from the creator of the system, surgeon Derek McMinn, FRCS.

Hip resurfacing acts like a cap on a tooth — except the cap is on the hip joint. The surgeon shaves a few centimeters of the femoral head — part of the hip bone socket — to remove diseased bone and tissue and then puts a high-carbide cobalt chrome metal cap over it instead of replacing the entire hip joint. The hip socket is also replaced with a metal cap.

Resurfacing allows patients to keep most of their natural bone structure, which improves stability.

Hip replacements become necessary when patients can no longer manage severe hip pain caused by osteoarthritis, dysplasia or avascular necrosis using medication, physical therapy or exercise. Approximately 330,000 hip replacements are done in the U.S. annually. As many as 60,000 of these patients could be candidates for hip resurfacing, analysts say.

Hip resurfacing using other materials has not had a strong success rate in the past, said Richard Schubert, MD, an orthopaedic surgeon on the medical staff at Baylor Dallas.

"Hip resurfacing was last done in this country in the 1970s," Schubert says. "But the system was made with thin plastic and it didn't do well. Everybody stopped doing it."

Since 1997, the Birmingham system has been implanted in more than 60,000 patients in over 27 countries. A clinical study of the resurfacing system shows a 98 percent success rate in patients who have had 10 to 14 years of follow-up care, Schubert says.

Last May, the U.S. Food and Drug Administration (FDA) approved the Birmingham system in this country in part because of its successful metal-on-metal track record, says Schubert. Mabrey was chair of the FDA panel that approved the Birmingham system and he provided a clinical presentation of the system's history and results to the panel.

Even with FDA approval, some surgeons initially have been wary of embracing the new system.

"I went into the training a skeptic," says Kurt Rathjen, MD, orthopaedic surgeon on the medical staff at Baylor Dallas, adding that the conventional total hip replacement has a success percentage in the high 90s. "But now I am a firm believer in the Birmingham system. There are long-term benefits to keeping extra bone."


Leading candidates for hip resurfacing are men and women under age 60 with good bone stock who want to continue being active, says Schubert. For most patients, running sports, which are generally discouraged with total hip replacements, can be continued within just one year with resurfacing, he says.

"We're seeing quite a bit of demand," Schubert says. "There is a larger subset of people in their 40s and 50s with arthritis who want this."

The surgeons are cautious to add that the resurfacing won't last forever and may need to be revised in 10 to 15 years. The latest total hips may last 20 to 25 years or longer.

Floyd Landis, the American winner of last year's Tour de France, underwent the Birmingham hip procedure last October.

But a patient doesn't need to be a professional athlete to have the surgery.

Wardell Carraby, a 45-year-old Dallas police officer and marathon runner, had the surgery last June at Baylor. A runner since childhood, Carraby said the cartilage on his hip was worn.

"Every time I walked it felt like somebody was sticking me with a needle," he recalls.

Five weeks after the Birmingham resurfacing procedure, Carraby said he was back on his beat as a patrol officer — with no pain.

After he gets his doctor's green light in June, Carraby says, he plans to start slowly training for his 12th marathon.

A new clinical study comparing the Birmingham hip system with total hip replacement will begin this year at the Baylor Motion and Sports Performance Center, says Fabian Pollo, PhD, director of orthopaedic research at Baylor.

Some of those studies use the VICON MX Motion Capture System, made up of 12 high-speed, high-resolution digital video cameras mounted on the walls in the lab. Up to 50 markers the size of a dime or smaller are placed from head to toe on a patient's body before they perform common tasks such as walking or stair climbing.

"The cameras can track the markers in three-dimensional space," Pollo says. "It's like having thousands of video cameras on the same object. Together they give us any view you want."


One study, initiated by Karen McCain, PT, is measuring the effects of a new acute rehabilitation program using body-weight support treadmill training for patients after stroke versus a more traditional physical therapy regime, Pollo explains. The lab measures the patient's walking ability six months after stroke.

"What we have found so far is tremendous — there is a very significant difference in how patients walk when comparing the programs," he says. "We believe and hope that this study will support the need for all acute rehabilitation programs for patients after stroke to consist of this new modality, which can make a profound difference in a patient's functional outcome."

An FDA clinical trial, headed up by James Brodsky, MD, a foot and ankle surgeon on the medical staff at Baylor, is looking at the effects of a new total ankle replacement system, Pollo says. Baylor is one of 10 centers across the country involved with the trial, the results of which were presented at the American Academy of Orthopaedic Surgeons in February. Pollo says the study should be published sometime next year in The Journal of Bone and Joint Surgery.

In addition to clinical research, doctors around North Texas use the lab to further evaluate patients with movement abnormalities. For example, a young girl with cerebral palsy was evaluated in the lab to determine which surgical procedure might best enable her to improve her ability to walk. The center also helps improve the performance of athletes and dancers.

A new center for bone and soft-tissue tumors opens this spring at Baylor Dallas. Called the Baylor Sammons Bone Tumor Center, it will coordinate access to orthopaedic oncologists on the medical staff at Baylor Dallas and will be staffed by a nurse practitioner.

Wynne Snoots, MD, an orthopaedic surgeon on the medical staff at Baylor Dallas who has chaired the bone and soft-tissue committee at Baylor Sammons Cancer Center for 20 years, says, bone tumors occur in a small patient population but the conditions are complex and difficult to diagnose.

"If a patient has a disorder, a mass, we have to figure out what it is," he says. Diagnosis often requires multiple levels of testing, including X-rays, magnetic resonance imaging (MRI), computed tomography (CT) scanners and biopsies to help determine what type of cells make up the mass and whether it is a benign cyst, an infection or a malignant tumor.

The latter is rare — there are just 8,000 such cases a year, Snoots says. But the majority of such malignant tumors are from a cancer in another part of the body that has metastasized into the bone. So a malignant bone tumor is likely to be just the beginning of a cancer diagnosis for patients, he says.

Having a center that can coordinate multiple types of specialty physicians and a spectrum of diagnostic tools enables all parties to communicate instead of requiring the patient to go from department to department until the root cause of the bone tumor is discovered, says Al Mollabashy, MD, who joined Baylor two years ago as the second orthopaedic oncologist on the medical staff. In September, a third orthopaedic oncologist will join the medical staff.

"By centralizing the point of entry for patients, we can collect data from testing and make them accessible for all the doctors to have a place to view and discuss them," says Mollabashy.

Most patients are referred to the center from other local orthopaedists who probably have not seen a bone tumor or do not feel comfortable treating it, Snoots says.

"A lot of physicians would go 30 years and never see it," he says.  : :


For more information about Baylor's orthopaedic programs, call 1-800-4BAYLOR for a physician referral or use our on-line physician directory.