Apical and intermediate anchors without fusion improve Cobb angle and thoracic kyphosis in early-onset scoliosis

Corrective Maneuvers Used in Different Scoliosis Deformities With the Experience of 72 Operated Patients

PURPOSE

This study aimed to show the correction maneuvers used in scoliosis surgery and give hints and tips on achieving optimal correction with the help of visual content.

MATERIALS AND METHODS

Seventy-two scoliosis patients with 96 major curves operated between 2011 and 2018 evaluated retrospectively. Seven different correction maneuvers (Ucar convex rod rotation technique, cantilever technique, convex double-rod rotation technique, convex double-rod translation technique, double-rod rotation with coronal bending, convex rod rotation with coronal bending, direct vertebral rotation) were used in these surgeries alone or together. Each method is explained with figures and videos. Type of scoliosis, follow-up time, age, preoperative and postoperative degree of curvature, amount of correction, surgical time, amount of transfusion, hemoglobin level, and hospital stay were evaluated.

RESULTS

The mean follow-up was 42.5 (24-108) months, and the mean age was 15.8 (12-29) years. The mean preoperative scoliosis angle of the patients was 75.9 (50-139) degrees, and the final follow-up was 15.6 (5-40) degrees. The scoliotic deformity correction rate was 79.3%. The mean preoperative thoracic kyphosis of the patients was 58.7 (12-110) degrees, and the final follow-up was 41.2 (25-62) degrees. The mean surgical time was 293 (160-440) minutes. The mean hospitalization length was 5.8 (2-21) days. The blood delivered to patients during surgery and postoperative was 715 (300-1800) mL. There was a statistically significant difference between the preoperative and final follow-up scoliosis angle ( P =0.000).

CONCLUSIONS

Providing an ideal correction without damaging the spinal cord depends on correctly applying the correction maneuvers. The use of correction maneuvers alone or in combination in the appropriate order will shorten the duration of the case, decrease the amount of bleeding, shorten the hospital stay, increase the amount of correction, and reduce complications.

The Clinical and Imaging Outcome of the Tandem Growing Rod Technique in Early-Onset Scoliosis With the Proximal Upper Thoracic Curve Progression: A Modified Technique of Growing Rod

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The orthopaedic ability of traditional GR for severe EOS is limited. The proximal upper thoracic curve may progress during the lengthening procedure, which may lead to coronal imbalance and inhibit the longitudinal growth of the spine. In this retrospective cohort study, we investigated the clinical outcome of tandem GR.

METHODS

We modified the traditional technique by using two groups of GR devices to control the major and the proximal upper thoracic curve, connected the two groups of GR in series, and named it tandem GR. The clinical and imaging outcomes of the new technique were evaluated and compared with traditional technique.

RESULTS

Twenty one patients were enrolled in the tandem GR group, and 30 patients were treated with traditional GR as the control. The baseline parameters were consistent between the two groups. In the tandem GR group, the secondary curve progressed from 24.9 ± 3.9° to 31.4 ± 3.2° (P = .006) in the procedure with the traditional GR and improved to 18.4 ± 4.5° (P = .001) after the switch. Meanwhile, the clavicular angle aggravated from 1.6 ± 1.0° to 2.6 ± .7° (P = .041), and improved to 1.7 ± .8° after changed to the tandem GR (P = .033). At the final of the follow-up, the secondary curve was higher in the control group (27.1 ± 8.3° vs 18.4 ± 4.5°, P = .034), the clavicle angle was 2.4 ± 1.1° in control and 1.7 ± .8° in the tandem GR group (P = .028), the T1-S1 height was 28.2 ± 4.8 cm in the control and 33.3 ± 3.0 cm in the tandem GR group (P = .027). The average growth rate was 1.0 ± .3 cm/year in the control and 1.2 ± .4 cm/year in the tandem GR group (P = .046).

CONCLUSION

Tandem GR can effectively improve the proximal upper thoracic curve progression during the treatment of EOS. Compared with the traditional GR, tandem GR can achieve better curve correction, better shoulder balance, and retains more capacity for longitudinal spine growth.

