Total Knee Replacement With Tourniquet or Aquamantys

The participant will sit in a seated position and a stabilizing strap will be placed around the bottom of the participant's shank and attached to a hand-held dynamometer. The participant will be asked to slowly kick the foot as hard as they can into the dynamometer pad (muscle testing hardware), and force will be measured. Increased measured force indicates greater quadriceps strength. Measurements will be recorded for both the operative extremity and the non-operative extremity, and the results will be expressed as a percentage of the mean strength measured in operative extremities compared to that measured in non-operative extremities for each study group.

Pain will be measured using the visual analog scale (VAS), which assess pain levels on a scale from 0-10. Lower numbers indicate less pain while higher numbers indicate more pain.

Knee injury Osteoarthritis Outcome Score, Joint Replacement (KOOS,JR) patient-reported outcome score. The KOOS, JR contains 7 items from the original KOOS survey. Items are coded from 0 to 4, none to extreme respectively. KOOS, JR scores are reported here in a range from 0-28 with mean and standard deviation for each group at two and six weeks post-op. Higher scores represent better perceived knee function.

The Veterans Rand-12 Mental Component Score will be used to quantify the impact of the participants emotional health on their daily activities. The VR-12 consists of 12 questions, is scored from 0-100 with lower scores indicating that emotional health has a more dramatic impact on the participant's daily life.

The knee function questionnaire is a study-specific questionnaire to assess knee problems that may affect everyday life. It consists of three questions: one about walking support, one about going up stairs and one about coming down stairs. Responses are categorical, and will be used to compare the proportion of patients in each group that can walk without a walker or cane, or navigate stairs without the use of upper body support. The knee function questionnaire is not a graded scale, but will be used to assess the proportion of each group that self-reports the ability to perform these 3 tasks at each of the study time points.

This is a timed test used to measure mobility and function. Participants are positioned in a standard 16" office chair with their arms at their sides and back located against the back of the chair. Participants are instructed to stand and sit as quickly as possible 5 times. The test is timed using a stopwatch and the timer is stopped when the individual achieves a standing position on the 5th trial. Shorter times indicate better mobility and function.

Opioid use will be assessed with a single question with a binary response (either yes the participant is taking opioid medications or no they are not).

Strength will be assessed at multiple time points during the study. The participant will sit in a seated position and a stabilizing strap will be placed around the bottom of the participant's shank and attached to a hand-held dynamometer. The participant will be asked to slowly kick the foot as hard as they can into the dynamometer pad (muscle testing hardware) placed on the anterior aspect of the participant's distal tibia. One practice trial followed by 3 actual trials will be performed. The participant will receive a 30-second rest in between each trial and a 1-minute rest in between legs for each test to prevent fatigue. Increased measured force indicates greater quadriceps strength.