Orthopaedics and Biomechanics

Key Researchers

picture of MMRF researcher Dr. Joan BechtoldJoan Bechtold, PhD, earned her degree in Mechanical Engineering from the University of Minnesota. She is the Director of the Biomechanics Laboratory at Hennepin County Medical Center (HCMC). In addition, she is a Professor of Medicine at the University of Minnesota and Director of Orthopaedic Research at the Excelen Center for Bone and Joint Research and Education.


picture of MMRF researcher Dr. Andrew SchmidtAndrew H. Schmidt, MD, completed his Medical Degree at the University of California – San Diego. He is the Chief of HCMC’s Orthopaedic Surgery Department and a Professor of Medicine at the University of Minnesota. He has also been President of the Orthopaedic Trauma Association.

In medicine, the bones, muscles, joints, tendons, and ligaments are referred to collectively as the musculoskeletal system. Ailments of this system are some of the most common medical problems that people face. Musculoskeletal problems can arise from trauma, injury, and disease, and affect people from all walks of life. The American Academy of Orthopaedic Surgeons estimates that one in seven Americans suffer from an orthopaedic injury or disease each year, resulting in $215 billion in healthcare costs.

Researchers in the field of orthopaedics and biomechanics study the musculoskeletal system and its problems. At HHRI, this work is conducted in the Orthopaedic Department by Andrew Schmidt and the research staff and by Joan Bechtold.

Orthopaedic Department

Dr. Schmidt is a leading researcher in musculoskeletal trauma and its complications. He is the site Principal Investigator for the Major Extremity Trauma Research Consortium (METRC) funded by the United States Army Medical Research Acquisition Activity, also collaborating with the prime awardee, Johns Hopkins University that brings many civilian trauma centers together to work with military surgeons to study battlefield injuries and improve care for injured military personnel. The results of this research are also applied to improve treatment of civilian trauma.

Biomechanic Laboratory

Through Dr. Bechtold’s direction, the lab develops and tests specialized materials and devices for improved fracture care and joint replacement. Many new and improved surgical devices and technologies have been developed, tested, and optimized for clinical use through their research efforts. These include new devices and procedures for spinal injuries and hip and knee replacements, new devices to treat fractures, and best practices for managing orthopedic infections.

Back and spine injuries are the most common orthopaedic impairment. The lab is evaluating methods for treating spinal injuries, including procedures that fuse the spine and others that restore motion to the spine. Using real-time 3-D cameras, they examine the motions of the spine under varying treatment scenarios. Using this information, they hope to determine which procedures produce favorable conditions in patients.

Joint replacement has become a routine procedure as medical technology has improved the performance of artificial joints. However, significant improvement is needed to reduce the number of revisions (replacements of artificial joints) that need to be performed. Dr. Bechtold is collaborating with researchers from Aarhus University in Denmark to examine novel bone/implant interfaces that may improve outcomes for revision joint replacement. They are looking at different materials and surface micro-textures that could improve bone’s adhesion to the implanted device, which should help reduce the need for revisions.

To treat bone fractures, surgeons often implant a plate and screw it on to the bone to increase stability and promote healing. Varying the location of the screw/bone interface can impact how quickly the fracture heals. The lab is looking at which locations result in the fastest healing. They are also examining the impact that special screws, called locking screws, have on fracture healing, and seek to optimize their number and location. Using locking screws near the fracture appears to increase stability and may thereby promote healing, however, their cost is higher and they may cause unwanted difficulties during removal.

The lab is researching how growth factors and antibiotics can speed the healing process for orthopaedic injuries. Results are promising and show that using growth factors and antibiotics can reduce healing time and allow physicians to remove implanted devices sooner.