Research

Dr. Langohr’s research is in the general area of solid mechanics, and includes the design and analysis of mechanical components, the tribological assessment of interacting surfaces, and the finite element analysis of mechanical and biological structures.

One of the main components of Dr. Langohr’s research interests includes the tribological assessment of orthopaedic implants using both computational and in-vitro methods. The wear of joint replacement devices in-vivo is of paramount importance, since the failure of these devices once implanted requires revision surgery to replace. Furthermore, the articular wear debris remains in the joint space and can cause adverse reactions and bone resorption. The wear performance of these devices can be assessed using in-vitro joint simulator wear testing, which imparts similar loading and motion conditions to what would be observed in-vivo. Dr. Langohr’s lab includes several such joint simulators permitting the wear analysis of shoulder, elbow, hip, and knee implants. These devices can also be analyzed using finite element computational methods to assess the contact mechanics between the articulating surfaces of such devices. The knowledge gained from in-vitro and in-silico testing of such devices can aid in the development and improvement of current joint replacement technologies.

Finite element analysis can also be used to assess the response of mechanical structures to applied loads. Dr. Langohr’s research also includes the investigation of the load transfer from orthopaedic joint replacement implants to bone. Replacing bone with a stiff metallic implant alters bone loading, which can result in atrophy. Finite element analysis can be used to assess the magnitude of the change in bone stress following joint reconstruction, and can help improve the design of components such as humeral and femoral stems such that pre-operative bone loading is preserved to prevent atrophy.

Projects:

  1. In-vitro wear testing of interacting surfaces, including orthopaedic joint replacement implants.
  2. The computational modelling of articular contact mechanics, including total and hemiarthroplasty joint replacements, as well as intact cartilaginous surfaces.
  3. Finite element analysis of the load transfer from orthopaedic implants to bone, and the resulting impact on bone stress compared to intact.