Scoliosis secondary to a hemivertebra: seven patients with gradual improvement without treatment

Histology and chronological magnetic resonance images of congenital spinal deformity: An experimental study in mice model

BACKGROUND

The natural history of the congenital spinal deformity and its clinical magnitude vary widely in human species. However, we previously reported that the spinal deformities of congenital scoliosis mice did not progress throughout our observational period according to soft X-ray and MRI data. In this study, congenital vertebral and intervertebral malformations in mice were assessed via magnetic resonance (MR) and histological images.

METHODS

Congenital spinal anomalies were chronologically assessed via soft X-ray and 7 T MR imaging. MR images were compared to the histological images to validate the findings around the malformations.

RESULTS

Soft X-ray images showed the gross alignment of the spine and the contour of the malformed vertebrae, with the growth plate and cortical bone visible as higher density lines, but could not be used to distinguish the existence of intervertebral structures. In contrast, MR images could be used to distinguish each structure, including the cortical bone, growth plate, cartilaginous end plate, and nucleus pulposus, by combining the signal changes on T1-weighted imaging (T1WI) and T2-weighted imaging (T2WI). The intervertebral structure adjacent to the malformed vertebrae also exhibited various abnormalities, such as growth plate and cartilaginous end plate irregularities, nucleus pulposus defects, and bone marrow formation. In the chronological observation, the thickness and shape of the malformed structures on T1WI did not change.

CONCLUSIONS

Spinal malformations in mice were chronologically observed via 7 T MRI and histology. MR images could be used to distinguish the histological structures of normal and malformed mouse spines. Malformed vertebrae were accompanied by adjacent intervertebral structures that corresponded to the fully segmented structures observed in human congenital scoliosis, but the intervertebral conditions varied. This study suggested the importance of MRI and histological examinations of human congenital scoliosis patients with patterns other than nonsegmenting patterns, which may be used to predict the prognosis of patients with spinal deformities associated with malformed vertebrae.

Morphological analysis of isolated hemivertebra: radiographic manifestations related to the severity of congenital scoliosis

PURPOSE

The natural history of congenital scoliosis (CS) caused by hemivertebra varies greatly. This study aimed to explore the association between the morphology of hemivertebra and the severity of CS, since the diagnosis of the hemivertebra.

METHODS

Patients with isolated (single fully segmented) hemivertebra were enrolled. The degree and progression of deformity were compared by three morphological parameters of hemivertebra, comprising whether the width of hemivertebra extends across the central vertical line of lower adjacent vertebra (midline); the lateral height ratio (LHR, lateral height of hemivertebra× 2/(lateral height of HV-1 plus HV + 1) with the cut-point being 0.9; and the sagittal position of hemivertebra that was divided into the lateral and posterolateral group.

RESULTS

In total, 156 patients (mean age 9.7 ± 6.2 years, 81 males) were enrolled. The number of thoracic, thoracolumbar (T12/13-L1), and lumbar hemivertebrae were 63, 41, and 52, respectively. Hemivertebrae across the midline had larger scoliosis and kyphosis (58.3 ± 20.6° vs. 42.8 ± 15.0°, P <  0.001; 45.1 ± 32.5° vs. 29.5 ± 25.7°, P = 0.013, respectively). Hemivertebrae with LHR ≥0.9 was associated with larger scoliosis (55.7 ± 20.6° vs. 41.4 ± 13.3°, P <  0.001). Larger scoliosis and kyphosis were observed in posterolateral hemivertebrae (54.4 ± 21.0° vs. 44.4 ± 15.6°, P = 0.026; 51.4 ± 31.5° vs. 20.6 ± 17.1°, P <  0.001, respectively). Co-occurrence of more than one of the three positive parameters above indicated higher annual progression (5.0 ± 2.2° vs. 3.3 ± 1.3°, P <  0.001).

