A new look at quadriceps tendon - Is it really composed of three layers?

BACKGROUND The aim of this study was to qualitatively and quantitatively describe the anatomy of the QT including its size, its layers and relationship between layers. METHODS Sixty lower limbs (15 females and 15 males fixed in 10% formalin were examined. A retrospective analysis of 20 thigh MRI examinations was performed (10 males, and 10 females). RESULTS In all dissected specimens, the quadriceps femoris was composed of 4 layers: superficial (first layer), middle (second layer), middle-deep (third layer) and deep (fourth layer). The first layer (superficial) was formed by the rectus femoris tendon and fascia. The second layer was composed of tendons of the vastus medialis and superficial part of the vastus lateralis. The third layer was formed by the intermediate part of the vastus lateralis. The fourth layer was composed of the tendon of the vastus intermedius. This type of anatomy was visualized in 4 males and 2 female on MRI scans. CONCLUSION The findings of this study provide a detailed anatomy of the quadriceps tendon. There were 4 different layers of the QT consistently found in all specimens. The first layer was independent and composed by the rectus femoris tendon, the second was formed by the superficial part of the vastus lateralis and vastus medialis. The third layer was formed by the intermediate part of the vastus lateralis, and the deepest fourth layer was composed of the vastus intermedius. This detailed structural anatomy was also able to be visualized on MRI scans.