Sacral agenesis: evaluation of accompanying pathologies in 38 cases, with analysis of long-term outcomes

Sacral Agenesis

Sacral agenesis (SA) is a rare congenital neurological disorder characterized by the incomplete development of the sacral spine. This work summarizes the scientific literature on SA, including the following sections: pathogenesis, epidemiology, risk factors, genetics, clinical manifestations, radiological classification, diagnosis, and management. The aim of this work is to provide the most up-to-date and comprehensive medical narrative literature review for this rare congenital disease. This narrative review used PubMed, MEDLINE, Science Direct, and Embase databases. Between December 2022 and September 2023, the following terms were used for the inclusion of original articles: "rare disease," "caudal regression," "diabetic embryopathy," and "sacral agenesis.? The International Sacral Agenesis/Caudal Regression Association participated in reviewing this manuscript and drafting a paragraph on behalf of those living with this condition. The clinical manifestations of SA are heterogeneous. The most prevalent manifestations involve peripheral neurological, motor, urinary, and digestive issues. The prognosis depends on the severity and associated abnormalities. Patients usually exhibit normal mental function but require a multidisciplinary evaluation and largely supportive treatment that enables them to live successful lives. More awareness and research are needed.

Optimizing sacral screw fixation in patients with caudal regression syndrome

PURPOSE

The aim of this study is to evaluate and compare techniques and outcomes associated with two different technique of pelvic screw insertion in patients with caudal spine absence.

METHODS

A cohort of patients with varying degrees of caudal structural regression, serves as the focal point of this investigation. Pelvic configurations were classified based on established criteria to facilitate comparative analysis. Each patient underwent spinal surgical interventions, with a follow-up period extending beyond 2 years. The primary surgical interventions predominantly involved spinal stabilization coupled with correction of scoliosis and kyphosis through one or two pairs of pelvic screws.

RESULTS

In this study, we investigated a cohort of 22 patients with caudal spine absence, encompassing diverse conditions, such as lumbo-sacral aplasia, hemisacrum, and lumbar absence, with preserved sacrum. Following spinal surgery, notable improvements were observed in scoliosis and pathological lumbar kyphosis, with several patients achieving significant functional milestones such as independent ambulation. There were no significant differences in short-term complications between patients undergoing single versus double pair pelvic screw implantation. Long-term complications, primarily non-fusion, were notably more prevalent in patients undergoing fixation with a single pair of pelvic screws.

CONCLUSION

Surgical intervention, particularly spinopelvic fixation, demonstrated promising outcomes in terms of improving spinal deformities. The implantation of two pairs of pelvic screws demonstrates greater reliability compared to the insertion of a single pair, diminishing the risk of non-fusion.

Caudal Agenesis: Classification Based on the Pathoembryogenesis of the Spinal Cord

BACKGROUND AND OBJECTIVES

Caudal agenesis (CA) is a congenital disease characterized by lower vertebral bone defects. Previous classifications for CA were based on the levels of bony defects or the conus medullaris. We created a new pathoembryogenic classification that takes into account the level of conus, considering both its shape and filum. We evaluated its accuracy in reflecting the neurological status and the need for untethering.

METHODS

Patients with radiologic studies available on our institute's electronic image view system between 1985 and 2019 were reviewed. Our classification categorized patients with CA into 3 groups: the failure of formation (a conus level > L1 or normal level conus with a blunt shape), the failure of regression (a conus level < L3 or normal level conus with a thickened filum or a filar lipoma), and the normal (a normal level conus without specific abnormalities). We analyzed which of the following 3 classifications better reflects the neurological status and the probability of recommending untethering: classifications based on (1) bony defect level, (2) conus level, and (3) pathoembryogenic mechanism.

RESULTS

A total of 89 patients were included in this study. The pathoembryogenic classification revealed more significant differences in motor or sensory deficits compared with other classifications (failure of formation: 42%; failure of regression: 16%; and normal: 0%, P = .039). In addition, the pathoembryogenic classification emerged as a significant or suggestive predictive factor for motor and sensory deficits (motor: odds ratio 11.66, P = .007; sensory: odds ratio 5.44, P = .066). Notably, only the pathoembryogenic classification exhibited a significant difference in the probabilities of recommending untethering between groups (failure of formation: 42%; failure of regression: 81%; and normal 12%, P < .001).

CONCLUSION

The correlation between bony classification and spinal cord abnormalities was exaggerated. Our new pathoembryogenic classification was valuable in prognosticating neurological status and identifying the patient group more likely to require untethering among patients with CA.

