Anterior approach to the subaxial cervical spine in children: a brief review

Anterior cervical corpectomy and fusion in a 7-year-old boy: a case report

Bicycle mishap, a common and ordinary event occurring in children, can have devastating consequences associated with cervical spine injury. Furthermore, either diagnosis or surgical management of cervical spine injury in children is a challenging issue. This research report a challenging case of an anterior cervical corpectomy and fusion with plating in a 7-year-old boy due to cervical spine instability with spinal cord compression after a bicycle mishap. After 20 months of the primary surgery, the titanium-based cervical plate was removed by a second surgery to allow the growth of the cervical spine.

Pediatric occipitocervical fixation: radiographic criteria, surgical technique, and clinical outcomes based on experience of a single surgeon

OBJECTIVE If left untreated, occipitocervical (OC) instability may lead to serious neurological injury or death. Open internal fixation is often necessary to protect the neurovascular elements. This study reviews the etiologies for pediatric OC instability, analyzes the radiographic criteria for surgical intervention, discusses surgical fixation techniques, and evaluates long-term postoperative outcomes based on a single surgeon's experience. METHODS The charts of all patients < 18 years old who underwent internal OC fixation conducted by the senior author were retrospectively reviewed. Forty consecutive patients were identified for analysis. Patient demographic data, OC junction pathology, radiological diagnostic tools, surgical indications, and outcomes are reported. RESULTS The study population consisted of 20 boys and 20 girls, with a mean age of 7.3 years. Trauma (45% [n = 18]) was the most common cause of instability, followed by congenital etiologies (37.5% [n = 15]). The condyle-C1 interval had a diagnostic sensitivity of 100% for atlantooccipital dislocation. The median number of fixated segments was 5 (occiput-C4). Structural bone grafts were used in all patients. Postsurgical neurological improvement was seen in 88.2% (15/17) of patients with chronic myelopathy and in 25% (1/4) of patients with acute myelopathy. Preoperatively, 42.5% (17/40) of patients were neurologically intact and remained unchanged at last follow-up, 42.5% (17/40) had neurological improvement, 12.5% (5/40) remained unchanged, and 2.5% (1/40) deteriorated. All patients had successful fusion at 1-year follow-up. The complication rate was 7.5% (3/40), including 1 case of vertebral artery injury. CONCLUSIONS Occipitocervical fixation is safe in children and provides immediate immobilization, with excellent survival and arthrodesis rates. Of the radiographic tools evaluated, the condyle-C1 interval was the most predictive of atlantooccipital dislocation.

Clinical Case Report of Expansive Laminoplasty for Cervical Myelopathy Due to Both Disc Herniation and Developmental Cervical Spinal Canal Stenosis in Older Adolescents

Reports on adolescent patients with cervical myelopathy who underwent anterior cervical discectomy and fusion are scarce. However, to our knowledge, no cases of expansive laminoplasty for cervical myelopathy associated with progressive neurological deficit after a series of conservative treatment, caused by both disc herniation and developmental cervical spinal canal stenosis, have been reported.From January 2006 to July 2012, we retrospectively studied 3 patients in late adolescence presenting with cervical myelopathy who underwent expansive unilateral open-door laminoplasty at our hospital. The outcomes after the surgery were evaluated according to the Japanese Orthopedic Association scores.Symptoms presented by these patients were due to both disc herniation and developmental cervical spinal canal stenosis. No major complications occurred after the surgical procedures. The median follow-up time was 66 months (range 36-112 months). The Japanese Orthopedic Association scores after surgery showed a significant increase. Long-term outcomes after surgery were satisfactory according to the evaluation criteria for the Japanese Orthopedic Association scores. However, the ranges of motion of the cervical spine decreased, especially the ranges of motion on flexion after surgery showed a significant decrease.Expansive laminoplasty is helpful for older adolescent patients with cervical myelopathy due to both disc herniation and developmental cervical spinal canal stenosis, presenting with progressive neurological deficit after long conservative treatment.

Computed tomography parameters for atlantooccipital dislocation in adult patients: the occipital condyle-C1 interval

OBJECT

Atlantooccipital dislocation (AOD) in adults cannot be diagnosed with adequate specificity and sensitivity using only CT or plain radiography, and the spine literature offers no guidelines. In children, the most sensitive and specific radiographic measurement for the diagnosis of AOD is the CT-based occipital condyle-C1 interval (CCI). The goal of the current study was to identify the normal CCI in healthy adults and compare it with the CCI in adults with AOD to establish a highly sensitive and specific cutoff value for the neuroimaging diagnosis of AOD.

