Does early thoracic fusion exacerbate preexisting restrictive lung disease in congenital scoliosis patients?

Clinical and radiographic evolution of graduate patients treated with magnetically controlled growing rods: results of a French multicentre study of 90 patients

PURPOSE

The purpose of this study was to investigate patients with early-onset scoliosis (EOS) who completed their electromagnetic lengthening rod program to assess the demographics of this population and to analyze the evolution of clinical and radiological parameters and the occurrence of complications.

METHODS

This was a multicenter study with 10 French centers. We collected all patients with EOS who had undergone electromagnetic lengthening between 2011 and 2022. They had to have reached the end of the procedure (graduate).

RESULTS

A total of 90 graduate patients were included. The mean follow-up time over the entire period was 66 months (25.3-109). Of these, only 66 patients (73.3%) underwent definitive spinal arthrodesis at the end of the lengthening phase, whereas 24 patients (26.7%) kept their hardware in situ with a mean follow-up time from the last lengthening of 25 months (3-68). Patients had an average of 2.6 surgeries (1-5) over the entire follow-up. Patients had an average of 7.9 lengthenings for a mean total lengthening of 26.9 mm (4-75). Analysis of the radiological parameters showed a percentage reduction in the main curve of 12 to 40%, depending on the etiology, with an average reduction of 73-44°, and an average thoracic height of 210 mm (171-214) for an average improvement of 31 mm (23-43). There was no significant difference in the sagittal parameters. During the lengthening phase, there were a total of 56 complications in 43 patients (43.9%; n = 56/98), of which 39 in 28 patients (28.6%) resulted in unplanned surgery. In the graduate patients, there were a total of 26 complications in 20 patients (22.2%), all of which resulted in unscheduled surgery.

CONCLUSION

MCGR, allow to decrease the number of surgeries, to progressively improve the scoliotic deformity and to reach a satisfactory thoracic height at the price of an important complication rate linked in particular to the complexity of the management of patients with an EOS.

LEVEL OF EVIDENCE II

Spontaneous induced bone fusion in minimally invasive fusionless bipolar fixation in neuromuscular scoliosis: a computed tomography analysis

PURPOSE

Posterior spinal fusion (PSF) at skeletal maturity is still the gold standard in children with neuromuscular scoliosis (NMS) who underwent fusionless surgery. The aim of this computed tomography (CT) study was to quantify the spontaneous bone fusion at the end of a lengthening program by minimally invasive fusionless bipolar fixation (MIFBF), that could avoid PSF.

METHODS

NMS operated on with MIFBF from T1 to the pelvis and at final lengthening program were included. CT was performed at least five years postoperatively. The autofusion was classified as completely or not fused at the facets joint (on both coronal and sagittal plane, right and left side, from T1 to L5), and around the rods (axial plane, right and left side, from T5 to L5). Vertebral body heights were assessed.

RESULTS

Ten patients were included (10.7y ± 2 at initial surgery). Mean Cobb angle was 82 ± 20 preoperatively and 37 ± 13 at last follow-up. CT were performed on average 6.7y ± 1.7 after initial surgery. Mean preoperative and last follow-up thoracic vertebrae height were respectively 13.5 mm ± 1.7 and 17.4 mm ± 1.7 (p < 0.001). 93% facets joints were fused (out of 320 analyzed joints), corresponding to 15/16 vertebral levels. Ossification around the rods was observed in 6.5±2.4 levels out of 13 in the convex side, and 4.2 ± 2.2 in the concave side (p = 0.04).

CONCLUSIONS

This first computed quantitative study showed MIFBF in NMS preserved spinal growth, while it induced 93% of facet joints fusion. This could be is an additional argument when questionning the real need for PSF at skeletal maturity.

Definitive fusions are better than growing rod procedures for juvenile patients with cerebral palsy and scoliosis: a prospective comparative cohort study

PURPOSE

This study compared the outcomes of juvenile patients with cerebral palsy (CP) and scoliosis who underwent spinal fusion (SF) versus growing rod (GR) surgery.

METHODS

Two prospective multicenter registries were queried for patients 8-10 years old with minimum 2-year follow-up who underwent SF or GR surgery (no MCGR). Demographics, radiographs, complications, and outcome scores were recorded.

RESULTS

There were 35 patients in the SF and 15 in the GR group. The mean age at surgery was 10 and 9.3 years in the SF and GR groups, respectively (p = 0.004). In the SF group preoperatively, the major curve measured 86° and 80° in the GR group (p = 0.40). "Definitive" surgery in the GR group consisted of SF in 10, implant retention in three, and implant removal in two. The SF group had 60.8% and the GR group had 45.0% correction following "definitive" surgery (p = 0.03). In the SF group, 8 patients and in the GR group, 9 patients (SF = 22.9%, GR = 60.0%) had a complication (p = 0.01). In the SF group, two patients (5.7%) had reoperations for infection; eight patients (53.3%) in the GR group had reoperations for infection and implant complications (p < 0.001). In the SF group, 23/30 parents (76.6%) noted that the child's life "improved a lot." In the GR group, 3/6 parents (50.0%) noted they were "neutral" about their child's ability to do things, 2/6 (33.3%) were "very dissatisfied."

