Risk Factors and Predictors Of Subsequent ACL Injury After ACL Reconstruction: Prospective Analysis Of 2801 Primary ACL Reconstructions

Abstract

Objectives:Retear of an ACL after an ACL reconstruction (ACLR) is devastating for all involved. Understanding risk factors and predictors of subsequent ACL tear after an ACLR is vital for patient education of subsequent risk of injury and if a predictor is modifiable, to make adjustments to minimize the risk of repeat ACL tear. The objectives of this study were 1) to identify the risk factors and predictors for ispilateral and contralateral ACL tears after primary ACLR and 2) to compare retear risk between the 2002/03 and 2007/08 cohorts. This is the largest and most comprehensive prospective analysis of this kind in the literature.Methods:Data from the 2002-2008 MOON database was used to identify risk factors for ACL retear. Subjects who had a primary ACLR with no history of contralateral knee surgery and had 2 year follow-up data were included. Subjects who had multiligament surgery were excluded. Graft type (auto-BTB, auto-hamstring, allograft), age, Marx score at time of index surgery, sport played post ACLR, sex, smoking status, lateral meniscus tear at the time of ACLR, medial meniscus tear at the time of ACLR, BMI, and MOON site were evaluated to determine their contribution to both ipsilateral retear and contralateral ACL tear. The analysis was repeated using the 2002/3 and 2007/8 cohort and included age, graft, sex, and Marx. An ANOVA with post-hoc analysis was performed to detect significant differences in age and Marx score by graft type over time.Results:A total of 2801 subjects met all inclusion/exclusion criteria. There were 165/2801 (5.89%) ipsilateral and 177/2801 (6.32%) contralateral ACL tears identified in the cohort at the two year follow-up. The odds of ipsilateral retear are 1.68 times greater for hamstring autograft (p=0.04) and 4.67 times greater for an allograft (p<0.001) compared to auto-BTB. The odds of ipsilateral retear decrease by 8% for every yearly increase in age (p < 0.001) and increases by 6% for every increased point on the Marx score (p = 0.017). The odds of contralateral ACL tear increase by 7% for every increased point on the Marx score (p = 0.004) and decreases by 5% for every one point increase in BMI (p = 0.03). In 2002/3, there were 61/815 (7.5%) retears compared to 37/1056 (3.5%) in 2007/8. The odds of retear by for the 2002/03 and 2007/08 cohorts are summarized in table 1. The mean age (figure 1) of subjects receiving BTB and hamstring remained constant over time whereas the mean age of subjects receiving allograft rose by seven years (p < 0.001). Hamstring use was a predictor of retear compared to BTB in the 02/03 group (7.9% vs. 4.2%), but not in the 07/08 group (4.1% vs. 3.4%).Conclusion:Age, activity, and graft type were predictors of increased risk of ipsilateral graft failure after ACLR. Higher activity and lower BMI were found to be risk factors in contralateral ACL tears. Allograft use in young active patients was shown to be a risk factor for graft retear in the 02/03 group, subsequent to this, graft choice changed to using allografts in older and less active ...

CORR Insights®: Does Combined Intra- and Extraarticular ACL Reconstruction Improve Function and Stability? A Meta-analysis

“…Although ACL reconstruction is a successful operation, resulting in a high likelihood of return to play, recent data from the Multicenter Orthopaedic Outcomes Network group and others found that its results are not as good as we think, particularly in young patients and high-level (high school and collegiate) athletes [1,2]. Many patients do not return to activities that they previously participated in, and some studies [1,2] have found a high frequency of ACL graft rupture and contralateral ACL rupture, particularly in young, active patients in the first 1 to 2 years after reconstruction.…”

CORR Insights®: Does the Utilization of Allograft Tissue in Medial Patellofemoral Ligament Reconstruction in Pediatric and Adolescent Patients Restore Patellar Stability?

“…With regard to ligament reconstructions in young athletes in general, it has been well documented that the use of allograft tissue for primary ACL reconstruction in young athletes is associated with an increased risk of graft rupture [3,4,7]. However, given the dissimilarities between the ACL and the MPFL in terms of anatomy and function, it may not be appropriate to apply findings from the ACL literature to those patients undergoing MPFL reconstruction.…”

Biomechanical Adaptations After Fatiguing Exercise in Healthy and ACL Reconstructed Individuals

“…157 About 45% of reconstructions use the BPTB autograft compared to approximately 36% with HG, with the remaining 19% of reconstructions using an allograft. 83,92 Both autograft reconstructions (BPTB and HG) are currently more common than allograft reconstructions. 83,92 Autograft choice does not alter clinical outcomes after ACLR, 81 with exception to increased anterior knee and kneeling pain with BPTB.…”

“…83,92 Both autograft reconstructions (BPTB and HG) are currently more common than allograft reconstructions. 83,92 Autograft choice does not alter clinical outcomes after ACLR, 81 with exception to increased anterior knee and kneeling pain with BPTB. 127 …”

“…15,59 These protocols result in fatigue using exercises that simulate movements experienced during sport and activity, however do not incorporate the aerobic component of prolonged sport participation. Graded treadmill exercise has been used previously to test cardiopulmonary fitness 92 and is commonly used to induce neuromuscular fatigue. 17,73 Fatiguing exercise protocols that challenge both anaerobic and aerobic systems and simulate the demands of sports may be best suited for assessing fatigue-related biomechanical adaptations that are more generalizable to highly active athletes participating in prolonged and intense sport environments.…”