Anterior cruciate ligament (ACL) injuries are one of the most common and debilitating injuries experienced by athletes. While many patients successfully undergo ACL reconstructions, long-term failure rates have been reported between 2% to 27% resulting in the need for revisions. One of the main causes for the failure of ACL reconstruction is osseous malalignment (coronal versus sagittal). This review discusses the pathology behind osseous malalignment and provides insights into the origins that helped advance our understanding of our treatment, the high tibial osteotomy.