CONCLUSIONS

SF treatment for juvenile patients with CP and scoliosis resulted in fewer complications and unplanned reoperations and better radiographic outcomes compared with GR. Quality of life improvements were also better in the SF group.

LEVEL OF EVIDENCE

Level III.

Outcomes of Definitive Spine Fusion Using All-pedicle-Screw Constructs in Skeletally Immature Patients Aged 8 to 10 Years With Severe Idiopathic Early-Onset Scoliosis

BACKGROUND

The choice between growth-sparing techniques or definitive spine fusion for severe idiopathic early-onset scoliosis (IEOS) in skeletally immature patients aged 8 to 10 years represents a challenging dilemma. Although growth-sparing techniques show high complication rates in severe IEOS, the outcomes of definitive fusion in borderline skeletally immature patients with severe IEOS have not been investigated. We aimed to investigate the outcomes of early definitive fusion using all-pedicle-screw constructs in skeletally immature patients aged 8 to 10 years with severe IEOS.

METHODS

The inclusion criteria were as follows: IEOS, age 8 years or above, major coronal curve ≥90 degrees, thoracic height >18 cm, no history of previous spine surgery, no intraspinal anomalies and at least 3 years of postoperative follow-up. Patients underwent instrumented spinal fusion with all-pedicle-screw constructs and multiple Ponte osteotomies. All patients completed the Scoliosis Research Society 22 revision (Arabic version) questionnaire and Body Image Disturbance Questionnaire-Scoliosis version (BIDQ-S) preoperatively and at the last follow-up.

RESULTS

Fifty-five patients (24 males, 31 females; mean age: 8.96 y; range: 8 to 10 y) with severe IEOS met the inclusion criteria (mean follow-up period: 4.1±0.6 y; range: 3 to 5 y). The mean major coronal Cobb angle improved significantly (P<0.001) from 107±12.5 degrees to 26.8±6.8 degrees. Mean thoracic kyphosis improved significantly (P<0.001) from 57.2±15.8 degrees to 31.2±4.4 degrees. The loss of correction at the latest follow-up was nonsignificant. The total Scoliosis Research Society 22 revision (SRS-22r) score improved significantly from 2.5±1 to 4.3±0.7. The mean BIDQ-S score improved significantly from 4.1±0.3 to 1.6±0.3. The immediate postoperative gains in the mean thoracic height (T1-T12) and spinal height (T1-S1) were 14.9% and 19.6%, respectively, and the overall height increase at the latest follow-up was 17.8% and 23.8%, respectively. One patient underwent revision for implant failure (rod breakage).

CONCLUSION

Early definitive fusion for skeletally immature patients with severe IEOS yielded excellent correction with major improvements in patient quality of life. Severe IEOS poses a significant risk, but definitive fusion can potentially mitigate that risk in patients aged 8 to 10 years.

The 18-cm Thoracic-Height Threshold and Pulmonary Function in Non-Neuromuscular Early-Onset Scoliosis: A Reassessment

Thoracic spine height is cited as a crucial outcome measure in the treatment of early-onset scoliosis (EOS) because of its reported relationship to pulmonary function tests (PFTs). An 18-cm threshold has been proposed, although this single parameter might be overly simplistic for cases of different etiologies and deformity magnitude. We aimed to reevaluate pulmonary function in patients undergoing corrective surgery, assessing the role of residual scoliosis as well as spine elongation

The influence of early thoracic fusion on the pulmonary function of patients with idiopathic scoliosis in the early period of the second growth peak with different Risser signs

Background

Previous reports confirmed early spinal fusion may compromise pulmonary function and thoracic development in skeletal immature patients with scoliosis. However, the different effects in patients with various Risser signs remain unknown. This study aimed to compare the influence of early thoracic fusion on pulmonary function and thoracic growth in patients with idiopathic scoliosis (IS) with closed triangular cartilage (TRC) and different Risser signs.

Methods

Thirty-six patients with IS and a closed TRC were retrospectively selected and divided into the low Risser (LR, Risser sign ≤2, 22 patients) and high Risser (HR, 2<Risser sign≤4, 14 patients) groups. Patient age, Risser sign, main Cobb angle, thoracic kyphosis, and fusion levels were recorded. Perioperative and minimum of 2-year follow-up pulmonary function and thoracic diameters were compared between both groups.

Results

There were no differences in patients’ general characteristics between two groups. The preoperative forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were 2.06±0.43 L and 2.50±0.49 L, respectively, in the LR group, and 2.31±0.49 L (p = 0.067) and 2.74±0.56 L (p = 0.122), respectively, in the HR group. While these values significantly increased postoperatively, to 2.62±0.46 L (p < 0.001) and 3.09±0.69 L (p < 0.001), in the LR group, they remained unchanged in the HR group [2.53±0.56 L (p = 0.093) and 2.70±0.98 L (p = 0.386), respectively]. The FEV1/FVC in both groups was >80% before and after surgery. The T1-T12 and anteroposterior thoracic diameter significantly increased after surgery in both groups, while the maximum inner chest diameter only increased in the LR group at the final follow-up. However, there were no significant differences in respiratory function and thoracic data between both groups.

Conclusion

For patients with IS, early fusion did not deteriorate pulmonary function or thoracic development in TRC-closed patients whose Risser sign was ≤2 compared with those with a Risser sign >2.

