Total Joint Replacement Program

Educational Grant from Smith & Nephew Back to Top

Educational grant from Smith & Nephew supports residency joint rotation program.

Smith & Nephew Advanced Surgical Devices has demonstrated its commitment to advancing medical research, innovation, and education with an educational grant to The Campbell Foundation in support of education and research in adult reconstruction.

Smith & Nephew's grant to the Foundation will help sponsor the Total Joint Rotation of the Campbell Clinic-University of Tennessee Orthopaedic Residency Program. The grant will help underwrite the cost of educating 24 Campbell Clinic residents in the subspecialty area of joint replacement.

Dr. Terry Canale, President of The Campbell Foundation, said, "This grant demonstrates that Smith & Nephew recognizes the vital role highly-trained physicians play in the healthcare continuum. We look forward to working with Smith & Nephew to take orthopaedic education to new levels of excellence while offering our patients hope for better, more active lives."

The Campbell Clinic-University of Tennessee Orthopaedic Residency Program enables aspiring orthopaedic surgeons to develop and refine their clinical, surgical, and research skills. The accredited, five-year program has a total of 40 full-time residents and ranks in the top eight percent of orthopaedic residency programs in the nation. Nearly 500 medical school graduates vie for the eight positions open each year.

Residents in the program participate in the total joint rotation in their second, fourth, and fifth years. During each rotation, residents spend approximately 50 percent of their time in clinical activities and 50 percent in surgical duties, a practice that allows them to experience continuity of patient care from initial exam and evaluation, through surgical or non-surgical treatment and post-operative rehabilitation.

During the total joint rotation, residents are instructed and mentored by faculty members from the Campbell Clinic staff who have interest and training in the subspecialty of total joint replacement. Physicians who serve on the total joint rotation faculty include Dr. Andrew Crenshaw, Dr. John Crockarell, Dr. James Guyton, Dr. James Harkess, Dr. Robert Heck, Dr. David LaVelle, Dr. Anthony Mascioli, and Dr. Patrick Toy.

The residency program benefits significantly from monthly Journal Club meetings during which the teaching staff and residents review and discuss articles from the Journal of Bone and Joint Surgery and subspecialty journals. Dr. John Crockarell plans to start a Total Joint Journal Club using articles from the Journal of Arthroplasty for discussion. The educational grant helps provide each resident with an individual subscription to the Journal of Arthroplasty. A number of major books and electronic resources will also be added to the Total Joint Library, including the Orthopaedic Knowledge Update series from the American Association of Orthopaedic Surgeons.


Computer Knee Simulator to Improve Total Knee Replacement Outcomes Back to Top

Modern medicine, for all its miracles, is still an inexact science in many areas. Efforts to make it less so, generally taken place in research labs and facilities across the world, where doctors, engineers, and highly specialized experts work together conducting trials and studies while recording and measuring outcomes. Ongoing research is what advances medical knowledge and skill, and it gives mankind the miracles that increase functionality and save lives.

Dr. William M. Mihalko, Associate Professor, and Dr. John Leicester Williams, Affiliated Professor of Biomedical Engineering at UTHSC from the University of Memphis, are two such researches working to develop a virtual knee simulator that will allow surgeons to perform total knee replacement surgeries, known as a total knee arthroplasty (TKA), on an individualized, patient-by-patient basis. Mihalko and Williams

Dr. Mihalko (left) and Dr. Williams (right) is developing the computer model with the ultimate goal of enabling surgeons to align the knee implant more accurately in accordance with the patient's specific anatomical characteristics for the best results and longest implant wear. Dr. Mihalko is holding a computer-navigated pointer, which allows surgeons to record specific anatomical landmarks during surgery. In his life hand, he holds the upper portion of a total knee implant. By allowing the computer to track the implant and a patient's own anatomy, a customized approach to the surgery is being developed.

"Developing a computer-based model is important because right now we fit every patient into just one set of parameters in the operating room," said Dr. Mihalko, a Campbell Clinic total joint surgeon. "In other words, we align and insert our implants the same way, regardless of the patient's sex, size, age health, or other individual characteristics."

