On Monday, May 9, 2016 MensHealth.com published a fantastic article dealing with 5 different body parts that are extremely sensitive to pain featuring medical insight from Dr. Spiel!
Below is an excerpt featuring Dr. Spiels take on the front and back of the knee for the full article click here!

4. The front and back of your knee
Like your tibia, the front of your knee doesn’t have much in the way of padding from muscle or fat.

Plus, the top layer of bone in your knee cap, called the periosteal layer, is loaded with sensory nerves, explains Douglas J. Spiel, M.D., a board certified radiologist who specializes in interventional pain.

The back of your knee cap is also unprotected. It sits in a ridge between the middle and the sides of your thigh bone, or femur.
“When it gets banged up, you bruise the back of the knee cap and the femur,” Dr. Spiel says. In other words, you’re getting two hits—and pain signals from two places—for the price of one.