The Association Between Younger Age, Higher Baseline Activity Level, and Increasing Tibial Slope With Revision Anterior Cruciate Ligament Reconstruction
Lafi S. Khalil, Connor W. Hoban, Michael Dubé, Sercan Yalcin, Xiaojuan Li, William Zaylor, Carl Winalski, , Thomas E. Anderson, Lutul D. Farrow, Brian Leo, Paul M. Saluan, Kurt P. Spindler, Kim Stearns, James S. WilliamsBackground:
Recent literature has demonstrated an increased risk of graft rerupture after anterior cruciate ligament (ACL) reconstruction (ACLR) utilizing hamstring tendon (HT) autograft in young, high-demand athletes. Increasing attention has been directed toward evaluating posterior tibial slope (PTS) as a risk factor for ACLR failure.
Purpose:
To evaluate the relationship between PTS and risk of subsequent revision ACLR in a prospective cohort with a minimum 2-year follow-up while accounting for previously established patient and surgical risk factors.
Study Design:
Case-control study; Level of evidence, 3.
Methods:
Prospective data were collected for patients undergoing primary ACLR using HT autograft between February 2015 and February 2018. Cases performed by fellowship-trained surgeons at a single institution were included. Age, sex, body mass index, Marx activity score, hamstring diameter, and PTS were analyzed for associations with graft failure using mixed-effects modeling and multivariable regression, controlling for patient and surgical characteristics. Two-year outcomes included ipsilateral revision ACLR and contralateral primary ACLR. PTS was measured on magnetic resonance imaging (MRI) utilizing a 2-circle technique.
Results:
Of 376 eligible patients with ≥2-year follow-up, 332 (90.4%) knees had adequate MRI for analysis. The median age was 23 years, 41% were female, the median BMI was 25.5 kg/m 2 , and 31% had baseline Marx scores ≥12. Within 2 years, 58 patients (15.4%) underwent ipsilateral knee surgery, and 27 (7.2%) required revision ACLR. Contralateral knee surgery in 29 patients (7.61%) included 20 (5.25%) who underwent primary ACLR. Interrater reliability demonstrated good agreement for medial PTS (intraclass correlation coefficient [ICC], 0.79 [95% CI, 0.66-0.88]) and moderate agreement for lateral PTS (ICC, 0.60 [95% CI, 0.41-0.76]). Multivariable modeling demonstrated that when adjusting for age, sex, sports, autograft diameter, and PTS, only age significantly predicted ACL revision, while a higher baseline Marx score predicted any ipsilateral surgery. PTS was not associated with revision or subsequent surgery, and only 7 of 332 patients had PTS ≥12°.
Conclusion:
In patients undergoing primary ACLR with HT autograft, younger age and higher baseline activity predicted revision ACLR at 2 years. Medial (mTS) and lateral tibial slopes (lTS) were not independently predictive of subsequent ACL surgery.