Review Question - QID 218018

A 22-year-old male who is a former college football player presents to your office with complaints of knee pain and instability. He previously underwent hamstring autograft ACL reconstruction his freshman year of college, but states his knee has never felt, "quite right." Knee radiographs demonstrate no arthritic changes. Full length standing radiographs demonstrate a normal mechanical axis bilaterally with a posterior tibial slope of 7°. Varus stress radiographs show an increase in lateral joint space of 5mm compared to the contralateral knee. On examination, he has a 3B Lachman, negative posterior drawer, no laxity with valgus stress, and significant laxity with varus stress at 30° but not at 90°. Dial testing demonstrates a 10° increase in external rotation at 30° but not at 90°. You schedule him for revision ACL reconstruction using a BPTB autograft. What is the most likely reason this revision procedure will fail?