Ligament · Neck

Posterior atlantoaxial ligament

Ligamentum atlantoaxiale posterius

A thin broad membrane closing the space behind the joint between the first and second neck vertebrae, passing from the lower border of the atlas's posterior arch to the upper edges of the laminae of the axis. It is the local representative of the ligamentum flavum, the elastic sheet that bridges the back of the canal between every pair of vertebrae lower down — the same structure, thinned out at the level that has to rotate more than any other. It completes the back wall of the vertebral canal here and is drawn tight by forward bending.