Objective
The purpose of this study is to highlight our technique for freehand placement of juxtapedicular screws along with intraoperative computed tomography (CT) and radiographic results.
Methods
Consecutive patients with adult idiopathic scoliosis undergoing primary surgery by the senior author were identified. All type D (absent/slit like channel) pedicles were identified on preoperative CT. Three-dimensional visualization software was used to measure screw angulation and purchase. Radiographs were measured by a fellowship trained spine surgeon. The freehand technique was used to place all screws in a juxtapedicular fashion without any fluoroscopic, radiographic, navigational or robotic assistance.
Results
Seventy-three juxtapedicular screws were analyzed. The most common level was T7 (9 screws) on the left and T5 (12 screws) on the right. The average medial angulation was 20.7° (range, 7.1°–36.3°), lateral vertebral body purchase was 13.4 mm (range, 0–28.9 mm), and medial vertebral body purchase was 21.1 mm (range, 8.9–31.8 mm). More than half (53.4%) of the screws had bicortical purchase. Two screws were lateral on CT scan, defined by the screw axis lateral to the lateral vertebral body cortex. No screws were medial. There was a difference in medial angulation between screws with (n = 58) and without (n = 15) lateral body purchase (22.0 ± 4.9 vs. 15.5 ± 4.5, p < 0.001). Three of 73 screws were repositioned after intraoperative CT. There were no neurovascular complications. The mean coronal cobb corrections for main thoracic and lumbar curves were 83.0% and 80.5%, respectively, at an average of 17.5 months postoperative.
Conclusion
Freehand juxtapedicular screw placement is a safe technique for type D pedicles in adult idiopathic scoliosis patients.

Pseudarthrosis in the setting of 3-column osteotomies such as vertebral column resection (VCR) is not well described, and pseudarthrosis at the VCR site itself has never been reported. This study reports pseudarthrosis with 4-rod implant failure at a multilevel VCR site. The authors report a case of pseudarthrosis in a patient treated previously for severe segmental thoracolumbar kyphosis resulting in significant pain and myelopathic signs in the setting of radiation therapy for metastatic myeloma. This patient initially underwent 2-level VCR (T11, T12) and fusion from T4-sacrum. This was complicated by pseudarthrosis and associated with same-level 4-rod fracture, resulting in prominent, painful implants, and worsening kyphosis. This patient underwent revision VCR during which time significant motion was found only at the site of the prior VCR with a loose anterior cage. A new expandable VCR cage was placed and the spine was reinstrumented, resulting in significant improvement in coronal and sagittal alignment. Pseudarthrosis at a VCR site has not been previously described. Technical considerations presented in the revision procedure include a 6-rod spanning construct, meticulous endplate repreparation, and the generous use of osteo-inductive and -conductive augments to promote solid fusion.