Clinical and radiological evaluation of caudal regression syndrome

Caudal regression syndrome is a form of segmental spinal dysgenesis involving the caudal spinal column, ranging from segmental coccygeal agenesis to extensive thoracolumbar agenesis with varying degrees of spinal cord dysgenesis. A majority of caudal regression cases are sporadic but maternal pre-gestational diabetes mellitus is an important risk factor. Imaging is an integral part of management of caudal regression syndrome. Antenatal diagnosis on obstetric ultrasound and evaluation with fetal MRI is ideal. Early postnatal diagnosis and/or detailed evaluation with MRI is essential for early management to improve outcomes. Pang classification categorizes caudal regression syndrome into two categories based on the position of the conus while Renshaw classification is based on the degree of vertebral column agenesis. Caudal regression syndrome may be associated with several additional anomalies, both spinal and extraspinal. A number of genitourinary and gastrointestinal anomalies have been described in association with caudal regression syndrome. The field of view of MRI of the lumbosacral spine in caudal regression syndrome needs to be extended to visualize the retroperitoneal structures without the use of a saturation band. Syndromic associations may be suspected, and additional imaging performed, based on findings of extended field of view MRI of the spine. Associated sacral masses and filar abnormalities need to be identified and may also require surgical treatment. The multisystem nature of this disease necessitates a multimodality approach to the evaluation and management of caudal regression syndrome with close cooperation between pediatric neuroradiologists and body radiologists as well as multiple clinical teams. Appropriate early management with surgical correction as necessary can significantly improve prognosis and survival in caudal regression syndrome.

Long-term outcomes in sacral agenesis

INTRODUCTION

Sacral agenesis (SA) includes a range of clinical presentations of varying severity, with implications for function and quality of life (QoL). Diagnosis is often made perinatally, and prognostic discussions become an important aspect of parental counselling. This study engaged SA sufferers and their caregivers to obtain objective, long-term patient reported outcome data.

METHOD

Patients with radiologically confirmed SA from a single tertiary spinal unit underwent retrospective medical record review. Patients were then contacted by telephone to complete QoL questionnaires including EQ-ED-5L for adults and EQ-ED-Y for < 16-year-olds. Additional information including Renshaw grade, employment, living situation and bladder function was also collected.

RESULTS

Twenty-six patients with SA were identified. Mean age is 23.35 years (range 0.92-63.53), 13 M:17F. Renshaw grade ranged from 1 to 4. Sixty-eight percent had associated kyphoscoliotic deformities. The majority (70%) had either impaired or absent bladder control, and 80% need walking aids to mobilise. Twenty patients completed the questionnaire (10 adults and 10 < 16-year-olds). Mean EQ-ED-5L index for adults was +0.474 (range -0.1 to +0.089, 1 = best), with a lower mean value of +0.287 (range -0.54 to +1) for the < 16-year cohort. Those undergoing spinal fusion procedures had significantly lower scores (-0.08 v +0.44, p = 0.022).

CONCLUSION

This study provides an objective record of the QoL of individuals with SA, illustrating a wide variety of outcomes, with differences between younger and older individuals which may reflect the results of a long-term adaptive process. The implications for individuals should be carefully tailored to the specific deformity and the likely underlying neurological deficits.

Caudal Regression Syndrome First Diagnosed in Adulthood: A Case Report and a Review of the Literature

Background: Caudal regression syndrome (CRS) is a rare congenital malformation characterized by incomplete development of the lower spine and spinal cord. Its estimated incidence ranges from 1 to 2 per 100,000 live births, leading to a spectrum of clinical presentations. Although most cases are diagnosed during childhood, only a small number of cases have been documented in adults in the medical literature. Case Report: A 27-year-old woman underwent an outpatient magnetic resonance imaging (MRI) of the thoracolumbar spine due to severe lower back pain experienced for the first time. Despite congenital leg abnormalities and multiple childhood surgeries, no further investigations were conducted at that time. MRI revealed congenital anomalies consistent with CRS, including coccygeal agenesis, L5 sacralization, and spinal cord defects. The patient also had a long-standing pilonidal cyst treated conservatively, now requiring operative treatment due to an abscess. Conclusions: This report underscores a rare case of CRS initially misdiagnosed and mistreated over many years. It emphasizes the importance of considering less common diagnoses, especially when initial investigations yield inconclusive results. This clinical case demonstrates a highly valuable and educative radiological finding. In the literature, such cases with radiological findings in adults are still lacking.