Dual Growing Rods Combined With the Apical Convex Control Pedicle Screw Technique Versus Traditional Dual Growing Rods for the Surgical Treatment of Early-Onset Scoliosis: A Case-Matched 2-Year Study

BACKGROUND

Combination of apical control convex pedicle screws (ACPS) with traditional dual growing rods (TDGRs) had better apex control ability for early-onset scoliosis (EOS); however, there is a paucity of studies on the ACPS technique.

OBJECTIVE

To compare 3-dimensional deformity correction parameters and complications between the apical control technique (DGR + ACPS) and TDGR in the treatment of EOS.

METHODS

A retrospective case-match analysis consisting of 12 cases of EOS treated with the DGR + ACPS technique (group A) from 2010 to 2020, and matched with TDGR case (group B) at a ratio of 1:1 by age, sex, curve type, major curve degree, and apical vertebral translation (AVT). Clinical assessment and radiological parameters were measured and compared.

RESULTS

Demographic characteristics, preoperative main curve, and AVT were comparable between groups. The correction ability of the main curve, AVT, and apex vertebral rotation were better in group A at index surgery ( P < .05). The increase in T1-S1 and T1-T12 height was large in group A at index surgery ( P = .011, P = .074). The annual increase in spinal height was slower in group A, but without significant difference. The surgical time and estimated blood loss were comparable. Six complications occurred in group A, and 10 occurred in group B.

CONCLUSION

In this preliminary study, ACPS seems to provide better correction of apex deformity, while attaining the comparable spinal height at 2-year follow-up. Larger cases and longer follow-up are needed to achieve reproducible and optimal results.

Hybrid technique versus traditional dual growing rod technique to treat congenital early-onset scoliosis: a comparative study with more than 3 years of follow-up

OBJECTIVE

The authors' objective was to compare the intermediate outcomes of patients with severe congenital early-onset scoliosis (CEOS) treated with posterior vertebrectomy/hemivertebrectomy with short fusion and dual growing rods (hybrid technique [HT]) and those treated with traditional dual growing rods (TDGRs).

METHODS

A retrospective study of patients who underwent the HT and TDGR technique for CEOS was conducted. The inclusion criteria were CEOS (age < 10 years), Risser stage 0, treatment with HT or TDGR, index surgery performed between 2004 and 2017, and minimum follow-up of 3 years. For patients who completed lengthening procedures, the last lengthening procedure was considered the latest follow-up. Demographic, radiographic, clinical, and patient-reported outcomes and revisions were compared between groups.

RESULTS

Sixty-one patients with CEOS were included in this study, with 16 treated with HT and 45 with TDGR technique. There were no differences in age at index surgery, duration of treatment, or number of lengthening procedures. The lengthening interval was longer in the HT group. The preoperative mean ± SD main curve was 81.8° ± 17.1° for the HT group and 63.3° ± 16.9° for the TDGR group (p < 0.05). However, main curve correction was better in the HT group, and no differences in residual curve were found between groups. Although the preoperative apex vertebral translation (AVT) of the HT group was greater, the correction of AVT was better in the HT group (p < 0.05). No differences in T1-S1 and T1-12 height were found between groups at the latest follow-up. The growth of T1-S1 height was less in the HT group (p < 0.05), whereas the growth of T1-12 height was similar between groups. Patients in the HT group had a lower risk of mechanical complications but higher risks of dural tears and neurological complications.

CONCLUSIONS

HT may provide better correction and apex control ability than TDGR for EOS patients with severe and rigid deformity at the apex level, and it significantly decreased the risk of mechanical complications with little influence on growth of the thoracic spine. HT may be an option for patients with severe CEOS with large asymmetrical growth potential around the apex of the curve.

Comparison of surgical interventions for the treatment of early-onset scoliosis: a systematic review and meta-analysis

OBJECTIVE

Several growth-preserving surgical techniques are employed in the management of early-onset scoliosis (EOS). The authors' objective was to compare the use of traditional growing rods (TGRs), magnetically controlled growing rods (MCGRs), Shilla growth guidance techniques, and vertically expanding prosthetic titanium ribs (VEPTRs) for the management of EOS.

