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 Studies o 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)
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
Post-Test Imaging o OCT Crimp period o PLM Crimp angle Crimp arc-length Crimp base length
Acknowledgments o Dr. Adam Hsieh o Hyunchul Kim o Dr. Yu Chen o Thomas Harrod o Rebecca Thomas o 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 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
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.