Association of spinal cord abnormalities with vertebral anomalies: an embryological perspective

PURPOSE

To analyze the relationship between spinal cord and vertebral abnormalities from the point of view of embryology.

METHODS

We analyzed the clinical and radiological data of 260 children with different types of spinal cord malformations in combination with vertebral abnormalities.

RESULTS

Among 260 individuals, approximately 109 presented with open neural tube defects (ONTDs), 83 with split cord malformations (SCMs), and 83 with different types of spinal lipomas. Pathological spina bifida emerged as the most frequent vertebral anomaly, affecting 232 patients, with a higher prevalence in ONTD. Vertebral segmentation disorders, including unsegmented bars, butterfly vertebrae, and hemivertebrae, were present in 124 cases, with a higher prevalence in SCM. The third most common spinal anomaly group consisted of various forms of sacral agenesis (58 cases), notably associated with blunt conus medullaris, spinal lipomas, and sacral myelomeningocele. Segmental aplasia of the spinal cord had a typical association with segmental spinal absence (N = 17).

CONCLUSION

The association between SCM and neuroenteric cyst/canal and vertebral segmentation disorders is strong. High ONTDs often coincide with pathological spina bifida posterior. Type 1 spinal lipomas and focal spinal nondisjunction also correlate with pathologic spina bifida. Segmental spinal absence or dysgenesis involves localized spinal and spinal cord aplasia, sometimes with secondary filar lipoma.

Feasibility and safety study of wearable cyborg Hybrid Assistive Limb for pediatric patients with cerebral palsy and spinal cord disorders

Introduction

The wearable cyborg Hybrid Assistive Limb (HAL) is the world's first cyborg-type wearable robotic device, and it assists the user's voluntary movements and facilitates muscle activities. However, since the minimum height required for using the HAL is 150 cm, a smaller HAL (2S size) has been newly developed for pediatric use. This study aimed to (1) examine the feasibility and safety of a protocol for treatments with HAL (2S size) in pediatric patients and (2) explore the optimal method for assessing the efficacy of HAL.

Methods

This clinical study included seven pediatric patients with postural and motor function disorders, who received 8-12 sessions of smaller HAL (2S size) treatment. The primary outcome was the Gross Motor Function Measure-88 (GMFM-88). The secondary outcomes were GMFM-66, 10-m walk test, 2- and 6-min walking distances, Canadian Occupational Performance Measure (COPM), a post-treatment questionnaire, adverse events, and device failures. Statistical analyses were performed using the paired samples t-test or Wilcoxon signed-rank test.

Results

All participants completed the study protocol with no serious adverse events. GMFM-88 improved from 65.51 ± 21.97 to 66.72 ± 22.28 (p = 0.07). The improvements in the secondary outcomes were as follows: GMFM-66, 53.63 ± 11.94 to 54.96 ± 12.31, p = 0.04; step length, 0.32 ± 0.16 to 0.34 ± 0.16, p = 0.25; 2-MWD, 59.1 ± 57.0 to 62.8 ± 63.3, p = 0.54; COPM performance score, 3.7 ± 2.0 to 5.3 ± 1.9, p = 0.06; COPM satisfaction score, 3.3 ± 2.1 to 5.1 ± 2.1, p = 0.04.

Discussion

In this exploratory study, we applied a new size of wearable cyborg HAL (2S size), to children with central nervous system disorders. We evaluated its safety, feasibility, and identified an optimal assessment method for multiple treatments. All participants completed the protocol with no serious adverse events. This study suggested that the GMFM would be an optimal assessment tool for validation trials of HAL (2S size) treatment in pediatric patients with posture and motor function disorders.

Atypical caudal regression syndrome with lumbar agenesis, hypoplastic sacrum without sacroiliac joints in the eastern Democratic Republic of Congo: a case report

The agenesis of any segment of the lower spinal column referred to as "caudal regression syndrome" (CRS) is a rare congenital defect of the spine. This malformation is characterized by the absence of some or the entire lumbosacral vertebral segment. Etiological factors remain unknown. We report an atypical caudal regression syndrome with lumbar agenesis, disconnected from the remaining hypoplastic sacrum, in the Eastern part of the Democratic Republic of Congo (DRC).An 11-month-old female infant with no particular fetal or maternal history presented limb weakness with flexed knees and flanges in the popliteal fossae, sphincter atony, and a sensation of emptiness on palpation in the lumbosacral region. A 3D CT scan of the spine showed the absence of the lumbar spine and disconnection of the upper segment of the thoracic spine from the hypoplastic sacrum. We noted also the absence of the sacroiliac joints bilaterally and an unusual trigonal shape of the iliac bones. MRI and sonographic examination are required in the investigation of the disease. The management is multidisciplinary and depends upon the degree of the defect. Spine reconstruction has proven to be a valuable management technique but has many complications. We wanted to draw the medical world's attention to the existence of this extremely rare malformation in the east of the Democratic Republic of Congo, a mining area.

