Pediatric seatbelt injuries: diagnosis and treatment of lumbar flexion-distraction injuries

Temporary Monosegmental Fixation Using Multiaxial Percutaneous Pedicle Screws for Surgical Management of Bony Flexion-Distraction Injuries of the Thoracolumbar Spine: A Technical Note

Introduction

The efficacy of minimally invasive surgeries for thoracolumbar flexion-distraction injuries (FDIs) has been reported, but those surgeries were monosegmental fusion surgeries of two adjacent vertebrae with bone grafts or temporary fixations using percutaneous pedicle screws (PPSs) that were at least bisegmental. Our idea was to fuse the fracture itself, not to fuse the fractured vertebra with an adjacent vertebra or to stabilize the fractured vertebra by bridging rostrally/caudally adjacent intact vertebrae, specifically when the displacement is minimal. This study aimed to present the surgical techniques of reduction and temporary monosegmental fixation of neurologically intact thoracolumbar bony FDIs using multiaxial PPSs, which can minimize the surgical invasiveness and preserve all motion segments, as well as report three cases treated with this procedure.

Technical Note

When the fracture extended from the vertebral body to the spinous process at the same level, screws were placed into the fractured vertebra rostrally to the fracture along the rostral endplate, and the caudally adjacent vertebra was instrumented beyond the fracture line. When the fracture extended from the vertebral body to the spinous process of the rostrally adjacent vertebra, screws were placed into the fractured vertebra caudally to the fracture line, and the rostrally adjacent vertebra was instrumented. The kyphotic deformity was reduced through ligamentotaxis by using MPPSs in the rostral vertebra as rigid joysticks to apply direct buttress leverage to the rostral endplate. Intraoperative blood loss was minimal. The correction of kyphotic deformity and its durability were acceptable, and the segmental range of motion of the two affected vertebrae from flexion to extension was maintained after implant removal.

Conclusions

This surgery can act as the least-invasive option for the management of thoracolumbar bony FDIs to allow early ambulation without external bracing and to preserve all the motion segments.

Purely Ligamentous Flexion-Distraction Injury in a Five-Year-Old Child Treated with Surgical Management

Chance fractures by definition are a type of flexion-distraction injury with concomitant vertebral body fracture. Although uncommon in the pediatric population, they are associated with motor vehicle accidents and typically involve the thoraco-lumbar spine. Injury occurs when the spine rotates about a fixed axis, such as a lap belt. Our case reports the management of a five-year-old girl involved in a head-on collision who suffered a purely ligamentous flexion-distraction injury (Chance-type injury, without bone involvement) at the L2-L3 vertebral level. Previously these injuries were managed conservatively with serial casting; however, we present a case in which surgical management was used. A five-year-old girl sustained multiple injuries after being involved in a high-speed motor vehicle accident. At presentation, there was obvious abdominal bruising with a seat-belt sign and marked kyphosis of the spine with severe tenderness at the L2-L3 level. She required immediate exploratory laparotomy for her intraabdominal injuries. After stabilization, an orthopedic consult was deemed necessary. She was found to have occipital-cervical injury with mild anterolisthesis of C2 on C3 and disruption of the apical ligament. There was evidence of bilateral dislocation of the L2-L3 facet joints with marked disruption of the posterior ligaments and a hematoma sack. She required open reduction and internal fixation with an L2-L3 laminectomy, pedicle screw and rod placement. The kyphotic deformity was reduced using a compression device and stable alignment was achieved intraoperatively.

This was a rare and difficult case with limited evidence on the appropriate management of such an injury. Due to the severe instability of her injury, a surgical approach was taken. At two years postoperative, the patient is neurologically intact and pain free. Imaging revealed stable alignment of her lumbar hardware. Ultimately, this has resulted in an excellent outcome at the current follow-up.

[Fractures of the thoracic and lumbar spine in children and adolescents]

BACKGROUND

Only 1.5-2% of all fractures in children and adolescents are fractures of the thoracic and lumbar spine. Treatment is most often conservative. This study compares the own experience with the recent literature.

