Walker Lab: Projects

Etiology of Osteoarthritis

We are carrying out experiments on the loaded knee, in normals and in patients with early osteoarthritis (OA), using MRI imaging, to investigate the possibility that a dysfunctional meniscus leads to overstressing and failure of the articular cartilage.

Early Intervention Treatment

We are developing a treatment for symptomatic early OA, with the criteria of resurfacing only the worn areas of cartilage, retaining the remaining joint structures, feasible by small-incision surgery, simple low-cost instrumentation, and durable. A specially constructed wear test machine, and finite-element analysis are being used to design the optimally shaped components.

Unicompartmental Knee Replacement (UKR)

Following studies which showed that more cases of arthritis could be treated with a unicompartmental replacement, we are carrying out further development of the MAKO system, by testing new modular components in our up-and-down crouching machine, and by applying finite-element analysis to the formulation of new components and fixation methods for enhanced durability.

Total Knee Replacement (TKR)

Although TKR is very successful both in terms of function and durability, function may still not be optimal for the more active patients. We are developing a new "Guided Motion TKR" which is designed to restore the "medial stability-lateral mobility" characteristics of the anatomic knee. Possible designs are being tested in comparison with currently used cruciate retaining and sacrificing designs, using special-purpose machines.

Effectiveness of Rehabilitation

A rapid return to normal function after TKR is a major advantage, for which studies are ongoing. Foot-to-ground pressures and extension strength are used as indicators to determine whether the Early Discharge Program helps or hinders the speed of recovery. More recently we have initiated a study using accelerometers to measure knee stability, which would have extensive application to the knee after injuries and after various treatments.