Difficulty turning your head?

​The very top two segments of your neck, C1 and C2, is responsible for approximately 50% of neck turning. When you have neck pain, turning is often a painful motion to perform, making some activities challenging such as driving, grocery shopping, or playing sports. By directly addressing C1-C2, you can almost always feel immediate pain relief and increase in overall neck range of motion. 
The anatomy of C1 and C2 are delicate as there are a lot of sensitive structures at this region. Because of that, getting a high velocity manipulation at this region is generally advised against in the world of physical therapy. A better hands-on treatment for this region is muscle energy technique (MET). It is a fancy term for manipulating the stiff joints with your own muscular force. Other treatments such as self-corrective exercise or dry needling can also be helpful.
Unless there is a fracture or chronic instability, surgical fusion should be the last resort. As you can imagine, you will lose about half of your ability to turn your head for the rest of your life. The quality of life will be greatly compromised, especially if you are young.