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DESCRIPTION
The Effect of Tensile Strength Loss on Collagen Organization in Anterior Cruciate Ligament Grafts Post-Reconstruction Surgery. Team LEGS. ACL Injuries. http://www.youcanbefit.com/images/ACL%20tear.bmp. ACL Reconstruction. - PowerPoint PPT PresentationTRANSCRIPT
The Effect of Tensile Strength Loss on Collagen Organization
in Anterior Cruciate Ligament
Grafts Post-Reconstruction Surgery
Team LEGS
ACL Reconstruction
o In 2000, over 2 billion dollars were spent on about 175, 000 ACL reconstructions (Spindler and Wright, 2008)
o No consensus among surgeons on the ideal surgical/graft choices, fixation methods, etc.
o 3 Common Graft Types
Previous Studieso Graft degradation – tension loss in
the long-run after surgery (Arnold et al., 2005)
o Graft tension directly related to laxity of the knee (Friedrich et al., 1998)
o Crimping patterns of other tendon and ligaments as related to short term mechanical stress (Franchi et al., 2009)
Uniqueness of Project
o This study will analyze:
Three graft types
Performance of grafts under long term mechanical loading
Relation of performance to collagen fiber morphology using Optical Coherence Tomography (OCT)
Passive Knee Motion
Continuous passive knee motion emulator
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Research Questions
o How does the rate of tension loss differ among commonly used grafts during and after CPM?
o How do the differing morphologies of these graft tissues relate to their variable biomechanical performance?
Hypotheses
o Different grafts will have different rates of tension loss during CPM
o The microstructural organization of collagen is related to the rates of tension loss among the grafts
Methodology Overview
o Experimental Set-up Specimen
Preparation Experimental Groups
o Pre-Test Imaging OCT PLM
o ACL Reconstruction Tension transducer
o CPMo Post-Test Imaging
Experimental Set-Up
o 5 pairs of kneeso Experimental
Groups Control Experimental
o Specimen Preparation Harvest grafts Storage
Pre-Test Imaging
o Optical Coherence Tomography (OCT) “optical ultrasound” Instant, direct; no
sample preparation
o Polarized Light Microscopy (PLM) Transmit visible
light through sample Tissue fixation
Acknowledgments
o Dr. Adam Hsieho Hyunchul Kimo Dr. Yu Cheno Thomas Harrodo Rebecca Thomaso Courtenay Barrett
Timeline: Successes
Received $1500 from HHMI Undergraduate Research Fellowship
Contacted Maryland State Anatomy Board for specimen
Obtained lab & storage space Obtained Imaging Equipment Obtained testing equipment Contacted orthopedic surgeon Wrote thesis proposal
Timeline: Sophomore Year
Contact more experts, particularly surgeons Continue to collect/review relevant
literature/articles for final thesis Apply to more grants (NSF, ACCIAC) Design team website Start training for lab techniques: histology,
cutting tissue, MTS testing
Timeline: Junior Year
Data collection Present research/progress at the fall Colloquium Present poster at the spring Undergraduate
Research Day Develop an outline for the final thesis and
complete the first 3 chapters (Introduction, Literature Review, Methodology)
Continue to review literature Apply to more grants Submit paper for journal publication if possible Update website as needed
Timeline: Senior Year
Finish data collection and analysis Complete senior thesis Confirm at least 5 experts to sit on the panel
of reviewers/discussants Present and defend team thesis at the Team
Thesis Conference Final updates for website
Timeline: Senior Year
Finish data collection and analysisComplete senior thesisConfirm at least 5 experts to sit on
the panel of reviewers/discussantsPresent and defend team thesis at
the Team Thesis Conference
References
o Arnold, M. R., Lie, D. T. T., Verdonschot, N., de Graaf, R., Amis, A. A., & van Kampen, A. (2005). The remains of anterior cruciate ligament graft tension after cyclic knee motion. American Journal of Sports Medicine, 33(4), 536-542.
o Franchi, M., Quaranta, M., Macciocca, M., De Pasquale, V., Ottani, V., & Ruggeri, A. (2009). Structure relates to elastic recoil and functional role in quadriceps tendon and patellar ligament. Micron, 40(3), 370-377.
o Friederich, N. F., & O'Brien, W. R. (1998). Anterior cruciate ligament graft tensioning versus knee stability. Knee Surgery, Sports Traumatology, Arthroscopy, 6(1), S38-S42.