METHODS

A systematic review of electronic databases, including Ovid MEDLINE and Cochrane, was performed. Outcomes of interest included correction of Cobb angle, T1-S1 distance, and complication rate, including alignment, hardware failure and infection, and planned and unplanned reoperation rates. The percent changes and 95% CIs were pooled across studies using random-effects meta-analysis.

RESULTS

A total of 67 studies were identified, which included 2021 patients. Of these, 1169 (57.8%) patients underwent operations with TGR, 178 (8.8%) Shilla growth guidance system, 448 (22.2%) MCGR, and 226 (11.1%) VEPTR system. The mean ± SD age of the cohort was 6.9 ± 1.2 years. The authors found that the Shilla technique provided the most significant improvement in coronal Cobb angle immediately after surgery (mean [95% CI] 64.3% [61.4%-67.2%]), whereas VEPTR (27.6% [22.7%-33.6%]) performed significantly worse. VEPTR also performed significantly worse than the other techniques at final follow-up. The techniques also provided comparable gains in T1-S1 height immediately postoperatively (mean [95% CI] 10.7% [8.4%-13.0%]); however, TGR performed better at final follow-up (21.4% [18.7%-24.1%]). Complications were not significantly different among the patients who underwent the Shilla, TGR, MCGR, and VEPTR techniques, except for the rate of infections. The TGR technique had the lowest rate of unplanned reoperations (mean [95% CI] 15% [10%-23%] vs 24% [19%-29%]) but the highest number of planned reoperations per patient (5.31 [4.83-5.82]). The overall certainty was also low, with a high risk of bias across studies.

CONCLUSIONS

This analysis suggested that the Shilla technique was associated with a greater early coronal Cobb angle correction, whereas use of VEPTR was associated with a lower correction rate at any time point. TGR offered the most significant height gain at final follow-up. The complication rates were comparable across all surgical techniques. The optimal surgical approach should be tailored to individual patients, taking into consideration the strengths and limitations of each option.

A comparison of growth among growth-friendly systems for scoliosis: a systematic review

BACKGROUND CONTEXT

The optimal method for surgical treatment of early onset scoliosis is currently unknown. Although the aim of growth-friendly systems is to reduce the curve and maintain growth, there is no consensus on how to measure spinal growth during and after the treatment. Different measurements of different segments (T1-S1, T1-T12, instrumented length) are used for different time points to evaluate growth. The aim of this review is to assess what measurements are used and to compare the growth-friendly systems based on spinal growth during treatment.

METHODS

The electronic MEDLINE, EMBASE, and Cochrane databases were systematically searched for original articles that reported growth for traditional growing rods (TGR), vertical expandable prosthetic titanium rib expansion technique (VEPTR), Shilla, magnetically controlled growing rods (MCGR), and Luque-trolley systems. All measurements were recorded, and weighted averages calculated in centimeter per year were compared.

RESULTS

We included 52 studies (26 TGR, 12 MCGR, 6 VEPTR, 4 Luque trolley, 1 Shilla, and 3 mixed). Often only one segment was reported (T1-S1 length in 22 studies, T1-T12 length in two studies, and instrumented length in five studies). The remaining 22 studies reported T1-S1 length in combination with T1-T12 length (15 studies) or instrumented length (eight studies). Spinalgrowth achieved by initial correction only was a considerable 3.9 cm (based on 34 studies) as well as the spinal growth achieved by the final fusion surgery (2.3 cm in four studies). To specifically assess growth achieved with the system, length gain after initial surgery and before final fusion in growth system graduates was considered. Only four TGR studies reported on this "true" spinal growth with 0.6 and 0.3 cm/y in the T1-S1 and T1-T12 segment, respectively.

CONCLUSIONS

Reporting on spinal growth is currently inadequate and does not allow a good comparison of different techniques. However, all systems often report growth similar to Dimeglio's T1-S1 spinal growth of 1 cm/y. It should be recognized though that a considerable portion of the reported spinal growth is the result of the initial and final surgical correction and not due to the growth-friendly implant.