Case report: Sacral agenesis in two boxer dogs: clinical presentation, diagnostic investigations, and outcome

Two boxer dogs from the same litter were presented at 3 months of age for urinary and fecal incontinence. Both dogs had an abnormal tail consisting of a small stump, an atonic anal sphincter, and absent perineal reflex and sensation. Neurological evaluation was indicative of a lesion of the cauda equina or sacral spinal cord. Radiology and CT scan of the spine displayed similar findings in the two dogs that were indicative of sacral agenesis. Indeed, they had 6 lumbar vertebrae followed by a lumbosacral transitional vertebra, lacking a complete spinous process, and a hypoplastic vertebra carrying 2 hypoplastic sacral transverse processes as the only remnant of the sacral bone. Caudal vertebrae were absent in one of the dogs. On MRI, one dog had a dural sac occupying the entire spinal canal and ending in a subfascial fat structure. In the other dog, the dural sac finished in an extracanalar, subfascial, well-defined cystic structure, communicating with the subarachnoid space, and consistent with a meningocele. Sacral agenesis-that is the partial or complete absence of the sacral bones-is a neural tube defect occasionally reported in humans with spina bifida occulta. Sacral agenesis has been described in human and veterinary medicine in association with conditions such as caudal regression syndrome, perosomus elumbis, and Currarino syndrome. These neural tube defects are caused by genetic and/or environmental factors. Despite thorough genetic investigation, no candidate variants in genes with known functional impact on bone development or sacral development could be found in the affected dogs. To the best of the authors' knowledge, this is the first report describing similar sacral agenesis in two related boxer dogs.

Allowing Standing and Assisted Steps in a Patient With Renshaw Type IV Sacral Agenesis: A Case Report of a Novel Surgical Approach

CASE

A 6-year-old boy with a Renshaw type 4 sacral agenesis presented paraplegia and rigid, "Buddha-like" lower-limb contractures, including severe knee pterygia, which made crawling and sitting difficult. Staged surgical treatment involved bilateral knee disarticulation, soft tissue surgery, and bifocal femoral osteotomies for lower-limb reorientation. At 18 months postoperatively and after prosthetic fitting, the patient can stand and take steps with assistance.

CONCLUSION

This effective surgical strategy achieves standing in a troublesome orthopaedic congenital condition. The intervention should be tailored to specific orthopaedic disorders and the wishes of patients and families, aiming to improve function.

Caudal Regression Syndrome-A Narrative Review: An Orthopedic Point of View

Abnormalities in cellular differentiation during embryo-fetal period may lead to various malformations of the spine. Caudal regression syndrome (CRS) is a group of defects with premature growth/development termination of the vertebral column. CRS can be divided into three types: sirenomelia, complete absence of the sacrum and partial absence of the sacrum. Genitourinary and gastrointestinal anomalies are common, with neurogenic bladder and bowel incontinence. Treatment of patients with CRS is complex and multidisciplinary and should be comprehensive. The most common orthopedic problems are: spinal deformity (kyphosis and scoliosis), spinopelvic instability and lower limbs deformities.

Disorders of Secondary Neurulation: Suggestion of a New Classification According to Pathoembryogenesis

