Cost-Effective Growing-Rod Domino-Technique Constructs for Early-Onset Scoliosis: A Technical Note

Abdul Kadir Hadar; Dimas Harendra Soeharto Putra; Greesia D.M. Whitiana

doi:10.21182/jmisst.2025.02607

Abstract

Objective

Early-onset scoliosis (EOS) poses a significant therapeutic dilemma, as progressive spinal curvature during early growth can compromise thoracic development and pulmonary function. The growing-rod domino technique has emerged as an important surgical strategy, allowing serial deformity correction while preserving spinal growth and reducing the need for repeated surgical interventions.

Methods

We report a technical case study of a 9-year-old girl with idiopathic EOS who presented with a right thoracic Cobb angle of 107° and a compensatory lumbar curve of 62°, Risser stage 0, and a restrictive pulmonary pattern (forced vital capacity 72% predicted). Under general anesthesia with continuous neurophysiological monitoring, rod constructs were anchored proximally at T2–4 and distally at L3–4 using unilateral pedicle screws. The rods were contoured to maintain sagittal balance and tunneled submuscularly. A 20-mm intraoperative distraction was performed. Postoperative management included early mobilization, outpatient magnetic lengthening, and serial radiographic assessments.

Results

Intraoperative distraction reduced the thoracic and lumbar curves to 42° and 20°, respectively, with stable somatosensory evoked potential and motor evoked potential signals maintained throughout the procedure. The patient was extubated without complications, mobilized on postoperative day 2, and discharged on postoperative day 4. At 6-month follow-up, outpatient growing-rod activations achieved an additional 5 mm of spinal length. Radiographs confirmed sustained deformity correction, preserved spinal growth, and intact instrumentation. No perioperative or follow-up complications, including infection, implant failure, or autofusion, were observed. Clinically, the patient demonstrated improved trunk symmetry and respiratory function.

Conclusion

Growing-rod constructs using the domino technique provide a safe, effective, and patient-centered approach for the management of severe EOS. By achieving meaningful deformity correction while allowing continued spinal growth and reducing overall surgical burden, the growing-rod domino technique represents a valuable treatment option in skeletally immature patients, enabling deferral of definitive fusion until skeletal maturity.

Key Words: Scoliosis, Early-onset, Spinal rods, Operative surgical procedures, Spinal deformities

INTRODUCTION

Early-onset scoliosis (EOS) constitutes a distinct therapeutic challenge, as it can detrimentally affect spinal balance and thoracic growth during a pivotal developmental window [1]. If left unaddressed, the deformity may progress and lead to restrictive pulmonary disease, cardiopulmonary dysfunction, and considerable morbidity. The growing-rod approach—in which 2 rods are fixed proximal and distal to the curvature and periodically lengthened—has become the preferred surgical strategy for EOS, facilitating deformity correction while safeguarding ongoing spinal growth [2,3]. This method enables gradual realignment of the spine and reduces the likelihood of premature fusion, particularly in children younger than 8 years who exhibit large or rapidly worsening curves

Numerous investigations have confirmed that growing-rod constructs effectively achieve both deformity correction and axial length restoration. Traditional dual-rod systems typically yield coronal-plane corrections of approximately 45%–55% and promote an average spinal-height increase of 4–6 cm across the treatment period [4,5]. However, these results are usually evaluated over several years of follow-up. Complications such as rod fracture, anchor pullout, crankshaft progression, and unintended autofusion often occur later in the treatment course. Short-term outcomes alone do not adequately represent the full spectrum of mechanical and clinical risks associated with distraction-based systems.

Magnetically controlled growing rods (MCGRs), although producing slightly smaller distraction increments per adjustment, attain comparable long-term outcomes while obviating the need for repeated surgical procedures. In a multicenter series, Akbarnia et al. [6] reported a mean curve reduction of 51% and a 48 mm gain in T1–S1 length at 2 years with MCGR, alongside lower rates of infection and wound complications than seen with conventional implants. By comparison, growth-guided approaches such as the Shilla technique demonstrate similar early deformity correction but frequently achieve reduced overall length gains (mean, ~2.7 cm) and exhibit higher incidences of implant migration and unintended autofusion [7,8]. Definitive spinal fusion remains a salvage strategy in EOS, generally avoided in very young patients to prevent adverse effects on ongoing skeletal growth and pulmonary development.

