High-grade congenital spondylolisthesis is rare. This article presents an illustrative case of a prenatally diagnosed rare spinal condition as well as reviews congenital spinal anomalies in newborns.
A 25-year-old gravida 3 para 1011 mother was diagnosed with pregestational diabetes at 7 weeks gestation and initiated on insulin therapy. Her hemoglobin A1c improved after beginning insulin therapy (from 12% to 5.4%) and the patient continued to be observed in the maternal fetal medicine (MFM) department. Maternal serologies were negative. Amniotic fluid measurements were appropriate for gestational age. The mother reported normal fetal movement. Abdominal circumference measurement of the fetus was greater than the 97th percentile. At 33 weeks gestation, the mother had a routine ultrasound demonstrating an abnormal angulation of the fetal spine in the lower cervical/upper thoracic level. The fetus was noted to be moving all extremities and without signs of arthrogryposis (limited fetal movement and excess connective tissue around the joints with significant contractures).1 The mother was referred for fetal magnetic resonance imaging (MRI), which was completed at 35 weeks gestation and showed abnormal kyphosis with associated moderate anterolisthesis of the midcervical cord resulting in a cervical spine stenosis without evidence of spinal cord abnormalities. There was no evidence of myelomeningocele or spinal dysraphisms (Figure 1).
Fetal magnetic resonance image performed at 35 weeks gestation shows cervical anteriorcervicolithesis of fetal spine (circle).
A prenatal interdisciplinary conference was held, which included teams from MFM, neonatology, and pediatric neurosurgery. The known spinal anomaly, large abdominal circumference measurement, and maternal diabetes raised concern for how the infant would tolerate a vaginal delivery, and the team was unsure if the spinal deformity could allow for the cardinal movements of labor. Given these concerns, and the lack of available evidence on the best mode of delivery for this type of malformation, the team recommended primary cesarean delivery at 38 weeks and 5 days gestation. A cesarean delivery would enable the delivery of the infant with the least amount of spinal manipulation and impact on the cervical spine. Delivery before 39 weeks gestation was the goal to attain a controlled delivery, before the fetus further descended into the pelvis and with hopes of limiting excessive fetal growth in the setting of maternal diabetes.
At 38 weeks and 1 day of gestation, the mother presented in early labor. Given the prior interdisciplinary discussion and plan, the decision was made to move forward with urgent primary low transverse cesarean delivery in the setting of persistent uterine contractions and cervical effacement. In addition to standard delivery room equipment and advanced airway equipment, a laryngeal mask airway (LMA) and a rigid cervical spine papoose immobilizer board were present for immediate use. In this illustrative case, a 3,470-gram (75th percentile) child was delivered, dried, and stimulated. The hips and cervical spine were stabilized with a rigid cervical spine papoose board immobilizer. APGAR (activity, pulse, grimace, appearance, respiration) scores were 9 and 9 at 1 and 5 minutes, respectively. The infant voided while under the radiant warmer. Initial physical and neurologic examination in the delivery room noted no obvious anomalies, equal movement of all extremities, and appropriate muscle tone and bulk in upper and lower extremities. There were symmetric palmar grasp reflexes and an upgoing Babinski reflex bilaterally; patellar and biceps reflexes were brisk and symmetric; no clonus was appreciated; and the suck reflex was present with no high arched palate noted. There were no visible abnormalities of the skin overlying the spine. The infant was admitted to the neonatal intensive care unit (NICU) for further evaluation and treatment.
NICU Course and Diagnosis
The patient remained in the cervical spine papoose board immobilizer and was transferred to a Level IV NICU for neurosurgical and orthopedic evaluation. MRI and computed tomography (CT) imaging scans were performed on postnatal day 0 and 1, respectively (Figures 2 and 3). MRI was performed under sedation provided by the anesthesia team, without the need for an artificial airway, to ensure the patient remained still during the duration of the study to allow for optimal images. CT scan was performed without sedation while the patient was in the spine immobilizer. On day 3 after birth, the patient was taken to the operating room with the orthopedics team for an examination under anesthesia. The cervical spine was then examined under fluoroscopy, which demonstrated instability between the C6 and C7 vertebrae with significant anterior displacement of C6 on C7.
