Fig 2.

Guidewire position. The patient is supine, with the head on the left and the feet on the right; a left knee is shown. The patellar guidewire (Arthrex) has been drilled from the midpoint of the medial patellar aspect to the superolateral corner of the patella (asterisk). The tip of the femoral guidewire has been located in the anatomic insertion of the MPFL on the medial aspect of the knee (arrow). After position control under fluoroscopic guidance using the method described by Schöttle et al.,³ the guidewire has been drilled perpendicular to the femoral cortex outside the lateral aspect of the knee.