BackgroundAlthough several studies have detailed the origin, shape, and insertion of the anterior cruciate ligament (ACL), there is still no consensus on the location of the appropriate point for the positioning of the femoral and tibial tunnels for its grafting. The purpose of this study is to review the literature on the variability in the positioning of femoral and tibial tunnels when a graft reconstruction of the ACL has to be performed. MethodsA systematic search was carried out on the literature published in the Medline, Embase, Central, Cochrane, and Lilacs databases, using MesH and free terms. A selection was made by title and summary and a review of complete texts. The publications were classified by topic, and a narrative presentation of the findings was made. ResultsA total of 25 studies were included. Variability was found in the selection of areas of origin and insertion of the ACL in both cadaveric models and patients. Among the anatomical repairs for the positioning of the femoral tunnel are the intercondylar crest, bifurcated crest, the resident's crest, clockwise or counter-clockwise direction, remnant of the ACL, and for the tibial tunnel, the anterior horn of the lateral meniscus. There was also variability in the intra-surgical methods and imaging aids, such as the use of the antero-medial arthroscopic portal, Bernard's quadrants, fluoroscope, and navigated fluoroscope. Only one study evaluated the variability in positioning between and within each surgeon, showing relative consistency between them. DiscussionThe positioning site of tunnels for the reconstruction is determined by the experience of the surgeon, since there are no objectively standardised guides to perform the reconstruction. Evidence LevelIV