ORIGINAL ARTICLE

Characteristics of Spinal Injuries Secondary to Nonaccidental Trauma Jeffrey Knox, MD,* John Schneider, MD,w Robert L. Wimberly, MD,z and Anthony I. Riccio, MDz

Background: Nonaccidental trauma (NAT) is considered an uncommon cause of spine trauma in the pediatric population. Little has been published on such injuries and no large series is available in the literature. The purpose of this study is to describe the incidence and characteristics of spine trauma secondary to NAT. Methods: An IRB-approved retrospective review of all patients presenting to a single level 1 pediatric trauma center with a spinal injury between 2003 and 2011 was performed. Patients were identified using our institution’s trauma registry. Medical records were reviewed to identify all spine injuries that occurred as a result of NAT. These cases were reviewed for details regarding injury mechanism, type and location of injury, associated injuries, and the treatment. Our institution’s NAT database was also queried to identify the total number of patients formally determined to have sustained any injury as a result of NAT during the same period. Results: NAT was the cause of 11/342 (3.2%) spine injuries diagnosed during the study period. A total of 726 cases of NAT were identified, with spine injury present in 1.5%. All patients with spine trauma secondary to NAT were under the age of 2 years with an average age of 7 months. Among patients below 2 years with spinal trauma, NAT was tied as the most common mechanism, resulting in 38% of injuries. Eight of the 11 patients’ spine injuries were cervical and 7 of these injuries were in the atlanto-occipital and atlantoaxial regions. Multilevel spine trauma was present in 64% of patients. Associated head and thoracic trauma was present in 73% and 36% of patients, respectively. Neurological injury was found in 54% of patients. The majority of injuries were treated nonoperatively and 1 patient required surgical management. Conclusions: NAT represents a very common yet often overlooked cause of spinal trauma in children under the age of 2 years. Because of its frequency in this age group, clinicians From the *Tripler Army Medical Center, Orthopedic Surgery Service, Honolulu, HI; wDepartment of Pediatrics, University of Texas Southwestern Medical Center and Childrens Medical Center; and zDepartment of Orthopedics, Texas Scottish Rite Hospital for Children and Childrens Medical Center, Dallas, TX. The views expressed in this manuscript are those of the authors and do not reflect the official policy or position of the Department of the Army, Department of Defense, or the US Government. The authors declare no conflicts of interest. Reprints: Anthony I. Riccio, MD, Department of Orthopedics, Texas Scottish Rite Hospital for Children and Childrens Medical Center, 1935 Medical District Drive, Dallas, TX 75235. E-mail: anthony. [email protected]. Copyright r 2013 by Lippincott Williams & Wilkins

376 | www.pedorthopaedics.com

should consider including an assessment of the spine in all young NAT patients. Patients with spinal trauma sustained as a result of NAT must undergo a thorough evaluation for associated injuries remote to the spine, neurological deficit, and multilevel spine injury. Summary: NAT is a common mechanism of spinal injury in patients below 2 years of age. Key Words: nonaccidental trauma, pediatric spine fracture, cervical spine (J Pediatr Orthop 2014;34:376–381)

N

onaccidental trauma (NAT) is a common cause of injury in the pediatric population. Although the incidence varies with age, it is estimated that between 2.4% and 23.8% of all pediatric blunt trauma is due to NAT and these patients often present with concomitant injuries to the head, thorax, abdomen, and musculoskeletal system.1,2 Injury to the spinal column represents an often overlooked3 injury secondary to NAT, with an incidence ranging from 0% to 0.3% of all NAT cases.2,4–6 Little has been published on such injuries, with the majority of published literature consisting of case reports and small case series. The purpose of this study is to assess the characteristics of spinal trauma secondary to NAT at a high-volume pediatric trauma center.

