Fig. 1.

Composite radiograph series of preoperative halo-gravity traction (HGT). Example of a 14-year-old patient with kyphoscoliosis, height 139 cm, and weight 29 kg. He had Cobb angles of 147° on preoperative full-spine standing radiographs and 129° on convex bending. At the beginning of HGT, he had a Cobb angle of 123°; on day 3 and on the final-HGT-radiograph directly before surgery, the Cobb angle was 117°. During HGT, the preop-FVC% of 39% increased to 48% until final pulmonary function testing before surgery, indicating a modest improvement in the Cobb angle but a valuable improvement in pulmonary function related to the straightening of the compensatory curves