Although reported complication rates for growing-rod constructs range from 34 % to 60 %—varying by implant design and patient cohort—most adverse events are amenable to management and tend to decline as surgeons accrue experience and devices evolve [9]. Growing rod with domino technique notably decrease the need for repeat interventions, and cost effective although mechanical failures and attenuation of distraction efficacy remain areas of concern. The capacity to preserve longitudinal growth while achieving incremental deformity correction underlies the superiority of growing rods for sustained spinal-height maintenance and pulmonary function preservation [9]. The objective of this study is to furnish a detailed technical exposition of growing-rod systems with domino technique to elucidate their operative techniques, complication spectra, and comparative outcomes in the treatment of EOS.

SURGICAL TECHNIQUE

1. Preoperative Planning

Full-length, standing posteroanterior and lateral radiographs were obtained to measure the coronal Cobb angle, evaluate sagittal balance, and determine curve flexibility. Supine bending and traction films were then performed to distinguish fixed versus flexible segments and to guide surgical planning. A whole-spine magnetic resonance imaging—comprising T1- and T2-weighted sequences in sagittal and axial planes—was obtained to exclude intraspinal anomalies (e.g., syringomyelia, tethered cord, or Chiari I malformation) that occur with increased frequency in this population and that might necessitate neurosurgical intervention prior to deformity correction (Figure 1).

After integrating curve morphology (Cobb angle, curve apex, and translation), residual growth potential (Risser stage 0–1 and Tanner stage I–II), and the patient’s overall medical status, a growing-rod construct was selected to permit controlled deformity correction while preserving spinal and thoracic growth. A single rod configuration was chosen, with proximal fixation at the upper end vertebrae (e.g., pedicle screws at T1–3) and distal anchors (e.g., hooks or pedicle screws at L3–5).

This selection was influenced by soft-tissue limitations along the concavity and the large curve stiffness. However, it is important to acknowledge that unilateral constructs are not the standard approach in EOS. Bilateral dual-rod constructs are consistently reported to provide greater mechanical stability, lower rod-breakage rates, and more predictable long-term correction. The limitations of a unilateral construct were explained to the caregivers during planning, and the choice was made based on the anatomical constraints of this specific patient.

2. Anesthesia and Patient Positioning

General anesthesia was induced using a combination of intravenous propofol (2–3 mg/kg), remifentanil infusion (0.1–0.2 μg/kg/min), and a non‐depolarizing neuromuscular blocker (rocuronium 0.6 mg/kg), with maintenance on sevoflurane (1.5–2.5 vol%) and intermittent fentanyl boluses. Rigid endotracheal intubation was performed, and invasive arterial blood pressure monitoring was established via a radial‐artery catheter. Continuous intraoperative neurophysiological monitoring—including bilateral somatosensory evoked potentials (SSEPs) of the tibial and median nerves and transcranial motor evoked potentials (MEPs) recorded from the abductor hallucis and thenar muscles—was initiated, with baseline signals acquired pre-positioning. Core temperature was maintained between 36.0°C and 37.0°C using forced-air warming, and mean arterial pressure was kept above 65 mmHg to optimize spinal cord perfusion.

The patient was positioned prone on a Jackson radiolucent spinal table with chest pads spaced approximately 12 cm apart to permit unrestricted abdominal excursion. Pelvic bolsters were configured to offload pressure from the iliac crests, and the abdomen was allowed to hang freely. The head was secured in a padded, neutral-alignment Mayfield headrest, and the arms were tucked at the sides with the elbows flexed less than 90°, all pressure points padded with gel cushions. A postpositioning neuromonitoring check confirmed stable SSEPs and MEPs prior to incision.

3. Surgical Exposure

Two separate 6–8 cm longitudinal midline incisions were marked: one in the upper thoracic region spanning T1–3 and another in the lower lumbar region over L3–5. Subperiosteal dissection of the paraspinal musculature exposed the posterior elements—laminae, facet joints, and transverse processes—at the planned anchor vertebrae. Dissection was deliberately confined to these levels to preserve the muscular and ligamentous integrity of the intermediate segments, thereby minimizing spontaneous autofusion. Hemostasis was achieved throughout using bipolar cautery set to 20 W and topical hemostatic agents (oxidized regenerated cellulose). In neuromuscular or pelvic-obliquity cases requiring extended fixation, the exposure was lengthened cranially or caudally to accommodate iliac or sacral anchors.

