All a moitor with a USB port on it is just that it has a usb hub bult into it. The monitor in zero way uses the USB for display purposes.
HDMI is for video, there is no protocal that allows it to transport USB data on it so as everyone has said, no this does not exist.
Either just run the cables to your PC like normal, or mount a usb hub to the back of the monitor and run the cable from the hub to the computer.