METHODS

A total of 81 patients, 59 without AOD and 22 with AOD, were included in this study. Measurements obtained from thin-slice CT scans of the craniovertebral joint to assess atlantooccipital dislocation included the CCI, condylar sum, the Wholey and Harris intervals, Powers and Sun ratios, Wackenheim line, and Lee X-lines.

RESULTS

The group of patients without AOD included 30 men (50.8%) and 29 women (49.2%) with a mean age of 42.4 ± 16 years (range 19-87 years). The group of patients with AOD included 10 men (45.5%) and 12 women (54.5%) with a mean age of 38.2 ± 9.7 years (range 20-56 years). Interrater reliabilities within a 95% CI were all greater than 0.98 for CCI measurements. A total of 1296 measurements of the CCI were made in 81 patients. The mean CCI for non-AOD patients was 0.89 ± 0.12 mm, the single largest CCI measurement was 1.4 mm, and the largest mean for either right or left CCI was 1.2 mm. The mean condylar sum was 1.8 ± 0.2 mm, and the largest condylar sum value was 2.2 mm. Linear regression with age predicted an increase in CCI of 0.001 mm/year (p < 0.05). The mean CCI in AOD patients was 3.35 ± 0.18 mm (range 1.5 mm-6.4 mm). The shortest single CCI measurements in the AOD patients were 1.1 mm and 1.2 mm. The mean condylar sum for all 22 AOD patients was 6.7 ± 2.7 mm and the shortest condylar sums were 3.0 mm. Cutoff values for AOD were set at 1.5 mm for the CCI and 3.0 mm for the condylar sum, both with a sensitivity of 1 and false-negative rate of 0. Sensitivity for the Powers, Wholey, Harris, Sun, Wackenheim, and Lee criteria were determined to be 0.55, 0.46, 0.27, 0.23, 0.41, and 0.41, respectively.

CONCLUSIONS

The CCI is shorter in adult patients as opposed to the pediatric population. The revised CCI (1.5 mm) and condylar sum (3.0 mm) cutoff values have the highest sensitivity and specificity for the diagnosis of AOD in the adult population.

[Traumatic occipitocervical and atlantoaxial dislocation with clivus fracture in a child. Case report]

BACKGROUND

Cranieovertebral junction lesions in the paediatric population are associated with a low survival rate, which has declined in recent years. Neurological disability is a major concern due to the high economical cost it represents. Paediatric patients are more susceptible to this lesion because of hyperextension capacity, flat articulation, and increased ligamentous laxity. Survival after these kinds of injuries has been more often reported in adults, but are limited in the paediatric population.

CLINICAL CASE

A case is reported of an 8-year-old male with occipitocervical and atlantoaxial dislocation associated with clivus fracture, brain oedema, and post-traumatic subarachnoid haemorrhage (SAH). A halo vest system was placed with no traction. One month after the trauma the patient was surgically treated with C1 and C2 trans-articular screws, occipitocervical fixation with plate and screws, and C1- C2 fixation with tricortical bone graft and wires without complication. He has now returned to school and is self-sufficient.

CONCLUSIONS

With better pre-hospital medical care and with improved surgical techniques the mortality rate has declined in this kind of lesion.

Circumferential fixation with craniofacial miniplates for a cervical spine injury in a child

Unstable pediatric cervical spine injuries present significant challenges in terms of fixation. Given the smaller cervical vertebral bodies in the preschool-aged population, commercially available pediatric cervical fixation instrumentation may be unsuitable because of the inappropriately large size of the screws and plates. The authors describe a 2-year-old girl who sustained an unstable C6-7 distraction injury during a motor vehicle accident. Because of the small size of her vertebral bodies, standard cervical spine instrumentation was not feasible, and posterior wiring alone was believed to be insufficient because of the complete distraction of all 3 spinal columns. The patient was taken to the operating room where craniofacial plates with an inherent locking mechanism were used to circumferentially stabilize the cervical spine. Follow-up examination 6 months postoperatively demonstrated stable cervical spine alignment and fusion with no evidence of the failure of either the anterior or posterior hardware. The use of craniofacial miniplates with an intrinsic locking mechanism represents a superior alternative for both anterior and posterior cervical fixations when spinal instrumentation is needed in the pediatric age group.

