Research

Research Opportunities

The program emphasizes both basic and clinical research. A full-time staff of more than 35 research professionals, including 9 PhDs, is constantly developing new cutting edge orthopedic projects. Rush is one of the best funded orthopedic departments in the country with multiple NIH grants as well as significant private funding. Collaboration with the talented research faculty enables residents to meet research requirements with high-quality translational and clinical research studies.

Areas of ongoing investigation include:

• Stress analysis of total hip and total knee prostheses
• Bone remodeling
• Biomechanics
• Materials analysis of orthopedic implants
• Development of new prosthetic devices
• Tissue engineering
• Bone biology
• Cartilage biochemistry
• Growth factors
• Intervertebral disc biology
• Clinical outcome studies

Clinical research takes place within the various orthopedic specialties, and is complemented by the basic science departments listed below.

THE RUSH ARTHRITIS AND ORTHOPEDIC INSTITUTE

The Rush Arthritis and Orthopedics Institute brings together world-renowned physicians and scientists dedicated to developing and providing effective diagnosis, treatment, education and research of all musculoskeletal disorders. The Institute consists of three Departments: The Department of Orthopedic Surgery (Chairman, Joshua J. Jacobs, M.D.), the Department of Biochemistry (Chairman, Ted Oegema, Ph.D.), the Department of Anatomy and Cell Biology (Chairman, D. R. Sumner, Ph.D.) and the Section of Rheumatology in the Department of Internal Medicine (Director, Joel Block, M.D.). Jorge O. Galante, M.D., D.Med.Sci., the previous Chairman of the Department of Orthopedic Surgery, is the Director of the Arthritis and Orthopedic Institute, and the Department and Section Heads are Co-Directors of the Institute. The Institute fosters close collaborative interactions. The majority of investigators in the three Departments are members of the Institute, and conjoint appointments between departments are common. The geographical proximity of the academic and attending clinicians to the basic scientist increases and guarantees the potential for consultation and collaboration. The Institute’s main strength and major role is to consolidate, integrate and solidify approaches, which, in amalgamation, will yield novel, significant research results that will ultimately improve patient care.

Because the intellectual environment provided by the diversity of professionals in musculoskeletal diseases currently in place is conducive to the generation and development of novel ideas and new scientists, the Rush Arthritis and Orthopedic Institute also focuses upon unique training programs. Over the last decade, the four academic entities comprising the Rush Arthritis and Orthopedic Institute have produced over 100 postdoctoral fellows specializing in the different disciplines represented by the Institute

SECTION OF BIOMECHANICS

Director, Raghu N. Natarajan, Ph.D.

The Section of Biomechanics in the Department of Orthopedic Surgery, headed by Dr. Natarajan, focuses on research of the spine and the lower extremities. Dr. Natarajan is director of the Computer Assisted Orthopedic Biomechanics Laboratory that focuses on finite-element-modeling (FEM) studies. Nozomu Inoue, M.D., Ph.D., Director of the Orthopedics Biomechanics Laboratory, oversees experimental biomechanical projects. Validation of the models constructed by Dr. Natarajan is typically performed by Dr. Inoue. Professor Natarajan has a conjoint appointment in Orthopedic Surgery and Mechanical Engineering at the University of Illinois at Chicago. Dr. Natarajan’s work on FEM of the spine is internationally recognized. Dr. Inoue is an Associate Professor in the Department of Orthopedic Surgery, who moved to Chicago in 2003. Dr. Inoue's research focuses on the biomechanics of the spine and the effects of degenerative changes of discs and facet joints on segmental instability. Currently, his major research areas are the influence of mechanics on disc degeneration and studies of the altered biomechanical properties of the spinal motion segment due to disc and facet joint degeneration.

SECTION OF BIOMATERIALS

Director, Joshua J. Jacobs, M.D.

