Dual Growing Rod Research Articles

Do Pedicle Screws That Terminate in the Costovertebral Joint Compromise Proximal Anchor Fixation in a Dual Growing Rod Construct?

Growing rods (GRs) are used to treat early-onset scoliosis (EOS) recalcitrant to bracing and casting. Proximal anchor pullout, a known complication of GR constructs, can result in spinal cord injury if pedicle screw anchors are placed with a lateral-to-medial trajectory. To mitigate this risk, a more straightforward and potentially safer trajectory may result in screws that terminate within the costovertebral joint (CVJ). We asked, how often does CVJ placement occur and does this technique increase the rate of failure in GR constructs? We retrospectively reviewed 35 patients with EOS treated with dual GR with >2-year follow-up excluding patients with skeletal dysplasia or history of previous posterior instrumentation. Patient demographics, radiographic parameters, and implant constructs were assessed. Of patients meeting the inclusion criteria, 18/35 (51%) were females with an average age of 7.96 (range: 4.0 to 15.2) years at surgery with a follow-up of 3.7 (range: 2.0 to 7.7) years. Five (14%) patients had idiopathic EOS, 5 (14%) had congenital EOS, 12 (34%) had neuromuscular EOS, 10 (29%) had syndromic scoliosis, and 3 (9%) had another etiology for EOS. Among 195 proximal pedicle screws placed, 19 (10%) terminated within the CVJ, and 13 patients (37%) had at least 1 CVJ screw. Two patients (6%) experienced unilateral proximal pullout. In both patients, the anchors on the affected side included 1 of 2 screws within the CVJ. Both patients had constructs that included 2 screws on the side that pulled out and 3 screws on the side that did not. None of the remaining 17 CVJ screws led to implant failure. Pedicle screw placement within the CVJ is common and does not appear to significantly contribute to proximal screw pullout; however, it may contribute to unilateral implant failure in constructs employing only 2 proximal screws, where 1 of those 2 screws terminates within the CVJ. Construct modifications should be considered in this scenario. Level III.

Long-Term Radiographic and Pulmonary Function Outcomes After Dual Growing-Rod Treatment for Severe Early-Onset Scoliosis.

We evaluated long-term outcomes (radiographic parameters and pulmonary function) at a minimum follow-up of 5 years after use of dual growing rods (DGRs) to treat severe early-onset scoliosis (sEOS). Among a total of 112 patients who were diagnosed with early-onset scoliosis (EOS) and were treated with DGRs between 2006 and 2015, 52 patients had sEOS, with a major Cobb angle of >80°. Of these patients, 39 with a minimum follow-up of 5 years had complete radiographic and pulmonary function test results and were included. The Cobb angle of the major curve, T1-S1 height, T1-T12 height, and maximum kyphosis angle in the sagittal plane were measured on radiographs. Pulmonary function test results were collected in all patients before the initial operation (preoperatively), 12 months after the initial operation (postoperatively), and at the last follow-up. The changes in pulmonary function and complications during treatment were analyzed. The mean age of patients before the initial operation was 7.7 ± 1.2 years, and the mean follow-up period was 75.0 ± 14.1 months. The mean number of lengthenings was 4.5 ± 1.3, and the mean interval between lengthenings was 11.2 ± 2.1 months. The Cobb angle improved from 104.5° ± 18.2° preoperatively to 38.1° ± 10.1° after the initial surgical procedure (postoperatively) and 21.9° ± 8.6° at the final follow-up. The T1-S1 height increased from 25.1 ± 4.0 cm preoperatively to 32.4 ± 3.5 cm postoperatively and to 39.5 ± 4.0 cm at the final follow-up. However, no significant difference was detected between the increased pulmonary function parameters at 1 year and those before the operation (p > 0.05), except for residual volume, whereas pulmonary function parameters had significantly increased at the final follow-up (p < 0.05). During the treatment period, 17 complications occurred in 12 patients. DGRs are effective in treating sEOS in the long term. They allow longitudinal growth of the spine, and the correction of the spinal deformity can provide conditions that make improving pulmonary function possible in patients with sEOS. Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Growing rod technique with prior foundation surgery and sublaminar taping for early-onset scoliosis.

