browneyedbaby,
It is not uncommon for patients to be able to feel the plate and screws, especially if they are thin (don't have a lot of adipose for padding (ie subcutaneous fat)).
While it is nice to place the plate on the side of the metacarpal, sometimes the fracture pattern does not allow it, and the surgeon also does not want to disturb the muscles that attach on the side of the bone.
As to the numbness around the incision, that is very common. Any time the skin is cut, small skin nerves are also severed. Usually, over time, the sensation will return, as the nerve endings grow back into the area. However, it does take quite a while, and in some cases, the sensation never returns to normal. But, this rarely bothers patients, as you really don't go around feeling with the back of your hand.
The itching is part of the healing process. It will decrease as the tissues continue to heal. Just try not to scratch directly on the scar, it is very easily damaged at this point.
It takes about 4 to 6 weeks for the bones in the hand to unite. And, the fracture line can stay visible for several weeks after the fracture has actually healed. So, you are just now getting to the time where the bones are solidly united. But, getting the bones to heal is just the first step. All of the soft tissue that was damaged at the time of the break, also have to heal, then be rehabilitated.
One of the most common problems with metacarpal fractures is adhesion of the extensor tendons. This is why it is so important to do range of motion exercises of the fingers as much as possible, to try to reduce the chances of developing adhesions.
Once the wound is well healed, you can do deep friction massage to help break up any scar tissue between the skin and tendons, and also between the tendons and the underlying periosteum (soft tissue covering of the bone).
But, you will continue to have some discomfort in the hand while the soft tissues are healing. It will get better as time and healing progress. If the presence of the plate bothers you, it can be removed once the fracture and soft tissues have completely healed. You try not to remove it until the soft tissue bed is mature enough to take another violation. Of course, if it is not bothering you at all, it can be left in forever.
Hope you continue to do well in your recovery. Continue to work on your finger range of motion, it is very important to your overall recovery. If you develop problems with scar tissue adhesions, try the deep friction massage.
Good luck.