My main research interest is orthopaedic biomechanics, specifically, the biomechanics of bone growth and development and medical image based modeling of knee mechanics.
My current focus is on the influence of mechanical forces on long bone growth. For example, there are many pediatric conditions in which abnormal loads appear to cause alterations in normal growth patterns leading to joint deformities. If we can understand the relationships between bone growth and mechanical stresses, we may be able to clinically predict appropriate treatments for these pediatric orthopaedic disorders. Current studies include an experimental model altering mechanical forces in the knee, coupled with a finite element model of the proximal tibia growth plate and histological analysis of chondrocyte morphology. In order to better understand the influence of mechanics on bone growth, we must also understand the mechanical behavior of growth plate tissue - a complex material from an engineering perspective. This tissue is a very dynamic biological structure, which is also a highly organized composite exhibiting non-linear material properties. By systematically trying to model and measure its properties, we may also develop techniques relevant to the study of other engineering materials.
In addition to the complexity of the growth plate tissue, the anatomical structures of most bones and joints present challenges for engineering modeling. To address this challenge, our approach has been to develop finite element models based on three-dimensional medical images, such as those from micro-computed tomography or magnetic resonance (MR) imaging. Although these models may be automatically generated, they often require the development of new finite element analysis tools. Nonetheless, this approach allows us to easily and accurately define the geometry of the model, thereby focusing our efforts on other aspects of the problem, such as the material properties, or loading conditions. Current studies involve collaborations with the Departments of Radiology and Electrical and Computer Engineering to study the kinematics of the normal and ACL-deficient knee joint. One novel approach is the development of a device to apply anterior loads to the tibia within the MR scanner to study the role of the meniscus and other passive restraints in stabilizing the knee. MR images are automatically segmented to provide geometry and kinematic input for finite element modeling.