Total Knee Arthroplasty: Functional and Clinical Outcomes

The purpose of this study is to assess the differences in functional and patient reported outcomes between total knee replacement (TKA) implants. In addition, this work will examine the correlation between functional assessments and patient reported outcomes following surgery. All subjects will complete assessments preoperatively, 4-6 weeks following TKA and then one year following TKA. Subjects will complete a series of patient reported outcomes as well as a series of functional outcomes at each of the time points of interest. The analysis will include a repeated measures design to determine differences between groups across time as well as correlations between the functional and patient reported outcomes. This work will hopefully determine the importance of using objective functional outcomes following TKA as well as determining the need for patient assessments out to one year following surgery.

The number differences in subjects analyzed from baseline to 6 weeks to 52 weeks are due to the fact that we did not use the 6 week time point in the final analysis based on the clinical decision that 6 weeks was too early in recovery to provide accurate information for clinical decision making. Therefore the patients used in the final analysis were those subjects who were able to and completed the assessment at pre-op and 1 year post-op which is how we get to the 20 subjects per group.

Change in Lower Quarter Y-Balance Test (YBT-LQ) (Dynamic Balance) From Baseline to 6 Weeks Following Total Knee Replacement

The lower quarter y-balance test (YBT-LQ) is a test of dynamic balance in unilateral stance that has been deemed to be reliable and valid. The YBT-LQ consists of each patient standing on one leg and reaching as far as they can with their non-stance leg in the anterior, posteromedial and posterolateral direction while standing on the other foot on a centralized stance platform. The composite score is calculated as the sum of the three reach directions divided by 3 time the limb length and will be reported as a percentage of limb length.

Change in Lower Quarter Y-Balance Test (YBT-LQ) (Dynamic Balance) From Baseline to 52 Weeks Following Total Knee Replacement

The lower quarter y-balance test (YBT-LQ) is a test of dynamic balance in unilateral stance that has been deemed to be reliable and valid. The YBT-LQ consists of each patient standing on one leg and reaching as far as they can with their non-stance leg in the anterior, posteromedial and posterolateral direction while standing on the other foot on a centralized stance platform. The composite score is calculated as the sum of the three reach directions divided by 3 time the limb length and will be reported as a percentage of limb length.

Each subject will complete three walking trials at a self-selected comfortable walking speed along a 5 meter walkway in order to record walking speed at each time point.

Each subject will complete three walking trials at a self-selected comfortable walking speed along a 5 meter walkway in order to record walking speed at each time point.

Change in University of California, Los Angeles (UCLA) Activity Score From Baseline to 52 Weeks Following Total Knee Replacement.

The UCLA activity score is a validated patient reported outcome of overall physical activity. Results on a scale of 1 to 10, 1 is "Wholly Inactive, dependent on others, and can not leave residence" and 10 is "Regularly participates in impact sports".

University of California, Los Angeles (UCLA) Activity Score at 6 Weeks Following Total Knee Replacement.

The UCLA activity score is a validated patient reported outcome of overall physical activity. Results on a scale of 1 to 10, 1 is "Wholly Inactive, dependent on others, and can not leave residence" and 10 is "Regularly participates in impact sports".

Change in Knee Injury and Osteoarthritis Outcome Score (KOOS) Total From Baseline to 52 Weeks Following Total Knee Replacement.

The KOOS is a standardized and validated patient outcome score that assesses functional limitation in patient with knee problems. KOOS consists of 5 subscales; Pain, other Symptoms, Function in daily living (ADL), Function in sport and recreation (Sport/Rec) and knee related Quality of life (QOL). The previous week is the time period considered when answering the questions. Standardized answer options are given (5 Likert boxes) and each question is assigned a score from 0 to 4. A normalized score (100 indicating no symptoms and 0 indicating extreme symptoms) is calculated for each subscale.

The FJS is a patient reported measure of how bothersome the total joint replacement is for them, how much it affects daily activity and how much they are aware of the implant. The FJS is a 12-question survey regarding functional outcome, pain, stability, daily living, activity and sport. Scoring is from 0 to 4 with 0 as the best outcome; a low score means high satisfaction. Not all questions must be answered to score, all responses are summed and the total is divided by number of completed items multiplied by 25, with the final result subtracted from 100. The score range is from 0 to 100 with the highest score of 100 indicating the best outcome (the joint is completely "forgotten") and 0 indicating the worst outcome.

The KSS is a patient reported measure of knee function that is specific to patients who are scheduled to receive or have previously had a total knee replacement. This outcome measures both patient reported pain and function changes from prior to surgery through recovery. The score range is from 0 to 100. The highest score of 100 points will be obtained by a well-aligned knee with no pain, 125 degrees of motion, and negligible anteroposterior and mediolateral instability.

The sit to stand test requires patients to stand up and sit down as many times as possible in 10 seconds from a standard arm chair.

The timed up and go requires a patient to rise from a chair walk three meters around a piece of tape and return to the chair again as quickly as possible.

Inclusion Criteria: Patients requiring primary total knee replacement Patients willing and able to comply with the follow-up visits and evaluations Patients willing to sign informed consent approved by the Institutional Review Board Exclusion Criteria: Patients with inflammatory arthritis Patients with diabetic neuropathy Patients unable to ambulate without the use of an assistive device prior to surgery Patients unable to stand in single limb stance on each foot prior to surgery.