METHODS An IRB-approved retrospective review was conducted at a single high-volume level I pediatric trauma center. The hospital’s medical records and trauma registry were queried for all patients diagnosed with spinal trauma between 2003 and 2011. Spinal injury was defined as injury to the vertebral column or neural elements between the occipitocervical and lumbosacral junctions. Minor injuries such as contusions or strains were not included for analysis. Pathologic fractures and injuries in patients with preexisting vertebral anomalies were also excluded. The mechanism of injury was determined from the medical records in all patients. NAT was documented as the causative mechanism only after an independent evaluation by our medical center’s NAT specialty team. These physicians perform in-depth investigation of all children with findings or a history concerning for NAT. Cases that J Pediatr Orthop



Volume 34, Number 4, June 2014

J Pediatr Orthop



Volume 34, Number 4, June 2014

were indeterminate for NAT as the mechanism for injury were excluded. Medical records were reviewed for demographic data to include age and sex. The presence of associated injuries, the patient’s neurological status upon arrival, and the documented changes in neurological status during an ensuing in-patient stay were recorded. At our institution, all children undergoing a diagnostic workup for possible NAT receive a complete radiographic skeletal survey that includes anteroposterior and lateral imaging of the entire spine. Magnetic resonance imaging (MRI) of the spine is obtained on a case-by-case basis in these patients. The decision to obtain an MRI is made upon clinical suspicion for spinal trauma based upon physical examination or as a result of abnormal plain radiographic findings indicative of the potential for more extensive or ligamentous injury. In addition, it is the imaging protocol of our radiology department to perform an MRI of the cervical spine in all children undergoing an MRI of the head to evaluate for traumatic brain injury resulting from suspected NAT. Plain radiographs and MRI studies were reviewed by the senior author (A.I.R) to determine injury characteristics, including the level of injury and injury pattern. Injury levels were divided into 3 regions: cervical (atlanto-occipital junction through C7), thoracic (T1-T12), and thoracolumbar/ lumbar (T12-L1 interspace through L5-S1 interspace). The Revised Pediatric Trauma Score (RTS) was obtained from the medical records as documented by the initial treating provider. This scoring system includes the Pediatric Trauma Score plus the Glasgow Coma Score (GCS) converted to a 4-point scale. The Pediatric Trauma Score represents a validated system that assesses patient size, airway, blood pressure, level of consciousness, fractures, and soft-tissue injury. This system has been correlated with morbidity and mortality in pediatric trauma patients.7,8 Addition of the converted GCS to the Pediatric Trauma Score generates the RTS with a range from  6 to 16. All patients presenting to our trauma center are assigned an RTS as a matter of routine during the initial trauma evaluation. If the scoring worksheet was incomplete, available data from the initial presentation were used to calculate the appropriate score, if possible. Length of hospital stay was documented. We recorded any treatment for the spinal injury either during the hospital stay or during any subsequent inpatient treatment after discharge from the initial hospitalization. For those patients who were initially treated at an outside hospital, medical records from the institution that provided initial care were used to obtain documentation of any treatment rendered before transfer. Determination that a child’s injuries are due to NAT at our institution is made by a multidisciplinary team led by a pediatrician specializing in NAT. An intensive review of the patient’s history, caretaker interviews, physical examination findings, radiographic imaging results, and specialist consultations is performed to document NAT as the mechanism of injury. Every case of NAT is documented in an NAT Registry as part of our larger Trauma Registry. This NAT Registry was queried to determine the total r

2013 Lippincott Williams & Wilkins

Spinal Injuries Secondary to Nonaccidental Trauma

number of children who were deemed to have sustained any injury secondary to NAT during the study period. This number was compared with those presenting with spinal injuries secondary to NAT to determine the incidence of spine trauma resulting from NAT.

