A base component (24) for a tibial implant has a lateral compartment (40) and a medial compartment (42) spaced from the lateral compartment defining an open central section (52) therebetween. A connecting portion (44) connects the medial and lateral compartments at an anterior end (26) of the base component (24) which anterior end is located adjacent the anterior tibia. The open central section (52) of the base component intermediate the spaced medial and lateral compartments (40, 42) is open to a posterior end of the base component. The medial and lateral compartments have a bone contacting surface (20) and a superiorly facing surface. The connecting portion has a curved anteriorly facing surface (26) and has a first angled surface (28) extending at an angle from adjacent the anterior end (26) of the base component at a bone contacting surface (20) of the connecting portion superiorly to a posterior end of the connecting portion. The first angled surface (25) defining an anterior end of the open central section.
