Results of open reduction and internal fixation for complex articular fractures around the knee are poor, particularly in elderly osteoporotic patients. Open reduction and internal fixation may lead to an extended hospital stay and non-weight-bearing period. This may lead to occurrence of complications related to decubitus such as thrombo-embolic events, pneumonia and disorientation. Primary arthroplasty can be a valuable option in a case-based and patient-specific approach. It may reduce the number of procedures and allow early full weight-bearing, avoiding the above-mentioned complications. There are four main indications: 1) Elderly (osteoporotic) patients with pre-existing (symptomatic) end-stage osteoarthritis. 2) Elderly (osteoporotic) patients with severe articular and metaphyseal destruction. 3) Pathological fractures of the distal femur and/or tibia. 4) Young patients with complete destruction of the distal femur and/or tibia. The principles of knee (revision) arthroplasty should be applied; choice of implant and level of constraint should be considered depending on the type of fracture and involvement of stabilizing ligaments. The aim of treatment is to obtain a stable and functional joint. Long-term data remain scarce in the literature due to limited indications.