Posterior Correction with Segmental Pedicle Screw Fixation Alone in Severe Adolescent Idiopathic Scoliosis Over 70 degrees

Kim, Jin Hyok; Suk, Se Il; Ahn, Jong Kuk; Kim, Sung Soo; Chung, Kook Jin; Lim, Dong Ju; Sung, Ki Hyuk

Abstract

PURPOSE: To evaluate the results of a posterior procedure with segmental pedicle screw fixation in severe adolescent idiopathic scoliosis > or =70 degrees.
MATERIALS AND METHODS
Twenty-three adolescent idiopathic patients with a curve magnitude > or =70 degrees subject to segmental pedicle screw fixation were analyzed retrospectively with a minimum follow-up of 2 years (2-7.8 years). There were 19 females and 4 males with a mean age of 14.9 years. All patients, except for 4 patients with King type I, were subjected to thoracic curve fusion. Twenty patients showed a thoracic curve > or =70 degrees (70-96), and 4 patients had a lumbar curve > or =70 degrees (70-77), preoperatively. The preoperative and postoperative standing roentgenograms were used to check the radiological parameters.
RESULTS
The mean preoperative thoracic curve was corrected from 79.5+/-9.1 degrees to 25.3+/-5.8 degrees at the most recent follow-up, showing a correction of 67.9+/-7.8% and loss of correction of 2.5+/-1.9%. The mean preoperative lumbar curve was corrected from 72.3+/-3.3 degrees to 30.0+/-10.1 degrees at the most recent follow-up (58.4+/-14.8% curve correction, 2.4+/-2.5% loss of curve correction). The mean preoperative lowest instrumented vertebral tilting was corrected from 30.0+/-7.4 degrees to 10.5+/-5.6 degrees, showing a correction of 64.8+/-20.9%. The preoperative thoracic kyphosis improved from 28.3+/-11.2 degrees (0-50 degrees) to 35.0+/-9.1 degrees (22-53 degrees) postoperatively. There was neither pseudoarthrosis nor complications related to the pedicle screws at the most recent follow-up.
CONCLUSION
Segmental pedicle screw fixation without an anterior release procedure in severe adolescent idiopathic scoliosis produced a satisfactory deformity correction with no significant loss of the curve correction. This procedure obviates the need for the anterior release and reduces the complications associated with anterior surgery.