RESULTS A total of 342 children were diagnosed with a spine injury during the study period. Of these patients, 11 were documented as injured secondary to NAT for a rate of nonaccidentally induced spine trauma of 3.2%. Eight patients were male and 3 were female. The average age of these patients was 0.6 years (range, 0.1 to 1.9 y). As all children with nonaccidental spine trauma were under the age of 2 years, a closer examination of all patients with spinal injuries within this 0- to 2-year old age group was undertaken. Only 29 spine injuries were diagnosed in children 2 years of age or younger during the study period. In addition to the 11 patients injured due to NAT, 11 injuries resulted from motor vehicle collisions, 4 resulted from pedestrian versus motor vehicle incidents, and 3 occurred as the result of a fall. Within this age group, 38% (11/29) of patients sustained spinal injuries as a result of NAT. Moreover, NAT was as common a mechanism of injury for spinal trauma as motor vehicle collisions. Injuries were primarily located in the cervical spine with 8/11 (73%) patients sustaining injuries in this region. Within this group, injuries to the upper cervical spine predominated, with 7 patients sustaining injuries at the atlanto-occipital junction or atlanto-axial spine. Therefore, 64% (7/11) of patients sustained injuries to the upper cervical spine and 88% of all cervical spine trauma occurred cephalad to the subaxial spine. Injuries to the thoracic, thoracolumbar, and lumbar spine were less common with 1 patient sustaining thoracic compression fractures, 1 sustaining a lumbar compression fracture, and 1 sustaining an isolated ligamentous injury to the thoracolumbar junction. Seven patients (64%) presented with multilevel injuries resulting in a total of 21 levels of injury and an average 1.9 levels per patient. Five patients sustained injuries at 2 levels and 3 patients sustained injuries at 3 levels. Of those with multilevel trauma, 6 had injuries at contiguous levels and 1 patient had injuries at both contiguous and noncontiguous levels. MRI was obtained in all 11 patients either during their initial trauma evaluation or subsequent hospitalization. Three patients underwent MRI due to concerns for potential ligamentous or occult injury based upon physical examination findings and clinical suspicion. Two of these patients had normal radiographs with MRI revealing the presence of unrecognized ligamentous injuries. The third patient had T8-T10 compression fractures with an MRI that demonstrated no associated soft-tissue trauma. Eight patients received an MRI of the spine in conjunction with a head MRI ordered to assess for cerebral trauma. Seven of these patients had normal plain radiographs with MRI diagnostic for purely ligamentous www.pedorthopaedics.com |

377

J Pediatr Orthop

Knox et al



Volume 34, Number 4, June 2014

TABLE 1. Summary of Children Injured Secondary to Nonaccidental Trauma Patient

Neurological Status

Associated Injuries

1 2 3 4 5 6

Age (y) 0.6 0.5 1.0 0.1 1.9 0.6

T8-10 compression fractures AO, C1-2 ligamentous C1-2 ligamentous AO, C1-2 ligamentous AO, C1-2 ligamentous L2 compression fracture

Injury

Normal Hemiplegia Hemiplegia Normal Hemiplegia Normal

7

1.0

T12-L1 ligamentous

Normal

8 9

0.2 0.4

AO, C1-2 ligamentous AO, C1-2 ligamentous, dens fracture

Hemiplegia No function

10

0.2

C1-2, multilevel cervical ligamentous

No function

11

0.3

C7-T3 flexion-type injury

Normal

None SDH, SAH SDH, skull fracture Pulmonary contusion SDH, SAH, EDH Skull fracture, intracranial hemorrhage, rib fractures, liver laceration, adrenal hematoma, clavicle fracture Pulmonary contusion, rib fractures, spinal EDH SDH, closed head injury Cervical spine EDH, cerebral edema, traumatic brain injury, multiple extremity fractures Cerebral edema, adrenal injury, rib fractures, brain death SDH, SAH, skull fractures, rib fractures, multiple extremity fractures

Trauma Score* 16 3 6 1 10 13

11 5 1

6 5

*Revised Pediatric Trauma Score. EDH indicates epidural hematoma; SAH, subarachnoid hematoma; SDH, subdural hematoma.

