X-Ray assessment of the effect of pedicle screw on vertebra and spinal canal growth in children before the age of 7 years

Abstract

Purpose To determine the reliability of pedicle screws placed in children younger than 7 years of age, and to evaluate the effect of pedicle screw insertion on further growth of the vertebra and spinal canal. Methods A retrospective study of 35 consecutive patients through Jan 2003-Dec 2010 for congenital scoliosis in \7 years children was performed at one spine center. Patients undergoing pedicle screw instrumentation of at least two levels, which had been followed-up for at least 24 months were included. Measurements were performed in instrumented and adjacent non-instrumented levels. The effect of pedicle screw insertion on further growth was evaluated. Results The average age at surgery was 4.4 year (53 months, range, 23-84 months). 190 segments in 35 patients met the inclusion criteria. 77 segments had no screws and 113 had at least one screw. There was a significant difference between the pre-operative and final follow-up values of the measurement of spinal canal and vertebral body parameters (P \ 0.001). No significant difference existed between growth rates of vertebral bodies and the sagittal diameters of spinal canal with or without screws. The growth rates of vertebral bodies in lumbar spine were higher than in thoracic spine in both instrumented and adjacent groups. Conclusion Pedicle screw instrumentation does not cause a retardation effect on the development of vertebral bodies and the spinal canal in children at an early age. It is a safe and reliable procedure to achieve a stable fixation.

Does addition of crosslink to pedicle-screw-based instrumentation impact the development of the spinal canal in children younger than 5 years of age?

“…The findings of the current study are complementary to the previous studies [7][8][9][10][11] in terms of the instrumentation's effect on the spinal canal in pediatric spine. By measuring the same vertebrae on the CT scans postoperatively and at the last follow-up, we have observed that pedicle screws insertion in children younger than 5 years of age do not alter the growth of the spinal canal.…”

“…Although the effect of pedicle screws on the development of the growing spine remains controversial, the consensus held is that the fusion region in the pediatric spine should include as few vertebrae as possible to minimize the impact on the longitudinal growth of the immature spine [8,11]. However, shortening of the fixation region, accompanied by the tiny pedicles and the thin cortical vertebral shells in pediatric patients, most likely leads to weak fixation strength and perhaps increases the likelihood of pedicle screw pull-out [12,13], correction loss [14], crankshaft phenomenon [15] and quadrilateral shift [16].…”

Does pedicle screw fixation under age 5 cause spinal canal narrowing? A CT study with minimum 5 years follow-up

“…There are very few clinical and radiological studies which evaluated the effect of pedicle screw instrumentation before age 5 years, on the growth of vertebra and spinal canal development [1][2][3]. Ruf et al [2] and Xue et al [1] in their series evaluated immature spinal growth of their patients mostly with plain radiographs.…”

“…Ruf et al [2] and Xue et al [1] in their series evaluated immature spinal growth of their patients mostly with plain radiographs. Olgun et al [3] used preoperative computerized tomography (CT) scans or magnetic resonance imaging (MRI) and compared postoperative CT scans to evaluate the effect of pedicle screw instrumentation on vertebral body and spinal canal growth in a group of patient with minimum 2 years follow-up.…”

“…Pedicle screw fixation allows three column fixation of the vertebral body and has shown superior biomechanical properties over the other fixation techniques [1]. In the last 15 years, there has been a trend towards use of pedicle screws in pediatric patients for surgical treatment of spinal disorders.…”