U of R ME : Faculty-Lerner

Amy L. Lerner
Associate Professor of Mechanical Engineering, Biomedical Engineering & Orthopaedics
Hopeman 215
Phone: (585) 275-7847
Fax: (585) 256-2509
amlerner@me.rochester.edu

Ph.D., University of Michigan (1996), B.S., University of Delaware (1990)

Please also check my "personal web page" for further details about me and my research.

My main research interest is orthopaedic biomechanics, specificaally, the biomechanics of bone growth and development and medical image based modeling of knee mechanics.

My current focus is on the influence of mechanical forces on long bone growth. For example, there are many pediatric conditions in which abnormal loads appear to cause alterations in normal growth patterns leading to joint deformities. If we can understand the relationships between bone growth and mechanical stresses,we may be able to clinically predict appropriate treatments for these pediatric orthopaedic disorders. Current studies include an experimental model altering mechanical forces in the knee, coupled with a finite element model of the proximal tibia growth plate and histological analysis of chondrocyte morphology. In order to better understand the influence of mechanics on bone growth, we must also understand the mechanical behavior of growth plate tissue - a complex material from an engineering perspective. This tissue is a very dynamic biological structure, which is also a highly organized composite exhibiting non-linear material properties. By systematically trying to model and measure its properties, we may also develop techniques relevant to the study of other engineering materials.

In addition to the complexity of the growth plate tissue, the anatomical structures of most bones and joints present challenges for engineering modeling. To address this challenge, our approach has been to develop finite element models based on three-dimensional medical images, such as those from micro-computed tomography or magnetic resonance (MR) imaging. Although these models may be automatically generated, they often require the development of new finite element analysis tools. Nonetheless, this approach allows us to easily and accurately define the geometry of the model, thereby focusing our efforts on other aspects of the problem, such as the material properties, or loading conditions. Current studies involve collaborations with the Departments of Radiology and Electrical and Computer Engineering to study the kinematics of the normal and ACL-deficient knee joint. One novel approach is the development of a device to apply anterior loads to the tibia within the MR scanner to study the role of the meniscus and other passive restraints in stabilizing the knee. MR images are automatically segmented to provide geometry and kinematic input for finite element modeling.

Representative Publications

1. Effects of Childhood Obesity on Three-Dimensional Knee Joint Biomechanics During Walking.
Gushue, David L MS*; Houck, Jeff PT, PhD*+; Lerner, Amy L PhD*. Journal of Pediatric Orthopedics. 25(6):763-768, November/December 2005.

2. Rabbit Knee Joint Biomechanics: Motion Analysis and Modeling of Forces during Hopping. Gushue, D.L., Houck, J.R., and Lerner. A.L. Journal of Orthopaedic Research, 23(4): 735-742, 2005.

3. Stresses and Strains in the Medial Meniscus of an ACL-deficient Knee under Anterior Loading: A Finite Element Analysis with Image-Based Experimental Validation.Yao, J., Snibbe, J.C., Maloney, M.D., Lerner, A.L. J. Biomechanical Engineering (in press)

4. Fibronectin Matrix Polymerization Increases the Tensile Strength of a Model Tissue. Gildner CD, Lerner AL, Hocking DC. Am J Physiol Heart Circ Physiol, (2004), in press.

5. The use of sequential MR image sets for determining tibiofemoral motion: reliability of coordinate systems and accuracy of motion tracking algorithm. Lerner AL, Tamez-Pena JG, Houck JR, Yao J, Harmon HL, Salo AD, Totterman SM. J Biomech Eng, (2003), 125:246-53.

6. Case Study of a Giving Way Episode Experienced during a Stepping Down Task by a Subject with an ACL-deficient Knee. Houck JR, Gushue DL, Lerner AL, Yack HJ. Journal of Orthopaedics and Sports Physical Therapy, (2003), 33:273-82.

7. A System for Tracking Kinematics of the Human Knee with Sequential MR Image Sets: Reliability of Coordinate Systems and Accuracy of Motion Tracking Algorithm. Lerner AL, Tamez-Pena JG, Houck JR, Yao J, Harmon HL, Salo AD, Totterman SMS. Transactions of the Orthopaedic Research Society, (2002).

8. Analysis of Muscle and Joint Contact Forces in an ACL-Deficient Subject During a Giving Way Episode Occurring while Stepping Down, Gait and Clinical Movement. Gushue DL, Lerner AL, Houck J. Analysis Society transactions, Gait and Posture, (2002).

9. Viscoelastic effects in sonoelastography: impact on tumor detectability. Taylor LS, Richards MS, Moskowitz AJ, Lerner AL, Rubens DJ, Parker KJ. IEEE Ultrasonics Symposium Proceedings, (2001).

10. MRI for evaluation of early osteoarthritis in the rabbit knee. Thut DC, Lerner AL, Rubin SJ, Kwok WE, Puzas JE, Seo GS, Totterman SMS. Transactions of the Orthopaedic Research Society, (2001).

11. MR Imaging of the loaded normal and ACL deficient knee joint. Totterman SMS, Boyd KC, Houck J, Kwok WE, Salo AD, Lerner AL. ISMRM & ESMRMB Joint Annual Meeting, Glasgow, Scotland, (2001).

12. The induction of congenital spinal deformities in mice by maternal carbon monoxide exposure. Loder RT, Hernandez MJ, Lerner AL, Winebrener DJ, Goldstein SA, Hensinger RN, Liu CY, Schork MA. J Pediatr Orthop, (2000), 20:662-6.
13. Motion of the meniscus during passive flexion predicted by a 3D finite element model based on MR imaging. Zhang H, Totterman SMS, Perucchio R, Lerner AL. Advances in Bioengineering, (2000).

14. Investigation of the poroelastic behavior of the rabbit growth plate cartilage. Barthelat F, Fonck D, Lerner AL. Advances in Bioengineering, (1999).