Ultrasonography imaging of the anterolateral ligament using real-time virtual sonography

Abstract

Background: The anterolateral ligament (ALL) functions as a stabilizer in the internal rotation of the knee.

Ultrasonographic assessment of the anterolateral ligament of the knee in healthy subjects

“…In most cases LIGA was identified in a superficial situation, but in 3.8% of the knees in our series LIGA was crossing ALL, and in 12.2% (18 out of 148 of the ALL identified by both evaluators) it could be identified having a direct relation with its distal band. In our study, no clear demonstration of fibers directly connecting the body of the lateral meniscus with the ALL was possible, as Oshima stated in his work 16 . The ALL proximal band seems to be in some cases difficult to recognize, because this band could be found to be always thinner, but, anyway, if the ALL could be identified, its proximal end could also be identified above the popliteal fossa (Fig.…”

“…Recently, the ALL of the knee was identified by MRI studies, cadaveric anatomical dissections and finally by ultrasonographic evaluations 6,16,18 . The ALL shares its origin on the lateral femoral condyle with the lateral collateral ligament (LCL © C I C E d i z i o n i I n t e r n a z i o n a l i been described 7,20 .…”

“…In our study, ALL was recognized using US in healthy subjects and an appropriate technical procedure was described for its recognition. A 30-35° of knee flexion was used as previously suggested by Parson's biomechanical essay 7 , and recently adopted in Oshima's study 16 . Cianca et al described a different approach in the identification of the ALL using 90° flexion of the knee 14 .…”

“…A second reference anatomical identification point at the distal portion of the ALL, near to its insertion on the tibia, was the recognition of the lateral inferior branch of the geniculate artery (LIGA) 4,16 ; this small artery was identified using color-doppler or power Doppler settings. Once the distal portion of the ligament was visualized, ALL relationship with the lateral meniscal body was evaluated 4,16,18 . Then the proximal portion of the ALL was followed until its origin on the lateral femoral condyle above the popliteal fossa.…”

“…At present only three studies identify the ALL on ultrasound (US) imaging. In 2014, Cianca et al reported an ultrasonographic description of the ALL in a case report 14 ; in 2015, Cavaignac et al studied US sensitivity in the detection of the ALL in 18 cadaveric knees 15 ; lastly, in a recently published study, Oshima et al evaluated the efficacy of US in demonstrating ALL in 9 healthy subjects 16 . Therefore, the aim of this study was to determine inter-observer agreement of the ultrasonography in the identification of the ALL and in the evaluation of its length and thickness in healthy subjects.…”