Orthopedics and Biomechanical Engineering

Orthopedics and Biomechanical Engineering

Keith Baar, Assistant Professor

CBS: Neuro, Physio & Behavior

Cranial (or anterior) cruciate ligament (CCL) rupture is one of the most common orthopedic conditions in dogs. CCL rupture results in instability within the stifle that initiates a downward spiral of synovitis, articular cartilage degeneration, and eventually osteoarthritis. Currently, intracapsular techniques replace the ruptured CCL with an autologous tissue or synthetic graft. However, these grafts aren't strong enough and so the repair is usually augmented with some form of extracapsular reconstruction. We have developed a viable alternative that should be strong enough on its own to return joint stability. Our unique method uses stem cells to engineer a ligament in vitro. Our current research is finalizing the optimal growth factor cocktail and mechanical intervention before beginning our implantation trails.

Blaine Christiansen, PhD

Musculoskeletal adaptation, post-traumatic osteoarthritis, bone, biomechanics

UCDMC Department of Orthopaedic Surgery

Dr. Christiansen is a faculty member in the Department of Orthopaedic Surgery and the Biomedical Engineering Graduate Group. His research investigates the adaptation of musculoskeletal tissues, particularly bone and articular cartilage, to the mechanical environment, injury, aging, or disease using small animal models. The musculoskeletal system has an innate ability to repair and optimize itself based on the mechanical demands placed on it. By studying this adaptation, we are able to uncover the underlying mechanisms that contribute to diseases such as osteoporosis and osteoarthritis. Musculoskeletal adaptation is quantified in these models using advanced imaging techniques, histology, and mechanical testing. Current projects in the Christiansen lab include investigation of biomechanical and biological mechanisms contributing to the development of post-traumatic osteoarthritis, investigation of systemic bone loss following bone fracture or other musculoskeletal injury, and determining the effect of peripheral sensory nerve function on bone metabolism and bone adaptation to the mechanical environment.

Please visit Dr. Christiansen's website at: http://www.ucdmc.ucdavis.edu/search/faculty/christiansen

Contact Dr. Christiansen at bchristiansen@ucdavis.edu

Derek Cissel

Research interests: Cartilage, biomechanics, diagnostic imaging

VM: Surgical & Radiological Sciences

Dr. Cissell is a veterinary radiologist specializing in equine diagnostic imaging, magnetic resonance imaging (MRI), and computed tomography (CT). His laboratory aims to improve the diagnosis and treatment of joint disorders by: (1) developing biomedical imaging techniques to detect early cartilage injury; (2) predicting tissue function via non-invasive imaging; and (3) applying imaging for assessing cartilage repair. The lab is engaged in research characterizing temporomandibular joint disorders in animals, using MRI to evaluate cartilage, and developing novel imaging protocols for imaging animal joints.

Please contact Dr. Cissell at ddcissell@ucdavis.edu for more information.

Damian Genetos, PhD

VM: Anatomy, Physiology and Cell Biology

My research focuses upon the skeletal system, its development, and the mechanisms whereby it adapts to changes in the local microenvironment.

The skeleton responds to changes in applied loads. Under conditions of reduced use (as occurs during spaceflight or prolonged bed rest), bone is resorbed; when excess loads are applied, more bone is made, to reduce the stress placed upon them. Osteoblasts, the bone-forming cells, are responsive to a variety of stimuli, and we have begun to characterize the downstream signaling events involved in the conversion of an external load into a bone-forming response. This process is termed mechanotransduction. Current areas of research include purinergic signaling and epigenetic regulation in response to in vitro loading.

I also examine how pericellular oxygen tension affects bone cells bone turnover, and bone repair. The oxygen tension within bone can vary under certain circumstances; for example, fracture and limb unloading promotes hypoxia in osteocytes. In collaboration with a colleague at Lawrence Livermore National Laboratory, we are examining the influence of altered oxygen tension perception upon Wnt and BMP signaling in mice.

Additionally, we study how aberrant bone formation can cause pathologic conditions, such as vascular calcification.

Please visit Dr. Genetos's website at: http://faculty.vetmed.ucdavis.edu/faculty/dgenetos/

J. Kent Leach, Ph.D.

Tissue engineering, bone, biomaterials

Research in the Leach laboratory is primarily in the broad area of TISSUE ENGINEERING. Within our research program, we seek to engineer functional replacement and temporary bridge tissues while also developing model systems to study physiological and pathophysiological tissue formation. We initially develop many of our projects with an eye toward bone tissue engineering, and these findings are subsequently applied to other areas of tissue repair including cartilage and cardiovascular engineering, as well as wound healing.

All projects in the lab are linked by the hypothesis that combinatorial approaches to tissue formation are superior to individual stimulation. More specifically, successful tissue engineering approaches will be realized upon the proper spatial and temporal presentation of cells, signaling molecules, biomaterials, and mechanical stimulation.

website: http://bme.ucdavis.edu/leachlab/

Denis Marcellin-Little, DEDV

VM: Surgery & Radiology

Service Chief, Small Animal Orthopedic Surgery

Dr. Marcellin-Little is a veterinary orthopedic surgeon with experience in 3-D reconstruction and analysis of musculoskeletal structures. His clinical focus is on total joint replacement and on the management of bone deformities. He has mentored more than 30 DVM students in STAR and STAR-like programs. 

