Segmental spinal dysgenesis: a report of early surgical intervention and outcome in a 14-month-old child

Segmental Spinal Aplasia: Anatomical Variations and Treatment Insights

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVE

The study aimed to analyze anatomical variants of segmental spinal aplasia (SSA) and investigate factors influencing surgical treatment outcomes, with a specific focus on the incidence of complications.

METHODS

The study focused on patients with SSA treated at a single medical center, with over two years of follow-up. Neurological function changes were evaluated using the modified Japanese Orthopedic Scale (mJOA). Functional independence was measured using the Functional Independence Measure (FIM/WeeFIM) scale, and complications, well-being, and reoperation instances were documented. Statistical analyses used ANOVA and Kruskal-Wallis test.

RESULTS

The predominant localization of SSA in 36 own cases occurs near or at the level of the thoracolumbar junction, often accompanied by significant spinal cord narrowing and a low position of the conus medullaris. Additionally, it frequently presents with aplasia of the lower ribs. Cervicothoracic SSA was more commonly associated with segmentation disorders (P = .04). The most common early complications were wound problems (17%) and neurological deterioration (17%); the most common late complications were: non-fusion (34%); 38% of patients required one or more revision surgery. The type, age of surgery, level of surgery, and initial neurological deficient did not significantly influence the incidence of complications or neurological and functional outcomes.

CONCLUSION

SSA, a range of anomalies appearing early in childhood, progresses gradually. Surgery involves vertebrectomy followed by interbody fusion and screw fixation, guided by neurophysiological monitoring. Surgery is recommended for worsening neurological symptoms, but conservative options like bracing can be considered, due to a high risk of complications.

Segmental spinal dysgenesis: insights from three consecutive cases and a review of the literature

OBJECTIVE

Segmental spinal dysgenesis (SSD) is a rare congenital spinal abnormality affecting the thoracic and lumbar region of the spine, as well as the spinal cord of neonates and infants. The purpose of the study was to analyze our institution's surgical case series to provide insights into our best practices to contribute to SSD management principles, while conducting a comprehensive literature review.

METHODS

Following institutional review board approval, a retrospective review of SSD surgical cases was examined to observe clinical findings, radiographic findings, management, surgical intervention, and outcomes. Keywords in the comprehensive literature review included SSD, congenital spinal dysgenesis, congenital spinal stenosis, spinal aplasia, and surgery.

RESULTS

Three cases underwent successful surgical management with either improvement or maintenance of neurological baseline. Patients were diagnosed at an average age of 2.7 months, while surgical intervention averaged at 40.3 months with fecal incontinence, neurogenic bladders, spinal cord compression, clubfoot, and concerns for worsening spinal deformity as surgical indicators. The average time for follow-up was 33.7 months and no complications were reported.

CONCLUSIONS

Operative management for SSD is a clinically complex decision that requires multidisciplinary input and care. Patients should be observed at neurological baseline and receive intervention at the appropriate time to allow sufficient growth for functioning without permitting drastic disease progression. Consideration of patient size and spinal instrumentation are significant towards surgical success.

Junctional Neurulation : A Junction between Primary and Secondary Neural Tubes

Recent case reports of junctional neural tube defect (JNTD) which is a peculiar type of spinal anomaly showing the functional disconnection of the primary and secondary neural tubes has risen interest in the process of junctional neurulation (the connection between the two neural tubes) during development. This article summarizes the clinical features of the JNTD and reviews the literature on the basic research on junctional neurulation.

An Unusual Case of a Conus Hanging by a Thread

We report a rare cause of paraparesis in a 2-year-old girl. Along with lower limb weakness, she presented with a neurogenic bladder and lower limb deformities. Her magnetic resonance imaging showed multiple dorsolumbar segmentation defects and a dysgenetic spinal cord segment between T10 and S1. A thin septum connected the lower end of the normal cord to a bulky conus at S1-2. These features were suggestive of type 1 segmental spinal dysgenesis. The findings were confirmed at surgery, and the child was referred for supportive care.

Do junctional neural tube defect and segmental spinal dysgenesis have the same pathoembryological background?

INTRODUCTION

Junctional neural tube defect (JNTD) is a recently introduced form of congenital spinal dysraphism that is characterized by functional disconnection between the primary and secondary neural tubes. The upper and lower cords appeared to be connected by a non-functioning band-like structure. JNTD is suspected to arise from a developmental error not corresponding to either primary or secondary neurulation, but rather between the two neurulation processes. On the other hand, segmental spinal dysgenesis (SSD) is an older entity of spinal anomalies in which a segment of the spine and spinal cord does not develop properly. The anomaly had been noted for the bony abnormality, as it is the most prominent feature. Based on the recent encounter of two cases resembling both entities, we sought the possibility that the two diseases may have the same pathoembryogenesis.

