Comparison of Early Definitive Fusion and Traditional Growing Rods in Early-onset Dystrophic Scoliosis in Neurofibromatosis Type 1: A Preliminary Report

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.

Clinical features and surgical treatments of scoliosis in neurofibromatosis type 1: a systemic review and meta-analysis

BACKGROUND

Neurofibromatosis type 1 (NF 1) is an autosomal-dominant tumor predisposition genetic disease affecting approximately 1 in 3000 live births. The condition could present various manifestations ranging from skin abnormalities to neurological tumors. The musculoskeletal system could also be frequently affected, and scoliosis is the most common orthopedic manifestation. Characterized by the early-onset and rapid progression tendency, NF 1-related dystrophic scoliosis presented discrepancies from idiopathic scoliosis in terms of natural history, clinical features, and management outcomes and thus required special attention. In the current study, the authors conducted a systemic review to outline the body of evidence of the natural history, clinical characteristics, surgical outcomes, and surgical complications of NF 1-induced scoliosis, aiming to provide an elucidative insight into this condition.

METHOD

Systemic review and meta-analysis were conducted according to the latest Preferred Reporting Items for Systematic Reviews Meta-Analyses (PRISMA) guidelines. The search was performed in Medline, Embase, and Web of Science Core Collection up to December 27, 2022, using related keywords. Clinical features such as frequencies, segmental involvement, and hereditary information were summarized and described qualitatively. Meta-analysis was conducted using R software and the 'meta' package to yield an overall outcome of efficacy and safety of surgical management, precisely, spinal fusion procedure and growing rods procedure. Corrective rate of Cobb angle, sagittal kyphosis angle, and T1-S1 length post-operative and at the last follow-up was used to evaluate the efficacy, and the occurrence of surgery-related complications was used to evaluate the safety.

RESULT

A total of 37 articles involving 1023 patients were included. Approximately 26.6% of the NF 1 patients would present with scoliosis. Patients tend to develop scoliosis at an earlier age. The thoracic part turned out to be the most affected segment. No obvious correlation between scoliosis and genotype or hereditary type was observed. Both spinal fusion and growing rod surgery have shown acceptable treatment outcomes, with spinal fusion demonstrating better performance in terms of effectiveness and safety. The growing rods technique seemed to allow a better lengthening of the spine. The mainstay post-operative complications were implant-related complications but could be managed with limited revision surgery. Severe neurological deficits were rarely reported.

CONCLUSION

Scoliosis, especially the subtype characterized by dystrophic bony changes, is a significant orthopedic manifestation of NF1. It has an early onset, a tendency to persistently and rapidly progress, and is challenging to deal with. The current review outlines the available evidence from the perspective of natural history, clinical features, and the treatment efficacy and safety of the mainstay surgical options. Patients with NF1 scoliosis will benefit from a better understanding of the disease and evidence based treatment strategies.

Paediatric syndromic scoliosis: proceedings of the half-day course at the 57th annual meeting of the Scoliosis Research Society

There are some syndromes that present with unique manifestations pertaining to the spinal column. A good working understanding of these common syndromes is useful for the spinal deformity surgeons and related healthcare providers. This review attempts to encompass these unique features and discuss them in three broad groups: hypermobility syndromes, muscle pathology-related syndromes, and syndromes related to poor bone quality. This review explores the features of these syndromes underpinning the aspects of surgical and medical management. This review represents the proceedings of the Paediatric Half-Day Course at the 57th Annual Meeting of the Scoliosis Research Society.

Comparison of treatment outcomes between growth-sparing instrumentation and definitive one-stage fusion for EOS patients ages 6-10 years

PURPOSE

To compare objective outcomes for EOS patients age 6-10 years treated by growth-sparing (GS) surgery or definitive one-stage correction and fusion (DF).

METHODS

We reviewed surgical, radiographic, PFT's, and EOSQ-24 outcomes for EOS patients > age 6 at index surgery treated at a single institution, minimum 2-year follow-up. Neuromuscular diagnoses were excluded.

RESULTS

47 patients underwent index surgery between age 6 and 10.9 years. Twenty-one had DF, 26 had GS surgery (13 MCGR, 13 TGR). Diagnoses included 15 congenital, 15 idiopathic, 17 syndromic. Age at index was 9.1 years DF, 7.8 GS (p < .001). Follow-up was 63-78 months. 18/26 GS cases converted to DF, 13 due to complications, which occurred in 8/21 DF cases vs 19/26 GS (p = .016). DF patients had fewer post-index surgeries (0.6 vs 3.7, p < .001). At follow-up there were no differences in curve magnitudes, %correction, T1-12/T1-S1 segment lengths, EOSQ-24 scores or PFTs. 18 patients converting to DF after initial GS had equal outcomes as DF initially. 31 patients > age 8 at index ("tweeners") were studied separately. 13 had GS surgery (7 MCGR), 18 had DF. At > 60 months follow-up, curve magnitudes, spine lengths, PFT's, or EOSQ scores were equivalent. DF patients had fewer procedures and complications.