An initial effort to define an early onset scoliosis "graduate"-The Pediatric Spine Study Group experience

PURPOSE

Increasingly, patients with early onset scoliosis (EOS) are completing a growth friendly surgical program followed by observation, removal of implants or a definitive spinal fusion. These patients are colloquially referred to as "graduates". A standardized definition of a graduate is needed for research and comparing the outcomes, family counseling, and a better understanding of the population.

METHODS

A 15-question electronic survey was completed by 39 experienced pediatric spine surgeons to identify factors salient to the definition of a graduate of EOS surgical programs. A Delphi/Nominal group technique session with nine questions was then performed face-to-face with 21 members of the Pediatric Spine Study Group to discuss and refine the definition. A follow-up electronic survey was then distributed to these same 21 members to gain consensus on the final definition.

RESULTS

From the initial survey, it was identified that a graduate did not require definitive spinal fusion after a growing program. From the Delphi session, it was determined that skeletal maturity was the most important factor in defining a graduate. A strictly defined minimum length of follow-up was not felt to be a prerequisite for qualification of graduation. After the final electronic version was distributed, > 80% of respondents agreed upon the final definition, thereby achieving consensus.

CONCLUSION

The Pediatric Spine Study Group recommends adoption of the following definition: a "graduate" is a patient who has undergone any surgical program to treat early onset scoliosis, and has reached skeletal maturity and does not have a planned surgical intervention for EOS in the future.

LEVEL OF EVIDENCE

V.

Clinical and health-related quality-of-life outcomes after early and late spinal fusion in pediatric patients with congenital scoliosis at 10-year follow-up

STUDY DESIGN

A retrospective comparative study.

OBJECTIVE

This study compares the effect of age at the time of surgery on clinical and health-related quality-of-life (HRQoL) outcomes at 10-year follow-up in pediatric patients with congenital scoliosis (CS). Several studies have evaluated the outcomes of surgical treatments of CS during the growth period; however, age at surgery and its long-term effects have been assessed in only a few case reports.

METHODS

We enrolled patients with CS who underwent spinal fusion at the age of 18 years or younger in our study. We evaluated 97 patients (38 males, 59 females; average age 16.5 years) who met our inclusion criteria, including the availability of outcome data for a minimum of 10-year post-surgery. We divided patients into two groups in terms of the age at surgery: early fusion (EF) and late fusion (LF) groups. Clinical outcomes included re-operations, major curve corrections immediately and at 10-year follow-up, Scoliosis Research Society (SRS)-22 questionnaire, and percentage forced vital capacity (%FVC).

RESULTS

The EF group (33 patients) and the LF group (64 patients) did not differ significantly in terms of demographics. In all domains, the EF group had better HRQoL than the LF group. More patients (52%) in the EF group required re-operation than in the LF group (23%). In addition, patients with short fusion (< 7 segments, p = 0.0011) and greater T1-T12 height (≥ 22 cm, p = 0.0088) had better %FVC than their counterparts.

CONCLUSIONS

Age at surgery might have some non-negligible impacts on patients' HRQoL and clinical outcomes. Our study highlighted the important factors in surgical considerations of choosing the appropriate timing for spinal fusion, performing shorter fusions, and achieving an acceptable curve correction without allowing further curve progression that required re-operations.

LEVEL OF EVIDENCE

Level III.

Is Growth-friendly Surgical Treatment Superior to One-stage Posterior Spinal Fusion in 9- to 11-year-old Children with Congenital Scoliosis?

BACKGROUND

The distraction-based growth-friendly technique has become a mainstay of treatment for young children with long-spanned congenital scoliosis. However, in patients who are 9 years to 11 years old, the choice is much less clear, and posterior spinal fusion is also a potential option.

QUESTIONS/PURPOSES

Comparing growth-friendly scoliosis surgery and posterior spinal fusion, which technique (1) provides greater correction of spinal deformity, (2) is associated with more surgical complications, and (3) results in greater improvement in pulmonary function tests, health-related quality of life scores, other patient-reported outcomes?

METHODS

Between 2009 and 2017, one spinal center performed 212 spinal interventions for scoliosis in patients aged between 9 years and 11 years old and who had open triradiate cartilage, including 40 patients with growth-friendly approaches (34 with growing-rod technique and six with a vertical expandable prosthetic titanium rib) and 172 with one-stage posterior spinal fusion, respectively. During this period, our general indications for using growth-friendly surgery were patients with open triradiate cartilage, major curve higher than 40°, and upper and lower end vertebrae involving at least eight segments. Twelve patients with a median (range) age of 9.3 years (9 to 11) treated with growth-friendly surgery met the following inclusion criteria: (1) had at least two lengthening procedures before definitive spinal fusion along with 2 years of follow-up after definitive spinal fusion; (2) had been followed until skeletal maturity (Risser grade ≥ 4); and (3) with complete radiographic and clinical data (health-related quality of life (HRQoL) and pulmonary function test results) preoperatively and at the latest follow-up. A group of patients between 9 years and 11 years old and underwent one-stage posterior spinal fusion was selected from our database of patients with congenital scoliosis. Our general indications for using one-stage posterior spinal fusion were patients with a major curve greater than 40°, and with thoracic height higher than 18 cm. Sixty-two patients who had open triradiate cartilage and had been followed until skeletal maturity (Risser grade ≥ 4) were accounted for. In this retrospective, controlled study, we matched patients in the posterior spinal fusion group to those 12 patients who had growth-friendly surgery by age, sex, pathologic findings, major curve size, and location of the apex of the major curve (2:1 matching provided 24 patients in the control group). The median (range) age was 9.8 years (9 to 11). We then compared the groups in terms of magnitude of correction and postoperative complications. Surgical complications, including infection, implant-related complications, and alignment-related complications were evaluated and classified using the surgical complications grading system. Pulmonary function tests and HRQoL were also compared between groups. Pulmonary function tests were performed at the same center with a spirometer. HRQoL were assessed by questionnaire, including the 24-item Early-onset Scoliosis questionnaire for parent-reported outcomes and the Scoliosis Research Society-22 questionnaire for patient-reported outcomes. All patients involved in this study gave their informed consent.

