You may have had the best type of operation available at the time of the accident. Fusion to hold the spine in place until it healed was (and still is) the standard of care in most places.
The ability to use screws to hold the fractured vertebra in place is a recent development. Advances in computer technology and imaging techniques have made this type of surgery possible. But it is expensive, requires a large facility, and isn't available everywhere yet.
The advantage of screw fixation over fusion is the obvious restoration of neck motion. Surgery to repair a Hangman's fracture of the C2 vertebra is a delicate operation and very difficult at best.
Real-time imaging is needed to allow the surgeon to see the spine after the patient is placed in the prone (face down) position. A special machine called Iso-C(3D) sends signals to a computer navigation system. The images are displayed on a TV screen during the operation.
Afterwards, CT scans and X-rays are used to verify the position of the spine. Once a segment is fused, it cannot be reversed.