Primary Knee Symposium: Biomechanical Considerations in the Knee

The History of Alignment in TKR – Kenneth Krackow, MD

Dr. Krackow reviewed the history of how surgeons attempted to achieve total knee alignment from the early 1970's to the present day. In the '70's, there was essentially no instrumentation - no alignment rods, and no cutting blocks - to help with alignment. This opened the door to the increased possibility of early loosening and instability. At the time, the general feeling was that the issue was cement (in terms of longevity). So attention was turned toward in growth fixation, which brought many new potential challenges to the table. PSlide A

This initiated a closer look into measured resection for more accurate preparation. With a classic approach, alignment gravitated to a neutral mechanical axis, perpendicular tibial cut, and a femoral cut perpendicular to the mechanical axis. Anatomic alignment focused on natural kinematics and minimal surface constraint with the joint line parallel to the ground. With the anatomic approach, what was observed was different than what was achieved with instruments.

In his current practice, Dr. Krackow uses the classic arthroplasty alignment because it is easier for him and reduces his probability for tibial varus. He outlined the reasons he believes this works for him. PSlide B

He concluded his presentation with a review five points on planning alignment. PSlide C PSlide D