Management of increased posterior tibial slope in ACL deficiency: A narrative review and recommendation of the Osteotomy Committee of the German Knee Society.

Increased posterior tibial slope (PTS) is a known risk factor for anterior cruciate ligament (ACL) deficiency and graft failure after ACL reconstruction (ACLR). Although many studies investigated different aspects related to the PTS, there is still a lack of comprehensive recommendations and practical guidelines, especially with regard to radiographic analysis, surgical indication and surgical technique. The aim of this narrative review is to present such recommendations, based on the existing literature (evidence Level 3-4), supplemented by the expert opinions of the Osteotomy Committee of the German Knee Society. A review of the literature was conducted to summarize the current evidence concerning biomechanical background, radiological measurement, indication for surgical correction and surgical techniques. Results were presented to a panel of surgeons with recognized expertise in the treatment of ACL injuries and wide experience in surgical correction of the PTS, and consensus was formed by informal discussion. These recommendations were developed and included: (1) measuring the PTS should be performed on long lateral radiographs using the mechanical axis, with attention to a correct rotational alignment (exact superimposition of the posterior tibial condyles). (2) Indication for surgical correction does not depend on a single fixed cut-off value of the PTS. It should be based on an individual risk assessment (e.g., degree of anterior tibial translation and instability, meniscal integrity, number and quality of previous ACLR, trauma mechanism: contact vs. non-contact, contralateral injury). (3) For correction of pathologic PTS, different surgical techniques of anterior tibial closing wedge osteotomies have been reported without clear superiority of one technique. However, an infratuberositary approach is recommended, because it has been shown to be technically easier and safer. LEVEL OF EVIDENCE: Level V, narrative review and expert opinion.