4. Anchor Placement

At the proximal thoracic incision, unilateral pedicle screws (5.5-mm diameter, polyaxial titanium) were inserted into T1–3 under direct visualization and confirmed with anterior-posterior (AP) and lateral view C-arm. Distally, contralateral site pedicle screws of 6.0-mm diameter were placed at L3–5. All screw trajectories were checked with a small-diameter pedicle probe and confirmed AP and lateral view C-arm (Figure 2).

5. Rod Contouring and Insertion

Two 5.5-mm titanium rods (traditional system) were contoured on a sterile bending template to reestablish physiological sagittal alignment—targeting 20° of thoracic kyphosis and 40° of lumbar lordosis. Rod lengths were calculated to span from the superior thoracic to the inferior lumbar anchors, allowing for 20–30 mm of future distraction at each end. A custom subfascial tunneling instrument was used to pass rods between incisions, and each rod was seated sequentially—commencing on the concave side—to effect preliminary 3-dimensional (3D) correction.

6. Domino Insertion and Distraction

While the pedicle screw and rod were placed securely, 2 dominos were added at the apex of the curve holding each unilateral rod. We obtained exposure for site of the domino insertion between T4 and L3. After the domino inserted, we confirmed if the domino was in the right apex point. Then, we did the distraction by specialized distraction tools. Distraction was performed by adding 10 times pressure to the instruments then the screw on the domino locked using screwdriver (Figures 3 and 4).

7. Bone Grafting and Wound Closure

Autogenous bone graft was harvested from the excised spinous processes of T1–3 and L3–5, morselized, and packed around the screw-rod interfaces to promote foundational fusion. Supplemental freeze-dried allograft chips were layered over the graft beds but were omitted from intermediate levels to preserve mobility. After copious saline irrigation, the wound was closed in anatomical layers: deep fascia, muscle and subcutaneous tissues with interrupted sutures, and skin with a running subcuticular suture, reinforced externally with skin adhesive. Sterile, occlusive dressings were applied.

8. Postoperative Management

The patient was extubated in the operating room after confirming adequate spontaneous ventilation and stable neurological examination. Upright posterior-anterior and lateral radiographs were obtained within 6 hours to verify implant position and spinal alignment. Early mobilization began 24 hours postoperatively, progressing from edge-of-bed sitting to ambulation with physical-therapy assistance. Scheduled rod lengthenings were planned every 6 months for traditional. Serial radiographic assessments at each visit evaluated distraction gains, alignment maintenance, and hardware integrity, with definitive posterior spinal fusion deferred until Risser stage ≥4.

9. Informed Consent

The patient was informed about the procedure and provided written consent for the use of intraoperative and follow-up data in this publication.

RESULTS

A 9-year-old female with early-onset idiopathic scoliosis underwent evaluation with standing, full-spine posteroanterior and lateral radiographs, which revealed a rigid right thoracic curve measuring 107° and a compensatory lumbar curve of 62°. Preoperative spirometry demonstrated a mild restrictive deficit (forced vital capacity 72% of predicted), attributable to thoracic cage deformity. Given her skeletal immaturity (Risser 0) and rapid curve progression, she was selected for insertion of growing rods with domino technique for thoracic to lumbar regions (Table 1).

Under general anesthesia with continuous somatosensory and motor‐evoked potential monitoring, unilateral pedicle screws were placed at T1–3 proximally and contralateral site at L3–5 distally. Titanium rods were contoured to restore physiological sagittal profiles and tunneled submuscularly. Intraoperative distraction of 20 mm yielded a reduction of the thoracic curve to 42° and the lumbar curve to 20°, with no significant changes in neuromonitoring signals. Intraoperative fluoroscopy and immediate postoperative radiographs confirmed accurate hardware placement and maintained coronal and sagittal alignment.

The patient’s postoperative course was uneventful. She was extubated in the operating room and transferred to recovery in stable condition. By postoperative day 1, she commenced assisted mobilization and was discharged on day 4 with intact neurological function, adequate pain control, and clean, well-healed incisions. Discharge radiographs demonstrated preservation of the intraoperative correction.

At 6-month follow-up visits, outpatient growing-rod distractions were performed. Serial radiographs showed an additional 5 mm of spinal lengthening and maintained coronal and sagittal alignment. There were no early complications such as wound infection, implant loosening, junctional kyphosis, rod fracture, or autofusion during this short follow-up period. However, the six-month duration is insufficient to assess long-term risks that typically arise in growing-rod treatment, including rod breakage, crankshaft progression, anchor pullout, or attenuation of distraction capability (Figure 5).