To contact Dr. Marcellin-Little, please email djmarcel@ucdavis.edu

Mike Mienaltowski, DVM, Ph.D.

Tendon repair, stem/progenitor cell biology

College of Agriculture and Environmental Sciences (See also: Biochemistry/Cell Biology, Genetics/Genomics and Translational Research)

My primary research interests include:

(1) the development, maturation, and repair of musculoskeletal connective tissues like tendon and ligament

(2) cellular mechanisms behind broiler muscle pathology

(3) the roles of the microbiome in proper gut transition in foals from birth to weaning.

In my musculoskeletal research projects, I am particularly interested in how differences in niche affect cells within the environment in growth and repair. Moreover, I am interested in the physiology of usage and elite performance as well as pathophysiology from over-usage, acute and chronic injury for all musculoskeletal tissues on all species as they might be related to use, environment, or genetics, and as they might be related to the manipulation of niche and collagen regulation genes. Furthermore, because the proper development of the musculoskeletal system  depends greatly upon proper foal growth and foal growth subsequently depends upon appropriate nutrition, I am interested in understanding how gut microbes facilitate healthy gut transitions in the foal.More information can be found at: http://animalscience.ucdavis.edu/faculty/mienaltowski/index.html

Contact information for Dr. Mienaltowski:  e-mail: mjmienaltowski@ucdavis.edu

Brian Murphy, DVM, PhD

VM: Pathology, Microbiology & Immunology (see also: pathology/virology)

I am an anatomical pathologist with an interest in viral pathogenesis.   My laboratory has a feline model of lentiviral latency and we our examining the mechanisms of viral persistence in the FIV-infected cat model.   We also have projects exploring FIP pathogenesis and a collaboration with Gilead Sciences to identify pharmacologic agents that will block replication of the FIP virus.  I am also interested in retroviral promoter function and how specific promoter sequences relate to viral tropism and pathogenesis. 

Please visit Dr. Murphy's website at: http://faculty.vetmed.ucdavis.edu/faculty/bmurphy/

Susan Stover, DVM, Ph.D., Dipl ACVS

JD Wheat Veterinary Orthopedic Research Laboratory 

Dr. Stover's research focuses on the diagnosis, treatment, and prevention of musculoskeletal injuries, predominantly in horses, but also in small animals. She specialized in equine surgery and lameness until devoting full time to research on musculoskeletal biomechanics and on the causes (epidemiology), development (pathology), and prevention (biomechanics) of musculoskeletal injuries in equine athletes. Current research focuses include 1) the effects of race surface and horseshoes on limb biomechanics (and thus risk for injury), 2) Racing Injury Prevention Program, and 3) investigating a systemic bone fragility syndrome that causes pathologic fractures in horses.

Her laboratory supports the research of undergraduate, professional (DVM), graduate, and postdoctoral students, as well as, clinical residents.  LAB:  Rm 1305 VM3A

Please visit Dr. Stover's website at: http://www.vetmed.ucdavis.edu/vorl/index.cfm

Aijun Wang, PhD

UC Davis Medical Center, Department of Surgery (see also: Translational Research, Biochemistry, Surgery)

My name is Aijun Wang. I am an assistant professor at the Department of Surgery, School of Medicine. My research interests center on engineering stem cells and biomaterials to develop novel regenerative medical therapies, especially surgical treatments for congenital anomalies. Since my employment as Co-Director of the Surgical Bioengineering Laboratory and an Assistant Professor at the University of California Davis School of Medicine in 2012, my lab has successfully combined tissue-engineering technologies with the most advanced fetal intervention, and developed novel biomaterial and stem cell-based treatments (including nanofibrous materials, fetal membrane, decelluarized extracellular matrix, iPSC-derived stem cells, placenta-derived stem cells) for devastating structural and genetic birth defects, such as spina bifida, hemophilia and congenital diaphragmatic hernia. Currently, we are extensively using the mouse, rat, guinea pig, rabbit and sheep experimental models to develop novel regenerative therapies. We are also adapting these novel therapies we developed in the lab for the treatment of naturally occurring diseases in companion animals.

Please visit Dr. Wang’s website at http://www.ucdmc.ucdavis.edu/surgery/research/wang.html or the  website  for  the  Surgical Bioengineering Laboratory at  http://www.ucdmc.ucdavis.edu/surgery/research/index.html

Contact Dr. Wang: aawang@ucdavis.edu.

Clare Yellowley

Department of Anatomy, Physiology and Cell Biology

Dr Yellowley is a orthopedic cell biologist in the department of Anatomy, Physiology and Cell Biology in the Vet School. We are focused on normal bone physiology, bone pathology (fracture) and bone tissue regeneration. We employ both in vitro cell culture models, in vivo fracture models and genetically modified mice. Our current projects involve assessing the influence of mechanical load and oxygen availability on bone cell signaling, the role of hypoxia-inducible transcription factors in osteocytes, the ability of stem cells to enhance fracture healing and muscle bone interactions.

Please visit Dr. Yellowley's website at: http://faculty.vetmed.ucdavis.edu/faculty/cyellowley/