injuries in 6 and ligamentous injuries with an associated dens fracture in the seventh. The remaining patient had an L2 compression fracture on plain radiographs. MRI of the cervical spine in this patient showed no abnormalities and MRI of the lumbar spine showed mild edema within the terminal spinal cord. When taken as a whole, MRI was diagnostic of unrecognized ligamentous or combined bony/ligamentous injuries in 9/11 (82%) patients. When classified by injury type, isolated ligamentous injuries were the most common and were present in 8/11 (73%) patients. Seven isolated ligamentous injuries occurred in the cervical spine and 1 occurred in the thoracolumbar junction. Compression fractures were present in 2 patients (18%). One patient sustained extensive upper cervical ligamentous injuries with an associated dens fracture. Associated injuries were common in this patient population with 10/11 (91%) patients sustaining at least 1 other significant injury. Head injury was most common, present in 8/11 (73%) patients. Of these head injuries, 50% presented with severe head injuries with a GCS of 3 on arrival. Thoracic injuries were present in 5/11 (45%) patients, 2 sustained associated fractures, and 2 sustained injuries to the abdominal viscera (18%). Patients who sustained injuries secondary to NAT presented with an average RTS of 7 (range,  1 to 16). One patient died during the initial hospitalization resulting in a 9% overall acute mortality rate. This patient presented with severe cerebral trauma with no demonstrable neurological function on arrival. Neurological deficit was present in 6 patients. Two of the 11 patients (18%) presented with no demonstrable neurological function and 4 (36%) presented with hemiplegia. No patients were definitively identified with deficits

378 | www.pedorthopaedics.com

solely due to spinal cord or cranial nerve injury. Because of the high rate of concomitant cerebral trauma, it was impossible to determine the definitive source of neurological injury in these patients (see Table 1 for details). The majority of patients were treated nonoperatively with either cervical collar immobilization (5 patients) or observation (5 patients). One patient (9%) who sustained a combined atlanto-occipital and atlantoaxial ligamentous injury with a dens fracture required open reduction and occiput to C5 fusion for craniocervical instability (Fig. 1). Although this 4-month-old patient presented with severe head trauma and no demonstrable neurological function, his marked occipitocervical instability was felt to carry the potential for ongoing damage to neurological structures and death. Extension of the fusion to C5 was performed to obtain improved construct stability in the presence of extensive ligamentous trauma and largely cartilaginous lateral masses that limited fixation rigidity. Of the 10 patients who survived their injuries, 3 had normal function and normal radiographic alignment of the spine at final follow-up. All 6 patients with neurological insults at the time of presentation had persisting neurological deficits. One patient was lost to follow-up. The sole patient treated operatively had radiographic fusion of the cervical spine and required no further surgical interventions for management of his occipitocervical injury. At 4 years from the time of injury, he remains neurologically devastated with nonambulatory spastic quadriparesis, blindness, G-tube dependence for feeding, and profound mental retardation. During the study period, the query of our institutions NAT Registry revealed that a total of 726 children were evaluated for an injury or injuries ultimately deemed to be r

2013 Lippincott Williams & Wilkins

J Pediatr Orthop



Volume 34, Number 4, June 2014

Spinal Injuries Secondary to Nonaccidental Trauma

FIGURE 1. A 4-month-old male presenting to ER with respiratory distress, numerous soft-tissue contusions, and multiple extremity fractures. A, Lateral radiograph of the cervical spine shows no obvious fractures or abnormal alignment. B, STIR sagittal MRI shows increased T2 signal between the occiput and lateral mass of C1 as well as between the lateral masses of C1 and C2 consistent with intra-articular fluid and capsular distention secondary to disruption of these articulations. C, STIR sagittal MRI shows undulation of the posterior longitudinal ligament throughout the upper cervical spine, frank disruption of the tectorial ligament, fracture of the odontoid process, interspinous ligament disruption with widening of the posterior elements of C1 and C2, and extensive posterior soft-tissue edema with attenuation of the nuchal ligament. D, Lateral radiograph after occipitocervical fusion (occiput to C5).

secondary to NAT. As 11of these patients sustained spinal trauma, the prevalence of spine injury in all patients with documented NAT was 1.5% (11/726).

DISCUSSION This study represents the largest series of spine injury secondary to NAT identified in the literature. Overall, NAT was an uncommon cause of spinal trauma, responsible for only 3% of all spinal injuries during the study period. However, among children between 0 and 2 years of age, NAT was responsible for 38% of spinal injuries and was as common a cause of spinal injury in this age cohort as were motor vehicle collisions. Prior studies have reported similar r

