Aim of the work is to present a technical approach for revision of cases with recurring knee instability after undergoing an ACL reconstruction surgery, and results of such technique. The study was based on 39 patients, 6 females and 33 males seen along the course of the study. A new technique for tunnel evaluation using CT was developed along the course of the study. A statistical study of inter-observer reliability of X-ray use in tunnel evaluation was also conducted. Technical errors represented 56.4% of our series. The technical errors represent the main cause of recurrent instability following ACL reconstruction. Vertical tunnel position is the most common error associated with femoral tunnel positioning. The addition of an extra articular tenodesis helps improve the outcome by providing adequate control of the pivot shift.