Obligatory Post-Marketing Clinical Follow-up (PMCF) as part of the post marketing surveillance plan for the product under investigation For this PMCF only CE-marked medical devices will be used within their intended purpose and no additional invasive or other stressful examinations are to be carried out (acc. to MPG §23b).

This non-interventional clinical study (NIS) is conducted to clinically confirm the safety and performance of the Aesculap® APT VEGA System® PS components under routine conditions. The VEGA System® PS is an established TKA design, and there is a long-lasting experience in the use of PE for TKA in general and for APT components in particular; thus a NIS is thought to be sufficient to give the required confirmation. For this NIS only CE-marked medical devices will be used within their intended purpose and no additional invasive or other stressful examinations are to be carried out (acc. to MPG §23b). As part of the post marketing surveillance plan an obligatory Post-Marketing Clinical Follow-up (PMCF) is required for the product under investigation.

Inclusion Criteria:

• Patients requiring primary TKA because of severe knee joint conditions that cannot be treated through other therapies;
• degenerative osteoarthritis;
• rheumatoid arthritis;
• posttraumatic arthritis;
• symptomatic knee instability;
• knee stiffness or deformation of the knee joint;
• Age ≥ 18 years;
• Patient signed informed consent

Exclusion Criteria:

• Age younger than 18 years
• Any prior joint replacement at the index knee
• Unable or unwilling to return for postoperative follow-up
• Patient did not sign informed consent
• Joint conditions that can be treated by reconstructive surgery (e.g. osteotomy)
• Acute or chronic infections near the joint, or systemic infections
• Secondary diseases that could influence joint implant functionality
• Systemic diseases and metabolic disorders
• Severe osteoporosis or osteomalacia
• Severely damaged bone structures that could prevent stable implantation of implant components
• Bone tumors in the region of implant fixation
• Bone malformations, axial misalignments or other bone conditions that rule out implantation of a prosthetic joint
• Expected overload on the joint implant, especially due to high patient weight or intense physical strain and activity
• Dependency on pharmaceutical drugs, drug abuse, or alcoholism
• Fever, infection or inflammation (systemic or local)
• Pregnancy
• Mental illness
• Severe osteopenia (or any other medical or surgical finding) that would preclude any benefit from the implants
• Combination with implant components from other manufacturers
• Inadequate patient compliance
• Foreign body sensitivity to the implant materials
• All cases not listed under indications

adult patients