CONCLUSION

Three positive parameters, width across the midline, LHR ≥0.9, and posterolateral position were associated with a more severe deformity in patients with isolated hemivertebra. Hemivertebrae with more than one positive parameter may cause progressive deformity, and thus need prompt surgery.

LEVEL OF EVIDENCE

Prognostic, level IV.

Congenital Cervical Scoliosis Treated with Concave Side Distraction with Three-Dimensional Printed Titanium Cage

STUDY DESIGN

Single-center, retrospective study.

OBJECTIVE

Hemivertebra resection is the only treatment option for congenital cervical scoliosis (CCS). However, this procedure is complex and technically demanding. It often requires a considerably long operation, and there is substantial intraoperative bleeding. Therefore, we have attempted to treat CCS with a concave side distraction comprising a three-dimensional (3D) printed titanium cage. The purpose of this study is to evaluate the safety and efficacy of this technique for the treatment of patients with CCS.

METHODS

A series of 22 patients with CCS who underwent a concave side distraction technique between 2019 and 2021 were retrospectively reviewed and analyzed. Radiological measurements included the Cobb angle of the distraction segments, the kyphosis angle, the range of movement, and the distraction correction angle. Student's t-test and Spearman correlation analysis were used for statistical analysis. p < 0.05 was considered statistically significant.

RESULTS

The study included 12 males and 10 females whose ages ranged from 6 to 14 years old (9.8 ± 2.1 years old). Follow-up times ranged from 15 to 30 months (25.8 ± 3.6 months). Among 22 patients, two patients developed a postoperative C5 nerve root palsy and recovered after being treated with conservative treatment for 6 months. The duration of surgery ranged from 229 to 756 min (389 ± 112 min), and the estimated volume of blood loss ranged from 100 to 600mL (235 ± 121 mL). The coronal Cobb angle (p < 0.001), kyphosis angle (p < 0.05), and range of movement (p < 0.001) between the last follow-up and preoperative period were significantly different. A total of 28 segments were distracted, and the Cobb angle of the distraction segment ranged from 2.4 to 14.1° (8.5 ± 3.0°). There were six upper cervical spines (8.9 ± 1.9°) and 22 lower cervical spines (8.4 ± 3.2°) with no significant difference between them (p = 0.130). In addition, there was no correlation between the angle of the concave side distraction and patients' age (r = 0.018, p = 0.315). The fusion was solid between the bone and the customized 3D-printed pore metal cage at the final follow-up.

CONCLUSION

The concave side distraction comprising a customized 3D-printed titanium cage implantation can provide satisfactory correction results and is a safe and reliable procedure for treating CCS.

The conservative treatment of congenital scoliosis with hemivertebra: Report of three cases

INTRODUCTION

Scoliosis is the most common type of congenital vertebral disease. This spinal disorder may be due to a failure of formation, segmentation, or a combination thereof. Complete failure of formation causes hemivertebra which can lead to unbalanced growth and deformation. Statistically, 25% of congenital curves do not evolve, 25% progress slightly, while the remaining 50% develop quickly and require treatment. Hemivertebrae can be divided into three types: non-segmented, semi-segmented, and fully-segmented. The fully-segmented types are most likely to progress. Hemivertebra in the thoracolumbar region shows higher rates of progression compared with those in the lumbar area. The treatment may be either conservative or surgical. In general, bracing is not recommended in short and rigid curves, although it may help process secondary curves.

OBJECTIVE

To assess the effectiveness of bracing in congenital scoliosis due to hemivertebra.

CASES PRESENTATION

Searching in our database, we found three cases of patients with congenital scoliosis due to fully-segmented hemivertebra. The first of them was 6 years old at the time of diagnosis with a fully-segmented hemivertebra in L5, determining an L1-L5 (S1) lumbar curve. The second one was 10 years old at the time of diagnosis with a fully-segmented hemivertebra in L2 and a T11-L4 (L5 sacralized) thoracolumbar curve. The last one was 3 years old at the time of diagnosis with a fully-segmented hemivertebra in L3 (in six lumbar bodies), determining a thoracolumbar curve T12-L4.

