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. K-wires were placed at each location. A lateral radiograph was obtained, and distances of the proximal K-wire relative to the PCEL and metaphyseal flare were measured. The location of the proximal K-wire relative to the radiographic safe isometric area was assessed by 2 independent observers. Intrarater and inter-rater reliability was calculated for all measurements using intraclass coefficients (ICCs). Results: There was excellent intrarater and inter-rater reliability for all radiographic measurements (.908 to .975 and .968 to .988, respectively). In 5/10 specimens, the proximal K-wire was outside of the radiographic safe isometric area, with 4/5 anterior to the PCEL. Overall, the mean distance from the PCEL was 1 mm ± 4 mm (anterior), and the mean distance from the metaphyseal flare was 7.4 mm ± 2.9 mm (proximal). Conclusion: A landmark-based technique referencing the FCL origin was inaccurate in the placement of femoral fixation within a radiographic safe isometric area for LET. Therefore intraoperative imaging should be considered to ensure accurate placement. Clinical Relevance: These findings may help to decrease the likelihood of misplacement of femoral fixation during LET by showing that landmark-based methods without intraoperative image guidance may be unreliable.

INTRODUCTION: Quadriceps ruptures, especially isolated rectus femoris ruptures, are uncommon among young and healthy individuals. CASE REPORT: We describe an 18-year-old collegiate sprinter with a rectus femoris tendon rupture who continued to have significant pain and dysfunction despite non-operative management. He was concurrently found to have femoroacetabular impingement and a labrum tear as well. Following an extensive trial of non-operative management, operative fixation of the rectus femoris rupture with Achilles allograft reconstruction was performed in addition to arthroscopic labrum fixation and femoroplasty. Postoperatively, he returned to sport with improved mobility and decreased pain. CONCLUSION: Surgical rectus femoris tendon reconstruction with Achilles allograft is a valid option for patients who fail conservative treatment.