2013 Lippincott Williams & Wilkins

rates, with NAT causing between 0% and 3% of pediatric spine injuries.4,5,9–11 Such injuries occur primarily in very young children with only a few cases reported in children over the age of 2.5,9,10,12,13 The primary location of injury in our series was the cervical spine, which was present in 8/11 (73%) of patients. Children have a predisposition toward injuries in the cervical spine due to anatomic and biomechanical factors including a fulcrum of motion centered in the upper cervical spine, underdeveloped uncinate processes, and more horizontally oriented facet joints.14 As a result, up to 79% of spine injuries in children occur in the cervical spine15 with up to 83% in the upper cervical spine.16 www.pedorthopaedics.com |

379

Knox et al

Existing published reports on spine trauma secondary to NAT show a roughly equal distribution between the cervical and thoracolumbar injuries.5 Prior reviews on this subject have stated that the thoracolumbar spine is the most common site of injury.9,17 As these prior reports consist only of small case series or case reports, they were unable to accurately determine and compare patterns of injury. Our series, however, demonstrated a significantly different distribution with the majority of injuries in the cervical spine. As upper cervical spine injuries may often present with little external signs such as soft-tissue edema, a low threshold for imaging this area should be maintained to avoid missing significant pathology in these children. Ligamentous injury without bony pathology was common in our series and present in 73% of our study population. Such injuries in NAT have been proposed to be secondary to a flexion-extension and rotation type moment such as would occur during vigorous shaking. A variety of injury types have been previously described secondary to NAT ranging from mild compression fractures to severe fracture dislocations with neurological injury.18–23 Prior studies have stated that compression fractures represent the most common injury pattern secondary to NAT.20 The utility of MRI in the identification of spinal injury in NAT patients cannot be underemphasized as MRI proved to be diagnostic in 82% of patients in our series. Neurological injury was common in our series with 36% of patients presenting with hemiparesis and 18% without demonstrable neurological function on arrival. The etiology of the neurological injury is often challenging to determine due to both the young age of the patients and the high rate of concomitant head injury. In addition to neurological injury, children who present with spinal injury secondary to NAT often present with multiple additional injuries.18,23 In our series, head and thoracic injuries were the most common associated injuries, present in 73% and 36%, respectively. Children requiring hospital admission for NAT commonly present with multiple injuries frequently mandating intensive care admission. Head, thoracic, and abdominal trauma frequently result from NAT and are more commonly due to this mechanism than following an unintentional trauma.1,5,12,24 Limitations of this study include its retrospective design, reliance upon registry entries for injury identification, and the relatively small number of children with spine trauma secondary to NAT upon whom characterization of these injuries was based. In addition, it is exceedingly likely that several spine injuries among those children who sustained NAT were never diagnosed. Our own data have demonstrated that the vast majorities of identified spinal injuries in such patients are ligamentous in nature and could therefore easily be missed without the use of MRI or dynamic radiographs. Furthermore, our cohort had a high incidence of serious and potentially lifethreatening associated injuries, particularly to the head and thorax, which may have diverted clinical focus or diagnostic workup away from potential spine injuries,