The aim of this study was to show the surgical results of growing rod (GR) surgery with prior foundation surgery (PFS) and sublaminar taping at an apex vertebra. Twenty-two early-onset scoliosis (EOS) patients underwent dual GR surgery with PFS and sublaminar taping. PFS was performed prior to rod placement, including exposure of distal and proximal anchor areas and anchor instrumentation filled with a local bone graft. After a period of 3-5 months for the anchors to become solid, dual rods were placed for distraction. The apex vertebra was exposed and fastened to the concave side of the rods using sublaminar tape. Preoperative, post-GR placement, and final follow-up radiographic parameters were measured. Complications during the treatment period were evaluated using the patients' clinical records. The median age at the initial surgery was 55.5 months (range 28-99 months), and the median follow-up duration was 69.5 months (range 25-98 months). The median scoliotic curves were 81.5° (range 39°-126°) preoperatively, 30.5° (range 11°-71°) after GR placement, and 33.5° (range 12°-87°) at the final follow-up. The median thoracic kyphotic curves were 45.5° (range 7°-136°) preoperatively, 32.5° (range 15°-99°) after GR placement, and 42° (range 11°-93°) at the final follow-up. The median T1-S1 lengths were 240.5 mm (range 188-305 mm) preoperatively, 286.5 mm (range 232-340 mm) after GR placement, and 337.5 mm (range 206-423 mm) at the final follow-up. Complications occurred in 6 patients (27%). Three patients had implant-related complications, 2 patients had alignment-related complications, and 1 patient had a wound-related complication. A dual GR technique with PFS and sublaminar taping showed effective correction of scoliotic curves and a lower complication rate than previous reports when a conventional dual GR technique was used.

Outcomes of growing rods in a series of early-onset scoliosis patients with neurofibromatosis type 1.

Early-onset scoliosis (EOS) is not uncommon in patients with neurofibromatosis type 1 (NF1). Despite conservative treatment, spinal deformities progress and require early surgical intervention. To avoid potential interference with chest and trunk growth, growing rods (GRs) have been used effectively in EOS of various etiologies. In this study the authors sought to analyze the outcomes of GRs in EOS patients with NF1. This was a retrospective single-center cohort study that included consecutive EOS patients with NF1 who were treated with GRs and were followed up for a minimum of 2 years. Clinical and radiological analyses were performed preoperatively and until the last follow-up. From to 2008 to 2017, 18 patients (6 male, 12 female) underwent GR surgery (14 single GRs, 4 dual GRs) at a mean age of 8 ± 2.1 years. Mean follow-up was 5 ± 2.4 years. Fifty-five lengthenings were performed at a mean rate of 3 lengthenings per patient (range 0-7). Ten of 14 single GRs (71%) were converted into dual GRs during treatment. No patient underwent definitive posterior spinal fusion (PSF) at GR treatment completion. The mean initial and last follow-up major curves were 57° and 36°, respectively (p < 0.001, 37% correction). The average T1-S1 increase was 13 mm/yr. Six of 9 hyperkyphotic patients had normal kyphosis at last follow-up. There were 26 complications involving 13 patients (72%), with 1 patient who required unplanned revision. The primary complications were instrumentation related, consisting of 17 proximal hook dislodgments, 6 distal pedicle screw pullouts, and 2 rod fractures. Only 1 patient experienced a mechanical complication after dual GR implantation. There were no wound infections. The GR technique provided satisfactory spinal deformity control in EOS patients with NF1 while allowing substantial spinal growth. Adequately contoured dual GRs with proximal hooks placed in nondystrophic regions should be used to minimize implant-related complications. Surgeons should not attempt to correct kyphosis at GR implantation.

Outcomes at Skeletal Maturity of 34 Children With Scoliosis Treated With a Traditional Single Growing Rod.