MATERIAL AND METHODS

Over a 48 month period all patients with fractures of the thoracic and lumbar spine, younger than 16 years were included prospectively. Of the patients 67 underwent follow-up investigations after 3-36 months.

RESULTS

The average age of the patients was 11.9 years. Sports (53%) and traffic (28%) accidents were most frequent. Fractures most often appeared in the mid-thoracic (47%) and thoracolumbar spine (41%). Operative treatment was performed in 9 cases (10.4%). Secondary loss of alignment was not observed neither after conservative nor operative treatment. Neurological deficits (n=2) did not completely improve.

CONCLUSIONS

Most fractures of the thoracic and lumbar spine heal fast and without any sequelae. Unstable fractures of type B and C (exclusively occurring as a result of traffic accidents) need operative stabilization as in adults.

Flexion-distraction injuries in children and adolescents

Flexion-distraction injuries represent an uncommon pattern of injury in the pediatric population. Although this is a well-studied topic in adults, the literature on such injuries in children and adolescents is relatively sparse, with only low levels of evidence available to guide treatment. These injuries carry a high rate of concomitant injuries and a high morbidity and mortality in this population. Proper understanding of these complex injuries is important to ensure proper management and avoid complications.

Chance fractures in the pediatric population

OBJECT

The pediatric Chance fracture (PCF) is an uncommon injury, but it has been increasingly reported. Knowledge is limited to few case reports and short series. To understand the various aspects of this injury, the authors reviewed the current literature.

METHODS

A literature search was conducted using the PubMed and Ovid online databases and relevant key words. All articles that were in English and provided information regarding PCF as a sole or part of the objective were retrieved.

RESULTS

Seventy-three articles were found to fulfill the inclusion criteria. Relevant information about PCF collected from these articles included: 1) mode of trauma, 2) associated injuries, 3) radiological classification, and 4) treatment.

CONCLUSIONS

Chance fractures in children are potentially devastating injuries largely caused by motor vehicle collisions, and these fractures may be more common than previously thought. Concomitant intraabdominal injuries are common and should be suspected, particularly when a seat belt sign is observed. Blunt abdominal aortic injuries are rarely associated, but should be evaluated for and treated appropriately. Magnetic resonance imaging is best for defining ligamentous injury, which aids in defining the pattern of injury, facilitating appropriate treatment regimens.

The effect of postoperative immobilization on short-segment fixation without bone grafting for unstable fractures of thoracolumbar spine

BACKGROUND

Controversy regarding the fixation level for the management of unstable thoracolumbar spine fractures exists. Often poor results are reported with short-segment fixation. The present study is undertaken to compare the effect of fixation level and variable duration of postoperative immobilization on the outcome of unstable thoracolumbar burst fractures treated by posterior stabilization without bone grafting.

PATIENTS AND METHODS

A randomized, prospective, and consecutive series was conducted at a tertiary level medical center. Thirty-six neurologically intact (Frankel type E) thoracolumbar burst fracture patients admitted at our institute between February 2003 and December 2005 were randomly divided into three groups. Group I (n = 15) and II (n = 11) patients were treated by short-segment fixation, while Group III (n = 10) patients were treated by long-segment fixation. In Group I ambulation was delayed to 10th-14th postoperative day, while group II and III patients were mobilized on third postoperative day. Anterior body height loss (ABHL) percentage and increase in kyphosis as measured by Cobb's angle were calculated preoperatively, postoperatively, and at follow-up. Denis Pain Scale and Work Scales were obtained during follow-up.

RESULTS

Mean follow-up was 13.7 months (range 3-27 months). At the final follow-up the mean ABHL was 4.73% in group I compared with 16.2% in group II and 6.20% in group III. The mean Cobb's angle loss was 1.8 degrees in group I compared with 5.91 degrees in group II and 2.3 degrees in group III. The ABHL difference between groups I and II was significant (P = 0.0002), while between groups I and III was not significant (P = 0.49).