Recently, advanced knowledge on secondary neurulation and its application to the clinical experience have led to the deeper insight into the pathoembryogenesis of secondary neurulation with new classifications of the caudal spinal dysraphic entities. Here, we summarize the dynamic changes in the concepts of disordered secondary neurulation over the last two decades. In addition, we suggest our new pathoembryogenetic explanations for a few entities based on the literature and the data from our previous animal research. Disordered secondary neurulation at each phase may cause various corresponding lesions, such as (1) failed junction with the primary neural tube (junctional neural tube defect and segmental spinal dysgenesis), (2) dysgenesis or duplication of the caudal cell mass associated with disturbed activity of caudal mesenchymal tissue (caudal agenesis and caudal duplication syndrome), (3) abnormal continuity of medullary cord to the surrounding layers, namely, failed ingression of the primitive streak to the caudal cell mass (myelomeningocele), focal limited dorsal neurocutaneous nondisjunction (limited dorsal myeloschisis and congenital dermal sinus), and neuro-mesenchymal adhesion (lumbosacral lipomatous malformation), and (4) regression failure spectrum of the medullary cord (thickened filum and filar cyst, retained medullary cord and low-lying conus, terminal myelocele, and terminal myelocystocele). It seems that almost every anomalous entity of the primary neural tube may occur in the area of secondary neurulation. Furthermore, the close association of the caudal cell mass with the activity of caudal mesenchymal tissue involves a wider range of surrounding structures in secondary neurulation than in primary neurulation. Although the majority of the data are from animals and many theories are still conjectural, these changing concepts of normal and disordered secondary neurulation will provoke further advancements in our management strategies as well as in the pathoembryogenetic understanding of anomalous lesions in this area.

Different distal fixation anchors in lumbosacral spinal deformities associated with sacral agenesis: which one is better?

OBJECTIVE

Sacral agenesis (SA) is a rare congenital malformation of the spine. There has been a paucity of clinical research to investigate the surgical outcome of spinopelvic fixation in these patients. In this study, the authors aimed to evaluate the outcome of different distal fixation anchors in lumbosacral spinal deformities associated with SA and to determine the optimal distal fixation anchor.

METHODS

Patients with diagnoses of SA and lumbosacral scoliosis undergoing spinopelvic fixation with S1 screws, iliac screws, or S2-alar-iliac (S2AI) screws were analyzed. The main curve, coronal balance distance, and pelvic obliquity were compared at baseline, postoperatively, and during follow-up in three groups. The complications were also recorded.

RESULTS

A total of 24 patients were included: 8 patients were stratified into group 1 (S1 screws), 9 into group 2 (iliac screws), and 7 into group 3 (S2AI screws). The main curves were well corrected postoperatively (p < 0.05) in all groups. Coronal balance showed a tendency of deterioration during follow-up in patients with S1 screws (from 18.8 mm to 27.0 mm). Regarding pelvic obliquity, patients with both iliac and S2AI screws showed significant correction (from 3.7° to 2.3° and from 3.3° to 1.6°). Implant-related complications were rod breakage in 3 patients and infection in 1 patient in group 2, and no implant-related complications were observed in group 3. There were 3 cases of unilateral S1 pedicle screw misplacement in group 1.

CONCLUSIONS

Spinopelvic fixation is a safe and effective procedure that can achieve coronal correction in lumbosacral scoliosis associated with SA. Compared with S1 and iliac screws, S2AI screws as distal fixation anchors can achieve a more satisfactory correction with fewer implant-related complications.

Disorders of Secondary Neurulation : Mainly Focused on Pathoembryogenesis

Recent advancements in basic research on the process of secondary neurulation and increased clinical experience with caudal spinal anomalies with associated abnormalities in the surrounding and distal structures shed light on further understanding of the pathoembryogenesis of the lesions and led to the new classification of these dysraphic entities. We summarized the changing concepts of lesions developed from the disordered secondary neurulation shown during the last decade. In addition, we suggested our new pathoembryogenetic explanations for a few entities based on the literature and the data from our previous animal research. Disordered secondary neurulation at each phase of development may cause corresponding lesions, such as failed junction with the primary neural tube (junctional neural tube defect and segmental spinal dysgenesis), dysgenesis or duplication of the caudal cell mass associated with disturbed activity of caudal mesenchymal tissue (caudal agenesis and caudal duplication syndrome), failed ingression of the primitive streak to the caudal cell mass (myelomeningocele), focal limited dorsal neuro-cutaneous nondisjunction (limited dorsal myeloschisis and congenital dermal sinus), neuro-mesenchymal adhesion (lumbosacral lipomatous malformation), and regression failure spectrum of the medullary cord (thickened filum and filar cyst, low-lying conus, retained medullary cord, terminal myelocele and terminal myelocystocele). It seems that almost every anomalous entity of the primary neural tube may occur in the area of secondary neurulation. Furthermore, the close association with the activity of caudal mesenchymal tissue in secondary neurulation involves a wider range of surrounding structures than in primary neurulation. Although the majority of the data are from animals, not from humans and many theories are still conjectural, these changing concepts of normal and disordered secondary neurulation will provoke further advancements in our management strategies as well as in the pathoembryogenetic understanding of anomalous lesions in this area.

