Partial ACL tears augmented with distally inserted hamstring tendons and over-the-top fixation: an MRI evaluation

This study evaluated the mid-term MRI appearance of partial ACL tear augmentation with quadrupled distally inserted hamstrings, while preserving the intact ACL bundle. Twenty-eight patients with ACL partial tear underwent augmentation. After 15-40 months follow-up, patients were evaluated clinically and by MRI. The mean IKDC score at follow-up was 93.8. Twenty-five patients were rated as excellent, three as fair. The mean tibial tunnel section area decreased by 27%. A correlation was noted between the clinical and MRI results: the graft was not visible or continuous with high intensity areas and the mean decrease in the tunnel section area was 3% in the three cases rated as fair. The graft appeared continuous and low intensity and the reduction in tibial tunnel section area was 30% in the cases with excellent clinical results. The residual part of the ACL was still recognizable in 79% of cases. The tibial hamstring attachment appeared normal in 93% of cases. In conclusion, excellent results correlated with a decrease in tunnel size and normal graft appearances on MRI. The poor results showed that the graft was not visible or not continuous, with high intensity areas and intra-ligamentous cystic formation within the tunnel. MRI scanning is useful in evaluating hamstring ACL grafts after reconstruction.