RESULTS

We utilized a Milwaukee brace for the first patient, a Boston brace for the second patient, and a Progressive Action Short Brace (PASB) for the third patient. At the beginning of the treatment, the Cobb angles measured 23°, 53°, and 25°, respectively. During treatment, the Cobb angles measured 22°, 35°, and 15°, respectively. At the end of treatment, the Cobb angles measured 18°, 45°, and 12°, respectively. At long-term follow-up, the curves measured 20°, 45°, and 12° Cobb angles, respectively.

CONCLUSIONS

Comparing our cases with those found in the literature we can confirm the ability of conservative treatment to change the natural history of congenital lumbar scoliosis due to failure of formation. From our experience, in all cases of CS with hemivertebra, before considering a surgical approach, conservative treatment should be implemented as early as possible without waiting for the progressive deformation of the adjacent normal vertebrae.

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.

A review of the hemivertebrae and hemivertebra resection

Hemivertebra (HV) is a congenital spinal abnormality. Most hemivertebrae have normal growth plates so create a progressive deformity with growth leading to asymmetric loads on adjacent vertebrae which also show an asymmetric growth. We review the condition and its treatment.

Current Concepts - Congenital Scoliosis

Background:

Congenital scoliosis is one of the ‘difficult to treat’ scenarios which a spine surgeon has to face. Multiple factors including the age of child at presentation, no definite pattern of deformity and associated anomalies hinder the execution of the ideal treatment plan. All patients of congenital scoliosis need to be investigated in detail. X rays and MRI of spine is usually ordered first. Screening investigations to rule out VACTERL (Visceral, Anorectal, Cardiac, Tracheo-esophageal fistula, Renal and Lung) abnormalities are required. They are cardiac echocardiography and ultrasonography of abdomen and pelvis. CT scan is required to understand the complex deformity and is helpful in surgical planning.

Methods:

A comprehensive medical literature review was done to understand the current surgical and non surgical treatment options available. An attempt was made to specifically study limitations and advantages of each procedure.

Results:

The treatment of congenital scoliosis differs with respect to the age of presentation. In adults with curves more than 50 degrees or spinal imbalance the preferred treatment is osteotomy and correction. In children the goals are different and treatment strategy has to be varied according to the age of patient. A single or two level hemivertebra can easily be treated with hemivertebra excision and short segment fusion. However, more than 3 levels or multiple fused ribs and chest wall abnormalities require a guided growth procedure to prevent thoracic insufficiency syndrome. The goal of management in childhood is to allow guided spine growth till the child reaches 10 - 12 years of age, when a definitive fusion can be done. The current research needs to be directed more at the prevention and understanding the etiology of the disease. Till that time, diagnosing the disease early and treating it before the sequels set in, is of paramount importance.

Conclusion:

The primary aim of treatment of congenital scoliosis is to allow the expansion of chest and abdominal cavity, while keeping the deformity under control. Various methods can be categorized into definitive (hemivertebrectomy) or preventive (guided growth). Casting, Growth rods, Convex Epiphysiodesis are all guided growth measures. The guided growth procedure either ‘corrects the deformity’ or will have to be converted to a final fusion surgery once the child completes the spinal growth which is preferably done around 10 - 12 years of age. Future directions should aim at genetic counselling and early detection.

Hemivertebra Resection With Instrumented Fusion by Posterior Approach in Children

STUDY DESIGN

We conducted a retrospective study of patients with congenital scoliosis due to hemivertebra (HV) and performed resection with instrumentation through posterior approach-only with long term follow-up.

OBJECTIVES

The objective of this study was to assess results of HV resection by posterior approach-only with instrumentation between 2002 and 2011.