Surgical growth guidance with non-fused anchoring segments in early-onset scoliosis

PURPOSE

Surgical treatment of early-onset scoliosis (EOS) requires a balance between maintained curve correction and the capacity for spinal and thoracic growth. Spinal fusion creates irreversible conditions that prevent the implementation of further treatment methods. Our hypothesis was that non-fused anchors in growth guidance show a comparable outcome as the technique described in the literature, which involves spondylodesis of the anchoring segments.

METHODS

This retrospective study analysed 148 surgeries in 22 EOS patients (11 female, 11 male) over a 15-year period. Patients underwent surgery with non-fused anchors and growth guidance techniques. Scoliosis, kyphosis, growth and anchoring segments were measured. For the latter, a new measuring technique was developed. Complications were recorded and classified.

RESULTS

The mean Cobb angle reduced from 73.5 ± 24.4° to 28.4 ± 16.2° (60.2 ± 22.9%, p < 0.001) at the last follow-up. Spinal growth T1-S1 and T1-T12 were 41.1 ± 23.3 mm and 24.9 ± 16.6 mm (p < 0.001), respectively. Growth at the cranial and caudal anchoring segment was 1.5 mm/segment/year and 1.9 mm/segment/year, respectively. A total of 63 complications were documented in 20 patients, with 40 requiring unplanned revision surgery. Definitive spondylodesis was performed in three patients.

CONCLUSION

Patients demonstrated a significant spinal growth including the anchoring segments. A comparable correction in Cobb angle and the type of complications was noted, although the rate of device-related complications was higher. No permanent impairment was reported. The rate of device-related complications is acceptable and outweighed by the significant degree of growth preservation and more flexible and individualised treatment strategy for patients with EOS. These slides can be retrieved under Electronic Supplementary Material.

Comparison of Intended Lengthening of Magnetically Controlled Growing Rods: Ultrasound Versus X-Ray

BACKGROUND

In the treatment of early onset scoliosis (EOS), there has been a trend to use magnetically controlled growing rods (MCGR) in order to reduce the number of surgeries. To confirm the amount of lengthening, spine radiographs were required. Recently, ultrasound (US) has been added to monitor lengthening of MCGR to avoid radiation exposure. Our aim was to determine whether US is as accurate as plain radiography (x-ray) in determining the amount of length achieved at individual MCGR lengthening episodes.

METHODS

Retrospective study; inclusion criteria: EOS cases with dual MCGR with minimum 12 months follow-up. Intended lengthening IL (mm), lengthening on US (mm) and x-ray (mm) were documented from medical records for both right and left rods. Primary (no surgery before MCGR) and conversion (other types of instrumentation were replaced with MCGR) cases were reviewed separately. P-values determined with analysis of variance.

RESULTS

Sixteen cases with 100 lengthening episodes met the inclusion criteria. Eleven were primary MCGR cases with 67 episodes. Mean follow-up was 19±5 months. Significant differences were found between IL (3.4±1 mm), US (2.7±1.9 mm), and x-ray (4.1±2.2 mm) (P<0.001). The difference between IL and x-ray was minimal, but statistically significant (P=0.046). US showed statistically lower values than both IL (P=0.001) and x-ray (P<0.001). The mean ratio of x-ray/IL, US/IL, and US/x-ray were 1.1, 0.75, and 0.84, respectively. Five conversion cases had 33 episodes. Mean follow-up was 21±2 months. Significant differences were found between IL (3.4±0.8 mm), US (1.3±0.8 mm), and x-ray (1.7±0.9 mm) (P<0.001) but there was no significant difference between US and x-ray (P=0.283). IL was significantly higher than both US (P< 0.001) and x-ray (P<0.001). The mean ratio of x-ray/IL, US/IL, and US/x-ray were 0.64, 0.41, and 1.1, respectively.

CONCLUSIONS

US can provide confirmatory information of noninvasive lengthening of MCGR. However, US tended to underestimate the achieved length as measured by x-ray in primary cases. Conversion cases demonstrate better concordance between US and x-ray but in these cases less overall length was achieved at each lengthening episode.

