Summary

Following a treatment approach of primary active rehabilitation nearly 50 % of children with ACL injury may cope well and have healthy menisci even through to adulthood without ACL reconstruction.

Abstract

Background

There is no agreement regarding the best treatment approach for skeletally immature children with anterior cruciate ligament (ACL) injuries. High-quality studies with long-term follow-up are lacking, and evidence to support decision-making is limited.

Methods

The aim was to evaluate clinical results (functional and patient-reported outcome, activity level, new injuries, surgical history and complications) in young adults who sustained an ACL injury before the age of 13 years and were treated with active rehabilitation with the option of later ACL reconstruction if needed.
This prospective case series included 46 children younger than 13 years of age with a total, intrasubstance ACL injury. None of these patients had additional injuries that warranted early surgery. At final follow-up at mean 8 years after time of injury, 44 patients remained in the study. A test battery was conducted at baseline, 1 and 2 years and at final follow-up at skeletal maturity. The test battery included functional tests (hop tests and isokinetic muscle strength tests of quadriceps and hamstrings), patient-reported outcome measures (including the Knee and Osteoarthritis Outcome Score KOOS and the International Knee Documentation Committee Subjective Knee form IKDC) and clinical examination. Medical records were reviewed to assess surgical history and complications. In addition, bilateral 3.0 Tesla MRI and long standing radiographs were conducted at skeletal maturity. Diagnostic MRI and bilateral 3.0 Tesla MRI at 1 and 2 years follow-up were also available.

Results

At mean 8 years follow-up, 24 patients (54 %) had undergone ACL reconstruction, and 16 patients (36 %) had undergone meniscal surgery. Mean leg symmetry indexes for hop and strength tests were consistently above 90 %, except for the single hop and hamstrings muscle strength for ACL-reconstructed patients. Mean IKDC scores were 86.3 ± 13.7 for the ACL-reconstructed patients and 90.6 ± 11.8 for the non-reconstructed patients. Forty patients (91 %) remained active in sports, but 29 patients (66 %) reduced their activity level to non-pivoting sports. Over a period of 9.5 years 16 patients (36%) sustained a new meniscal tear since baseline. At the final MRI 9.5 years after injury 28 patients (65%) had healthy menisci and no patient had signs of osteoarthritis.

Conclusion

Active rehabilitation may have a role in treatment of some ACL injured children. Nearly 50 % of children may cope well even through to adulthood without ACL reconstruction. The other half may develop instability which warrants ACL reconstruction and approximately one third may require meniscal surgery.