ACL Reconstruction In High School and College-aged Athletes: Does Autograft Choice Affect Recurrent ACL Revision Rates?

Abstract

Objectives: Physicians’ and patients’ decision-making process between bone-patellar tendon-bone (BTB) versus hamstring autografts for ACL reconstruction (ACLR) may be influenced by a patient’s gender, laxity level, sport played, and/or competition level in the young, active athlete. The purpose of this study was to determine the incidence of subsequent ligament disruption for high school and college-aged athletes between autograft BTB versus hamstring grafts for ACLRs. Our hypothesis is there would be no recurrent ligament failure differences between autograft types at 6-year follow-up. Methods: Our inclusion criteria were patients aged 14-22 who were injured in sport (basketball, football, soccer, other), had a contralateral normal knee, and were due to have a unilateral primary ACLR with either a BTB or hamstring autograft. All patients were prospectively followed at two and six years and contacted by phone and/or email to determine whether any subsequent surgery had occurred to either knee since their initial ACLR. If so, operative reports were obtained, whenever possible, in order to document pathology and treatment. Multivariable regression modeling controlled for age, gender, ethnicity/race, body mass index, sport and competition level, activity level, knee laxity, and graft type. The six-year outcomes of interest were the incidence of subsequent ACL reconstruction to either knee. Results: Eight hundred thirty-nine (839) patients were eligible, of which 770 (92%) had 6-year follow-up for subsequent surgery outcomes. The median age was 17, with 48% females, and the distribution of BTB to hamstring was 492 (64%) and 278 (36%) respectively. Thirty-three percent (33%) of the cohort was classified as having “high grade” knee laxity preoperatively. The overall ACL revision rate was 9.2% in the ipsilateral knee, 11.2% in the contralateral normal ACL, and 19.7% had one or the other within 6 years of the index ACLR surgery. High-grade laxity (OR: 2.4; 95% CI: 1.4, 3.9; p=0.001), autograft type (OR: 2.1; 95% CI: 1.3, 3.5; p=0.004), and age (OR: 0.8; 95% CI: 0.7, 0.96; p=0.009) were the 3 most influential predictors of a recurrent ACL graft revision on the ipsilateral knee, respectively, whereas the sport of the index injury (OR: 0.3; 95% CI: 0.2, 0.7; p=0.002) was the most influential predictor of a subsequent primary ACL reconstruction on the contralateral knee. The odds of a recurrent ACL graft revision on the ipsilateral knee for patients receiving a hamstring autograft were 2.1 times the odds of a patient receiving a BTB autograft (95% CI: 1.3, 3.5). For low-risk patients (5% incidence of graft failure), a hamstring graft can increase the risk of recurrent ACL graft revision by 5 percentage points, from 5% to 10%. For high-risk patients (35% incidence of graft failure), a hamstring graft can increase the risk of recurrent ACL graft revision by 15 percentage points, from 35% to ˜ 50%. An individual prediction risk calculator for a subsequent ACL graft revision can be determined by the nomogram in Figure 1. Conclusion: There is a high rate of subsequent ACL tears in both the ipsilateral and contralateral knees in this young athletic cohort, with evidence suggesting that incidence of ACL graft revisions at 6 years following index surgery is significantly higher in hamstring autograft compared to BTB autograft. Figure 1. Risk Calculator for Autograft BTB versus Hamstring ACLR Ipsilateral Graft Failure at Six Years. For each athlete determine the points assigned on the top “points” line for Age, BMI, Sex, Sport of Injury, High-grade knee laxity, Autograft graft type, and baseline Marx activity level. Calculate the patient’s total points from all these risk factors and place mark on the “total points” scale on the bottom 0-350. Then from this point on the total point’s line observe the predicted percentage risk of failure on the very bottom scale from 5 to 50%.