CONCLUSION

For patients age 6-10.9 years, outcomes were no different at > 5 year follow-up between DF and GS groups. DF patients had fewer total surgeries and complications. Equal outcomes also occurred for tweeners. As a result, GS treatment does not appear to benefit patients > age 8.

Outcomes and Safety of Traditional Growing Rod Technique in the Treatment of Early-onset Dystrophic Scoliosis Secondary to Type 1 Neurofibromatosis With Intraspinal Rib Head Dislocation in Children

PURPOSE

The purpose of this study was to investigate the outcomes and safety of traditional growing rod (TGR) in the treatment of early-onset dystrophic scoliosis secondary to type 1 neurofibromatosis (NF1-EOS) with intraspinal rib head dislocation (IRH) in children.

METHODS

From September 2006 to June 2020, 21 patients with NF1-EOS were treated with TGR. The patients comprised 13 boys and 8 girls with a mean age of 7.1±1.5 years. Two patients had IRH-induced nerve injury [American Spinal Injury Association (ASIA) grade D]. No neurological symptoms were found in the other patients. The intraspinal rib proportion, apical vertebral rotation, apical vertebral translation, coronal main thoracic curve, trunk shift, thoracic kyphosis, lumbar lordosis, sagittal balance, and T1-S1 height were measured before and after TGR implantation and at the last follow-up. Complications were also evaluated.

RESULTS

The mean follow-up time was 3.4±2.0 years. An average of 3.1 times (range: 1 to 8 times) lengthening procedures were performed in each patient. The intraspinal rib proportion was significantly lower postoperatively than preoperatively (22±11% vs. 33±18%, respectively; P <0.001), and no significant correction loss was found at the last follow-up (24±12%, P= 0.364). Compared with the measurements before TGR implantation, the major coronal curve and T1-S1 height after TGR implantation and at the last follow-up were significantly different ( P <0.05). Significant correction of apical vertebral translation, thoracic kyphosis, lumbar lordosis, and sagittal balance were noted after TGR implantation, and no significant correction loss was found at the last follow-up ( P >0.05). Ten complications occurred in 7 patients. Two patients with nerve injury recovered after the operation. No neurological complications were found during the follow-up.

CONCLUSIONS

TGR is a safe and effective therapy for NF1-EOS with IRH where there was no direct compression of the spinal cord, which was confirmed by preoperative magnetic resonance imaging. Through this procedure, IRH could be partly removed from the spinal canal.

LEVEL OF EVIDENCE

Level III.

Spinal screening, malignancy, medical therapy, and surgical correction of deformity in pediatric patients with neurofibromatosis type 1: a systematic review

The objective of this systematic review was to synthesize evidence regarding spinal screening recommendations, types of spinal and thoracic neurofibromatosis type 1 (NF1) tumors, medical therapy for NF1-associated neoplasms, and treatment with magnetically controlled growing rods (MCGRs) or cervical kyphosis correction in pediatric patients with NF1. We queried PubMed, Embase, Cochrane Library, Web of Science, Scopus, Clinicaltrials.gov, and medRxiv for studies reporting spinal screening recommendations, prognosis, and medical therapy for NF1-associated spinal tumors and MCGR use or cervical kyphosis correction in pediatric NF1 patients, yielding 758 publications, 33 of which were included. There is no consensus on spinal screening interval. Computed tomography is recommended for postoperative monitoring. Patients with gangliomas and spinal neurofibromas had nearly complete symptom resolution after resection. Plexiform neurofibromas were most commonly treated with resection and laminectomy; some patients reported tumor enlargement after intervention. Malignant nerve sheath tumors have high rates of metastasis even after chemoradiation and resection. MEK-inhibitors produced limited regression in tumor size. Sirolimus and thalidomide reduced tumor size but caused more severe adverse effects than MEK-inhibitors. Improvements in major curves and T1-T12 height gain were reported after MCGR intervention. Anteroposterior arthrodesis produced the greatest correction of dystrophic cervical kyphosis. There may be value in establishing standardized spinal screening protocols for pediatric NF1 patients. Surgical correction of NF1-associated spinal deformity is effective, though current medical therapies for spinal tumors have limited success. Areas for further investigation include determining appropriate screening intervals, choice of medical therapy for spinal tumors, and long-term outcomes of MCGRs. Level of Evidence: IV.

