- Discussion:
    - frequently double curves balance out & do not produce cosmetic deformity;
    - they do not tend to progress unless > 60 deg at skeletal maturity;
    - operative indications:
           - marked progression of curves;
    - disadvantages of surgery:
           - instrumentation must be applied to almost the entire spine;
           - long spinal fusions may lead to:
                 - degenerative changes below level of fusion leading to chronic pain;
                 - pseudarthrosis
                 - loss of lordosis;
                 - kyphotic deformity:
                       - develops secondary to degeneration of the discs;
                       - esp common in females approaching menopause;
                       - because kyphosis may narrow of spinal canal, secondary spinal stenosis may also develop as well