Postnatal computed tomography scan. There is failure of normal cervical segmentation at the levels C2-3 (*) and C5-6 (^) with rudimentary intervertebral disc spaces and close approximation of the vertebral bodies and posterior elements at these levels. Failure of normal vertebral segmentation is also seen at level C7-T1 with fusion of the vertebral bodies at this level (arrow). Additionally, the C6 vertebra appears somewhat hypoplastic. There is complete anterolisthesis of the C6 vertebral body over C7, measuring up to 0.8 cm anterior translation from the expected alignment on transaxial views.
Postnatal magnetic resonance image obtained on the day of birth (T2 image). Note that severe anterolisthesis of the C6-C7 intervertebral junction measuring approximately 0.8 cm in the sagittal plane (arrow). The image also shows bilateral facet dislocation with ligamentous injury to the anterior and posterior longitudinal ligament, and there is severe central canal stenosis at the level of the anterolisthesis. There is no magnetic resonance evidence for cord signal abnormality.
Given these findings, the orthopedics team fitted the patient in a custom brace and discharged the patient home with the goal of further growth before definitive surgical intervention. Due to the position of the brace, the patient was unable to feed by mouth and was discharged on nasogastric tube feeds and instructed to remain supine.
The patient remained in the custom brace and had weekly orthopedic appointments. Nine weeks after birth, the patient weighed 5.3 kilograms and underwent C4-T1 posterior spinal fusion with autograft rib harvest and use of allograft and demineralized bone matrix for C6-C7 congenital spondyloptosis with cervical spine instability. The patient had baseline somatosensory evoked potentials and motor evoked potentials monitored from the bilateral upper and lower extremities during the procedure.
The patient was cared for in the pediatric intensive care unit during the postoperative period. When stable, the patient was transferred to the general pediatric ward and observed by the pain, orthopedics, and pediatric hospitalist services. The infant required low flow nasal cannula postoperatively for desaturations but was weaned to room air days after surgery. The patient was discharged home on postoperative day 10 in a custom brace with nasogastric tube feeds. At discharge, the patient had baseline tone in his upper and lower extremities with all extremities displaying antigravity movements. Patellar and biceps reflexes were symmetric and brisk with palmar grasp reflex intact bilaterally. The patient was able to regard faces and track visual stimuli. With the patient still in the brace, the family brought the infant to the orthopedics clinic weekly for skin assessments. Protective skin dressings were used to prevent skin breakdown at areas of contact with the brace. To our knowledge, this is the first reported case of a prenatally diagnosed congenital spondyloptosis of the cervical spine.
The cervical spine is composed of seven vertebral bodies. The C1 vertebra is also known as the atlas and the C2 vertebra is known as the axis. The C2 vertebra has a protrusion (odontoid process, or dens) that allows the atlas to rotate.2 Each vertebral body is separated by an intervertebral disc and the spinal canal is widest at the upper part of the cervical spine and narrows with neck extension.2 The upper cervical spine is responsible for rotational movements of the head, making these joints intrinsically unstable.3
The lower cervical spine is responsible for flexion and extension of the head. The pediatric cervical spine can adapt to abnormal positioning with adaptive movement in the other portion of the cervical spine.2 Range of motion of both the upper and lower cervical segments decreases with age.3
C1, the atlas, is formed by three primary ossification centers: the anterior arch and two neural arches. These neural arches surround the anterior arch and, in later development, fuse to form the posterior arch.2 The anterior arch is ossified in 20% of neonates at birth and becomes visible as an ossification center by age 1 year.2 Neural arches appear approximately in the 7th fetal week.2
C2, the axis, has a more complex development. This vertebra has four ossification centers at birth: one for each neural arch, one for the body, and one for the dens. The dens forms from two separate ossification centers that fuse by the 7th fetal month.2
Although C1 and C2 have unique development, the caudal five vertebrae develop similarly. Each of these originate from three primary ossification centers, with half being derived from the caudal sclerotome and the adjoining half from the cranial sclerotome.3,4 There can be variation in vertebral formation during embryogenesis and ossification resulting in abnormalities.4
Definitions and Physical Examination
