The present invention relates to a modular knee prosthesis assembly kit for replacement of resected articular surfaces of a distal femur of a first patient side. The kit comprises at least one bi-condylar component sized and shaped to substantially replace resected posterior and distal condylar bone portions; and at least a first trochlear groove component and a second trochlear groove component, each sized and shaped to replace a resected trochlear groove bone portion. The first trochlear groove component comprises a first patella articulation path defining a first trochlear groove direction angle. The second trochlear groove component comprises a second patella articulation path defining a second trochlear groove direction angle. An assembly of the bi-condylar component and one of the first and second trochlear groove components forms a substantially complete femoral knee prosthesis. The second trochlear groove direction angle is different from the first trochlear groove direction angle.