Clinically, the patient demonstrated improved shoulder balance and trunk symmetry. Objective postoperative pulmonary function testing was not performed, which limits interpretation of respiratory improvement. Similarly, validated patient-reported outcome measures such as the Early-Onset Scoliosis Questionnaire-24 (EOSQ-24) or Pediatric Outcomes Data Collection Instrument (PODCI) were not obtained, which restricts assessment of functional and quality-of-life outcomes. Caregivers reported subjective improvement in appearance and daily activity tolerance.

DISCUSSION

The outcomes observed in this case underscore the utility of growing rods with domino technique for addressing advancing EOS while simultaneously safeguarding spinal growth. In contrast to traditional modalities—such as serial casting, bracing, or premature fusion—which often prove inadequate for severe, rapidly progressive deformities in very young children [10,11]. However, despite these advantages, it is important to recognize that distraction-based constructs also carry several potential risks. Complications such as proximal junctional kyphosis, anchor pullout, deep and superficial infection, crankshaft progression, and unintended autofusion are well documented in EOS literature and remain important considerations even when no early adverse events are observed.

A principal benefit demonstrated here from the technique was the capacity to effect significant 3D correction during the index procedure without committing the majority of spinal segments to fusion [12]. The distraction-driven mechanism permitted incremental realignment under direct neuromonitoring oversight, thereby mitigating neural-injury risk [13]. Early postoperative imaging confirmed the stability of the construct, and the device’s responsiveness during outpatient lengthenings affirmed its mechanical reliability. Furthermore, meticulous rod contouring ensured maintenance of physiological sagittal curvatures—a critical determinant of balanced global alignment that can be compromised by overly aggressive correction strategies [13].

From the patient and family standpoint, domino technique markedly lessened the cumulative psychological and physical stress associated with repeated operative lengthenings typical of traditional growing-rod protocols. This child thus avoided multiple anesthetic exposures and hospital admissions, and her caregivers reported high satisfaction with the minimally invasive, clinic-based distractions. The absence of early complications—such as surgical-site infection, implant fracture, or anchor loosening—further highlights the safety profile of domino technique in appropriately selected patients [14].

Nevertheless, vigilance through long-term follow-up remains imperative. As spinal growth continues, the potential for implant fatigue, rod breakage, and unintended autofusion persists, and definitive posterior fusion will ultimately be required upon skeletal maturity [15]. Regular radiographic surveillance is essential to verify sustained distraction efficacy and ongoing spinal lengthening. A multidisciplinary care model and thorough patient–family education are therefore key to optimizing outcomes. Collectively, this report adds to the growing evidence supporting domino technique as a reliable and effective modality for complex early spinal deformities.

Additionally, although the short-term results are promising, several critical limitations must be emphasized in accordance with current EOS literature. This report describes a single-patient experience using a unilateral construct, which is not considered standard of care. Bilateral growing-rod systems provide significantly greater mechanical stability and lower rod fracture rates, and therefore the outcomes here cannot be generalized or interpreted as equivalent to bilateral constructs. The follow-up period of 6 months is also insufficient to evaluate long-term complications that typically appear after 1 to 2 years, including rod fatigue, junctional kyphosis, anchor pullout, the crankshaft phenomenon, and unintended autofusion. Functional and quality-of-life outcomes likewise cannot be fully assessed because postoperative pulmonary function tests and validated patient-reported tools such as EOSQ-24 or PODCI were not obtained. Furthermore, although the title mentions cost-effectiveness, the manuscript does not include any data regarding implant cost, operative duration, hospitalization length, or frequency of distractions, and therefore no economic conclusion can be drawn. Future work should include longer follow-up, comparative cohorts using bilateral or magnetically controlled systems, systematic reporting of complications, validated functional outcome instruments, and structured cost analyses to clarify the long-term value of the domino-assisted construct.

CONCLUSION

This report underscores the favorable safety profile, therapeutic effectiveness, and practical utility of domino technique in the management of severe EOS. The intervention achieved marked 3D deformity correction while permitting ongoing vertebral and thoracic growth and obviating serious complications through percutaneous outpatient distractions. Initial follow-up confirmed construct integrity, enhanced respiratory mechanics, and improved trunk aesthetics, with both the patient and her family expressing high levels of satisfaction. These findings support domino technique as a compelling treatment modality for skeletally immature individuals, offering robust curve control, minimized cumulative surgical trauma, and preservation of future fusion options.