RESULTS

The posterior spinal fusion group achieved a greater correction magnitude at the latest follow-up (median [range] 46% [28 to 70] versus median 34% [9 to 58], difference of medians = 11%; p < 0.001) than the growth-friendly group. A higher proportion of patients in the growth-friendly group had complications than in the posterior spinal fusion group (7 of 12 versus 4 of 24; p = 0.03). There were no between-group differences in terms of pulmonary function tests. Few differences were found between the groups in terms of 24-item Early-onset Scoliosis parental impact (median [range] 60 [44 to 83] for the growth-friendly group versus median 71 [55 to 87] for the posterior spinal fusion group, difference of medians = 13; p = 0.001), financial burden (median 44 [30 to 55] for the growth-friendly group versus median 62 [53 to 75] for the posterior spinal fusion group, difference of medians = 16; p < 0.001) and the Scoliosis Research Society-22 self-image scores (median 3.8 [3.2 to 4.3] for the growth-friendly group versus median 4.4 [4.1 to 4.6] for the posterior spinal fusion group, difference of medians = 0.5; p = 0.006) at the latest follow-up, and those differences that were observed all favored the posterior spinal fusion group.

CONCLUSIONS

In light of the superior deformity correction and fewer observed complications with posterior spinal fusion, and the absence of important differences in validated outcomes scores or pulmonary function tests, posterior spinal fusion might be a better choice for 9- to 11-year-old children with long-spanned congenital scoliosis and limited growth potential in the intended instrumentation area.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Spinal Growth in Patients With Juvenile Idiopathic Scoliosis Treated With Boston Brace: A Retrospective Study

STUDY DESIGN

Retrospective comparative cohort.

OBJECTIVE

The aim of this study was to determine whether spinal growth is restricted by brace treatment in patients with juvenile idiopathic scoliosis (JIS).

SUMMARY OF BACKGROUND DATA

Spinal fusion can negatively affect spinal growth if performed before the growth spurt. Brace treatment is often given in this young population to control the spinal deformity while allowing spinal growth. It is unknown whether the applied pressure of brace treatment on spine results in growth restriction. The aim of the study is to evaluate spinal growth in braced JIS patients.

METHODS

A total of 49 JIS patients treated with Boston brace were retrospectively selected from a scoliosis database. T1-T12/T1-S1 perpendicular and freehand (height following the curvature of the spine) height were measured on radiographs of patients that had reached skeletal maturity and were matched with 49 controls without scoliosis. Spinal growth was calculated from brace initiation until cessation and was compared with normal spinal growth values as reported by Dimeglio.

RESULTS

The mean age of diagnosis was 7.4 years. The age of the braced scoliosis patients at skeletal maturity was 17.5 years. The average T1-T12 and T1-S1 freehand height measured by following the curvature of the scoliosis was 29.3 cm (±2.4) and 47.2cm (±4.0), respectively, and was not significant different from the control group. Brace treatment was initiated at a mean age of 11.2 and the mean age of cessation was 14.8. Spinal growth (freehand) during brace treatment was 1.10 cm/year for the thoracic spine and 1.78 cm/year for the full spine and was not significant different from normal values.

CONCLUSION

No significant influence of bracing on spinal growth could be detected in this cohort of JIS patients. The spinal height measurements at skeletal maturity were similar to matched controls. In addition, spinal growth did not significantly differ from Dimeglio normal growth data, indicating that the effect of bracing on spinal growth is absent or minimal.

LEVEL OF EVIDENCE

3.

The Natural History of Early-onset Scoliosis

BACKGROUND

Early-onset scoliosis (EOS) is defined as the diagnosis of a spinal deformity before the age of 5 years. It can be divided into idiopathic, neuromuscular/syndromic, and congenital etiologies.

METHODS

The literature on the natural history of EOS was summarized.

RESULTS

The natural history varies with the etiology of EOS. Idiopathic curves may benefit from early serial casting. The natural history of neuromuscular and syndromic scoliosis is highly dependent on the natural history of the underlying disorder. Congenital scoliosis has a variable prognosis depending on the location and extent of the congenital malformations.

CONCLUSIONS

Treatment of children with EOS is customized to the particular disorder. While lack of treatment has been shown to lead to increased mortality, extensive early definitive fusion may lead to thoracic insufficiency. Delaying definitive surgery and the use of growing instrumentation may provide benefit in maintaining pulmonary health.

