A family of tibial bearing components (12, 112, 212) for articulation with femoral condyles, each of the family of tibial bearing components defining a tibial bearing component coordinate system comprising: a bearing component transverse plane extending along a medial/lateral direction and an anterior/posterior direction; a bearing component coronal plane extending along a proximal/distal direction and the medial/lateral direction, said bearing component coronal plane perpendicular to said bearing component transverse plane; and; a bearing component sagittal plane extending along the anterior/posterior direction and the proximal/distal direction, said bearing component sagittal plane perpendicular to said bearing component transverse plane and said bearing component coronal plane, said family of tibial bearing components comprising a small tibial bearing component and a large tibial bearing component, said small and large tibial bearing components each comprising: an articular surface and an opposing distal surface (60, 160, 260), said distal surface parallel to the bearing component transverse plane, said articular surface including medial and lateral dished articular compartments sized and shaped for articulation with the femoral condyles, said medial and lateral dished articular compartments (16, 18; 116, 118; 216, 218) separated from one another by the bearing component sagittal plane, said articular and distal surfaces bounded by a tibial bearing periphery, said lateral articular compartment (18, 118, 218) comprising a plurality of coronal cross-sectional profiles defining a lateral set of coronal distal-most points spanning a lateral anterior/posterior extent (AP L), said lateral set of coronal distal-most points defining a lateral articular track (28, 128, 228) having an anterior portion and a posterior portion, said anterior portion defining a nominally straight line when projected onto the bearing component transverse plane, said anterior portion of said lateral articular track extrapolated posteriorly to define a lateral intersection point (P TL) with said tibial bearing periphery, said medial articular compartment (16, 116, 216) comprising a plurality of coronal cross-sectional profiles defining a medial set of coronal distal-most points spanning a medial anterior/posterior extent (AP M), said medial set of coronal distal-most points defining a medial articular track (26, 126, 226), said medial articular track defining a nominally straight line when projected onto the bearing component transverse plane, said medial articular track extrapolated posteriorly to define a medial intersection point (P TM) with said tibial bearing periphery, said lateral and medial intersection points joined by a posterior line, at least one of said lateral articular track and said medial articular track defining an acute angle (α) with said posterior line; characterised in that said acute angle of said small tibial bearing component is less than said acute angle of said large tibial bearing component. a bearing component transverse plane extending along a medial/lateral direction and an anterior/posterior direction; a bearing component coronal plane extending along a proximal/distal direction and the medial/lateral direction, said bearing component coronal plane perpendicular to said bearing component transverse plane; and; a bearing component sagittal plane extending along the anterior/posterior direction and the proximal/distal direction, said bearing component sagittal plane perpendicular to said bearing component transverse plane and said bearing component coronal plane, an articular surface and an opposing distal surface (60, 160, 260), said distal surface parallel to the bearing component transverse plane, said articular surface including medial and lateral dished articular compartments sized and shaped for articulation with the femoral condyles, said medial and lateral dished articular compartments (16, 18; 116, 118; 216, 218) separated from one another by the bearing component sagittal plane, said articular and distal surfaces bounded by a tibial bearing periphery, said lateral articular compartment (18, 118, 218) comprising a plurality of coronal cross-sectional profiles defining a lateral set of coronal distal-most points spanning a lateral anterior/posterior extent (AP L), said lateral set of coronal distal-most points defining a lateral articular track (28, 128, 228) having an anterior portion and a posterior portion, said anterior portion defining a nominally straight line when projected onto the bearing component transverse plane, said anterior portion of said lateral articular track extrapolated posteriorly to define a lateral intersection point (P TL) with said tibial bearing periphery, said medial articular compartment (16, 116, 216) comprising a plurality of coronal cross-sectional profiles defining a medial set of coronal distal-most points spanning a medial anterior/posterior extent (AP M), said medial set of coronal distal-most points defining a medial articular track (26, 126, 226), said medial articular track defining a nominally straight line when projected onto the bearing component transverse plane, said medial articular track extrapolated posteriorly to define a medial intersection point (P TM) with said tibial bearing periphery, said lateral and medial intersection points joined by a posterior line, at least one of said lateral articular track and said medial articular track defining an acute angle (α) with said posterior line; characterised in that said acute angle of said small tibial bearing component is less than said acute angle of said large tibial bearing component.