This is the five-year follow-up of the KANON trial, the first high-quality RCT comparing early ACL reconstruction plus rehabilitation versus rehabilitation with optional delayed reconstruction in young active adults. The central question: does operating early lead to better outcomes than waiting and watching?
The standard argument for early ACL reconstruction in young active patients rested heavily on the premise that restoring mechanical stability would prevent secondary meniscal injury and long-term osteoarthritis. This RCT directly tested that premise and found it does not hold at five years.
When a 22-year-old soccer player comes to clinic after an ACL tear, this paper is why rehabilitation is a legitimate first-line option — not a consolation prize. A structured rehab program with a clear surgical bailout for persistent instability (positive pivot shift plus symptoms) produces outcomes indistinguishable from operating immediately.
Practically: counsel patients that roughly half who choose rehab-first will never need surgery. Those who do cross over to reconstruction still do just as well as those who had it early.
One graft-selection nuance worth knowing: if you do reconstruct, patellar tendon grafts carry significantly higher patellofemoral OA risk at five years — a finding corroborated by longer-term cohort data and explained by patellar tendon shortening after harvest.
This is the five-year follow-up of the KANON trial, the first high-quality RCT comparing early ACL reconstruction plus rehabilitation versus rehabilitation with optional delayed reconstruction in young active adults. The central question: does operating early lead to better outcomes than waiting and watching?
The standard argument for early ACL reconstruction in young active patients rested heavily on the premise that restoring mechanical stability would prevent secondary meniscal injury and long-term osteoarthritis. This RCT directly tested that premise and found it does not hold at five years.
When a 22-year-old soccer player comes to clinic after an ACL tear, this paper is why rehabilitation is a legitimate first-line option — not a consolation prize. A structured rehab program with a clear surgical bailout for persistent instability (positive pivot shift plus symptoms) produces outcomes indistinguishable from operating immediately.
Practically: counsel patients that roughly half who choose rehab-first will never need surgery. Those who do cross over to reconstruction still do just as well as those who had it early.
One graft-selection nuance worth knowing: if you do reconstruct, patellar tendon grafts carry significantly higher patellofemoral OA risk at five years — a finding corroborated by longer-term cohort data and explained by patellar tendon shortening after harvest.