CONCLUSION

The short-segment fixation with amenable delayed ambulation is a valid option for the management of thoracolumbar burst fractures, as radiological results are comparable to that of long-segment fixation with the advantage of preserving maximum number of motion segments.

Lap-belt injury with complete avulsion of the spinal cord and cauda equina

The authors report a child who was involved in an automobile accident. The patient was restrained by a rear seat lap belt. Radiological examination revealed an L4 Chance-type fracture and ligamentous disruption at the L4-L5 interval. During superficial dissection of the paraspinal muscles for a spinal fusion procedure, the cauda equina and the lower spinal cord (several centimeters) were visible, completely transected and herniated into the extraspinal space through a disrupted thoracolumbar fascia. The clinician should be aware of the potentially devastating results following a lap-belt injury in which a Chance fracture is produced.

A model of experimental spinal cord trauma based on computer-controlled intervertebral distraction: characterization of graded injury

STUDY DESIGN

: A new model of experimental spinal cord injury is detailed based on the application of tensile (distraction) force to the vertebral column of the rat.

OBJECTIVES

: To develop an experimental model of graded spinal cord injury by application of tensile forces to the vertebral column.

SUMMARY OF BACKGROUND DATA

: Distraction is frequently an integral component of human spinal cord injury, but the acute application of tensile forces to the spinal cord has not been modeled rigorously.

METHODS

: A computer-controlled, motorized outrigger device was used to apply a longitudinal stretching force to sublaminar hooks oriented proximally at T9 and distally at T11. Distraction force was applied using a program that varied the length, speed, and duration of its distraction. A modified 14-point Tarlov score was used to establish the presence of hindlimb dysfunction. This score was correlated with acute changes in somatosensory-evoked potential amplitude, the comprehensive open-field test of locomotor function at 4 weeks, and postmortem measurements of serotonin content and metabolism in spinal cord rostral and distal to the site of injury.

RESULTS

: Of distraction parameters, only length of distraction correlated significantly with each outcome measure. For outcome measures, open-field test inventory and distal/proximal ratio of the spinal content of serotonin were correlated most closely with final Tarlov scores. Acute somatosensory-evoked potential amplitudes proved to be an excellent index of the acute injury but were poor measures of long-term outcome.

CONCLUSIONS

: Distraction-induced spinal cord injury was uniformly mild in rats with intact facet capsular ligaments, regardless of distraction parameters. Cutting the facet joint ligaments consistently generated outcome measures associated with mild, moderate, and severe spinal cord injury at 3-, 5-, and 7-mm distraction lengths, respectively.

Single-level fixation of flexion distraction injuries

Flexion distraction injuries of the thoracic and lumbar spine can be stabilized with a short construct spanning one motion segment. This surgical technique has not been well accepted because of the paucity of published outcomes of patients treated in this manner. The current study is a cohort of patients who underwent a standardized posterior open reduction and single-level fixation for this injury pattern. Independent observation prospectively followed the cohort for a minimum of 20 months with functional and radiologic outcomes determined. A significant (p < 0.0001) correction of deformity was achieved, from a mean preoperative kyphosis of 10.1 degrees to a mean postoperative lordosis of 0.9 degrees. No loss of correction occurred. The mean Oswestry score was 11.5, with 88% of patients having minimal disability. This prospective study demonstrates the efficacy of posterior open reduction and single-level fixation of flexion distraction injuries.

Pediatric spinal cord injuries: a case presentation

Spinal cord injuries (SCIs) in the pediatric population present a unique challenge to the caregiver in that both the physical injury and the growth and development issues need to be addressed simultaneously. Different types of injuries are anticipated than those seen in adults because of the developmental phases of the pediatric spinal cord. This article will review the differences between the pediatric and adult spinal cords, growth and development, and the types of injuries incurred by this population, followed by a case presentation.