Retrospective Review of ACL Reconstruction in Children 12 Years of Age or Younger

1. Retrospective Review of ACL Reconstruction in Children 12 Years of Age or Younger Dr. Answorth Allen, MD Dr. Steven Thorton, MD Hospital for Special Surgery Mariel Brady Tappan Zee High School

2. Review of Literature • Anderson, A.F. “Transepiphyseal replacement of the anterior cruciate ligament in skeletally immature patients. A preliminary report.” Journal of Bone and Joint Surgery. (2003):1255-1263. • Andrew, M., F.R. Noyes, and S.D. Barber-Westin. “Anterior cruciate ligament allograft reconstruction in the skeletally immature athlete.” American Journal of Sports Medicine. (1994): 48-54. • Micheli, L. J. et al. “Anterior cruciate ligament reconstruction in patients who are prepubescent.” Journal of Clinical Orthopedics. (1994): 44-47.

3. Anterior Cruciate Ligament • The Anterior Cruciate Ligament (ACL) is a broad ligament that connects the anterior tibial plateau to the posterior femoral intercondylar notch. • It prevents hyperextension of the knee, and controls rotation of the tibia on the femur.

4. ACL injury in Pediatric Patients • The question remains as to whether transphyseal ACL reconstruction in skeletally immature patients can be performed safely with minimal concern for physeal injury and subsequent deformity. Although current studies have shown favorable results, it is unknown whether these studies were performed in patients in whom the physes were functionally open. By selecting a known skeletally immature group, this question could be more thoroughly addressed. Also, this is the largest cohort of pediatric ACL patients to date.

5. Hypothesis • Partial and complete transphyseal ACL reconstruction in skeletally immature children, less than 12 years old, will result in no significant leg length discrepancies or malalignment issues secondary to physeal injury. • The purpose of this study is to see if there are any long-term problems related to surgery across the growth plate during ACL reconstruction in children. Specifically, we are looking to see if there is any loss of length in the leg, any angular deformities, or any loss of function that occurred after the surgery.

6. Materials and Methods • There were 9 patients included in the study. These patients have all had an ACL reconstruction when they were 12 years old or younger. • Each patient underwent a clinical examination of the knee. Then, three questionnaires were administered to the participants: the generalized questionnaire (to supplement the chart review), IKDC subjective knee evaluation form, and the Marx activity scale.

7. Materials and Methods (cont’d) • Next, participants were tested with the KT-1000, to compare the laxity of the reconstructed ACL to the healthy knee. • X-rays were also taken from hip to ankle to determine if there were any angular deformities in the leg.

8. Results and Conclusions • Our study confirmed our hypothesis. • There was no significant leg length discrepancy. • All patients returned to a Marx Activity Scale Rating of 20 (maximum). • According to the KT-1000, there was less than a 3 mm difference between the knees.

9. Results (cont’d) Of all the patients, 9 were completely satisfied with their surgery, and only one was mostly satisfied. 100% returned to the sport they had previously been playing.

10. Discussion • This study supports findings from previous research, that it is not only safe, but turns out to be more effective to operate on torn ACLs, even in skeletally immature children. • In conclusion, physical problems are very uncommon after ACL reconstruction in skeletally immature children, and early surgical stabilization may be beneficial.