CLINICAL RELEVANCE

Potential disturbance of growth must be considered in the treatment of young children with scoliosis.

Long-term Outcome of Early Fusions for Congenital Scoliosis

STUDY DESIGN

The current literature on outcomes of early fusions for early-onset scoliosis (EOS) has a short follow-up of 7.7 to 12.5 years, with many patients not at the end of growth. The forced vital capacity (FVC) at follow-up ranged from 40.8% to 64% of predicted. A study was undertaken to evaluate the long-term outcome of these fusions.

METHODS

The study is of congenital patients who had a fusion under age 8 years, with the current age being >20 years. A follow-up consisting of radiographs, outcome questionnaires, and pulmonary function tests was performed. Of the 42 patients identified, 20 were traced and 11 agreed to participate, and completed all the data. The average follow-up was 37 years. All the fusions included the thoracic spine, with an average of 10.2 levels fused, of which an average of 8.8 levels were thoracic.

RESULTS

The average scoliosis at presentation was 52°, 56° at surgery and 47° at follow-up. At follow-up, the average FVC was 53% of predicted, with an average PaO₂ of 86 and PaCO₂ of 44 mm Hg. The mean T1-T12 length was 20 cm. There was no correlation of the FVC percentage predicted and the proximal extent of the fusion, the T1-T12 length or the number of thoracic levels fused. The average ODI was 23. On the SF36, the average Physical Component t score was 50; with the average Mental Component t score was 52.

CONCLUSION

At a long-term average follow-up of 37 years, the patients had a low FVC of 53%, with one on permanent oxygen and 5 with dyspnea. The patients were functioning well at follow-up, but it is unknown what their function would be without surgery or with longer follow-up.

Complications following lengthening of spinal growing implants: is postoperative admission necessary?

OBJECTIVE The aim of this study was to evaluate the effect of postoperative admission status on 30-day perioperative complications in patients with growing spinal instrumentation undergoing surgical lengthening. METHODS This retrospective case-control study of records from the 2014-2015 National Surgical Quality Improvement Program-Pediatric database was performed to identify surgical lengthening procedures of spinal implants in patients with growing instrumentation by Current Procedural Terminology code. The 30-day postoperative complications were classified according to the Clavien-Dindo system. Patients were subdivided according to their postsurgical admission status. Admission status, American Society of Anesthesiologists (ASA) Physical Status classification, tracheostomy, neuromuscular diagnosis, ventilator dependence, and nutritional support were considered as possible risk factors in univariate and multivariate logistic regression analyses. RESULTS A total of 796 patients were identified (mean age 9.09 ± 3.44 years; 54% of patients were female), of whom 73% underwent lengthening on an inpatient basis. Patients with a tracheostomy or ventilator dependence were more likely to be admitted postoperatively. The overall rate of major complications was 3.5% and did not differ based on admission status (2.8% inpatient vs 3.8% outpatient, p = 0.517). On univariate analysis, ventilator dependence (9.5% vs 2.7%, p = 0.002), need for nutritional support (7.1% vs 2.5%, p = 0.006), and ASA class > II (4.8% vs 1.3%, p = 0.04) placed patients at a higher risk for any postoperative complications. Multivariate analysis identified only ventilator dependence as an independent risk factor for any perioperative complication. CONCLUSIONS Postoperative admission status did not affect the rate of 30-day perioperative complications, readmission, or rate of unplanned operations following lengthening of growing spinal instrumentation. Outpatient lengthening appears to be safe; however, consideration for postoperative admission should be given for those who are ventilator dependent.

VEPTR Implantation to Treat Children With Early-Onset Scoliosis Without Rib Abnormalities: Early Results From a Prospective Multicenter Study

BACKGROUND

Thoracoplasty and insertion of vertical expandable prosthetic titanium rib (VEPTR) for thoracic and spine distraction has been found to be effective in the treatment of early-onset scoliosis (EOS) with ribs anomalies and congenital vertebral anomalies. The aim of this study was to evaluate the efficacy of VEPTR in preventing further progression of scoliosis without impeding spinal growth in children with progressive EOS without rib abnormalities.

METHODS

This is a prospective, multicenter, observational cohort study. Erect radiographs were analyzed for coronal and sagittal curve and height measurements at preimplant, immediate postoperative, and at 2-year follow-up.

RESULTS

Sixty-three patients met inclusion: 35 males and 28 females. Mean age at time of implantation was 6.1±2.4 years. Etiologies included congenital (n=6), neuromuscular (n=36), syndromic (n=4), and idiopathic (n=17). The mean follow-up was 2.2±0.4 years. Scoliosis (72±18 degrees) decreased after implant surgery (47±17 degrees) followed by slight increase at 2-year follow-up (57±18 degrees), P<0.0001. Kyphosis (48±22 degrees) also showed significant decrease after implantation (40±14 degrees), but increased after 2 years (48±16 degrees), P<0.0001. Coronal spine height measurements including T1-T12 (15.7±3 cm) and T1-S1 (25±6 cm) showed significant increases after implantation surgery (17.7±4 cm and 28.6±6 cm, respectively) and at 2 years (18.4±4 cm and 29.1±5 cm, respectively), P<0.0001. The increase in coronal spine height represented 144% of expected age-matched T1-T12 growth and 193% of expected age-matched T1-S1 growth. Similarly, sagittal spine length of T1-T12 and T1-S1 increased from 16.9±2.7 cm and 27.1±3.9 cm, respectively preoperatively to 19.7±3.5 cm and 31.9±5.1 cm, respectively at 2-year follow-up, P<0.0001. The instrumented spine segment continued growth from 25.8±5.2 cm after implantation to 27.4±5.3 cm at 2-year follow-up, P<0.0001. Thirty-one patients (49%) had at least 1 complication with total of 58 complications.

