The purpose of this research study is to compare two different methods used to align the knee during a total knee arthroplasty (TKA): technology-assisted inverse kinematic alignment, and manual-instrumented gap balancing alignment. The first technique uses robotic or computer-assisted technology to help the surgeon place the knee implant based on the patient's individual anatomy, whereas the manual technique uses standard surgical instruments and manual methods to position and balance the knee implant during surgery. The main difference is that one approach uses robotic or computer assistance to help guide implant positioning, while the other uses traditional instruments and manual surgical techniques. Both methods are commonly used and are considered standard care. The goal of this study is to understand whether one method results in better knee motion, function, and recovery after surgery in patients with higher body weight.

Inclusion Criteria:

• Being an adult (age >= 18 years)
• Being indicated for Total Knee Arthroplasty (TKA) for the treatment of non-inflammatory knee osteoarthritis by the PI or sub-investigators.
• Having a body mass index (BMI) >= 35 kg/m2

Exclusion Criteria:

• Patients who are unable to provide written consent
• Being under-age (age < 18 years)
• Having a BMI < 35 kg/m2
• Having a non-elective TKA
• Having a diagnosis of secondary or inflammatory, rheumatic, psoriatic, osteoarthritis of the index knee
• Having a local or widespread infection
• Being pregnant - Women who become pregnant at any point throughout the research study will become excluded/ineligible and will immediately stop all study activities.
• Women who are capable of becoming pregnant and not currently on contraceptives will be excluded from this study because it will be difficult to obtain the weightbearing CT using the standard CT shield for pregnant women.
• Having had a previous open surgery of the index knee
• Presence of local or widespread infection
• Having a revision TKA
• Having a simultaneous bilateral TKA
• Not being able to safely conduct study procedures - If patients are wheelchair bound or require an assistive device to stand for 5 minutes, they will be excluded from this study.
• Non-English speakers
• Prisoners

This study will be using the OpenCap motion capture system to collect gait data of participants. These recordings are stored in the OpenCap server and thus are shared with the OpenCap developers. Participants can request the removal of these recordings.

Upon enrolling the first subject.

Only the OpenCap developers will have access to the information.