Feasibility and safety of using thoracic and lumbar cortical bone trajectory pedicle screws in spinal constructs in children: technical note

Abstract

<jats:p>Thoracic and lumbar cortical bone trajectory pedicle screws have been described in adult spine surgery. They have likewise been described in pediatric CT-based morphometric studies; however, clinical experience in the pediatric age group is limited. The authors here describe the use of cortical bone trajectory pedicle screws in posterior instrumented spinal fusions from the upper thoracic to the lumbar spine in 12 children. This dedicated study represents the initial use of cortical screws in pediatric spine surgery.</jats:p><jats:p>The authors retrospectively reviewed the demographics and procedural data of patients who had undergone posterior instrumented fusion using thoracic, lumbar, and sacral cortical screws in children for the following indications: spondylolysis and/or spondylolisthesis (5 patients), unstable thoracolumbar spine trauma (3 patients), scoliosis (2 patients), and tumor (2 patients).</jats:p><jats:p>Twelve pediatric patients, ranging in age from 11 to 18 years (mean 15.4 years), underwent posterior instrumented fusion. Seventy-six cortical bone trajectory pedicle screws were placed. There were 33 thoracic screws and 43 lumbar screws. Patients underwent surgery between April 29, 2015, and February 1, 2016. Seven (70%) of 10 patients with available imaging achieved a solid fusion, as assessed by CT. Mean follow-up time was 16.8 months (range 13–22 months). There were no intraoperative complications directly related to the cortical bone trajectory screws. One patient required hardware revision for caudal instrumentation failure and screw-head fracture at 3 months after surgery.</jats:p><jats:p>Mean surgical time was 277 minutes (range 120–542 minutes). Nine of the 12 patients received either a 12- or 24-mg dose of recombinant human bone morphogenic protein 2. Average estimated blood loss was 283 ml (range 25–1100 ml).</jats:p><jats:p>In our preliminary experience, the cortical bone trajectory pedicle screw technique seems to be a reasonable alternative to the traditional trajectory pedicle screw placement in children. Cortical screws seem to offer satisfactory clinical and radiographic outcomes, with a low complication profile.</jats:p>

Clinical and Radiological Results of Treating Lumbar Spondylosis With Cortical Bone Trajectory Screws

“…The solid fusion rate was achieved in 92% of operated levels; this rate was comparable to those reported in previous studies [1,2]. Sakura et al reported solid bone fusion in 90.9% of operated levels after single-and two-level fusions in a group of 22 patients [2].…”

“…The cortical bone trajectory (CBT) technique is an alternative method of pedicle screw xation. CBT can be applied to many paediatric and adult spinal pathologies, including spondylolisthesis, deformities, failed traditional lumbar pedicle screws, adjacent-segment disease, and trauma [1][2][3][4][5]. In traditional trajectory (TT) transpedicular screw xation, the trajectory in the transverse plane is from lateral to medial, which requires the application of strong muscle retraction.…”

Cortical Trajectory Pedicle Screws for the Fixation of Traumatic Thoracolumbar Fractures

“…Although our study consisted of only 12 cases in the CBT subgroup, this is comparable to the other cohorts in the current literature. The use of CBT has been expanded to other settings, with one recent study analyzing its application in pediatric populations [ 4 ]. Sellin et al demonstrated that the use of CBT in three pediatric patients with unstable traumatic thoracolumbar fractures was a reasonable, feasible, and safe alternative to traditional PS [ 4 ].…”

“…Traditional pedicle screws (PS) are used as the most common fixation method for unstable traumatic thoracolumbar fractures. While cortical bone trajectory pedicle screws (CBT) have greater contact with cortical bone, it is predominately used for single level fusion in patients with lumbar degenerative pathologies and comorbidities that compromise bone quality [ 1 - 4 ]. We postulated that, due to increased biomechanical stability and pullout strength (POS), CBT is a noninferior treatment option [ 5 - 7 ].…”

“…Recent clinical research has demonstrated that CBT is an effective alternative to PS [ 4 , 10 - 11 ]. Multiple studies have supported CBT’s positive biomechanical properties under both physiological and nonphysiological stresses; however, others demonstrate inferiority in axial rotation and lateral bending [ 1 , 2 , 5 - 7 , 12 ].…”