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Updated: Aug 12, 2026

A Spine Robotic-Assisted Navigation System for Pedicle Screw Placement
Published on: May 11, 2020
Transpedicular eggshell osteotomies for congenital scoliosis using frameless stereotactic guidance
M R Mikles1, G P Graziano, Hensinger aR
1Section of Orthopaedic Surgery, University of Michigan Hospitals, Ann Arbor, Michigan, USA.
Study Design:
Three cases of multiplanar congenital scoliosis corrected by a transpedicular eggshell osteotomy using frameless stereotactic guidance are reported.
Objective:
To show an alternative surgical technique for correcting and fusing complex congenital spinal curves.
Summary Of Background Data:
Children with congenital scoliosis can have progressive curves causing significant multiplanar deformities. In older children, traditional approaches to spinal corrective surgery including fusion in situ, convex growth arrest, and hemivertebra excision can achieve only limited corrections.
Methods:
Three older patients who had congenital scoliosis with significant multiplanar curves underwent one-stage posterior transpedicular eggshell osteotomy. Three-dimensional reconstructive images and frameless stereotactic guidance were used for preoperative selection of osteotomy levels and accurate placement of pedicle screws. After completion of the osteotomy, closure was obtained with extension of the hips.
Results:
The average coronal correction of the major curve was 28.7 degrees (range, 22-33 degrees ). The average correction of the plumb line or lateral displacement from the center of the trunk was 4.8 cm (range, 3-7.5 cm). A significant kyphotic deformity was corrected 38 degrees, and a pelvic tilt was reduced from 7 to 3 cm.
Conclusions:
One-stage posterior reduction eggshell osteotomy can be used to correct a sagittal and/or coronal congenital spinal curve imbalance. Frameless stereotactic guidance for solid pedicle screw fixation was essential to the achievement of rigid spinal stabilization before arthrodesis. Transpedicular eggshell osteotomy is a technique that should be considered for older patients who have congenital scoliosis with multiplanar spinal abnormalities.

