Morphological risk factors for ACL ruptures in skeletally immature children and adolescents – a systematic review

Abstract Background: The incidence ACL injuries in skeletally immature patients has drastically increased over the last decades. The role of morphology of the knee is still unknown in this population. The purpose of this study was to review the literature for the influence of knee morphology on the risk of ACL injury in skeletally immature patients. Methods: Systematic review according to PRISMA guidelines. MEDLINE, Embase and Cochrane were searched in December 2022 for studies reporting on knee morphology and ACL injury in skeletally immatures. Inclusion criteria were English or Dutch studies reporting primary ACL injuries associated with a morphological parameter in skeletally immature patients. Case control studies were included. Results: After screening 1204 studies, a total of 16 studies were included of which parameters of 14 studies were included in the meta-analyses. These studies investigated 26 knee morphological parameters risk factors as potential risk factor for ACL injury in skeletally immatures. Meta-analyses identified a smaller notch width index (0.26 vs 0.27) steeper medial and lateral tibial slope (respectively 4.8 ° vs 3.6 ° and 4.3° vs 2.8°) and higher lateral/medial tibial slope ratio as risk factors for ACL injury in skeletally immature patients. Conclusions: A small notch width index (NWI), steeper medial and lateral tibial slope and higher lateral/medial tibial slope ratio (LTS/MTS) were identified as a risk factors for ACL injuries. Future studies should identify the influence of growth on these risk factors and assess if these are risk factors for graft failures after ACL reconstruction. Level of evidence: Level III