Stabilizing a patient's knee

A leg holder assembly includes a leg support apparatus and a rail attachment mechanism. The leg support apparatus includes a planar support apparatus and a plurality of adjustable arms. The adjustable arms are pivotable. A patient's leg can be received within a space defined between the adjustable arms and rested on the planar support apparatus. The leg support apparatus also includes a support shaft. The rail attachment mechanism includes a body and a plurality of attachment arms. The rail attachment mechanism can be secured to the rail of an operating table by hooking the arms of the rail attachment mechanism over the rail of the operating table. A slot formed within the body of the rail attachment mechanism receives the support shaft and enables the support shaft to be slid into and out of the slot for attachment and detachment of the leg support apparatus to the operating table.