Table 1.

Diagnostic criteria for MRI identification of the ALL and deep portion of the ITT [9]

Anterolateral Ligament (ALL)

Low-signal band on PD sequences

Seen on two sequences under cross-reference

Extra-articular structure

Origin at the postero-proximal region of the femoral epicondyle

Running in an antero-distal direction deep to the ITT

Crossing the lateral collateral ligament in its proximal third

Inserting on the anterolateral tibia midway between Gerdy’s tubercle and the fibular head

Deep portion of the ITT (dITT)

Kaplan fiber complex

Low signal band on PD sequences

Seen on two sequences under cross-reference

Extra-articular structure

Running postero-lateral and continuing distally from the intermuscular septum

Fibers connecting the ITT to the proximal ridge of the distal femur

Seen on 2 consecutive slices

Capsulo-osseous layer

Low signal band on PD sequences

Seen on two sequences under cross-reference

Fibers starting from the region of the Kaplan fiber complex

Running to the anterolateral tibia

ALL Anterolateral Ligament, ITT Iliotibial Tract, PD proton density