This MOON prospective cohort study (n=926) used multivariable logistic regression to identify independent predictors of ACL graft rupture. A model was built from one surgeon's data to control for operative technique and rehabilitation protocol, then validated across 6 academic centers. Only two variables survived multivariable modeling: graft type and patient age.
A 14-year-old athlete asking about graft choice deserves a number, not a vague preference. This paper gives you one: a 22% retear risk with allograft versus 6.6% with autograft — a 15-percentage-point absolute difference that is hard to argue away.
When counseling any patient under 25, lead with the NNT: you need to choose autograft in only 7 to 8 patients to prevent one additional failure. That is a compelling case for harvest morbidity.
Past age 30, the calculus shifts. The absolute risk difference shrinks to 4% at age 30 and 2% at age 40. NNT of 25 and 50, respectively. For the older, lower-demand patient who wants to avoid a hamstring harvest, allograft becomes a defensible option backed by the same dataset.
Sex, meniscus status, BMI, and revision status did not predict failure. So do not let those factors drive graft selection. Age and graft type are the variables that matter.
This MOON prospective cohort study (n=926) used multivariable logistic regression to identify independent predictors of ACL graft rupture. A model was built from one surgeon's data to control for operative technique and rehabilitation protocol, then validated across 6 academic centers. Only two variables survived multivariable modeling: graft type and patient age.
A 14-year-old athlete asking about graft choice deserves a number, not a vague preference. This paper gives you one: a 22% retear risk with allograft versus 6.6% with autograft — a 15-percentage-point absolute difference that is hard to argue away.
When counseling any patient under 25, lead with the NNT: you need to choose autograft in only 7 to 8 patients to prevent one additional failure. That is a compelling case for harvest morbidity.
Past age 30, the calculus shifts. The absolute risk difference shrinks to 4% at age 30 and 2% at age 40. NNT of 25 and 50, respectively. For the older, lower-demand patient who wants to avoid a hamstring harvest, allograft becomes a defensible option backed by the same dataset.
Sex, meniscus status, BMI, and revision status did not predict failure. So do not let those factors drive graft selection. Age and graft type are the variables that matter.