A Comparison of the Design of Tibia Stems in Cemented Total Knee Arthroplasty - Wedge Stem Versus I-beam Stem.

Inclusion Criteria: * Patients with one- or double-sided primary knee arthrosis. * Patients with a sufficient bone quality for implantation of knee prosthesis. * Informed and written patient consent. Exclusion Criteria: * Patients with neuromuscular or vascular diseases in the affected leg. * Patients who peroperatively are estimated unsuitable for knee arthroplasty e.g. due to bone cysts or dilution of the bone mass. * Patients who use non-steroid anti-inflammatory drugs (NSAID) and cannot refrain from taking them postoperatively (this includes COX-2-inhibitors). * Patients with osteoporosis estimated from the preoperative x-ray or former diagnosis of osteoporosis. * Patients with knee arthrosis following fracture sequelae. * Women, who are pregnant or are at risk of getting pregnant throughout the 2 year follow-up.