Retrospective case series. To analyze the outcomes at skeletal maturity of patients treated with a single traditional growing rod (GR). To compare results of patients according to whether posterior spinal fusion (PSF) was performed at treatment completion. Few studies examined the end results of GRs at skeletal maturity. There is no agreement on requirement of PSF at GR treatment completion. Clinical and radiological analysis of consecutive patients with severe and/or progressive scoliosis treated initially with traditional single GR. Group comparisons of patients with PSF and without fusion surgery at treatment completion. Thirty-four patients underwent traditional single GR implantation at a median age of 11.7 years. Median follow-up was 6.5 years. At last follow-up, T1-S1 distance was increased by a median 116 mm (P < 0.001) and median major curve Cobb angle was changed from 55° preoperatively to 30° (P < 0.001). Complications included 26 rod fractures, 1 implant prominence, 4 proximal junctional kyphosis, 2 proximal hook dislodgments, and 2 wound infections. At the beginning our experience, PSF was performed systematically in 17 patients. Relying on spinal ankylosis, 17 patients were subsequently not fused at GR treatment completion (single GR removed N = 2, single GR retained N = 7, dual GR surgery N = 8). There were no statistical differences between groups in improvements of radiological parameters from preoperative GR insertion to last follow-up. No GR fracture occurred after dual GR surgery. Single GR allows curve control and promotes spinal growth. Dual GR is, however, recommended for rod fracture prevention and better correction maintenance. In patients with satisfactory deformity correction at skeletal maturity, one may consider retaining dual GR instead of performing PSF. 4.

Vertebral Growth Around Distal Instrumented Vertebra in Patients With Early-Onset Scoliosis Who Underwent Traditional Dual Growing Rod Treatment.

Retrospective radiographic study. To investigate the growth of the vertebrae around distal instrumented vertebra (DIV) in patients with early-onset scoliosis (EOS) who underwent dual growing rod (DGR) treatment. Previous studies indicated that DGR was likely to preserve or even stimulate the spinal growth. However, report pertaining to the effect of growing rod on the growth of individual vertebral body is rare. The EOS patients treated with DGR who had at least four lengthenings and 5-year follow-up were enrolled. Spine radiographs at index surgery and final follow-up were reviewed. The height, width, and depth of vertebral body from DIV-2 to DIV+2, and the height of the adjacent intervertebral space (IVS) were measured. The percentage of growth was calculated. Thirty-one patients (mean age, 6.2 ± 2.5 years old) met the inclusion criteria, 74.2% (23/31) of whom were female. The average follow-up was 6.2 years (range, 5.0-10.4 yr). The measured vertebrae were divided into DIV group (n = 65), DIV- group (DIV-1 and DIV-2, n = 60), and DIV+ group (DIV+1 and DIV+2, n = 47). There were 33, 90, and 78 measured IVSs in DIV, DIV-, and DIV+ group, respectively. The total percentage growth of vertebral height was significantly higher in DIV- group than that in DIV and DIV+ groups (56.6 ± 20.3% vs. 45.6 ± 18.0% and 42.7 ± 16.2%, respectively, P ≤ 0.001). The vertebrae in DIV- group also had the highest annual height growth rate (8.7 ± 2.6% vs. 7.0 ± 2.4% and 6.6 ± 2.0%, respectively, P ≤ 0.001). A significant decrease of IVS height was observed in DIV- and DIV groups (P ≤ 0.001). Traditional DGR with periodical distraction stimulated the longitudinal growth of the two segments immediately above DIV in patients with EOS. DGR technique had a negative effect on the development of intervertebral discs within distracted levels. 3.

Hybrid Growing Rod Technique of Osteotomy With Short Fusion and Spinal Distraction