LEVEL OF EVIDENCE

Level III.

A re-evaluation of the effects of dual growing rods on apical vertebral rotation in patients with early-onset scoliosis and a minimum of two lengthening procedures: a CT-based study

OBJECTIVE This study aimed to evaluate the correction results of traditional dual growing rods (DGRs) on axial rotation using CT scans and to further explore the relationships between axial and torso deformities in patients with early-onset scoliosis (EOS). METHODS Patients with EOS who were treated with traditional DGRs between January 2006 and December 2014 were retrospectively reviewed. Plain radiographs were used to assess the degree of coronal and sagittal deformity. The apical vertebral rotation (AVR) and rib hump (RH) were measured on CT scans at the apical vertebra. Pearson or Spearman rank correlation analyses were used to analyze the associations between spinal and torso deformities. RESULTS A total of 27 patients (10 boys and 17 girls, average age 6.5 ± 1.7 years) were enrolled in this study. The average number of lengthenings per patient was 5.0 ± 1.9, with a mean follow-up duration of 52.9 ± 18.2 months. The apical vertebral translation, apical vertebral body-rib ratio (AVB-R), AVR, and RH parameters were significantly decreased after the initial surgery (p < 0.05) but showed notable progression at the latest follow-up evaluation (p < 0.05). The preoperative AVR and its correction after index surgery were significantly correlated with the preoperative values as well as with the corrections of the major Cobb angle, AVB-R, and RH. During the follow-up period, significant correlations were found between the deterioration of AVR and the AVB-R and also between the deterioration of AVR and the RH from the initial surgery to the latest follow-up. CONCLUSIONS Significant AVR correction can be achieved by DGR techniques after the initial surgery. However, this technique weakly prevents the deterioration of AVR during the follow-up period.

Treatment of early-onset scoliosis with a hybrid of a concave magnetic driver (magnetic controlled growth rod) and a contralateral passive sliding rod construct with apical control: preliminary report on 17 cases

BACKGROUND CONTEXT

Magnetic controlled growth rods (MCGRs) are increasingly popular for surgical treatment of severe early-onset scoliosis (EOS), because they allow noninvasive extensions with good growth maintenance. We combined an MCGR with a contralateral passive sliding rod construct with apical control on the convex side to improve efficiency in terms of costs and three-dimensional (3D) correction.

PURPOSE

To investigate the feasibility, 3D correction, spinal growth, and complications of the apical control MCGR sliding rod hybrid.

STUDY DESIGN

Two-center retrospective cohort study.

PATIENT SAMPLE

A consecutive series of 17 children with EOS from two European spine centers were treated with the hybrid principle: 13 primary cases and 4 conversion cases from other growth instrumentation. Median age at surgery was 9 years (range: 6-18). Median follow-up time was 24 months (range: 12-31).

OUTCOMES

Cobb angles (frontal Cobb, kyphosis, lordosis), rotation, spinal length gain, growth rate, and complications.

METHODS

Radiographs and patient files were reviewed. All the patients received fully financed treatment within the national public health-care systems.

RESULTS

Mean preoperative frontal Cobb angle was 59°, reduced postoperatively to 30° and was maintained throughout follow-up. Mean rotation of the apical vertebra improved from 27° to 18°, but was partially lost over time. Kyphosis decreased and lordosis was largely unaltered. Instrumented spine growth was maintained at a mean of 12 mm per year. One child had surgical revision because of progressive trunk shift, unrelated to the technique. The same child fell and sustained T1 and T2 fractures that were treated conservatively. Another child is planned for revision because of MCGR distraction failure.

CONCLUSION

These early results show satisfactory frontal Cobb curve reduction and maintenance of spinal growth after using a new hybrid concept of a single magnetic growth rod and contralateral apical control sliding rods. A single magnetic growth rod in this combination may work equally well as traditional or dual magnetic growth rods. This new concept may represent a significant gain in both cost-effectiveness of growth rod treatment and 3D correction in EOS.