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.

Management and surgical outcomes of dystrophic scoliosis in neurofibromatosis type 1: a systematic review

OBJECTIVE

Neurofibromatosis type 1 (NF1) dystrophic scoliosis is an early-onset, rapidly progressive multiplanar deformity. There are few studies on the surgical management of this patient population. Specifically, perioperative morbidity, instrument-related complications, and quality-of-life outcomes associated with surgical management have not been systematically evaluated. In this study, the authors aimed to perform a systematic review on the natural history, management options, and surgical outcomes in patients who underwent NF1 dystrophic scoliosis surgery.

METHODS

A PubMed search for articles with “neurofibromatosis” and either “dystrophic” or “scoliosis” in the title or abstract was performed. Articles with 10 or more patients undergoing surgery for NF1 dystrophic scoliosis were included. Data regarding indications, treatment details, morbidity, and outcomes were summarized and analyzed with descriptive statistics.

RESULTS

A total of 310 articles were identified, 48 of which were selected for full-text review; 30 studies describing 761 patients met the inclusion criteria. The mean age ranged from 7 to 22 years, and 99.7% of patients were younger than 18 years. The mean preoperative coronal Cobb angle was 75.2°, and the average correction achieved was 40.3°. The mean clinical follow-up in each study was at least 2 years (range 2.2–19 years). All patients underwent surgery with the intent of deformity correction. The scoliosis regions addressed were thoracic curves (69.6%) and thoracolumbar (11.1%) and lumbar (14.3%) regions. The authors reported on a variety of approaches: posterior-only, combined anterior-posterior, and growth-friendly surgery. For fixation techniques, 42.5% of patients were treated with hybrid constructs, 51.5% with pedicle screw–only constructs, and 6.0% with hook-based constructs. Only 0.9% of patients underwent a vertebral column resection. The nonneurological complication rate was 14.0%, primarily dural tears and wound infections. The immediate postoperative neurological deficit rate was 2.1%, and the permanent neurological deficit rate was 1.2%. Ultimately, 21.5% required revision surgery, most commonly for implant-related complications. Loss of correction in both the sagittal and coronal planes commonly occurred at follow-up. Five papers supplied validated patient-reported outcome measures, showing improvement in the mental health, self-image, and activity domains.

CONCLUSIONS

Data on the surgical outcomes of dystrophic scoliosis correction are heterogeneous and sparse. The perioperative complication rate appears to be high, although reported rates of neurological deficits appear to be lower than clinically observed and may be underreported. The incidence of implant-related failures requiring revision surgery is high. There is a great need for multicenter prospective studies of this complex type of deformity.

Early-Onset Spinal Deformity in Neurofibromatosis Type 1: Natural History, Treatment, and Imaging Surveillance

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Early-onset scoliosis (EOS) or kyphosis is common in patients with neurofibromatosis (NF) and is characterized by rapid progression of deformity.

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Traditional growing rods provide good functional and deformity outcomes in patients with NF and EOS; magnetically controlled growing rods (MCGRs) also provide good deformity correction, although high rates of revision have been reported after their use.

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Among patients with NF type 1 (NF1), morphologic characteristics of the spinal deformity are different in those with paraspinal neurofibromas than in those without paraspinal tumors.

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Patients with NF1 are at low risk for developing malignant peripheral nerve sheath tumors during childhood (<1%) and their lifetime (8% to 12%), and routine imaging surveillance for malignancy in the absence of symptoms should be clinically directed.

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Further investigation is needed to standardize screening for EOS in children with NF1 and to develop guidelines for ideal imaging modalities, including their frequency and a timeline.

[Spinal deformity in neurofibromatosis type 1]

BACKGROUND

With a prevalence of up to 60%, spinal deformity represents the most common skeletal manifestation of neurofibromatosis type 1. The deformity can occur as a non-dystrophic or as a less common dystrophic type. This distinction is of great relevance because the therapeutic strategy is completely different in each case.

NON-DYSTROPHIC TYPE

The non-dystrophic type can be treated like idiopathic scoliosis due to the comparable behavior of both entities. However, care must be taken regarding the so-called modulation. Modulation describes the formation of dysplasias of the spine. This will result in a progression behavior as known from the dystrophic type.

DYSTROPHIC TYPE

For the dystrophic type, different spinal dysplastic changes are typical. These lead to a rapid progression of deformity and a lack of response to conservative treatment. If untreated, severe and grotesque deformities can arise. This type of deformity requires early surgical intervention, even in childhood. The knowledge about the peculiarities of this disease in general, as well as the typical changes of the spine are prerequisites to managing these often-challenging situations.