Fig. 1

Non-operative treatment was performed on the 28 year-old male patient with an acute anterior collateral ligament (ACL) injury that had occurred while playing soccer 1 week ago. a, b T2-weighted magnetic resonance (MR) sagittal image of the knee indicates a midsubstance ACL rupture. Initial physical examination was Lachman test grade 1 and pivot-shift test grade 1, and the Tegner activity score before the injury was 7.0. c, d T2-weighted MR image of the same patient treated non-operatively according to our program shows a well-healed ACL at 1 year after injury. At 2 years after the injury, physical examination was Lachman test grade 0 and pivot-shift test grade 0, and the Tegner activity score was 7.0