Ralph, Max2016-10-202016-10-202016-06https://hdl.handle.net/1794/2035947 pages. A thesis presented to the Department of Human Physiology and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, Spring 2016.Background. Total knee arthroplasty (TKA) is becoming increasingly common in the United States. Over 3.4 million older US adults are predicted to undergo primary TKA annually by the year 2030, and over 4.5 million Americans already live with a primary knee prosthesis. Immediately following surgery, significant muscle atrophy occurs, compromising strength and functional mobility of the patient. Essential amino acid supplementation has been proven to mitigate post-operative muscle atrophy in TKA patients at the level of whole muscle, and this strategy has the potential to attenuate individual muscle fiber atrophy as well. Metl,ods. Data collection for this Honors Thesis is part of an ongoing double-blind, placebo-controlled randomized clinical trial. This Honors Thesis will present blinded raw data from 14 patients who have completed the study. Patients are randomized to ingest either 20 g of EAAs or placebo twice daily between meals for 1 week before and for 6 weeks after TKA. At baseline, 2 and 6 weeks post-TKA, an MRI was performed on each leg to measure muscle mass over time. In addition, each subject had bi-lateral biopsies performed in the operating room just prior to surgery and again at either 1 or 2 weeks post-TKA (random allocation within each cohort). Digital analysis methods were developed to quantify muscle volume (MRI) and muscle cell cross-sectional area (histology) . Results. This blinded study is not yet complete and therefore this Honors Thesis will not report any results. The data reported are coded and randomized in order to maintain the integrity of the clinical trial. Conclusion. Unfortunately, the effectiveness of essential amino acid supplementation in attenuating muscle atrophy cannot be assessed in this Honors Thesis. However, the precision of the analysis techniques developed here can be evaluated and confirmed. Furthermore, the clinical importance of EAA supplementation in potentially decreasing post-operative muscle atrophy in TKA patients is substantiated as this surgery is becoming increasingly prominent in the US.en-USCreative Commons BY-NC-ND 4.0-USBiologyMuscle PhysiologySkeletal MuscleMuscle AtrophyTotal Knee ArthroplastyOsteoarthritisSarcopeniaThesis / Dissertation