Retrospective study. The current study aimed to evaluate the effectiveness of the hybrid growing rod (GR) technique for the treatment of young children with congenital scoliosis (CS). Congenital vertebral anomalies within long-spanned kyphoscoliosis were difficult to be managed by either definitive spinal fusion or standard GR technique. Hybrid technique of one-stage posterior osteotomy with short fusion and GR distraction was proposed in previous studies. There is, however, paucity of data regarding its effectiveness. Thirteen patients (mean age, 5.4 ± 2.0 yr) who had undergone hybrid GR treatment were retrospectively reviewed, including 8 patients treated with single GR and 5 patients with dual GR. All of their radiographic data were measured, and surgical complications were recorded. On average, the current cohort had 4.1 ± 1.7 lengthening procedures. After the index surgery, the major curve improved remarkably from 86.4° ± 11.9° to 37.3° ± 12.4° (P < 0.001). The global kyphosis significantly decreased from 66.8° ± 16.1° to 33.3° ± 3.5° postoperatively. Both value remained steady during follow-up. There were no significant difference between single GR and dual GR groups in terms of the coronal deformity correction, whereas correction loss of global kyphosis in single GR group was significantly higher than that in dual GR group (P = 0.039). After the index surgery, T1-S1 height averagely gained 4.4 ± 0.8 cm and it grew at an average rate of 1.31 ± 0.24 cm/yr during the follow-up. Two complications were identified in two patients, including one with rod fracture and one with proximal junctional kyphosis. The hybrid GR technique was effective in correcting spinal deformity and allowing continuous spinal growth. The optimal indications were young children with apical vertebrae anomalies and a long-spanned kyphoscoliosis. 3.

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.

Staged insertion of growing rods in severe scoliosis.

The objective of this retrospective chart and radiographic review was to present the clinical outcomes and complication rate of a staged approach to modern dual growing-rod (GR) surgery when treating children with severe early onset scoliosis. Fifteen patients received a 6-mm dual GR system. During Stage 1, pairs of end vertebra were exposed in a subperiosteal fashion, instrumented, grafted, and fused. Stage 2 was performed, on average, 5months later (range 8-35weeks) and the fused foundations were connected with two growing rods under skull-femoral traction. Clinical and operative notes were reviewed and all complications were recorded. Radiographic measurements were assessed at pre-index, with intraoperative traction during Stage 1, post-Stage 2 and at most recent follow-up. Statistical analyses were performed to evaluate change in scoliosis and kyphosis. At initial surgery, the average age was 8.17 ± 1.5years. The mean Cobb angle was 88.1° ± 14.0°, corrected to 60.3° ± 8.7° (p < 0.001) with intraoperative traction in Stage 1, preserved after Stage 2 instrumentation (59.5° ± 9.6°, p = 0.69), and maintained with subsequent lengthenings (60.6° ± 12.8°, p = 0.73). Hyperkyphosis (11/15 patients) improved from 70.8° ± 15.7° to 46.6° ± 9.7° (p < 0.001). At minimum 2-year follow-up (range 24-80months, mean 49.5), the complication rate was 14 (0.93 complications/patient), including 6 rod breakages, 6 superficial infections, and 2 deep infections. No anchor migration or pull-out was noted. Seven patients have undergone definitive posterior spinal fusion. Staged insertion of dual GR systems permits strong distraction, with acceptable correction of severe deformities and minimal complications. These slides can be retrieved under Electronic Supplementary Material.

Biomechanical effects on adjacent segments of different growing-rod fixation in early onset scoliosis

Objective: To analyse the biomechanical effects on adjacent segments of different growing-rod (GR) fixation in early onset scoliosis through a finite element analysis method. Methods: A severe early-onset scoliosis patient was selected and the pre-operation and post-GR-operation (Upper instrumented levels: T(4), T(5). Lower instrumented levels: L(3), L(4)) whole spine 3-dimentional CT scan data were collected to build the finite models. Based on the different models, biomechanical differences on adjacent segments were analysed. Results: The stress on the adjacent structures decreased after the GR surgery compared with the pre-operation. Compared with the single GR, stress on T(3) vertebrae decreased by 6.2%, stress on T(3/4) disc decreased by 6.7%, stress on T(3/4) ligament decreased by 27.7%, stress on T(6) vertebrae decreased by 16.9%, stress on T(5/6) disc decreased by 1.2%, stress on T(5/6) ligament decreased by 40.4%, stress on L(2) vertebrae decreased by 32.6%, stress on L(2/3) disc decreased by 30%, stress on L(2/3) ligament decreased by 15.6%, stress on L(5) vertebrae decreased by 1.2%, stress on L(4/5) disc decreased by 15.7%, stress on L(4/5) ligament decreased by 100.0% in dual GR structure. The application of hook (s) on the upper instrumented vertebrae (s) decreased the stress on the cranial adjacent segment. Stress on T(3) vertebrae decreased by 2.8% and 2.2%, stress on T(3/4) disc decreased by 2.4% and 1.5%, stress on T(3/4) ligament decreased by 3.6% and 5.7% in single GR and dual GR models separately when the hook (s) were utilized. In the meanwhile, the stress on the adjacent segment was more concentrated in the single GR model. Conclusion: Dual-rod growing-rod and the application of hook (s) on the upper instrumented vertebrae could reduce the stress on the adjacent segments more effectively in patients with early onset scoliosis.

