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Chapter Summary
• Context: Early-onset scoliosis (EOS) represents a severe therapeutic challenge in spine surgery, demanding control of deformity progression without compromising spinal growth and pulmonary development in growing children. The emergence of guided growth techniques, particularly traditional growing rods (TGR), revolutionized this scenario by allowing the postponement or prevention of definitive vertebral fusion while ensuring axial trunk gain. However, managing these cases involves complex obstacles, such as the high rate of long-term mechanical and biological complications, the need for repetitive surgical distraction procedures, and the risk of unwanted spontaneous fusion. Furthermore, the surgeon faces the challenge of selecting the optimal implant configuration and the right time to intervene, balancing angular correction with anatomical preservation. Mastering preoperative planning, operative technique, and management until skeletal maturity is essential to reduce failures and optimize functional outcomes.
• Chapter Objective: This chapter enables the reader to understand and apply the traditional growing rod technique in early-onset scoliosis treatment. By the end of the reading, the professional will be able to indicate and contraindicate the procedure, perform detailed preoperative planning—including imaging evaluation and traction preparation—, execute surgical steps with anatomical preservation, manage the most frequent complications, and make evidence-based decisions upon reaching skeletal maturity.
• Overview and FundamentalsIndications and Contraindications Traditional growing rods (TGR) are indicated for progressive scoliosis diagnosed before 10 years of age that has failed conservative treatment with bracing, serial casting, or traction. They encompass neuromuscular, congenital, syndromic, and idiopathic etiologies, as well as patients with cerebral palsy, muscular dystrophy, or spinal muscular atrophy, aiming at spinal stabilization and maintenance of functional capacity. Absolute contraindications include active infection and severe clinical instability. Relative contraindications involve extremely rigid deformities without gradual correction capacity, severe hyperkyphosis, and severe pulmonary compromise, noting that prior halo-gravity traction with non-invasive ventilatory support can assist in reassessing severe respiratory cases. Preoperative Evaluation and Planning Planning requires full-length AP and lateral spine radiographs (standing or sitting) and supine traction radiographs to measure curve flexibility. Computed tomography is indicated in pelvic dysplasias or for planning bony anatomy at anchorage sites. Whole-neuraxis magnetic resonance imaging is mandatory to rule out secondary causes. Pulmonary and cardiological evaluation must be performed, highlighting the role of preoperative halo-gravity traction in curves greater than 90°, which reduces Cobb angulation and improves respiratory function. Step-by-Step Surgical Technique Under general anesthesia, multimodal neuromonitoring, and prone positioning, perioperative halo-femoral traction is applied to alleviate stress on the distraction system. The minimally invasive posterior approach performs subperiosteal dissection restricted to proximal and distal anchor sites, preserving musculature and vascularity in the intermediate segment to prevent autofusion. Proximal anchorage (usually T2-T4) preferentially uses sublaminar hooks at the most cephalad levels to decrease rigidity and prevent pull-out and proximal junctional kyphosis (PJK). Distal anchorage (lumbar or iliac) combines pedicle screws (which neutralize rotational forces) and subpedicular hooks (for axial load control). Dual rods are contoured and passed subfascially with the aid of a guide. Connectors (dominoes or inline tubes) should be positioned at the thoracolumbar transition. In the initial stage, distraction travel of the devices is preserved for subsequent surgeries, and cross-links (DTTs) are installed to ensure construct stability. Outcomes and Complications The TGR technique provides a final Cobb angle correction of around 44% and T1-S1 growth gain of approximately 1.0 cm/year, superior to other modalities, but at the expense of scheduled revision surgeries. Complications range from 22% to 48%, encompassing mechanical failures (rod breakage, implant loosening) and biological failures (infection, pseudarthrosis, autofusion, and PJK). At skeletal maturity (Risser 4), management may involve definitive posterior spinal fusion or retaining the dual construct; isolated implant removal without fusion is contraindicated due to the high risk of loss of correction.
• Clinical Application: Practical application centers on the systematic management of early-onset scoliosis, guiding the surgeon from patient selection to completion of growth. Faced with progressive curves in children under 10 years, preoperative workup with neuraxis MRI and pulmonary function tests prevents inappropriate interventions. In severe deformities (> 90°), instituting prior halo-gravity traction reduces surgical risk and optimizes flexibility. In the surgical act, technical precision requires perioperative halo-femoral traction and strictly localized subperiosteal dissection at the extremities, protecting the intermediate segment against autofusion. Choosing proximal anchorage with sublaminar hooks is a crucial decision to mitigate proximal junctional kyphosis. During follow-up, planning repetitive distraction procedures requires aseptic rigor and mechanical implant monitoring. Finally, upon reaching skeletal maturity (Risser 4), the surgeon must decide between definitive posterior fusion and implant maintenance, categorically avoiding isolated rod removal, which leads to deformity collapse in the vast majority of cases.
