LIVRE JDG 2016

We now know that the Segond fracture is an

injury of the anterolateral ligament (ALL).

This small image of an avulsion involving the

lateral aspect of the tibial plateau is visible on

the AP view of the knee X-ray.

Pathognomonic for an anterior cruciate

ligament (ACL) tear, it is therefore an avulsion

of the ALL’s distal enthesis (fig. 1).

Seven teams have studied MR imaging of the

ALL since 2014 [1].

The ALL is certainly visible with MRI but the

diagnostic capabilities vary depending on the

different portions identified.

Some of these studies use 2D acquisition

protocols with a 3 to 4 mm section thickness. It

appears to be difficult to study a thin structure

of under 2 mm with sections of this thickness

and it is therefore logical to assume that certain

poor results are due to the acquisition protocols.

The ligament appears as a physiological

hyposignal. It is relatively relaxed on the MRI,

which is performed with the knee bent at 20° to

30° with a distal tibial enthesis curved on

coronal sections.

It is also possible to see the ALL’s meniscal

attachments, whose morphology varies.

For greater precision and efficacy, ideally 3D

1mm-section sequences should be taken. They

are available on all new 3 Tesla MRIs and on

the latest generation 1.5 Tesla MRIs. With

these sequences, the MPR mode can be used to

study the ALL much more precisely.

In routine practice, we use T2-weighted 3D

sequences without a fat suppression technique.

The ligament is clearly visible as a physiological

hyposignal relative to its surroundings. The

lateral inferior genicular artery is clearly

ANTEROLATERAL

LIGAMENT IMAGING

B. BORDET, J. BORNE, A. PONSOT,

P.F. CHAILLOT, O. FANTINO

Fig. 1:

AP view of knee X-ray. Segond fracture

(arrow)