Caudal Agenesis : Understanding the Base of the Wide Clinical Spectrum

Caudal agenesis refers to the congenital malformation with the essential feature of the agenesis of the sacrococcygeal bone. It is associated with various types of spinal cord anomaly as well as with complex anomalies of genitourinary or gastrointestinal system. The wide spectrum of the disease can be attributed to its pathoembryological origin, the secondary neurulation. This review presents the definition, etiology, classification, and clinical features of the disease.

Impact of Rigid Fixation of the Pubic Symphysis for Spinopelvic Fixation in Two Cases of Lumbosacral Agenesis

Introduction

In patients with lumbosacral agenesis (SA), Renshaw type III or IV, lumbosacral instability is the primary cause of major clinical complications. Although they are usually treated with spinopelvic fusion, nonunion at the spinopelvic junction is a major complication due to the congenital sacropelvic abnormalities. The purpose of this study was to evaluate whether a combination of lumbosacral fixation and rigid fixation at the pubic symphysis could lead to postoperative bone union in patients with SA (Renshaw type III).

Methods

Retrospective case series study. We present the cases of two patients with SA, Renshaw type III, who were surgically treated by lumbosacral fusion using a posterior approach, and they exhibited nonunion at the lumbosacral junction.

Results

Case 1. A 10-year-old male underwent T8-S posterior fixation followed by multiple augmentations using allografts at the lumbosacral junction for delayed union. All additional procedures with bone graft using a posterior approach failed to achieve bone union; however, additional rigid fixation at the pubic symphysis resulted in a successful lumbosacral bone union.

Case 2. A 6-year-old male underwent vertical expandable prosthetic titanium rib (VEPTR) surgery with multiple rod extension procedures. Subsequently, at the age of 10 years, a combined two-stage anterior (L1-3) and posterior (T8-iliac) fixation with T9 hemivertebrectomy was performed. As a result of subsequent nonunion with screw loosening, additional rigid fixation at the pubic symphysis was performed 1 month after posterior fixation. Bone union was finally achieved 1 year after all the surgical interventions.

Conclusions

Rigid fixation at the pubic symphysis may play a significant role in achieving rigid bone union for unstable lumbopelvic connection, such as SA, Renshaw type III or IV.

Congenital pelvic skeletal anomalies: Clinical and radiographic evaluation of newborns with gastrointestinal malformation

BACKGROUND

Congenital pelvic skeletal anomalies (CPSA) may appear as isolated defects or in association with other anomalies like congenital malformations of the digestive system (CMDS). Minor CPSA in non-syndromic patients are often overlooked. We aimed to assess the frequency of CPSA in newborns with CMDS to review the diagnostic approaches.

STUDY DESIGN

A retrospective review of medical records of 201 newborns who underwent X-rays for different neonatal indications was conducted. In 122 patients CMDS were diagnosed and classified according to the ICD-10 classification; 79 non-CMDS patients acted as controls. Pelvic skeletal segments were examined by X-rays.

RESULTS

Patients with CMDS, showed a higher risk of CPSA (Odds ratio 2.89; 95% CI 1.34 6.23) and other associated malformations in comparison to non-CMDS patients. Newborns with malformations of the large intestine have the highest risk of adjacent CPSA (48%), as it is a developmental defect originating from the same somite. In addition to skeletal agenesis/hypoplasia, we reported dysmorphic and bifid vertebras, trident ileum, and elongated neural arches.

CONCLUSIONS

The high incidence of CPSA in CMDS suggests performing a routine radiographic pelvic evaluation in cases of CMDS in order to identify complex phenotypes that could originate from the same developmental field.

Descriptive and risk factor analysis of nonsyndromic sacral agenesis: National Birth Defects Prevention Study, 1997-2011

Sacral agenesis is a rare birth defect characterized by partial or complete absence of the sacrum. We sought to (a) describe case characteristics, (b) estimate birth prevalence, and (c) identify risk factors for nonsyndromic sacral agenesis using data from the National Birth Defects Prevention Study (NBDPS). The NBDPS was a population-based, case-control study involving pregnancies with estimated dates of delivery from October 1997 through December 2011. We estimated birth prevalence using all NBDPS eligible cases. Using self-reported maternal exposure information, we conducted multivariable logistic regression analysis to identify potential risk factors overall and among women without diabetes. The birth prevalence of sacral agenesis was 2.6/100,000 live births. In the multivariable analysis, multifetal pregnancy, pre-existing Type 1 diabetes, and pre-existing Type 2 diabetes were positively and significantly associated with sacral agenesis, albeit estimates were imprecise. Preexisting Type 1 diabetes was the strongest risk factor (adjusted odds ratio = 96.6, 95% confidence interval = 43.5-214.7). Among women without diabetes, periconceptional smoking was positively and significantly associated with sacral agenesis. Our findings underscore the importance of smoking cessation programs among women planning pregnancy and the importance of better understanding the role of glycemic control before and during pregnancy when designing interventions for primary prevention of sacral agenesis.

