Fibrin Clot Prevents Bone Tunnel Widening after ACL Reconstruction with Allograft


      Bone tunnel widening is a potential complication after ACL reconstruction. The aim of this study was to evaluate if adding a fibrin clot to the allograft for anatomic single-bundle ACL reconstruction would reduce tunnel widening.


      Fifty patients who underwent anatomic single-bundle ACL reconstruction were included. Twenty-five patients received an allograft alone and 25 patients received an allograft with fibrin clot. All patients underwent standard plain anterior-posterior and lateral radiographs of the operated knee immediately after surgery and at 1 year follow-up. The size of the tunnels was measured at both time points to calculate tunnel widening. A t-test was used to compare tunnel widening between the allograft and the allograft + fibrin clot group.


      There was significantly less tunnel widening in the allograft + fibrin clot group for the femoral tunnel width in the middle and distal portion of the tunnel and for the tibial tunnel width in the proximal and distal portions, as compared to the allograft only group.


      Adding a fibrin clot to the allograft in anatomic single-bundle ACL reconstruction reduces the amount of tunnel widening at one year follow-up.