Radiographic evaluation of anterior cruciate ligament reconstruction

Last revised by Hector Rivera-Melo on 15 Sep 2023

Radiographic evaluation of anterior cruciate ligament (ACL) reconstruction involves:

  • femoral component

    • a line is drawn along the posterior cortex of the femur

    • a second line is drawn along the roof of the intercondylar notch of the femur (Blumensaat line)

    • the point of intersection of these two lines should be at the inferior portion of the femoral component of the graft

    • the angle measured between a line drawn along the femur diaphysis and the femoral tunnel angle must be ~39°; angles of approximately ≤17° are associated with rotational instability

  • tibial component

    • the tibial component should be entirely posterior to and parallel or more steep than the line drawn along the roof of the intercondylar notch (Blumensaat line)

    • when the femoral tunnel is drilled through the tibial tunnel, it is recommended to drill the tibial tunnel at an angle of 65° to 70° in the coronal plane, tibial tunnel angle of ≥72° is associated with greater loss of flexion and anterior laxity

  • tibial or femoral canal widening

    • loss of parallel walls and increase in diameter >2 mm from reconstruction time

  • hardware complications

    • migration of Endobutton into the femoral canal

    • interposing soft tissue between Endobutton and femoral shaft 

    • migrated/displaced interference screw from the tibial or femoral canal

  • proud/intramuscular screw tip 

See also

ADVERTISEMENT: Supporters see fewer/no ads