How Does Hyperkyphotic Early-Onset Scoliosis Respond to Growing Rod Treatment?

Growing rods (GRs) pose a higher risk of kyphosis gain while improving coronal deformity with intermittent distractions in early-onset scoliosis (EOS), but in turn, increased kyphosis may also affect GR correction outcomes. However, there is a paucity of data regarding the effect of GRs on the sagittal spinal profiles in hyperkyphotic EOS. Thus, we aim to demonstrate how hyperkyphotic EOS responds to GRs treatment. Forty patients treated with GRs for EOS were included and categorized into a normal kyphosis (N) group [20 degrees≤thoracic kyphosis (TK)≤50 degrees] or hyperkyphosis group (K) group (TK≥50 degrees). Radiographic measurements were performed before and after the index surgery and at the last follow-up. The complications were identified and classified using the surgical complications grading system. The N group included 13 patients with dual GRs and 6 patients with a single GR. The K group consisted of 17 patients with dual GRs and 4 patients with a single GR. The mean age at surgery in the N and K groups was 6.2±1.8 and 6.4±2.1 years, respectively. The N and K groups, respectively, had an average number of lengthenings of 4.2±2.0 and 4.3±2.3, with an average follow-up of 4.7±1.9 and 4.6±2.1 years, respectively. In the K group, TK was markedly reduced after the index surgery and slightly increased during follow-up, whereas changes in TK in the N group were not significant. The complication rate in the K group was significantly higher than in the N group (81.0% vs. 47.4%, P=0.046). The most common implant-related and alignment-related complication in both groups was rod fracture (17.5%) and proximal junctional kyphosis (22.5%), respectively. The complication events in the N group were 5 with grade I and 5 with grade IIA, whereas in the K group there were 8 with grade I and 11 with grade IIA. GRs can effectively correct hyperkyphotic EOS, with the sagittal profile being successfully restored to normal range. However, hyperkyphotic EOS tends to experience more complications such as rod fracture and PJK. Level III.

Outcomes of Pelvic Fixation in Growing Rod Constructs: An Analysis of Patients With a Minimum of 4 Years of Follow-up

Study DesignRetrospective review. ObjectiveTo evaluate which distal anchors in growing rod (GR) constructs optimally correct major curve, pelvic obliquity, sagittal alignment, T1–S1 length, thoracic kyphosis, and lumbar lordosis with the fewest complications at 4 or more years' postoperative follow-up. Summary of Background DataPelvic fixation to the ilium and/or sacrum in GR constructs is used to treat patients with early-onset scoliosis. No studies have evaluated radiographical outcomes and complications in these patients at 4 or more years' follow-up. MethodsIncluded were 38 patients from a multicenter early-onset-scoliosis database with dual GRs anchored to the pelvis. Radiographic data included major curve, T1–S1 length, T5–T12 kyphosis, lordosis, sagittal alignment, and pelvic obliquity at preoperative and latest follow-up time points. Complications were evaluated for all anchor subtypes. ResultsMean follow-up time was 5.3 ± 0.1 years. GRs with distal anchors to the ilium significantly improved major curve (49%, p = .013) and pelvic obliquity (78%, p = .035) compared with constructs anchored to the sacrum only. Constructs with iliac fixation with S1 screws provided greater correction of lumbar kyphosis than constructs with iliac fixation and no S1 screws (p = .023). Constructs with a single caudal crosslink had a greater T1–S1 length at latest follow-up than constructs with combined cephalad and caudal crosslinks (p = .027). There were no significant differences in the rates of infection or instrumentation failure between iliac and sacral fixation groups. GR constructs with distal anchors that used a posterior superior iliac spine start point had a higher infection rate (60%) than those inserted via a sacral-alar-iliac technique (7%) (p = .002). ConclusionsGR constructs anchored to the ilium provide significant improvements in the major curve and pelvic obliquity at a minimum of 4 years of follow-up versus constructs anchored to the sacrum alone. Level of EvidenceLevel III, retrospective cohort study.

