Comparing two types of knee implant inserts in surgery

Inclusion Criteria:

* Patients scheduled to undergo primary total knee replacement with the MAKO-robotic arm, with one of the following indications:
* Painful, disabling joint disease of the knee resulting from: non-inflammatory degenerative joint disease (including osteoarthritis, traumatic arthritis or avascular necrosis) or rheumatoid arthritis.
* One or more compartments are involved;
* Moderate varus, valgus, or flexion deformity in which the ligamentous structures can be returned to adequate function and stability (meaning a varus, valgus or flexion deformity \< 15 degrees);
* Age between 18 and 70 years;
* ASA score I or II;
* A good nutritional state of the patient;
* Patients with a completely intact PCL at the time of surgery;
* Patient is able to understand the study and is willing to participate and to sign the Informed Consent;
* Patient is able to speak and write Dutch.

Exclusion Criteria:

* Contraindications manufacturer:
* Any active or suspected latent infection in or about the knee joint;
* Distant foci of infection which may cause hematogenous spread to the implant site;
* Any mental or neuromuscular disorder which would create an unacceptable risk of prosthesis instability, prosthesis fixation failure, or complications in postoperative care;
* Bone stock compromised by disease, infection or prior implantation which cannot provide adequate support and/or fixation to the prosthesis;
* Skeletal immaturity;
* Severe instability of the knee joint secondary to the absence of collateral ligament integrity and function;
* Metal in the operative or non-operative leg which lead to the creation of accuracy-reducing artefacts in the CT scan;
* Body Mass Index (BMI) of \> 35 kg/m2;
* Flexion contracture of 15 degrees and more;
* Varus/valgus contracture of 15 degrees and more;
* History of total or unicompartmental reconstruction of the affected joint;
* Bilateral operation;
* A Total Hip Arthroplasty (THA) on contralateral and/or ipsilateral side within the last year that is considered to have an unsatisfactory outcome (Patients with contralateral and/or ipsilateral THA \> 1 year ago with good outcome can be included in the study);
* A Total Knee Arthroplasty (TKA) on contralateral side within the last 6 months that is considered to have an unsatisfactory outcome. (Patients with contralateral TKA \> 6 months ago with good outcome can be included in the study);
* Patients who will need lower limb joint replacement for another joint within one year.
* Active or suspected latent infection in or about the knee joint;
* Osteomyelitis;
* Sepsis;
* A systemic or metabolic disorder leading to progressive bone deterioration, excluding rheumatoid arthritis;
* Vascular insufficiency, muscular atrophy;
* Neuromuscular or neurosensory deficiency, which would limit the ability to assess the performance of the device;
* Female patients planning a pregnancy during the course of the study;
* The patient is immunologically suppressed or receiving steroids in excess of normal physiological requirements.
* Patients bone stock is compromised by disease or infection which cannot provide adequate support and/or fixation to the prosthesis;
* A knee fusion to the affected joint;
* Patient has a known or suspected sensitivity or allergy to one or more of the implant materials;