Ectopic Fibres of Articularis Genu

Articularis genu is a vestigial muscle considered as the 5th part of the quadriceps. This is represented as the detached fibre bundles from the vastus intermedius. Morphologically the muscle is flat, thin, wispy. It shows highly variable attachments taking origin from the lower 1/4th of anterior surface area of the femoral shaft. Articularis genu may be considered as 5th head of quadriceps femoris. The variant morphology of the muscle may prevent incidental removal during total knee replacement, investigating osteoarthritis and so more.