Anterolisthesis is an abnormal alignment of the vertebrae in which the cephalad vertebra slips anterior to the caudal vertebra. Retrolisthesis, in contrast, occurs when the cephalad vertebra is posteriorly displaced relative to the vertebra below. Joint instability occurs when the articular components of a joint are altered or have the potential to become abnormal under certain circumstances.4 Spondylolisthesis describes the nonphysiologic translation of one vertebral body relative to the caudal vertebral body. Spondylolisthesis more commonly refers to anterolisthesis (forward slippage) but can also refer to retrolisthesis or lateral listhesis. Spondylolisthesis can be quantified using the Meyerding grading system (Table 1).5 Spondyloptosis occurs with greater than 100% subluxation of a superior vertebral body over an inferior vertebral body in the coronal or sagittal plane. It is the most severe form of translational spine injuries and results in severe biomechanical instability.6 The risk of cervical instability in cervical spondyloptosis can be life-threating with risk of spinal cord compression. Congenital cervical spine instability most commonly occurs in the upper cervical spine, with up to 50% of cases having atlantooccipital anomalies and instability.3 Down syndrome has an increased risk of atlantoaxial instability with a reported incidence of approximately 10% to 20%. Most of these patients are diagnosed radiographically and of these patients, only about 1% to 2% have symptomatic instability with neurologic complications.7 Other syndromes such as VACTERL association (vertebral anomalies, anal atresia, cardiac defects, tracheo-esophageal fistula, renal anomalies/rib fusions, and limb anomalies), or Klippel-Feil syndrome can be associated with congenital spine abnormalities. Regardless of its etiology, vertebral instability at any level is dangerous as it has the potential for neurologic involvement.3
Meyerding Grading System5
Identification of cervical injuries in the neonatal period is very difficult due to limitations in the neurological examination; determining the difference between volitional and reflexive movements is challenging.8 A complete physical examination is imperative and must include a detailed neurologic examination of the upper and lower limbs. Examiners should pay specific attention to signs of upper and lower motor neuron lesions. Hyperreflexia of the deep tendon reflexes or sustained clonus can indicate an upper motor neuron pathology, whereas hyporeflexia is more likely related to a peripheral nerve or nerve root pathology. It is important to test newborn reflexes and be aware of the infant's gestational age given the changing appearance of reflexes with development. As demonstrated in this illustrative case, an examination under anesthesia while monitoring for neurologic evoked potentials is helpful in determining the degree and severity of instability.
Epidemiology and Prognosis
There is limited literature about congenital spondyloptosis in the neonate. High-grade congenital spondylolisthesis is rare, with only a few cases described; the youngest documented patient was age 3.5 months.9,10
The incidence of congenital spinal anomalies is low and sporadic, with a rate in the general population of 1 per 1,000 to 1 per 2,000.11 Other published sources note that 5% of fetuses have vertebral anomalies, with 7 per 10,000 having a congenital union of two or more cervical vertebrae.2 Case reports have documented the need for posterior spinal fusion in the neonate in the setting of recent trauma, both accidental and nonaccidental.11 The etiology of bone malformations of the cervical spine is not fully understood and thought to be multifactorial, including vascular and genetic components.2 Chromosomal analysis has identified possible associated loci for certain deformities, such as hemi-vertebrate to chromosome 17, whereas chromosome 18 has been associated with multiple vertebral segmentation defects.12
Standard radiographs are the primary modality used in identification of pediatric cervical instability.6 Increased intraspinous distance, divergence of the articular processes, and widening of the posterior aspect of the disk space are indicative of cervical spine instability in the pediatric patient.2 In older pediatric patients who are able to follow verbal direction, flexion-extension radiographs can be helpful in the diagnosis of cervical spine instability, which occurs when there is significant translation between two vertebra in the extremes of motion.2,3,13 It is important to note that some radiographic features indicative of pathology in adults can represent normal development in children: (1) incomplete ossification and apophyses can mimic fractures, (2) prominence of prevertebral soft tissues, which would be concerning for edema or hemorrhage in adults, can be normal pediatric findings, and (3) absence of lordosis in children is normal up to age 16 years.2,3 In complex cases in which a detailed image of the soft tissue and spinal cord is necessary, MRI or CT scan should be considered.3 Both modalities have their strengths in diagnostic capability as MRI provides quality imaging of the soft tissue structures, extradural spaces, and spinal ligaments; however, in this illustrative case, the MRI was less informative in providing information regarding the bony structures. CT scan, however, provides exquisite detail of the bony structures, but has less definition and detail of the soft tissue structures and spinal cord. In addition, CT imaging is usually less time consuming, but providers must consider the exposure to radiation; MRI is more time intensive but does not expose the pediatric patient to radiation. In addition, depending on the age of the patient, pharmacologic sedation may be required to ensure optimal image acquisition. Thoughtful consideration should be given to the choice of imaging modality and its usefulness in diagnosis and treatment; in this illustrative case, CT scan and MRI were both necessary.