CONCLUSIONS

At 2-year follow-up, VEPTR was effective in treating EOS without rib abnormalities with 86% of patients having an improvement in scoliosis and 94% of patients having an increased spinal height as compared with preoperative values. This study proved that spine continues to grow after VEPTR instrumentation during the distraction phase. This amount of growth represents about 40% for T1-T12 and 31% for T1-S1 spine of the expected age-matched growth based on Dimeglio reference numbers. We find this growth important as it proves continuous spine growth with VEPTR treatment.

LEVEL OF EVIDENCE

Level II.

Outcomes of Primary Posterior Spinal Fusion for Scoliosis in Spinal Muscular Atrophy: Clinical, Radiographic, and Pulmonary Outcomes and Complications

BACKGROUND

Spinal muscular atrophy (SMA) is a progressive neuromuscular disease commonly including progressive scoliosis resulting in severe deformity and negatively affecting pulmonary function. Surgical correction and stabilization of this progressive deformity is generally recommended; however, the timing and method of surgical fixation remains controversial.

METHODS

Retrospective review of clinical, radiographic, and pulmonary function data from 16 children with SMA and surgically treated scoliosis between 1985 and 2013. Radiographic data included direct measures of major curve, coronal balance, pelvic obliquity, T1-T12 height, T1-S1 height, and T1-rod length. Estimations of rib collapse, thoracic cavity shape, and space-available-for-lung (T6:T12, width ratio; T6:T10, rib-vertebral-angle difference ratios; and lung height) were determined. Eleven patients were able to complete pulmonary function testing. Results were compared with published outcomes for growing rod constructs.

RESULTS

Posterior spinal fusion was performed at an average age of 9.8±3.6 years. The mean age at most recent follow-up was 19.4 years (range, 10 to 37 y), with a mean follow-up of 10.1 years (range, 3.1 to 26 y). Radiographic measurements improved from preoperative to latest follow-up as follows: major curve, 78±20 degrees to 27±24 degrees; coronal balance, 4.1±4.0 cm to 1.9±2.2 cm; pelvic obliquity (median), 23 to 5 degrees; T1-T12 height, 19±3 cm to 22±3 cm; T1-S1 height, 31±7 cm to 36±6 cm; T1-rod length, 0.8±1.1 cm (postop) to 2.8±1.6 cm (final); and space-available-for-lung ratio, 0.88±0.26 to 0.95±0.25. Rib collapse continued throughout the follow-up period in all but 1 patient. Pulmonary function testing demonstrated a decrease in rate of decline in forced vital capacity and forced expiratory volume when comparing preoperative with postoperative rates. Mean length of stay was 7.8±4.4 days. Complications included reintubation for low tidal volumes (n=1), pneumonia (n=1), superficial wound breakdown (n=1), and superficial infection (n=1).

CONCLUSIONS

Definitive posterior spinal fusion for treatment of scoliosis associated with SMA is effective at controlling curve progression and pelvic obliquity without negatively impacting the space-available-for-lung ratio, trunk height, or pulmonary function at 10 years follow-up.

LEVEL OF EVIDENCE

Therapeutic Level IV.

Performing a Definitive Fusion in Juvenile CP Patients is a Good Surgical Option

BACKGROUND

In juveniles with progressive curves, there is debate regarding the use of growth friendly implants versus definitive fusion. This study presents outcomes of juvenile cerebral palsy (CP) scoliosis patients who underwent definitive fusion before age 11.

METHODS

A review of a prospective, multicenter registry identified patients 10 years and younger who had a definitive posterior fusion for their CP scoliosis. Preoperative and postoperative demographic and radiographic changes were evaluated with descriptive statistics. Repeated measures analysis of variance were utilized to compare outcome scores.

RESULTS

Fourteen children with a mean age of 9.7 years (8.3 to 10.8 y) and a minimum of 2 years follow-up (range 2 to 3 y) were identified. The mean preoperative curve magnitude and pelvic obliquity was 84±25 degrees (range 63 to 144 degrees) and 25±14 degrees, respectively. All patients were skeletally immature with open triradiate cartilage. Three patients had unit rods with wires while the rest incorporated pedicle screws. Immediately postoperation, the average major curve was 25±17 degrees (P≤0.001, 71% correction rate). At most recent follow-up, the average major curve increased to 30±18 degrees (P≤0.001) for a 65% correction rate. Pelvic obliquity improved to 4±4 degrees (84% correction, P≤0.001) immediately postoperation and to 6±5 degrees (P=0.002) at latest follow-up for a 76% correction rate. None of the patients required revision surgery for progression. From pre to most recent follow-up, the CPchild Health outcome scores improved from 47 to 58 (P=0.019). One patient had a deep infection, and 1 patient had a broken rod that did not require any further treatment.