380 | www.pedorthopaedics.com

J Pediatr Orthop



Volume 34, Number 4, June 2014

especially in the absence of any neurological dysfunction. For these reasons, the true prevalence of spinal injury in victims of NAT may be higher than we report in this study. Although the overall incidence of spinal injury is low in children who have sustained NAT, it was found to be a relatively common cause of spinal injury in children under the age of 2 years. We therefore recommend a careful evaluation for the possibility of NAT in all children of this young age group with spine trauma, especially those without a more obvious mechanism of injury. Ligamentous injuries of the cervical spine predominate in the setting of NAT and a thorough examination of the cervical spine is recommended when NAT is suspected. Advanced imaging should be considered when the physical examination is equivocal or associated injuries impair assessment of neurological function. REFERENCES 1. DiScala C, Sege R, Li G, et al. Child abuse and unintentional injuries: a 10-year retrospective. Arch Pediatr Adolesc Med. 2000;154: 16–22. 2. Karmazyn B, Lewis ME, Jennings SG, et al. The prevalence of uncommon fractures on skeletal surveys performed to evaluate for suspected abuse in 930 children: should practice guidelines change? AJR Am J Roentgenol. 2011;197:W159–W163. 3. Avellino AM, Mann FA, Grady MS, et al. The misdiagnosis of acute cervical spine injuries and fractures in infants and children: the 12-year experience of a level I pediatric and adult trauma center. Childs Nerv Syst. 2005;21:122–127. 4. Cirak B, Ziegfeld S, Knight VM, et al. Spinal injuries in children. J Pediatr Surg. 2004;39:607–612. 5. Kemp AM, Joshi AH, Mann M, et al. What are the clinical and radiological characteristics of spinal injuries from physical abuse: a systematic review. Arch Dis Child. 2010;95:355–360. 6. Offiah A, van Rijn RR, Perez-Rossello JM, et al. Skeletal imaging of child abuse (non-accidental injury). Pediatr Radiol. 2009;39:461–470. 7. Narci A, Solak O, Turhan-Haktanir N, et al. The prognostic importance of trauma scoring systems in pediatric patients. Pediatr Surg Int. 2009;25:25–30. 8. Tepas JJ III, Mollitt DL, Talbert JL, et al. The pediatric trauma score as a predictor of injury severity in the injured child. J Pediatr Surg. 1987;22:14–18. 9. Brown RL, Brunn MA, Garcia VF. Cervical spine injuries in children: a review of 103 patients treated consecutively at a level 1 pediatric trauma center. J Pediatr Surg. 2001;36:1107–1114. 10. Carreon LY, Glassman SD, Campbell MJ. Pediatric spine fractures: a review of 137 hospital admissions. J Spinal Disord Tech. 2004;17: 477–482. 11. Haffner DL, Hoffer MM, Wiedbusch R. Etiology of children’s spinal injuries at Rancho Los Amigos. Spine (Phila Pa 1976). 1993;18:679–684. 12. Kemp AM, Dunstan F, Harrison S, et al. Patterns of skeletal fractures in child abuse: systematic review. BMJ. 2008;337:a1518. 13. Levin TL, Berdon WE, Cassell I, et al. Thoracolumbar fracture with listhesis—an uncommon manifestation of child abuse. Pediatr Radiol. 2003;33:305–310. 14. Lustrin ES, Karakas SP, Ortiz AO, et al. Pediatric cervical spine: normal anatomy, variants, and trauma. Radiographics. 2003;23:539–560. 15. Osenbach RK, Menezes AH. Pediatric spinal cord and vertebral column injury. Neurosurgery. 1992;30:385–390. 16. Mahan ST, Mooney DP, Karlin LI, et al. Multiple level injuries in pediatric spinal trauma. J Trauma. 2009;67:537–542. 17. Kocher MS, Kasser JR. Orthopaedic aspects of child abuse. J Am Acad Orthop Surg. 2000;8:10–20. 18. Cullen JC. Spinal lesions in battered babies. J Bone Joint Surg Br. 1975;57:364–366. r

2013 Lippincott Williams & Wilkins

J Pediatr Orthop



Volume 34, Number 4, June 2014

19. Dickson RA, Leatherman KD. Spinal injuries in child abuse: case report. J Trauma. 1978;18:811–812. 20. Ghatan S, Ellenbogen RG. Pediatric spine and spinal cord injury after inflicted trauma. Neurosurg Clin N Am. 2002;13: 227–233. 21. Kleinman PK, Zito JL. Avulsion of the spinous processes caused by infant abuse. Radiology. 1984;151:389–391.

r

2013 Lippincott Williams & Wilkins

Spinal Injuries Secondary to Nonaccidental Trauma

22. Rooks VJ, Sisler C, Burton B. Cervical spine injury in child abuse: report of two cases. Pediatr Radiol. 1998;28:193–195. 23. Swischuk LE. Spine and spinal cord trauma in the battered child syndrome. Radiology. 1969;92:733–738. 24. Pandya NK, Baldwin K, Wolfgruber H, et al. Child abuse and orthopaedic injury patterns: analysis at a level I pediatric trauma center. J Pediatr Orthop. 2009;29:618–625.

www.pedorthopaedics.com |

381

Characteristics of spinal injuries secondary to nonaccidental trauma.

Nonaccidental trauma (NAT) is considered an uncommon cause of spine trauma in the pediatric population. Little has been published on such injuries and...
160KB Sizes 0 Downloads 0 Views