This Level 3 cohort study followed 354 patients younger than 20 who had primary hamstring autograft ACL reconstruction. It quantifies graft rupture and contralateral ACL injury rates and examines how sex and age (<18 vs 18-19) influence reinjury risk.
When counseling a 16-year-old before ACL reconstruction, this paper gives you the numbers: roughly 1 in 3 young patients will reinjure an ACL, and a boy under 18 faces a 44% chance. The timing distinction is the key teaching point. Graft ruptures cluster early (74% within 2 years), aligning with the hamstring ligamentization window of 1 to 2 years when the graft is biologically weakest.
Contralateral injuries come later (mean 3.7 years), reflecting ongoing high-risk sport exposure rather than graft maturation. This supports the argument for delaying return to strenuous cutting and pivoting sports, possibly to 18 to 24 months, and for rigorous neuromuscular training and validated return-to-sport criteria.
The authors frame age as a proxy: younger patients return to high-risk sport (88% vs 53% in older patients) and may have incomplete neuromuscular maturation, both modifiable targets.
This Level 3 cohort study followed 354 patients younger than 20 who had primary hamstring autograft ACL reconstruction. It quantifies graft rupture and contralateral ACL injury rates and examines how sex and age (<18 vs 18-19) influence reinjury risk.
When counseling a 16-year-old before ACL reconstruction, this paper gives you the numbers: roughly 1 in 3 young patients will reinjure an ACL, and a boy under 18 faces a 44% chance. The timing distinction is the key teaching point. Graft ruptures cluster early (74% within 2 years), aligning with the hamstring ligamentization window of 1 to 2 years when the graft is biologically weakest.
Contralateral injuries come later (mean 3.7 years), reflecting ongoing high-risk sport exposure rather than graft maturation. This supports the argument for delaying return to strenuous cutting and pivoting sports, possibly to 18 to 24 months, and for rigorous neuromuscular training and validated return-to-sport criteria.
The authors frame age as a proxy: younger patients return to high-risk sport (88% vs 53% in older patients) and may have incomplete neuromuscular maturation, both modifiable targets.