METHODS AND RESULTS

Based on the impression that the two entities share important features, we compared the details of the two anomalies. First, our two recently encountered cases of JNTD were described. Second, previous reports of SSD were comprehensively reviewed. The two cases had the essential anomaly of the neural structures satisfying the definition of JNTD, as well as the elaborate spinal deformity as seen in SSD. In the previous literature on SSD, it was recognized that in addition to the bone anomaly, disconnected spinal cord was present. Hence, the two entities seem to have many similar clinical and neuroimaging features. The dysgenic spinal level is similar, and the disconnection between the primary and secondary neural tubes is found in the two diseases. The two neural tubes are connected by a band-like structure, with severe stenosis of the spinal canal at the level of the band. Both entities show segmental anomalies of the vertebrae in the thoracolumbar region, especially in the posterior element. Although the extent of shared features seems high, the previously suggested hypothetical pathoembryogenesis of SSD did not involve the process of junctional neurulation. We suggest that SSD shares the same origin as JNTD, and the bony abnormality may be a secondary phenomenon to the core error during neural tube development.

CONCLUSIONS

We propose that JNTD and SSD may be the same entity, originating from an error during junctional neurulation. As there is controversy regarding the treatment strategy for both entities, unified accumulation of clinical experience and analysis may help improve the management of patients.

Segmental Spinal Dysgenesis-"Redefined"

STUDY DESIGN

Retrospective single institutional observational study.

PURPOSE

Segmental spinal dysgenesis (SSD), a complex spinal dysraphic state caused by notochord malformation disorders, is named after its morphological presentation where a spine segment is dysgenetic, malformed or absent. This study's objective was to examine and reassess SSD imaging findings and correlate them with an embryological explanation.

OVERVIEW OF LITERATURE

Scott and his colleagues defined SSD as segmental agenesis or dysgenesis of the lumbar or thoracolumbar vertebrae and underlying spinal cord. Tortori-Donati and his colleagues defined it as a morphologic continuum ranging from hypoplasia to an absent spinal cord segment.

METHODS

Fifteen children, whose imaging findings and clinical features were consistent with SSD, were included in the study. Magnetic resonance imaging (MRI) was performed per institutional spine protocol.

RESULTS

Five children (33.3%) presented with a high-ending bulbous cord with no caudal segment, six (40%) presented with a dorsal or lumbar segmental dysgenetic cord with a low-lying, bulky caudal cord but without significant spinal canal narrowing, and four (26.6%) presented with segmental caudal dysgenesis with severe kyphoscoliosis, gibbus deformity, and spinal canal narrowing with a normal distal segment (normal or low-lying).

CONCLUSIONS

SSD is a complex spinal anomaly in children requiring clinical-radiological assessment followed by multidisciplinary management based on the extent and severity of the dysgenetic cord and the type of SSD. MRI plays a crucial role in both diagnosing and classifying SSD prior to surgical treatment to prevent further impairment.

Surgical Treatment of Thoracolumbar Segmental Spinal Dysgenesis: Optimal Type of Fusion

OBJECTIVES

We sought to evaluate long-term results of surgical treatment of thoracolumbar segmental spinal dysgenesis (SSD).

METHODS

We analyzed 8 patients with thoracolumbar SSD treated in our institution. Each case was evaluated for specific clinical and radiologic criteria and types and outcomes of treatment.

RESULT

The average age of primary surgery was 3.4 years (median 3.4 years, range 1.7-7 years). The average correction of kyphosis was 49.3° (mean 45°, from 25°-75°) and scoliosis 10.6° (mean 10°, from 0°-25°). Average follow-up time was 3.2 years (mean 2.6 years, from 1.8-5.6 years). Neurologic improvement was also achieved in all patients. The Japanese Orthopaedic Association scale score (Benzel's modification) was increased by 2.5 points on average (mean 2.5 points, from 2-5 points). One patient had complications: pseudarthrosis and rod fracture followed by refusion.

CONCLUSIONS

Our treatment strategy provides favorable deformity correction and neurologic improvement. It is limited by immature vertebral structures in newborns and infants, who should be carefully monitored from birth with braces until they reach the age when a fixing tool can be used.