A Landmark-Based Technique for Determining an Isometric Femoral Attachment Site for Lateral Extraarticular Tenodesis is Inaccurate.

Purpose: To evaluate the reliability and accuracy of a method of placing the femoral fixation location for lateral extra-articular tenodesis (LET) within a safe isometric area using anatomic landmarks.

Methods: Using a pilot cadaveric specimen, the center of the radiographic safe isometric area for femoral fixation of LET, defined as a 1 cm (proximal-distal) area located proximal to the metaphyseal flare and posterior to the posterior cortical extension line (PCEL), was located using fluoroscopy and found to be 20 mm directly proximal to the center of the fibular collateral ligament (FCL) origin. Using 10 additional specimens, the center of the FCL origin and a location 20 mm directly proximal was identified.