The Section of Biomaterials in the Department of Orthopedic Surgery, under the leadership of Dr. Jacobs, focuses upon the study of interactions between permanent orthopedic implants and the in vivo environment. This includes the degradative processes of implant materials within the physiologic milieu as well as reactions within the host. Wear and corrosion of orthopedic implant materials are currently active topics of investigation as is the systemic distribution of particulate and ionic degradation products. A major activity of this Section is the analysis of implants and tissues retrieved from patients at the time of death. Such autopsy retrieval analyses provide important and unique information concerning the long-term performance of permanent implant materials. There is considerable collaboration with Dr. Glant’s section concerning the factors at the molecular and cellular levels which trigger maintain and regulate particulate-induced pathological bone resorption in patients with loosened total hip replacements.

SECTION OF BONE BIOLOGY

Director, Dale R. Sumner, Ph.D.

The Section of Bone Biology in the Department of Orthopedic Surgery headed by Dr. Sumner focuses upon functional adaptation of bone (e.g., how implant-induced stress shielding causes bone loss after total joint replacement), enhancement of bone regeneration in the context of cementless fixation of total joint replacement and the role of bone in the initiation and progression of osteoarthritis. The bone remodeling studies include animal models and engineering analyses to aid in understanding underlying mechanisms. Enhancement of bone regeneration by members of the transforming growth factor-? (TGF-?) superfamily is under active investigation. The role of bone in osteoarthritis is being studied in living human subjects, animal models, and human autopsy samples. All of these studies depend upon significant interactions among the five research sections within the Department of Orthopedic Surgery (e.g., with Drs. Natarajan and Wimmer of the Section of Biomechanics on stress analyses and gait analyses, respectively), collaborations with Department of Anatomy and Cell Biology faculty and other members of the Arthritis and Orthopedics Institute in the Department of Biochemistry and the Section of Rheumatology, and joint projects with colleagues from outside the institution. Since May of 1997, Dr. Sumner has served as the Chairman of the Department of Anatomy and Cell Biology at Rush and this appointment has provided another mechanism for recruiting new investigators both from within the institution and from outside the institution to focus upon issues related to musculoskeletal injury and repair.

SECTION OF MOLECULAR MEDICINE

Director, Tibor T. Glant, M.D., Ph.D.

The Section of Molecular Medicine in the Department of Orthopedic Surgery is under the leadership of Tibor Glant, M.D., Ph.D., D.Sc. Dr. Glant holds a conjoint appointment in the Department of Biochemistry as a Professor. Dr. Glant’s major interests and research directions are: (i) the study of the immunopathology of extracellular matrix components; (ii) the autoimmune mechanisms of rheumatoid arthritis and in corresponding animal models; (iii) the signaling mechanisms which determine antigen specific Th1 and Th2 responses in autoimmune diseases including diverse effects of altered peptide ligands of arthritogenic epitopes; (iv) the antigen presentation mechanisms in normal and pathological (autoimmune) conditions; (v) the molecular polymorphism/diversity and disease-associated splicing variants of core proteins of various cartilage matrix molecules; (vi) the functional and pathophysiological aspects of domains of cartilage aggrecan, link protein and small proteoglycans, including the targeted disruption (knockout) and overexpression of these macromolecules; (vii) identification of (autoimmune) arthritis susceptible gene(s); (viii) the potential gene and immunotherapeutic interventions in autoimmune/inflammatory diseases, and (ix) the cellular and molecular (signaling) mechanisms of pathological bone resorption in failed total hip arthroplasties. All of these major directions involve basic molecular biology, biochemistry, cell biology, signal transduction and immunology studies. Dr. Glant, will be invaluable as a consultant on molecular biology approaches and techniques.

SECTION OF TRIBOLOGY

Director, Markus A. Wimmer, Ph.D.

The Tribology group, headed by Dr. Wimmer, investigates wear, friction and lubrication of artificial and natural joints. The goal is to expand the body of traditional orthopedic knowledge through bioengineering practices and to investigate new ideas that show potential for improving the physical capabilities of those who suffer from musculoskeletal ailments. To advance these technologies, Dr. Wimmer directs three major bioengineering programs. First, defining natural and artificial joint duty cycles leads to an in-depth understanding of joint kinematics, daily human activities, and the behavior of artificial joints under simulated conditions. Second, advancing orthopedic materials improves the wear characteristics of implanted components and increases their longevity. Last, the application of tribological approaches to tissue engineering provides natural tissues for the repair of articular cartilage defects.