Scoliosis does that affect all the ligaments at the spine, making them lax?

The opposite: Scoliosis is an abnormal curvature of the spinal column to either the right or the left. Actually, if the number of degrees of the curve is great enough it causes great undue stress and pressure and all elements of the spinal column including exiting nerve roots, bony formations, and the cord itself, which tightens up the ligaments beyond normal levels.