Intramedullary instruments provide a highly reliable landmark for varus-valgus alignment of the components in total knee arthroplasty while rotational alignment of the femoral component can be adjusted reliably by sighting the femoral epicondyles. Correct positioning of the joint line is essential to achieve stable ligament tension in flexion and extension. Varying thicknesses of femoral and tibial components allow the surgeon to place the joint line correctly and restore stability and ligament balance in virtually all knees without resorting to hinges or highly constrained implants.
Bone deficiency can be managed with allograft if rigid fixation of the implants can be achieved. Smooth stems that fit tightly in the medullary canal of the femur and tibia give excellent support for the articular portion of the implant, and allow cement less fixation and morselized allograft reconstruction of major bone defects.