The Effect of Dual Growing Rod Instrumentation on the Apical Vertebral Rotation in Early-onset Idiopathic Scoliosis

Treating progressive early-onset idiopathic scoliosis is challenging. Surgical treatment is indicated in patients whose curves progress despite nonsurgical treatment. Dual growing rod (DGR) technique allows control of the curve while permitting continued spine growth and pulmonary development. Correction in coronal and sagittal planes with this technique has demonstrated both clinically and radiologically in previous studies. It is shown that apical vertebra rotation (AVR) increases with single-rod instrumentation technique. The effect of DGR technique on AVR has not been investigated, yet. The aim of our study was to assess the impact of DGR instrumentation technique on the apical AVR. The study included 12 patients with early-onset idiopathic scoliosis treated with DGR technique. Mean follow-up was 74 months. Vertebral rotation angle in the apex of the curve in preindex surgery was measured with Perdriolle and Stokes' method. As pedicle shadows were masked by rods postoperatively, vertebral rotation angle of same levels in final computed tomography scans was measured using Aaro and Dahlborn's method. Standing anterior-posterior and lateral x-rays were measured for assessing Cobb angle, thoracic kyphosis, lumbar lordosis in coronal and sagittal planes preoperatively, postoperatively, and at the time of final follow-up. Mean age at the time of growing rod instrumentation was 69 (36 to 108) months. Mean follow-up was 77 (57 to 91) months. The mean preoperative AVR angle was 27 (18 to 38) degrees and decreased to 18 (4 to 35) degrees at the time of final follow-up. The difference between preoperative and final follow-up AVR was found to be significant (P=0.003). Preoperative mean Cobb angles were found to be 63.8 (40 to 98) degrees, 25 (10 to 46) degrees (60%) (P<0.001) after index surgery and at the time of final follow-up 20 (7 to 42) degrees (66%) (P<0.001). The mean thoracic kyphosis and lumbar lordosis angles were found to be 46 (20 to 90) and 34 (16 to 80) degrees at preoperative stage; 25 (12 to 50) and 22 (8 to 35) degrees at immediate postoperative stage; and 38 (16 to 83) and 37 (16 to 60) degrees at the time of final follow-up. This study proves that the DGR technique has no negative effect on transverse plane deformities. When compared with preoperative values, correction of the AVR during the treatment period suggests that DGR is effective in controlling the coronal and sagittal planes along with transverse plane deformities. Further studies are needed to prove that DGR treatment definitely prevents progression of AVR.

One-Stage Posterior Osteotomy With Short Segmental Fusion and Dual Growing Rod Technique for Severe Rigid Congenital Scoliosis

