Ron N Alkalay, PhD
Staff Scientist II_BIDMC
Orthopedic Surgery
Orthopedic Surgery
Contact Information
| Office: | RN-0113 |
| Phone: | 617-667-5185 |
| Fax: | 617-667-4561 |
| Email: | ralkalay@bidmc.harvard.edu |
| Address: | 330 Brookline Ave; RN-0113
Boston, MA 02215 |
Major Research Theme
|
My main research focuses the relationships between the structure and function of the vertebra and the intervertebral disc, the mechano-biological mechanisms involved in the effect of aging and disease on the functional competence of these anatomical structures and the effect and/or efficacy of spinal instrumentation and new treatment modalities in treating spinal disease. This work has three main components; 1) Biomechanics of the osteoporotic spine: Vertebral fragility fractures in osteoporotic patients are the result of the vertebra inability to sustain functional loading associated with daily living. The effect of osteoporosis related changes in the structure and mechanical response of single vertebra and whole spinal units and the role of complex loading scenarios, both low and high rate, on their fracture pattern is being investigated. As part of this effort, the efficacy of novel treatment methods in restoring the structural competence of the failed vertebral segment and the effects on these methods on the short and long-term mechanical response of the treated and adjacent segments is being assessed. For this purpose, the use of computational models, derived from MRI and CT imaging, to non-invasively predict the change in the material and structural properties of the spinal segment and ultimately its failure, are being explored. 2) Biomechanics of intervertebral disk degeneration: Elucidating the complex interactions between the mechanical forces acting on the disc and the biological processes responsible for its function, are paramount to the understanding of the processes underlying the initiation and progression of Intervertebral Disk Disease (IDD). We are investigating the use of MR derived volumetric diffusion maps, ADC and tensor, in conjunction with custom built MR compatible computer controlled spinal loading device, to clarify the effect of age related degeneration on the structure and mechanical competence of human thoraco-lumbar discs. Future work will include experimental and computational models to better understand the relationships between diffusion and tissue degradation as a function of the change in the constitutive mechanical properties of the disc’s tissues. This work will further enable the development and assessment of novel tissue engineering and cell-seeded constructs, and biological substances in arresting, and hopefully reversing, the effect of IDD. 3) The role of nutrition deficit in the initiation of intervertebral disc degeneration. The intervertebral disc is the largest avascular organ in the body relying, to a large extent, on the diffusion of nutrients through the vertebral end-plates for its metabolic needs. With age, these osteo-cartilaginous structures undergo marked changes in their structure and composition resulting in significant disruption and loss of diffusion pathways. Using a high resolution micro-CT imager and a new algorithm for assessment of volumetric porosity and canal connectivity, we are investigating the effect of age and disc degeneration on the structure of the vertebral end plate and its associated sub-chondral bone. In conjunction with the MR diffusion protocol, we aim the highlight the role of end-plate degeneration in initiation and progression of disc disease. 4) Biomechanics of spinal fusion: the mechanical and functional design of spinal fixation devices and their affect on the structural response of the instrumented spine is paramount for establishing an optimal mechanical environment to promote the healing of bone fusion mass. In collaboration with clinical and industrial partners, the Laboratory is active in helping to characterize and improve both current clinical and prototype instrumentation designs with the view that a fixation system, able to minimize the relative motion between spinal segments, creates a biomechanical environment that facilitates arthrodesis. |
Publications
External Recognition
| 2002 “The Structural Augmentation of the Failed osteoporotic Spine: Rational and Efficacy” Harvard medical School, Orthopedic Grand Rounds, Boston, MA 2000 “Experimental Approaches to Spine Surgery: Internal Fixation Systems and Biomaterials” AO Foundation Davos, Switzerland, 2000 “Spine Surgery: Internal Fixation Systems and Biomaterials” Robert Mathys Foundation Bettlach, Switzerland. 2002 “The Structural Augmentation of the Failed osteoporotic Spine: Rational and Efficacy” Institute for Biomedical Engineering, ETH, Zurich, Switzerland 2002 “Advances In Vertebroplasty: Rational, Efficacy and Prediction of Stabilization Using Medical Imaging” Biomedical Engineering faculty, Technion, Haifa, Israel. |
Major Collaborative Activities
| 2002- Institute for Biomedical Engineering, ETH University, Zurich, Switzerland Lecturer: Orthopedic Bioengineering course. 2000- Division of Engineering and Applied Sciences, Harvard university. Course Instructor: Engineering Sciences 242. Orthopedic Biomechanics HST 595: Tutorial in medical engineering and medical physics. Presented during Fall of 2000, 2001 and 2002. Lecture title: Orthopedic Bioengineering. HST 20: Musculoskeletal Pathophysiology. Presented during Fall of 2000, 2001 and 2002. Lecture title: Soft tissue Biomechanics. |
Investigator's Lab Web Site
| Research Lab URL | None listed |
| Harvard Catalyst Site: | Alkalay Harvard Catalyst Web Site |