Management of cervical spine injuries in young children: lessons learned

Previous studies have shown that the correct use of car safety seats can protect infants and children from vehicular injury. Although child passenger devices are increasingly used in the US, motor vehicle crashes continue to be the leading cause of death and acquired disability in infants and children younger than 14 years of age. These events are likely related, at least in part, to the high percentage of children who are unrestrained or improperly restrained. The authors present 2 cases of severe cervical spine trauma in young children restrained in car safety seats during a motor vehicle crash: 1) a previously healthy 14-month-old girl who was improperly restrained in a forward-facing booster seat secured to the vehicle by a lap belt, and 2) a previously healthy 30-month-old girl who was a rear seat passenger restrained in a car safety seat. This study points out the unique challenges encountered in treating cervical spine injuries in infants and young children, as well as the lessons learned, and emphasizes the significance of continuing efforts to increase family and public awareness regarding the importance of appropriate child safety seat selection and use.

Fusions at the craniovertebral junction

INTRODUCTION

The surgical management of craniovertebral junction instability in pediatric patients has unique challenges. While the indications for internal fixation in children are similar to those of adults, the data concerning techniques, complications, and outcomes of spinal instrumentation comes from experience with adult patients. Diminutive osseous and ligamentous structures and anatomical variations associated with syndromic craniovertebral abnormalities frequently complicates the approaches and limits the use of internal fixation in children. Cervical arthrodesis in the pediatric age group has the potential for limiting growth potential and causing secondary deformity. Recent advances in image analysis have enabled preoperative planning which is critical to evaluate the size of instrumentation and its relation to the patient's anatomy. Newer techniques have recently evolved and have been incorporated in the management of pediatric patients with requirement for craniocervical stabilization.

MATERIALS AND METHODS

Over 750 craniovertebral junction fusions have been reviewed in children. The indications for atlantoaxial arthrodesis were: (a) absent odontoid process, dystopic os odontoideum, absent posterior arch of C1; (b) Morquio's syndrome, Goldenhar's syndrome, Conradi's syndrome, and spondyloepiphyseal dysplasia. The acquired abnormalities of trauma, postinfectious instability, and Down's syndrome completed the indication in children. The indications for occipitocervical fusion were: (a) anterior and posterior bifid C1 arches with instability, absent occipital condyles; b) severe reducible basilar invagination, unstable dystopic os odontoideum, and unilateral atlas assimilation; (c) acquired phenomenon with traumatic occipitocervical dislocation, complex craniovertebral junction fractures of C1 and C2, after transoral craniovertebral junction decompression, cranial settling in Down's syndrome and inflammatory disease such as Grisel's syndrome. Instability was seen in children with clivus chordoma and osteoblastoma. Atlantoaxial fusions were performed mainly with interlaminar rib graft fusion and more recently with the transarticular screw fixation in the older patient. In the teenager, lateral mass screws at C1 and rod fixation were made; C2 pars interarticular screw fixation and C2 pedicle screw fixation. A C2 translaminar screw fixation is described. Occipitocervical fusions were made utilizing rib grafts below the age of 6. A contoured loop fixation was made in children above the age of 7, and recently, rod and screw fixation was also utilized.

RESULTS

Abnormal cervical spine growth was not seen in children who underwent craniocervical stabilization below the age of 5. The authors have reserved rigid instrumentation for children above the age of 10 years and dependent on the anatomy.

Cervical spine trauma in the pediatric patient

Injuries to the pediatric cervical spine occur infrequently. Numerous unique anatomic and biomechanical features of the pediatric spine render it much more flexible than the adult spine. These features give rise to significant differences in the presentation, diagnosis, treatment, and prognosis of pediatric cervical trauma compared with adults. Younger children more often suffer injury to the upper cervical spine with greater neurologic injury and fewer fractures. Once the child reaches the age of 10 years, he or she develops a more adult-type spine, and injuries are thus more similar to those seen in the adult population. The unique anatomic and biomechanical differences in the pediatric spine are discussed, along with the various common and unique injuries.