[Medial pivot, bicruciate retaining and co: Evidence of modern insert and implant designs].

backgroundIn the context of rising numbers in primary total knee arthroplasty, alternative insert designs are being established, which are supposed to show superior results in terms of knee joint kinematics, clinical results and long-term survival in comparison to the traditional cruciate retaining or posterior stabilized insert designs. MEDIAL PIVOT: The medial pivot design presents equivalent results to the cruciate retaining design with presumed superiority combined with kinematic alignment. DUAL PIVOT: Current data for the dual pivot design is still very limited. A benefit in comparison to traditional insert designs has not yet been demonstrated. ULTRACONGRUENT: Forthe ultracongruent design, similar clinical results and revision rates as for the posterior stabilized design have been shown so far, but a superiority in this respect cannot be indicated. BICRUCIATE RETAINING: The bicruciate retaining design does not present as a meaningful alternative to the traditional insert designs due to a more challenging surgical technique and significantly increased revision rates based on aseptic partial loosening.