If a spinal deformity is detected prenatally, the lower extremities should also be evaluated by ultrasonogram for positioning and functionality.14 Identification of vertebral anomalies also warrants close inspection for associated anomalies, as these may be part of a constellation of malformations, particularly VACTERL association.14 Amniocentesis can also provide information regarding any genetic abnormalities that may be present.14 When discussing a delivery plan, there continues to be no consensus on the recommended mode of delivery or timing of delivery for patients with congenital spondyloptosis.
Immediately after birth the spine should be stabilized. Routine care ensuring a stable airway and appropriate circulation should be followed. If an advanced airway is needed, care with intubation and the amount of neck extension necessary should be carefully monitored; an LMA should be considered as an alternative to traditional endotracheal intubation. Definitive treatment of the spondyloptosis requires surgical management, with the goal of stabilizing the spinal segments and decompressing the neural structures. The surgical approach and techniques used vary.15 Surgical intervention in cervical spine abnormalities in infants are rare, and there is limited literature available on cervical spine fusion in this young population.16
Surgical techniques include spondylectomy with progressive reduction of the dislocated spine segment, versus a minimally invasive technique with dorsal decompressions or combined posterolateral fusion with or without instrumentation.15 The timing of surgical repair is variable and usual indications for operative treatment include pain, progressive slippage, and neurologic involvement.15,17 A case report describing an 18-month-old who was diagnosed with congenital spondyloptosis of the L5-S1 vertebra reported a staged surgical repair resulting in 10-year follow-up outcomes with no back pain, gait abnormalities, or progression of the deformity.15 Another case report describes a 3-week-old infant with cervical fracture and dislocation with almost complete spinal cord transection resulting in quadriparesis after nonaccidental trauma. The infant underwent open surgical reduction with posterior fusion; 2 years postoperatively, the fusion remained stable with appropriate cervical alignment and the infant remains flaccid in the lower extremities yet has some movement in both hands.6 These case reports demonstrate the varying spectrum of the recovery of children after surgical repair in two very different lesions. Published literature on this topic is too limited to draw more significant conclusions.
This article describes a neonate with prenatally diagnosed cervical spondyloptosis. Although the incidence of congenital spinal abnormalities is 0.5 to 1 per 1,000 live births and can present with a multitude of clinical findings, this particular presentation is exceedingly rare. Early diagnosis and treatment, with proper stabilization in the delivery room, in addition to surgical management in the infant period are the mainstays of therapy. Prognosis of this condition is dependent on the severity of the malformation, time to stabilization, successful orthopedic and neurosurgical intervention, and proper adherence to follow-up.
