The goal of this clinical trial is to compare Robotic Assisted, functionally aligned vs Custom Made Total Knee Arthroplasty in patients with knee osteoarthritis. The main questions it aims to answer are:

• Which implant/philosophy yields better clinical outcomes?
• Which implant/philosophy yields better satisfaction?
• Which system is more OR efficient? Participants will be followed for 2 years postoperatively.

Inclusion Criteria:

• - The patient is a male or non-pregnant female between the ages of 40 and 90 years
• The patient requires a primary total knee replacement
• Patient is deemed appropriate for a cruciate retaining knee replacement
• The patient has a primary diagnosis of osteoarthritis (OA)
• The patient has intact collateral ligaments
• The patient is able to undergo CT scanning of the affected limb
• The patient has signed the study specific, ethics-approved, informed consent document
• The patient is willing and able to comply with the specified pre-operative and post-operative clinical and radiographic evaluations

Exclusion Criteria:

• - The patient has a history of total, unicompartmental reconstruction or fusion of the affected joint
• Patient has had a previous osteotomy around the knee
• The patient is morbidly obese (BMI > 41)
• The patient has a deformity which will require the use of stems, wedges or augments
• The patient has a varus deformity ≥ 15°
• The patient has a valgus deformity >3°
• The patient has a neuromuscular or neurosensory deficiency, which would limit the ability to assess the performance of the device
• The patient is unable to speak German
• The patient is pregnant