Sagittal radius of curvature, trochlea design and ultracongruent insert in total knee arthroplasty.

Multi radius (MR) total knee arthroplasty (TKA) has been associated with mid-flexion instability.Single radius (SR) TKA may provide better anteroposterior stability through single flexion axis and biomechanical advantage for quadriceps function.Medial pivot (MP) TKA and gradually reducing (GR) radius TKA produce better knee kinematics.Clinical outcomes are equivalent for SR, MR and MP TKA.Short-term studies have shown better clinical outcomes and kinematics for GR TKA.Thinner and narrow anterior flange, deeper trochlea groove and more anatomical trochlea design reduces patellofemoral complications in TKAUltracongruent inserts provide comparable clinical outcomes to posterior-stabilized TKA and cruciate retaining TKA. Cite this article: EFORT Open Rev 2019;4:519-524. DOI: 10.1302/2058-5241.4.180083.