- Filges I, Tercanli S, Hall JG. Fetal arthrogryposis: challenges and perspectives for prenatal detection and management. Am J Med Genet C Semin Med Genet. 2019;181(3):327–336. doi:10.1002/ajmg.c.31723 [CrossRef] PMID:31318155
- Lustrin ES, Karakas SP, Ortiz AO, et al. Pediatric cervical spine: normal anatomy, variants, and trauma. Radiographics. 2003;23(3):539–560. doi:10.1148/rg.233025121 [CrossRef] PMID:12740460
- Ghanem I, El Hage S, Rachkidi R, Kharrat K, Dagher F, Kreichati G. Pediatric cervical spine instability. J Child Orthop. 2008;2(2):71–84. doi:10.1007/s11832-008-0092-2 [CrossRef] PMID:19308585
- O'Rahilly R, Meyer DB. The timing and sequence of events in the development of the human vertebral column during the embryonic period proper. Anat Embryol (Berl). 1979;157(2):167–176. doi:10.1007/BF00305157 [CrossRef] PMID:517765
- Meyerding HW. Spondylolisthesis. J Bone Joint Surg. 1931;13:39–48.
- Holland CM, Kebriaei MA, Wrubel DM. Posterior cervical spinal fusion in a 3-week-old infant with a severe subaxial distraction injury. J Neurosurg Pediatr. 2016;17(3):353–356. doi:10.3171/2015.3.PEDS13568 [CrossRef] PMID:26613276
- Ali FE, Al-Bustan MA, Al-Busairi WA, Al-Mulla FA, Esbaita EY. Cervical spine abnormalities associated with Down syndrome. Int Orthop. 2006;30(4):284–289. doi:10.1007/s00264-005-0070-y [CrossRef] PMID:16525818
- O'Toole P, Tomlinson L, Dormans JP. Congenital anomalies of the pediatric cervical spine. Semin Spine Surg. 2011;23(3):199–205. doi:10.1053/j.semss.2011.04.005 [CrossRef]
- Borkow SE, Kleiger B. Spondylolisthesis in the newborn. A case report. Clin Orthop Relat Res. 1971;81(81):73–76. doi:10.1097/00003086-197111000-00010 [CrossRef] PMID:5133046
- Aribal S, Ulusoy OL, Ozturk E, Mutlu A, Enercan M. Congenital cervicothoracic spondyloptosis in a 7-month-old patient. Spine J. 2016;16(9):e575–e576. doi:10.1016/j.spinee.2016.01.220 [CrossRef] PMID:26892372
- Eleraky MA, Theodore N, Adams M, Rekate HL, Sonntag VK. Pediatric cervical spine injuries: report of 102 cases and review of the literature. J Neurosurg. 2000;92(1)(suppl): 12–17. PMID:10616052
- Oskouian RJ Jr, Sansur CA, Shaffrey CI. Congenital abnormalities of the thoracic and lumbar spine. Neurosurg Clin N Am. 2007;18(3):479–498. doi:10.1016/j.nec.2007.04.004 [CrossRef] PMID:17678750
- Brockmeyer DL, Ragel BT, Kestle JR. The pediatric cervical spine instability study. A pilot study assessing the prognostic value of four imaging modalities in clearing the cervical spine for children with severe traumatic injuries. Childs Nerv Syst. 2012;28(5):699–705. doi:10.1007/s00381-012-1696-x [CrossRef] PMID:22290498
- Upasani VV, Ketwaroo PD, Estroff JA, Warf BC, Emans JB, Glotzbecker MP. Prenatal diagnosis and assessment of congenital spinal anomalies: review for prenatal counseling. World J Orthop. 2016;7(7):406–417. doi:10.5312/wjo.v7.i7.406 [CrossRef] PMID:27458551
- Wild A, Jäger M, Werner A, Eulert J, Krauspe R. Treatment of congenital spondyloptosis in an 18-month-old patient with a 10-year followup. Spine. 2001;26(21):E502–E505. doi:10.1097/00007632-200111010-00021 [CrossRef] PMID:11679835
- Lowry DW, Pollack IF, Clyde B, Albright AL, Adelson PD, Lowry DW. Upper cervical spine fusion in the pediatric population. J Neurosurg. 1997;87(5):671–676. doi:10.3171/jns.1997.87.5.0671 [CrossRef] PMID:9347973
- Gaines RW, Nichols WK. Treatment of spondyloptosis by two stage L5 vertebrectomy and reduction of L4 onto S1. Spine. 1985;10(7):680–686. doi:10.1097/00007632-198509000-00015 [CrossRef] PMID:4071276
Meyerding Grading System5
||Degree of displacement (%)