The Pediatric ALL Evaluation and Trial

Studies have reported a rising incidence of anterior cruciate ligament (ACL) injuries in children and adolescents. Beck et al reported a 2.3% annual increase between 1994 and 2013. In New York State, the rate of pediatric ACL reconstruction climbed from 17.6/100,000 in 1990 to 50.9/100,000 by 2009. Other reports echo these findings. After ACL reconstruction, children are known to be at a higher risk for complications than adults. For example, while the rate of postoperative graft failure in adults was 3% to 4% in large national registries, as many as 12% to 19% of pediatric patients may sustain graft rupture. This can have substantial medical, financial, and psychosocial implications on the patient and family. Additionally, the results of revision ACL reconstruction are, on average, worse than after index surgery. Exploration of treatments that may lower the rate of re-injury is paramount in this population that is at highest risk.

In the adult population, a growing number of studies have suggested that concomitant reconstruction of the anterolateral ligament (ALL) with the ACL may help lower this risk. The ALL was likely first characterized in 1879 by the French surgeon Segond, who commented on the presence of a "pearly, resistant, fibrous band" in the lateral aspect of the knee. However, only in 2012 was the structure given the name "anterolateral ligament" after it was consistently identified in cadaveric specimens. Some studies suggest that the ALL is damaged during anterior cruciate ligament (ACL) injury, implying that it may supplement the ACL in providing rotational and translational stability. Biomechanical studies have confirmed that it likely plays a role in rotational stability.

A number of ALL reconstruction techniques have been developed with the hope of lowering the rate of re-injury after ACL reconstruction. Early literature in the adult population suggests that this may indeed be the case. Early case series suggested that concomitant ALL reconstruction resulted in high rates of return to sport and a low ACL graft failure rate (2.6%). Comparative retrospective studies in adults suggest better patient reported outcome scores, meniscal repair healing, and rates of return to sports when the ALL is reconstructed with the ACL compared to isolated ACL reconstruction. Finally, a prospective cohort study of adults reported that hamstring autograft ACL reconstruction with concomitant ALL reconstruction resulted in 3.1 times lower odds of graft failure than isolated hamstring ACL reconstruction and 2.5 times lower odds of failure than isolated patellar tendon ACL reconstruction.

The hypotheses to be tested in this study have never been evaluated in the pediatric population. Furthermore, the proposed investigation is a randomized controlled trial, which will allow it to provide novel results with high-level evidence. The results of such a study have the potential to change practice in a meaningful, tangible way and affect the outcomes of thousands of children annually. In addition to the medical and functional impact, there could also be important financial and psychosocial implications.

Inclusion criteria

• Age 18 and under
• Surgery within 6 months of injury
• Undergoing primary ACL reconstruction without previous injury or surgery
• Quadriceps tendon autograft ACL reconstruction
• Closing or closed physes

Exclusion criteria

• Over 18 years old
• Previous ipsilateral knee injury or surgery
• Neuromuscular or developmental disorders affecting knee anatomy, cognition, or neuromuscular control
• Other concomitant ligament reconstruction aside from the ALL (i.e., MCL, PCL, PLC)
• Revision ACL reconstruction
• ACL reconstruction with graft other than quadriceps tendon
• IT band (modified MacIntosh) ACL reconstruction
• A cartilage lesion requiring anything more than debridement
• Open physes requiring both femoral and tibial physeal-sparing technique