iiiABSTRACT CHRISTINA AVERY CALLAHAN. An Evaluation of Patient-Reported Outcome Measures and Level Walking Biomechanics in Total Knee Arthroplasty Patients. (Under the direction of DR. NIGEL ZHENG) Total Knee Arthroplasty (TKA) is frequently used to treat individuals who are in the end stages of knee osteoarthritis (OA). While level-walking may seem to be a simple activity of daily living for most, it can be challenging for those who experience severe OA. A complete understanding of both patient-perceived function and their actual biomechanical function is critical for establishing standardization in pre- and post-operative TKA procedures. The primary goal of TKA is to alleviate pain, increase range of motion, restore functional ability and improve the overall quality of life to those who have OA. While majority of patients report to have improved pain and function, there are a good amount that still remain unsatisfied and have gait abnormalities. The purpose of this study was to investigate both patient-reported outcome measures (PROMs) and biomechanical measures of function as well as analyze the correlations between the two. Evaluation of improvement in these variables as well as comparing TKA data to healthy controls was important for gaining a complete understanding of functional improvement. Multiple types of PROMs were used and the vertical ground reaction force (vGRF) was the variable of interest collected from gait analysis assessment. The results from this study reconfirmed findings from previous TKA research regarding the improvement of subjective measures of function following surgery. TKA subjects demonstrated significant improvement in PROMs over the course of the study iv and there were also significant correlations between the different types of PROMs used. Majority of the improvement in PROMs occurred from pre-op to 6-months and 6-months to 12-months. Based on these findings, it may be more time and cost-efficient to eliminate the 1-week and 1-month follow-ups. There was also improvement of vGRF variables of TKA subject from pre-op to 6-months post-op. TKA subjects demonstrated bilateral differences between the implant and non-implant at the pre-op assessment but improved to values similar to the healthy controls at the post-op assessment. TKA subjects demonstrate significant improvement in PROMs and improvement of vGRF. However, there were only few correlations found between the improvement of PROMs and the improvement of vGRF variables from pre-op to 6-months post-op. This study confirms that there is a gap between subjective and objective measures of function and more research and consistent findings will be necessary to close that gap.