The most common complication of TKA is abnormal patellar tracking.  A normal Q angle is the most important variable in proper patella tracking. It is critical to avoid surgical techniques that lead to an increase in the Q angle. 

Common Surgical errors include:

  • Internal rotation of the femoral component.
  • Medialization of the femoral component.
  • Internal rotation or medialization of the tibial prothesis.
  • Placing the patella prosthesis lateral on the patella.
  • Placing the patella prosthesis to low on the patella.
  • Cutting the patella bone to much or too little.
  • Not doing a lateral release when indicated.
  • Using the wrong design of prosthetic patella implant.
  • Choosing a femoral component with an unfriendly sulcus.
  • Using a femoral component with a too wide intercondylar box.