Improvements in Joint Replacement Enhance Quality of Life

When conservative medical treatment such as physical therapy, medication, and injections fail to preserve the natural function of a joint, patients often seek other options. They will find the most advanced surgical techniques are available Froedtert & The Medical College of Wisconsin Orthopaedic Surgery Clinic.

Medical College physicians take a multidisciplinary approach that focuses on surgical methods to treat joint pain and disorders while using the best available technology for optimal results. Physicians specializing in orthopaedic surgery perform reconstruction and joint replacement procedures in patients with advanced arthritis and other problems, including:

• Total hip replacements
• Total knee and other joint reconstructions
• Minimally invasive procedures

Orthopaedic surgeon James T. Ninomiya, MD, Associate Professor and Clinical Director of Research for the Department of Orthopaedic Surgery at the Medical College of Wisconsin, is one of the physicians who perform surgery on these patients. "The decision to proceed with joint replacement surgery is not one you would normally reach on your own. Your primary care physician and orthopaedic surgeon should assist you," according to Dr. Ninomiya. Patients are usually referred by their primary care doctors.

Less Invasive
Dr. Ninomiya and his colleagues study the newest techniques to bring the best care to patients. The surgeons are skilled in total joint reconstruction and revision and they often use minimally invasive surgical techniques to perform joint replacement surgery in patients who are appropriate for these approaches.

Minimally invasive surgery involves the use of small incisions or portals, in some cases using X-ray guidance, to help the surgeon place implants. The technique has been shown to work quite well and it offers substantial benefits to patients including decreased pain, faster recovery, and a more rapid return to their previous activity levels.

"With minimally invasive hip replacement, the results have been very encouraging," Dr. Ninomiya said. In fact, the surgical incisions are frequently less than three inches in length instead of 10 to 12 inches, as was the case with traditional hip surgery. Because there is less cutting of muscle, tendons and ligaments, patients recover more swiftly. They now are able to return home from the hospital after just a few days. "The average length of stay for a hip replacement is now two days compared to five days with traditional hip surgery," Dr. Ninomiya said.

Post-operatively, patients benefit from a team approach to recovery with a focus on wellness and rehabilitation. Because they have less blood loss and less pain with minimally invasive surgery, along with the use of new pain management technologies, patients often experience more rapid healing and reduced discomfort.

Implants Resemble Human Structure
One primary goal is to prevent patients from having to go through the trauma of surgery more than once. Therefore, surgeons use implants made of the best long-lasting materials available; in most instances a joint replacement should last at least 20 years or longer.

Artificial hip or knee joints typically are composed of two main materials, alloys of titanium and cobalt chrome. The metal implants are designed to allow bone to grow directly into the metal surface, providing solid fixation. Other techniques utilize cement for fixation.

A new material being used is called tantalum, a rare earth element, which is a soft, highly porous metal and can be woven into a spongy mass that looks much like a pad used to scour pots and pans. The stiffness of the metal compares to bone. "Tantalum is the most biocompatible metal known. You can tailor tantalum to match the mechanical aspects and load bearing functions of real bone. In fact, the cellular structure closely resembles that of bone," Dr. Ninomiya said.

Implants made of tantalum can approximate the physical and mechanical properties of bone more closely than other prosthetic materials. "When tantalum is used in implants, the body tends to grow around it and it becomes essentially a part of the person," Dr. Ninomiya explained. "We hope this will improve the longevity of implants, allowing them to last even longer without wearing out or becoming loose," he said.

Research and Development
More than 600 joint reconstruction and joint replacement procedures are performed each year at Froedtert & The Medical College Orthopaedic Surgery Clinic. "We see patients of all ages with a wide variety of diagnoses," noted Dr. Ninomiya. "Although most of our patients have arthritic conditions, we see and treat a much broader spectrum of hip and knee problems."

Arthroscopy of the hip is one such procedure. "This is a specialized technique that is not widely practiced, but is invaluable for younger patients who are not candidates for joint replacement surgery. It is a simple outpatient procedure that allows us to treat a variety of hip problems. This was previously impossible without the need for a large incision and associated hospitalization. Our results for these procedures have been very encouraging," Dr. Ninomiya said.

Physicians at the clinic see numerous complex cases for which they are continually developing new treatment techniques. "In addition to new longer-lasting joint replacement materials, we are looking into the development of new implant techniques," Dr. Ninomiya said. "We are also studying how the cells in human bone interact with the implants we now use. We are trying to understand the process from a cellular standpoint."

JoAnn Petaschnick
HealthLink Contributing Writer

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.