MU surgeon provides latest technology in knee arthritis surgery

B. Sonny Bal, M.D., an orthopaedic surgeon and joint-replacement specialist at MU Health Care is utilizing innovative methods to treat patients with osteoarthritis of the knee joint.

new uni-compartmental knee replacement (UCKR) component designed by Bal in collaboration with surgeons in Florida and Pennsylvania has reduced the need for total knee replacement (TKR) surgeries in many arthritic joints. The UCKR is a partial knee replacement and is suited for patients whose arthritis is localized to a portion of the knee joint. In contrast, total knee replacement is a more extensive procedure that replaces all the cartilage inside the knee joint, and it is appropriate for patients with widespread destruction of cartilage from arthritis.

The patients who can benefit from a UCKR procedure are those who have osteoarthritis confined to one half of the knee joint, either the inside of the knee or the outside," said Bal. "It is modular surgery, in the sense that the surgeon can address the diseased part of the joint and avoid removing normal cartilage, and supporting ligaments that could still serve the patient. It may be the preferred alternative for those patients who are experiencing considerable knee pain, but who do not have the extensive arthritis that would warrant a total knee replacement."

The partial knee replacement is a much less invasive procedure, compared to a TKR. This procedure minimizes bone removal, spares the knee ligaments, avoids major blood loss, and because of the component's small size, the operation can be done through a much smaller incision compared to that required for a complete knee replacement. The length of hospital stay and the need for physical therapy are reduced dramatically, with pain relief comparable to a TKR.

The components that we designed can be implanted with a minimum loss of bone. The part that attaches to the femur has a unique design feature that facilitates movement of the patient's kneecap, with a more natural feel," said Bal. "In addition, the instrumentation has been refined, which allows for a superior fit using a small incision."

The UCKR surgery typically takes less than an hour, and requires an incision that is about three inches long. After surgery, patients usually stay in the hospital for one to two days. While regaining full mobility can take about two weeks, patients can put full weight on the leg the day after surgery.

Bal is also an investigator in a clinical trial with 15 other medical centers in the United States, implanting zirconia ceramic femoral components in total knee replacements. Ceramic components in knee replacement are an innovative development that may prolong the service life of knee replacement surgery because of their durability and reduced wear. Earlier this year, Bal completed the initial feasibility study that was required by the FDA to approve this clinical trial that is presently under way at MU Health Care.

"This may be of interest to knee replacement candidates because the ceramic materials used in the bearings of artificial hip and knee replacements have demonstrated less wear, which could result in a longer-lasting implant," Bal said. "Existing clinical and laboratory data suggest that in selected patients, ceramic bearings may have superior long-term performance. As such, this advancement in the science of joint replacement is of particular relevance to the young, active, and heavy patient who would place the highest demand on an artificial joint."