Assessing the impact of distal femoral morphology using Citak's ratio: an independent risk factor for aseptic loosening in rotating hinge knee prosthesis.

Background: Aseptic loosening (AL) is a frequent complication after rotating hinge knee (RHK) prosthesis. Citak's ratio has recently been developed to describe and classify distal femoral morphology into 3 groups (A, B, C). It consists in a ratio between the diameters of the femoral canal at 20 cm from the knee joint line and at 2 cm from the adductor tubercle.