Survival of anterior cruciate ligament reconstruction in patients with Ehlers-Danlos syndrome: A comparison with anatomic risk factors in existing literature.

Background: Ehlers-Danlos Syndrome (EDS) is a connective tissue disorder characterized by joint hypermobility, ligamentous laxity, and frequent joint injuries. These features could increase the risk of anterior cruciate ligament (ACL) tears, typically managed through ACL reconstruction (ACLR). Surgical intervention in EDS is challenging due to potential complications such as poor wound healing and tissue fragility. Limited evidence exists regarding the outcomes of ACLR in EDS patients; therefore, in this study we aimed to evaluate survival rates of primary and revision ACLR and examine associated demographic and anatomic risk factors for failure after ACLR.

Methods: A retrospective review of 21 EDS patients (25 knees) who underwent ACLR between 1993 and 2023 was conducted. Patients with vascular EDS were excluded. Demographic and surgical data, including graft type, cause of injury, concomitant procedures such as meniscus repair and anatomical measurements (posterior tibial slope, intercondylar notch width, lateral femoral condyle morphology, tibiofemoral rotation and tibial tubercle- trochlear groove distance), were collected. Survival analysis was performed using Kaplan-Meier curves, with endpoints defined as ACLR failure or conversion to total knee arthroplasty (TKA). A multivariable survival analysis was used to identify predictors of outcomes. In addition, the influence of demographic and anatomical factors on the development of concomitant injuries and concomitant procedures were assessed. Anatomical factors were then compared with non-EDS patients from the existing literature.

Results: The overall survival rate was 85.7% at mean follow-up of 50 months. Primary ACLR showed significantly higher survival rates 93.8% compared to revision ACLR 62.5% at 50 months (p = 0.03). Sports injuries, particularly skiing, were the leading cause of ACL tears (62%). Anatomical differences, such as increased lateral femoral condyle ratio (LFCR) and tibiofemoral rotation (TFR), were observed compared to non-EDS, ACL-intact patients from the literature (p < 0.01). However, these factors did not predict failure or influence concomitant injuries.

Conclusion: This study demonstrates that ACLR in EDS patients achieves good survival rates. Anatomical risk factors differed significantly from non-EDS, ACL-intact patients, but were not predictive of failure, highlighting ligamentous laxity as the primary challenge.