Retrospective study. To evaluate the clinical outcomes of the hybrid technique of 1-stage posterior osteotomy with short segmental fusion and dual growing rod (GR) technique for severe rigid congenital scoliosis. As some types of congenital scoliosis consist of long curve including sharp deformities producing enormous asymmetric growth at apex, they cannot be well corrected with osteotomy and short segmental fusion. GR technique may be the best option. However, enormous asymmetric growth potential due to the sharp deformities at the apex will increase risk of complications, especially implant failures. Seven patients (2 males, 5 females) undergoing this hybrid technique for severe rigid congenital scoliosis were retrospectively reviewed. The patients' charts were reviewed. The analysis included age at initial surgery and the latest follow-up, number and frequency of lengthening, and complications. Radiographical evaluation included measured changes in scoliosis Cobb angle, thoracic kyphosis, lumbar lordosis, trunk shift, length of T1-S1, and instrumentation. The mean follow-up was 53.3 (30-77) months. The mean age at the initial surgery is 5.9 (2-10) years. The averaged lengthenings were of 5.3 per patient. The mean scoliosis improved from 81.4° to 40.1° after initial surgery and was 41.0° at the latest follow-up. The average T1-S1 length was of 1.23 cm per year. The space available for lung ratio increased from 0.86 to 0.96. Osteotomy with short fusion could help to improve the correction of the GR and eliminate the large asymmetric growth potential around the apex, with little influence to the length of the spine. Dual GR technique could maintain correction achieved at initial surgery while allowing spinal growth to continue. This hybrid technique may be an option for young patients who present sharp deformities with large asymmetric growth potential in a long congenital spinal deformity. 4.

Dual Growing Rods for the Treatment of Early-Onset Scoliosis.

The dual growing-rod technique involves implantation of a set of two rods and two anchor groups (upper and lower foundations) to exert frequent distractions to allow for spinal growth. Pay special attention to the effect of positioning on sagittal alignment. Use multimodality intraoperative neuromonitoring, including SSEPs, MEPs, EMG, and H-Reflexes. Avoid broad exposure of uninstrumented levels to prevent the risk of spontaneous fusion. The foundation is an assembly of at least four anchors at two or three vertebrae along with one or two rods. Use hooks or pedicle screws for the proximal foundation and use bilateral pedicle screws (a four-anchor construct) for the distal foundation. Cut two 4.5-mm rods and contour them to the appropriate sagittal and coronal alignment, being careful not to overcorrect in the sagittal and coronal planes. Place a tandem connector at the thoracolumbar junction to allow for future lengthening. Pass the preassembled rods and tandem connector from caudad to cephalad beneath the fascia, securing them to the foundation and performing the first lengthening. Gentle handling of the skin and associated deeper tissues is essential to avoid complications. These are the same as those for the initial surgery. Make one incision between the two connectors on or in line with the original incision. Lengthening can be performed inside or outside the tandem connector. See Step 9 for the initial surgery. The quantity and quality of research on growth-sparing techniques for early-onset scoliosis have increased substantially in the past three years. IndicationsContraindicationsPitfalls & Challenges.

Dual Growing Rods Technique for Congenital Scoliosis

Retrospective study. To evaluate clinical outcomes of dual growing rod (GR) technique in treating children with congenital scoliosis (CS). Published reports on the dual GR technique results of early-onset scoliosis demonstrate it to be safe and effective. However, the use of GR in congenital spinal deformities is controversial, and there have been no reports on the results and complications of dual GR technique for CS with large series of patients. During 2004 to 2009, a total of 30 patients with CS underwent dual GR procedures. Of the 159 total procedures conducted within the treatment period, 125 were lengthenings with an average of 4.2 lengthenings per patient. Five patients with severe rigid deformity or kyphosis had an osteotomy at apex vertebra with short segmental fusion. The analysis included age at initial surgery and final fusion (if applicable), number and frequency of lengthenings, and complications. Radiographical evaluation was conducted. The mean scoliosis improved from 72.3° to 34.9° after initial surgery and was 35.2° at the last follow-up or after final fusion. T1-S1 length increased from 25.42 to 29.03 cm after initial surgery and to 33.32 cm at last follow-up or after final fusion with an average T1-S1 length increase of 1.49 cm per year. The space available for lung ratio in patients with thoracic curves improved from 0.84 to 0.96 at the latest follow-up. Three patients reached final fusion. Complications occurred in 7 of the 30 patients, and they had a total of 13 complications. The dual GR technique is safe and effective in the treatment of selected cases of long, complex CS. It maintains correction achieved at initial surgery while allowing spinal growth to continue. And it has an acceptable rate of complications. The osteotomy at the apex vertebra with short segmental fusion of the severe rigid scoliosis or the patients with kyphosis could help to improve the correction and decrease the implant failures, with little influence on the length of the spine.