That means that a football linebacker's artificial knee is implanted and positioned the exact same way as a 98-pound ballerina's. It is Mihalko's and Williams's theory that if total knee replacements are inserted in a custom manner to fit the patient's individual characteristics, the percentage of TKAs that meet patient satisfaction will go up.

"We're trying to come up with a tool for the surgeon that helps him predict on an individual basis how a knee implant will function given anatomical variations in soft tissue, muscle forces, support, center of rotation, and those types of things," said Mihalko. "Currently, when we put an implant into a patient, we often have to just visualize some of those things- just take our best guess."

"And a patient won't know if his implant is suitable until he's healed-three months later!" added Dr. Williams. "It's like trying to fit an unconscious person with a pair of shoes. You know how to place the shoe and lace it up, but you really won't know how those shoes will fit-and whether the patient will be comfortable in them-until the person is well enough to walk in them himself."

The two researchers' collective goal is to develop a tool to use in the operating room, where the surgeon will enter the patient's specific anatomical parameters, and a computer model will instantly digitize where that particular patient's ligaments are attached, where his muscles insert around the knee, how his particular body makeup may affect the knee's performance, and other factors critical to a successful patient outcome. And developing such a tool is not easy.

"Our biggest problem is that the knee is such a complex and variable system," said Dr. Mihalko. "Coming up with a computer model that takes into account all of the thousands of variables and all of the ways you can move your knee is challenging to say the least."

Dr. Williams has worked for several years developing simulation software for a computer model that helps the researchers determine how a knee will react when they change implant positions, tighten ligaments, exert muscle forces, and subject the knee to various motions. Those computer predictions are then compared to an actual implanted knee.

"We use a mechanical simulator in the lab to test specimens to determine if the computer's predictions are accurate," said Dr. Mihalko. "In other words, do the two match up? Is what we're predicting in the computer model actually taking place with the real knee implant? If not, we adjust the computer model accordingly and repeat the process."

The mechanical simulator moves knee specimens into squats, lunges, flexes, and extensions. The researchers analyze how the implant reacts while it's still inside the knee, and then they physically remove the implant for further analysis.

"By conducting research this way, we can try to determine what was happening inside the knee while the implant is still in place," says Mihalko. "What factors affected the implant that could make it fail? This implant retrieval method helps us tweak the program and make it more accurate and helpful."

The biggest challenge facing the two researchers is funding. "I spend one0third of my time just writing grants," said Dr. Mihalko. "And this is important research. This type of analysis will introduce a personalized-medicine approach to total knee arthroplasty and allow the best change for the patient to have the longest-functioning, most successful implant during his lifetime. That's also important to those who receive the 600,000 total knee replacements every year."

Source: The Campbell Foundation Momentum

Total Knee Replacement Q & A Back to Top

with Dr. William M. Mihalko

What is a total knee arthroplasty?
It's where damaged cartilage and bone are surgically removed from the surface of the knee joint and replaced with a man made implant made of metal and plastic.

Dr. William M. Mihalko Dr. William M. Mihalko

What causes a person to need a total knee replacement?
The No. 1 cause is osteoarthritis. Various types of injuries can also lead to the need for a knee replacement.

Of the things we can control, what causes the most damage to our knees?
In overweight people, every extra pound of weight places four to five pounds more force on the knee. It's a magnified force. So if a person loses 20 pounds, the knees see 100 pounds less force and they'll last longer. Playing contact sports can also shorten the life of the knee.

How long do knee replacement last?
The average for knee replacement recipients is 65 years old, and the implant should last long as that patient is alive.

What happens when a replacement fails?
The patient feels pain, or the joint is unstable, meaning the patient has to again use a can or a walker. Ten to fifteen percent of knee replacements do not meet patient satisfaction. That is a statistic that our research aims to improve.

Contact Us

Department of
Orthopaedic Surgery and Biomedical Engineering

1211 Union Ave. Suite 520
Memphis, TN 38104

Pat Goedecke
Phone: (901) 448-5879
Fax: (901) 448-3208

Campbell Foundation Education Office
1211 Union Ave Suite 510
Memphis, TN 38104

Resident Program

Renee Poe
Education Coordinator
Phone: (901) 759-3275

Fellowship Program

Rosemary Bankston
Education Coordinator
Phone: (901) 759-3274