Decreased rectal meconium signal on MRI in fetuses with open spinal dysraphism

OBJECTIVE

To evaluate rectal meconium signal in fetuses with open spinal dysraphism and correlate findings with postnatal exam.

METHODS

This is a single-institution Institutional Review Board-approved Health Insurance Portability and Accountability Act (HIPAA) compliant retrospective analysis of fetal MRIs of open spinal dysraphism from 2004 to 2016. Fetuses with diagnostic T1-weighted images and postnatal follow-up at our institution were included.

RESULTS

A total of 115 fetuses (average gestational age 23.9 ± 3.6 weeks) met inclusion criteria. Of these, 80% (92/115) had T1 hyperintense rectal meconium signal. Average height of the meconium column, measured from the base of the bladder to its most inferior extent, was 9.2 ± 4.3 mm in fetuses ≥20-week gestational age and 11.1 ± 4.4 mm in fetuses ≥23-week gestational age (n = 110) . None had bowel dilation. One of 115 fetuses had a simple form of anorectal malformation allowing complete repair in the neonatal period, but this fetus had a normal meconium column height on fetal MRI of 22 mm. The remaining 23/115 fetuses with lack of normal rectal meconium signal were born without evidence of anorectal malformation.

CONCLUSION

Decreased or absent T1-hyperintense rectal meconium signal in fetuses with open spinal dysraphism does not correlate with imperforate anus postnatal and may be a reflection of neurogenic bowel in this patient population.

Urine retention as the first presentation of congenital absence of the sacrum: A case report of a rare clinical phenomenon

RATIONALE

Congenital absence of either a part of or the entire sacrum is rare, and only a few such cases have been reported until now. Most cases showed vertebral, pelvic, neurological, and visceral abnormalities, and the cases were usually quite serious. Only in rare cases was there urine retention without other symptoms.

PATIENT CONCERNS

We describe the case of a 28-years-old man who presented with urine retention.

DIAGNOSES

Urodynamic study confirmed that he had urinary retention, and magnetic resonance imaging (MRI) showed the absence of the sacrum.

INTERVENTIONS

He was treated with electro-acupuncture and medications to improve nerve function.

OUTCOMES

His symptoms showed clear improvement.

LESSONS

Although this case is rare, it indicates that the spine and pelvis may need to be examined when unexplained urinary retention occurs.

Surgical treatment of patients with myelomeningocele-related spine deformities: study of 26 cases

INTRODUCTION

Scoliosis, kyphosis, and sacral agenesis (SA) are common spine deformities in myelomeningocele (MMC) patients. Surgery of spine deformities in MMC patients is associated with various difficulties as infection, pathological skin breakage, instrumentation failure, and neurological deterioration. The purposes of this study are to share our clinical experience and discuss different surgical techniques which are defined in the literature.

PATIENTS AND METHOD

We retrospectively evaluated our database of patients with MMC who underwent surgical procedures for spine deformities from 2014 to 2016. Demographic and clinical data, surgical parameters, surgical techniques and levels, pre- and postoperative deformity angles, level of posterior fusion defect, spinal malformations, neurological evaluation of lower extremities and complications were collated. We divided the cases into three groups according to the type of deformities. The groups were lumbar kyphosis (Group 1), congenital scoliosis (Group 2), and paralytic scoliosis (Group 3).

RESULTS

There were 26 patients in the study. Fifteen patients were male and 11 patients were female. The median age of the patients was 8.03 (range = 3-17 years) at the time of operation. There were 10 patients in Group 1, 7 patients in Group 2, and 9 patients in Group 3. In Group 1, preoperative kyphosis angle varied between 51° and 160°, with an average of 95.7°. In Group 2, preoperative Cobb angle varied between 57° and 150°, with an average of 106.6°. Kyphosis was present in 4 patients. Preoperative kyphosis angle varied between 74° and 140°, with an average of 93°. In Group 3, preoperative Cobb angle varied between 45° and 145°, with an average of 72.5°.