CONCLUSIONS

Progressive scoliosis in juvenile CP patients requires the surgeon to balance the need for further growth with the risks of progression or repeated surgical procedures. Our study demonstrates that definitive fusion once the curves approach 90 degrees results in significant radiographic and quality of life improvements, but further follow-up is needed to determine whether those results remain after skeletal maturity.

LEVEL OF EVIDENCE

Level IV-therapeutic.

Micro CT Analysis of Spine Architecture in a Mouse Model of Scoliosis

OBJECTIVE

Mice homozygous for targeted deletion of the gene encoding fibroblast growth factor receptor 3 (FGFR3(-/-)) develop kyphoscoliosis by 2 months of age. The first objective of this study was to use high resolution X-ray to characterize curve progression in vivo and micro CT to quantify spine architecture ex vivo in FGFR3(-/-) mice. The second objective was to determine if slow release of the bone anabolic peptide parathyroid hormone related protein (PTHrP-1-34) from a pellet placed adjacent to the thoracic spine could inhibit progressive kyphoscoliosis.

MATERIALS AND METHODS

Pellets loaded with placebo or PTHrP-1-34 were implanted adjacent to the thoracic spine of 1-month-old FGFR3(-/-) mice obtained from in house breeding. X rays were captured at monthly intervals up to 4 months to quantify curve progression using the Cobb method. High resolution post-mortem scans of FGFR3(-/-) and FGFR3(+/+) spines, from C5/6 to L4/5, were captured to evaluate the 3D structure, rotation, and micro-architecture of the affected vertebrae. Un-decalcified and decalcified histology were performed on the apical and adjacent vertebrae of FGFR3(-/-) spines, and the corresponding vertebrae from FGFR3(+/+) spines.

RESULTS

The mean Cobb angle was significantly greater at all ages in FGFR3(-/-) mice compared with wild type mice and appeared to stabilize around skeletal maturity at 4 months. 3D reconstructions of the thoracic spine of 4-month-old FGFR3(-/-) mice treated with PTHrP-1-34 revealed correction of left/right asymmetry, vertebral rotation, and lateral displacement compared with mice treated with placebo. Histologic analysis of the apical vertebrae confirmed correction of the asymmetry in PTHrP-1-34 treated mice, in the absence of any change in bone volume, and a significant reduction in the wedging of intervertebral disks (IVD) seen in placebo treated mice.

CONCLUSION

Local treatment of the thoracic spine of juvenile FGFR3(-/-) mice with a bone anabolic agent inhibited progression of scoliosis, but with little impact on kyphosis. The significant improvement in IVD integrity suggests PTHrP-1-34 might also be considered as a therapeutic agent for degenerative disk disorders.

Outcome of Revision Surgery in Pediatric Spine Deformity Patients

STUDY DESIGN

Retrospective case series.

OBJECTIVES

To report the complications and outcomes of pediatric revision spine surgery and review the surgical indications and treatment methods.

BACKGROUND SUMMARY

Recent reports have shown the necessity of revision spine surgery for pediatric deformities. Many reports have shown the result of revision surgery for pediatric spinal deformity.

MATERIALS AND METHODS

We conducted a retrospective review of 638 patients with pediatric spinal deformity who were treated with surgery from 1996 to 2007. We identified 50 patients who underwent revision spinal fusion surgery with a minimum of 3 years of follow-up.

RESULTS

Mean follow-up was 4 years (range, 3-8.3 years). The diagnosis at index surgery was idiopathic scoliosis in 18 patients, congenital scoliosis in 13, neuromuscular scoliosis in 13, tumor and spinal arteriovenous malformation in 4, burst fracture in thoracic spine in 1, and Scheuermann kyphosis in 1. The primary surgeries were 1 hemi epiphysiodesis, 3 anterior spinal fusions, 4 posterior decompressions, 8 combined anterior and posterior spinal fusions, and 34 posterior spinal fusions. A total of 16 patients had pseudarthrosis, 12 decompensation, 11 progressive kyphosis, 8 crankshaft phenomenon, 2 infections, and 1 junctional degeneration. All 50 reoperations included spinal instrumentation and fusion. The revision surgeries were 2 anterior spinal fusions, 14 posterior fusions, and 34 combined anterior and posterior spinal fusions. Spine arthrodesis was obtained in 98% of patients (49 of 50) and complications occurred in 14% of patients (7 of 50). The Scoliosis Research Society Patient Questionnaire outcomes at the latest follow-up were as follows: total 3.95, function 3.88, pain 3.83, self-image 3.98, and mental health 4.04.

CONCLUSION

Pseudarthrosis was the most common indication for revision surgery, and bony union was achieved in 98% with revision surgery. Despite the complications, pediatric revision spine surgery can achieve successful outcomes.

Surgical and conservative treatment of patients with congenital scoliosis: α search for long-term results

Background

In view of the limited data available on the conservative treatment of patients with congenital scoliosis (CS), early surgery is suggested in mild cases with formation failures. Patients with segmentation failures will not benefit from conservative treatment. The purpose of this review is to identify the mid- or long-term results of spinal fusion surgery in patients with congenital scoliosis.

