Try pressing hard on the right hinge and check if this affects the touch capability at all.
Looking at the hardware maintenance manual for the laptop, the video cable (which includes the touchscreen) passes through the right hinge to get from the LCD assembly to the motherboard.
If the video cable is damaged, search online for 5C10T70886 to find suppliers that suit you best.
If that has no effect then use the manual to gain access to the LCD unit so that you can check that the video cable connection is secure at both ends, motherboard and LCD panel.
If still no good then you may have to replace the LCD panel as it is a complete module i.e. LCD screen and touchscreen, and not two separately replaceable components.
Here’s a link to the parts for the laptop. Click on Select Commodity > LCD Assemblies (2) to find the part numbers. There are 2 screen assemblies available for the model. I think that the 2nd part number is for a HD screen but I may be wrong. They are interchangeable with each other though. Usually the part number can be found on the back of the LCD panel if you decide to replace the screen and you wish to verify that you’re getting the correct one.