CONCLUSION

Spinal deformity in children with MMC has been considered to cause severe disability. Surgical treatment is a challenging procedure with a wide spectrum of complications, but can provide good correction of spinal deformity and pelvic obliquity, and improve the quality of life. Self-growing systems which are a new alternative to traditional growing rod systems, must be considered to preserve growing potential of spine.

How to Explore Fetal Sacral Agenesis Without Open Dysraphism: Key Prenatal Imaging and Clinical Implications

The estimated prevalence of fetal caudal dysgenesis is 1 per 100,000 births. The functional prognosis of sacral agenesis is dominated by the large spectrum of associated caudal malformations. Except for cases associated with hydrocephalus secondary to open spinal dysraphism or chromosomal anomalies, association with mental deficiency is rare. We propose a systematic prenatal approach to cases of fetal sacral agenesis based on 9 etiologic items: clinical context, type of sacral dysgenesis, associated spinal cord malformations, mobility of lower limbs, investigation of the presacral region, analysis of the gastrointestinal tract, analysis of the genitourinary tract, associated vertebral defects, and cytogenetic analysis.

Symptomatic lower urinary tract dysfunction in sacral agenesis: Potentially high risk?

Introduction

Sacral agenesis (SA) is a caudal regression anomaly that can cause neurogenic bladder but is not generally recognized as high risk. We studied the clinical presentation, upper urinary tract, bone and spine abnormalities, and urodynamic findings in patients with SA and compared them with related high-risk conditions, anorectal malformation (ARM), and cloacal malformation.

Materials and Methods

Patient records between May 2011 and December 2015 were identified and grouped into isolated SA without an overt anomaly (Group I), SA with overt caudal regression anomalies (Group II), and ARM or cloacal malformation without the SA (Group III). Distribution of clinical and urodynamic findings and factors associated with reduced eGFR were tested with rank sum test, t-test, and unadjusted odds (P < 0.05 significant) using R statistical program (version 3.1.3).

Results

Of 605 neurogenic bladder patients treated in the study period, 39 fulfilled the inclusion criteria. 12 were Group I, 5 Group II, and 22 Group III. Long-standing lower urinary symptoms were noted in all SA patients. Group I patients were older (14.5 years vs. 6 years and 5 years for II and III). Patients with SA (Group I and II) had poor compliance (6.7 ml/cmH₂O, interquartile range [IQR] 4-13.6 ml/cmH₂O), reduced age-adjusted bladder capacity (59%, IQR 22-85%), elevated end-fill pressure (22 cmH₂O, IQR 11-28 cmH₂O), hydronephrosis (88%), and reduction in eGFR (29%), all comparable to Group III. Most had Renshaw type II SA and tethered spinal cord rather than wedge-shaped termination. Limitations include small numbers and significant selection bias.

Conclusions

Symptomatic neurogenic bladder due to SA may cause renal damage similar to ARM but often eludes diagnosis.

Prenatal diagnosis of caudal regression syndrome and omphalocele in a fetus of a diabetic mother

The caudal regression syndrome is defined as total or partial agenesis of the sacrum and lumbar spine, frequently associated with other developmental malformations (orthopedic, neurological, genito-urinary, gastrointestinal…). Prenatal diagnosis is possible through fetal ultrasound (US) and magnetic resonance imaging (MRI). A case of fetal caudal regression syndrome with omphalocele from a diabetic mother is presented, demonstrating the sonographic, MRI, CT and X-Ray features diagnostic. We will also discuss neonatal findings, risk factors and prognosis of this condition.

Congenital talipes equinovarus and congenital vertical talus secondary to sacral agenesis

Sacral agenesis is a rare congenital defect which is associated with foot deformities such as congenital talipes equinovarus (CTEV) and less commonly congenital vertical talus (CVT). We report a 3-year-old Caucasian girl who was born with right CTEV and left CVT secondary to sacral agenesis. Her right foot was managed with a Ponseti casting method at 2 weeks, followed by an Achilles tenotomy at 4 months. The left foot was initially managed with a nocturnal dorsi-flexion splint. Both feet remained resistant and received open foot surgery at 10 months producing plantigrade feet with neutral hindfeet. At 19 months, she failed to achieve developmental milestones and examinations revealed abnormal lower limb reflexes. A full body MRI was performed which identified the sacral agenesis. We advocate early MRI of the spine to screen for spinal defects when presented with resistant foot deformities, especially when bilateral.