The Anterolateral Complex of the Knee.

Area of Science:

• Orthopedic surgery
• Anatomy
• Biomechanics

Background:

• Controversy exists regarding the precise anatomical structures of the anterolateral knee.
• Understanding these structures is crucial for effective surgical repair and reconstruction.

Purpose of the Study:

• To meticulously define the layer-by-layer anatomical organization of the anterolateral complex in the human knee.
• To clarify the composition and relationships of the key structures within this region.

Main Methods:

• A descriptive laboratory study involving layer-by-layer dissection of 20 fresh-frozen cadaveric knees.
• Systematic exposure, identification, and high-resolution digital imaging of anterolateral knee structures.
• Quantitative measurements were performed throughout the dissection process.

Main Results:

• The anterolateral complex comprises distinct layers, including the superficial and deep iliotibial band (ITB) as Layer 1.
• The ITB, reinforced by its capsulo-osseous layer, forms a functional unit from the Kaplan fibers to its tibial insertion.
• Layer 3 consists of the anterolateral capsule, with a discrete mid-third capsular ligament present in 35% of specimens.

Conclusions:

• The anterolateral complex is a functional unit composed of the superficial and deep ITB, capsulo-osseous layer, and anterolateral capsule.
• The anterolateral ligament described in recent literature may correspond to the capsulo-osseous layer or mid-third capsular ligament.
• Surgeons must exercise caution when reconstructing the anterolateral knee, recognizing its complex, multi-component nature.