Summary

Physeal sparing “Over-the-top” anterior cruciate ligament (ACL) reconstruction in skeletally immature patients resulted in high rate of reintervention at long term follow up, with lower clinical outcomes in patients aged younger than 13.

Abstract

Background

While the rate of anterior cruciate ligament (ACL) injuries in children and adolescents is increasing, evidence of long-term outcomes after ACL reconstruction in skeletally immature patients still lacks.

Purpose

to assess the long-term survivorship from failure and subsequent surgeries and to analyze the functional outcomes in skeletally immature patients who underwent ACL reconstruction with a physeal spearing over the top (OTT) technique.

Methods

The institutional database of single institution was retrospectively searched for skeletally immature patients who underwent ACL reconstruction between 2006 and 2016. Patients' characteristics and details of the surgery were obtained via clinical records review. All skeletally immature patients in our department underwent a physeal sparing OTT ACL reconstruction technique associated with a lateral tenodesis. Patients were contacted by phone and were asked to complete an online questionnaire. Ipsilateral and/or contralateral reoperations, KOOS score, Lysholm score, and Tegner Activity level were recorded. Survivorship was inspected through Kaplan Maier method with ipsilateral ACL revision as endpoint. Differences in demographics and PROMs were assessed through Student’s t-test. Conover’s test with Bonferroni correction for post-hoc comparison was used to assess differences between single time points.

Results

A total of 43 patients (rate of follow up 90%, average age at surgery 13.3 ± 1.6 years, 74% males) at mean follow-up of 11.0 ± 2.7 years were included. 9/43 (21%) had medial meniscus tear while 13/43 (30%) had lateral meniscus tear. 4 patients (9%) underwent Revision ACL Reconstruction in the ipsilateral knee at an average of 5.3 ± 2.4 years after surgery, with a failure rate of 5% at 5-year and 10% at 10- and 15-year. 4 patients (9%) underwent arthroscopy for a new meniscus tear, and further 5 patients (12%) underwent staple removals due to local discomfort. A total of 11 patients (26%) underwent at least one re-operation in the ipsilateral knee during the considered follow-up, after an average of 3.0 ± 2.1 years. Since 8 patients (19%) underwent Contralateral ACL reconstruction over the considered time frame, a total of 12 patients (28%) experienced a 2nd ACL injury after an average of 4.2 ± 2.8 years from surgery. KOOS subscales were all above the patient acceptable symptom state. Patients with <13 years at surgery showed worse Lysholm (82.0 vs 94.6, p=0.025) and KOOS-ADL (96.7 vs 99.9, p=0.025) compared to those with =13 years.

Conclusion

Despite a low rate of ACL failure (9%), more than one out of four (26%) skeletally immature patients who underwent physeal sparing OTT plus LET technique needed a further operation in the ipsilateral knee at long term follow up. Functional reported outcomes were lower in patients aged younger than 13.