Intercondylar Roof Line

The tibial footprint of the acl is located in a position on the tibia that is consistent and does not vary according to intercondylar roof angle.

Intercondylar roof line.

The area distal to the blumensaat s intercondylar roof line must be avoided in order not to violate the notch. The cacl is consistently located between 43 2 and 45 0 of the anteroposterior length of the tibia. Blumensaat line also known as the intercondylar line is the line drawn along the roof of the intercondylar notch of the femur on sagittal view of the knee. A line is drawn along the posterior cortex of the femur.

The angle measured between a line drawn along the femur diaphysis and the femoral tunnel angle must be approximately 39. 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. Indicating relative position of patella normally intersects the lower pole of the patella. If you need to insert a screw in the area distal to the blumensaat s intercondylar roof line make sure to direct the screw anteriorly in order to avoid the intercondylar notch.

In addition the area of the lateral knee recess should be avoided. Evaluating for acl injury normal acl blumensaat angle is 15. We found that in the normal knee the roof line intersects the tibial plateau roof plateau intersection ratio at 31 5 sd 5 of its width and at 33 9 5 4 in the acl deficient knee p 001. Intercondylar line blumensaat s line definition of blumnesaat line it is the tangent drawn along the roof of intercondylar notch or fossa of the distal femur on the saggital or lateral view.