PURPOSE: Anterior tibial closing wedge osteotomy (ATCWO) has been shown to significantly reduce failure rates of revision anterior cruciate ligament (ACL) reconstructions in patients with a posterior tibial slope (PTS) ≥12°. Recent findings suggest a slight but significant reduction of the medial proximal tibial angle (MPTA) resulting in a varus knee where the sagittal osteotomy plane is based on a total of two guide wires defining the osteotomy wedge without respecting the frontal plane. We hypothesize that the placement of a total of four guide wires intraoperatively can reduce the influence on the MPTA. METHODS: This study retrospectively reports on a two-centre series of 42 ATCWOs for PTS correction between January 2022 and December 2023 at two clinical centres. A total of four guide wires were placed based on a true lateral intraoperative view of the tibia, with two positioned each at the cranial and at the caudal pole of the osteotomy wedge, serving as guides for the saw to create the osteotomy, with careful attention to ensuring that the proximal and distal K-Wires were placed parallel to each other. A retrospective analysis was conducted by examining true lateral and anteroposterior radiographs to identify changes in sagittal and coronal plane alignment. RESULTS: The study included 19 women and 23 men, with a mean age of 29.7 ± 8.6 years with first-time ACL revision surgery and a minimum PTS of ≥12°. PTS decreased significantly from 14.5 ± 2.8° preoperatively to 8.2 ± 1.9° post-operatively ( CONCLUSION: With our technique of placing four guide wires to achieve precise guidance during the insertion of the osteotomy wedge, there is no substantial impact on the aMPTA during slope correction. LEVEL OF EVIDENCE: Level IV.