@andrewboot16282 most likely the ninges since they got stuck, unless you get them to move smoothly again. Soak those in some WD 40 and continue to work them until they are no longer sticking. Lubricate them after they are clean and dry with some 3-in-1 oil and work it into the hinges by opening and closing those a couple of times. If the hinges are bend or otherwise damaged, you will have to replace those.
Next parts to replace would be the middle frame where the hinges screw into and the LCD cover. Now, we do not know the condition of the top case, that is the part where the keyboard sites in etc. That you will have to evaluate as you open your computer.
To work on your Lenovo use the [document|35259]