SUMMARY AND BACKGROUND DATA

Hemiepiphysiodesis, arthrodesis in situ and resection without instrumentation had been performed in the past with different results. Hemivertebra resection with spinal instrumentation through anterior and posterior approach has been advocated as the treatment of choice.

METHODS

A total of 67 patients with 78 HV and 70 surgical procedures were evaluated. Thirty-five of the patients were females and 32 were males. The mean age of the patients was 5.5 years (from 0.8 to 16 yr), and the mean follow-up period was 6.55 years (from 2.1 to 10.8 yr). Eighteen patients presented additional pathologies: specific syndromes, cardiopathies, thoracic, abdominal, and bone malformations. Sixteen patients had partial HV while 51 had full mobility HV. Twenty-eight of the HV were thoracic, 16 thoracolumbar, 28 lumbar, and six lumbosacral.

RESULTS

The scoliosis mean preoperative angular value was 38.55°, and the mean postoperative angular value was 19.89°. The kyphosis mean preoperative angular value was 29.98° and the mean postoperative angular value was 15.41°. One rod was used in 38 surgical procedures (54.28%) and 2 rods in 32 procedures (45.72%). We used monoaxial screws in 45 patients, poliaxial screws in 17 patients, and both monoaxial screws and poliaxial screws in one patient. Screws and hooks were used in one patient and hooks in three patients. Arthrodesis was performed in 64 patients, and no complications were registered in those without arthrodesis. Postoperative orthesis was used in 57 opportunities. Several complications during or after HV resection by posterior approach-only were reported. Two patients suffered from intraoperative neurophysiological complications, which were resolved during surgery with minimum gestures and presented no sequelae. Two patients developed superficial infections and needed toilette and IV antibiotic therapy. Two patients needed an additional surgery due to secondary curves, 4.9 yr after primary surgery on average. One patient developed crankshaft.

CONCLUSIONS

We concluded that HV resection by posterior approach-only with instrumentation is a simple, secure, reliable, less invasive and well tolerated technique that can successfully resolve this kind of congenital scoliosis in children.

Hemivertebrae resection for unbalanced multiple hemivertebrae: is it worth it?

PURPOSE

To assess the correction effect of hemivertebra resection for unbalanced multiple hemivertebrae by measuring corresponding parameters in both coronal and sagittal planes on series posteroanterior and lateral radiographs and report the related complications.

METHODS

Twelve children with unbalanced multiple hemivertebrae were operated on by hemivertebra resection through a combined anterior and posterior approach or a posterior-only procedure. Mean age at time of surgery was 9.8 years (range 2-14 years). They were retrospectively studied with a mean follow-up of 48.7 months (range 30-60 months).

RESULTS

The mean Cobb angle of the main curve was 65.3° (range 45°-92°) before surgery and 13.8° (range 4°-30°) at the last follow-up. The correction rate was 80.0% (range 65.5-92.4 %). The compensatory cranial curve was corrected from 25.8° (range 5°-53°) to 11.7° (range 0°-34°) with a correction rate of 65.9% (range 33.3-100%), and the compensatory caudal curve was corrected from 32.4° (range 17°-57°) to 7.1° (range 0°-20°) with a correction rate of 81.4% (range 53.1-100%). The angle of segmental kyphosis was 41.3° (range 12°-76°) before surgery and 17.0° (range -12° to 45°) at the final follow-up. The coronal imbalance was -1.0 cm (range -3.5 to 3 cm) before surgery and 0.0 cm (range -1.0 to 1.5 cm) at the most recent follow-up. The sagittal imbalance was 0.9 cm (range -3.2 to 3 cm) before surgery and 0.6 cm (range -3.0 to 3.5 cm) at the most recent follow-up. Complications including pedicle fractures, and pseudarthrosis were found in two patients (20 %).

CONCLUSIONS

In the patients with unbalanced multiple hemivertebrae, hemivertebra resection allows for excellent correction in both the coronal and sagittal planes, and great care should be taken to reduce the rate of complications.