Methods

Retrospective and prospective studies were included, reporting on the outcome of surgery in patients with congenital scoliosis. Studies concerning a small numbers of cases treated conservatively were included too. We analyzed mid-term (5 to 7 years) and long-term results (7 years or more), both as regards the maintenance of the correction of scoliosis and the safety of instrumentation, the early and late complications of surgery and their effect on quality of life.

Results

A small number of studies of surgically treated patients were found, contained follow-up periods of 4-6 years that in the most cases, skeletal maturity was not yet reached, and few with follow-up of 36-44 years. The results of bracing in children with congenital scoliosis, mainly in cases with failure of formation, were also studied.

Discussion

Spinal surgery in patients with congenital scoliosis is regarded in short as a safe procedure and should be performed. On the other hand, early and late complications are also described, concerning not only intraoperative and immediate postoperative problems, but also the safety and efficacy of the spinal instrumentation and the possibility of developing neurological disorders and the long-term effect these may have on both lung function and the quality of life of children.

Conclusions

Few cases indicate the long-term results of surgical techniques, in the natural progression of scoliosis. Similarly, few cases have been reported on the influence of conservative treatment.

In conclusion, patients with segmentation failures should be treated surgically early, according to the rate of deformity formation and certainly before the pubertal growth spurt to try to avoid cor- pulmonale, even though there is lack of evidence for that in the long-term. Furthermore, in patients with formation failures, further investigation is needed to document where a conservative approach would be necessary.

Early definitive spinal fusion in young children: what we have learned

BACKGROUND

Early-onset scoliosis, when left untreated, leads to severe deformity. Until the last decade, treatment of progressive curves in young children often consisted of definitive spinal fusion. The recognition of thoracic insufficiency syndrome associated with definitive early fusion has led to the development of new surgical techniques developed to preserve spinal and thoracic growth in young patients with progressive scoliosis.

QUESTIONS/PURPOSES

We asked: (1) Does early definitive fusion arrest progression of spinal deformity? To what extent does early definitive spinal fusion influence (2) pulmonary function and (3) thoracic growth?

METHODS

A Medline search of the published literature on early-onset scoliosis, congenital scoliosis, and infantile scoliosis between 2008 and 2010 was performed on spinal fusion for early-onset scoliosis, focusing on studies reporting pulmonary function at followup.

RESULTS

Spinal deformity is apparently not well controlled by early fusion since revision surgery has been required in 24% to 39% of patients who underwent presumed definitive fusion in early childhood. Restrictive pulmonary disease, defined as forced vital capacity less than 50% of normal, occurs in 43% to 64% of patients who undergo early fusion surgery with those children who have extensive thoracic fusions and whose fusions involve the proximal thoracic spine at highest risk. Thoracic growth after early surgery is an average of 50% of that seen in children with scoliosis who do not have early surgery. Diminished thoracic spinal height correlates with decreased forced vital capacity.

CONCLUSIONS

The literature does not support routine definitive fusion of thoracic spinal deformity at an early age in children with scoliosis.

Does expansion thoracoplasty improve the volume of the convex lung in a windswept thorax?

BACKGROUND

Expansion thoracoplasty using the Vertical Expandable Prosthetic Titanium Rib increases the measured height and volume of the concave hemi thorax, but the effect on the convex, non-instrumented lung is unknown. The purpose of this study was to measure changes in lung volume and density in the convex lung after expansion thoracoplasty.

METHODS

The volume and density of the lungs was measured in 12 children with congenital scoliosis and fused ribs before and after concave expansion thoracoplasty using serial computed tomography scans.

RESULTS

There were 8 boys and 4 girls with an average age of 6.4 years at initial implant. The average length of follow-up was 17.5 months. All patients showed increased total lung volumes by an average of 250 cc (range 24 to 795 cc). The volume of the concave lung increased by an average of 55% and the lung density decreased by an average of 6%. The volume of the convex lung increased by an average of 60%, and the density decreased by an average of 7%. Nine of 12 patients showed improvement in density of the convex lung.

DISCUSSION

These findings suggest that concave expansion thoracoplasty increases overall lung volume in children with congenital scoliosis and fused ribs as measured by computed tomography scan. In addition, expansion thoracoplasty seems to have a beneficial effect on the convex, non-operated hemi thorax. Decreases in measured lung density suggest improved aeration of the lung, which may prove to be beneficial to overall pulmonary function.

LEVEL OF EVIDENCE

Level 4 therapeutic studies: case series.

Management of thoracic insufficiency syndrome

PURPOSE OF THE REVIEW

Thoracic insufficiency syndrome (TIS) was first characterized by Campbell and Smith in 2003, as the inability of the thorax to support normal respiration and growth. The range of thoracospinal disorders within TIS is broad and some have poor prognosis, but all have been challenging to treat effectively. This review will describe the common approaches and report on the published outcomes of each approach.

RECENT FINDINGS

Over the last 15 years progress has been made in refining the approach to treating TIS, and more recently functional outcomes have been published for some of the techniques used. A number of recent reports have demonstrated spinal growth that meets normal rates after insertion of expandable devices to support the spine and preserve growth. However, in the short term pulmonary function outcomes indicate stabilization of lung function as opposed to regaining function, though there is a paucity of published data.

SUMMARY

There are a number of effective surgical interventions for treating the underlying thoracospinal disorders in TIS; however, though the short-term effect on pulmonary function indicates stabilization the longitudinal effect still needs to be elucidated.