Femur fractures in the pediatric population: abuse or accidental trauma?

BACKGROUND: Child abuse represents a serious threat to the health and well-being of the pediatric population. Orthopaedic specialists will often become involved when child abuse is suspected as a result of the presence of bony injury. Distinguishing abuse from accidental trauma can be difficult and is often based on clinical suspicion. QUESTIONS/PURPOSES: We sought to determine whether accidental femur fractures in pediatric patients younger than age 4 could be distinguished from child abuse using a combination of presumed risk factors from the history, physical examination findings, radiographic findings, and age. METHODS: We searched our institution's SCAN (Suspected Child Abuse and Neglect) and trauma databases. We identified 70 patients in whom the etiology of their femur fracture was abuse and compared that group with 139 patients who had a femur fracture in whom accidental trauma was the etiology. RESULTS: A history suspicious for abuse, physical or radiographic evidence of prior injury, and age younger than 18 months were risk factors for abuse. Patients with no risk factors had a 4% chance, patients with one risk factor had a 29% chance, patients with two risk factors had an 87% chance, and patients with all three risk factors had a 92% chance of their femur fracture being a result of abuse. CONCLUSIONS: Clinicians can use this predictive model to guide judgment and referral to social services when seeing femur fractures in very young children in the emergency room. LEVEL OF EVIDENCE: Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Child abuse and orthopaedic injury patterns: analysis at a level I pediatric trauma center.

BACKGROUND: Child abuse is a serious threat to the physical and psychosocial well-being of the pediatric population. Musculoskeletal injuries are common manifestations of child abuse. There have been multiple studies that have attempted to identify the factors associated with, and the specific injury patterns seen with musculoskeletal trauma from child abuse, yet there have been no large studies that have used prospectively collected data and controlled comparisons. The purpose of our study was to describe the patterns of orthopaedic injury for child abuse cases detected in the large urban area that our institution serves, and to compare the injury profiles of these victims of child abuse to that of general (accidental) trauma patients seen in the emergency room and/or hospitalized during the same time period. METHODS: This study is a retrospective review of prospectively collected information from an urban level I pediatric trauma center. Five hundred cases of child abuse (age birth to 48 mo) were identified by membership in our institution's Suspected Child Abuse and Neglect database collected between 1998 and 2007. These cases were compared against 985 general trauma (accidental) control patients of the same age group from 2000 to 2003. Age, sex, and injury type were compared. RESULTS: Victims of child abuse were on average younger than accidental trauma patients in the cohort of patients under 48 months of age. There was no difference in sex distribution between child abuse and accidental trauma patients. When the entire cohort of patients under 48 months were examined after adjusting for age and sex, the odds of rib (14.4 times), tibia/fibula (6.3 times), radius/ulna (5.8 times), and clavicle fractures (4.4 times) were significantly higher in child abuse versus accidental trauma patients. When regrouping the data based on age, in patients younger than 18 months of age, the odds of rib (23.7 times), tibia/fibula (12.8 times), humerus (2.3 times), and femur fractures (1.8 times) were found to be significantly higher in the child abuse group. Yet, in the more than 18 months age group, the risk of humerus (3.4 times) and femur fractures (3.3 times) was actually higher in the accidental trauma group than in the child abuse group. CONCLUSIONS: Patients who present to an urban level I pediatric trauma center and are victims of abuse are generally younger, and have an equal propensity to be male or female. It is important for the clinician to recognize that the age of the patient (younger or older than 18 mo and/or walking age) is an important determinant in identifying injury patterns suspicious for abuse. Patients below the age of 18 months who present with rib, tibia/fibula, humerus, or femur fractures are more likely to be victims of abuse than accidental trauma patients. Yet, when patients advance in age beyond 18 months, their presentation with long bone fractures (ie, femur and humerus) is more likely to be related to accidental trauma than child abuse. LEVEL OF EVIDENCE: level III, prognostic study.

Occipitalization of the atlas in children. Morphologic classification, associations, and clinical relevance.

BACKGROUND: Occipitalization is defined as a congenital fusion of the atlas to the base of the occiput. We are not aware of any previous studies addressing the morphologic patterns of occipitalization or the implications of occipitalization in children. We present data on what we believe is the largest reported series of children with occipitalization studied with computed tomography and/or magnetic resonance imaging, and we provide a description of their clinical characteristics. METHODS: We retrospectively reviewed all cases of occipitalization in children included in our spine database. Patient charts and imaging studies were reviewed. A new morphologic classification of occipitalization was developed from the two-dimensional sagittal and coronal reformatted computed tomographic reconstructions and/or magnetic resonance images. The classification includes four patterns according to the anatomic site of occipitalization (Zones 1, 2, and 3 and a combination of those zones), and it was applied to this group of patients. Imaging studies were also reviewed for evidence of cervical instability and for other anomalies of the craniovertebral junction. RESULTS: Thirty patients with occipitalization were identified. There were twenty-four boys and six girls with a mean age of 6.5 years. The morphologic categorization was Zone 1 (a fused anterior arch) in six patients, Zone 2 (fused lateral masses) in five, Zone 3 (a fused posterior arch) in four, and a combination of fused zones in fifteen. Seventeen patients (57%) had atlantoaxial instability, and eight of them had an associated C2-C3 fusion. Eleven patients (37%) had spinal canal encroachment, and five of them had clinical findings of myelopathy. The highest prevalence of spinal canal encroachment (63%) was noted in patients with occipitalization in Zone 2. CONCLUSIONS: Occipitalization is associated with abnormalities that lead to narrowing of the space available for the spinal cord or brainstem. The risk of atlantoaxial instability developing is particularly high when there is an associated congenital C2-C3 fusion. Two-dimensional sagittal and coronal reformatted computed tomographic reconstructions and/or magnetic resonance images can help to establish the diagnosis and permit categorization of occipitalization in three zones, each of which may have a different prognostic implication.

Traumatic atlanto-occipital dislocation in children.

BACKGROUND: Traumatic atlanto-occipital dislocation in children and adolescents is a rare and often fatal injury. Although historically most reported cases have been fatal, the advent of modern prehospital care has led to an increase in survival following this injury. As a consequence, some patients may achieve or maintain satisfactory neurologic function following early intervention, stabilization, and definitive management. We analyzed the data on children and adolescents in whom traumatic atlanto-occipital dislocation had been treated with modern resuscitation techniques at our institution. METHODS: Atlanto-occipital dislocation is defined as disruption of the ligaments and other supporting soft tissues as indicated by displacement in either a transverse or vertical direction. With use of the Trauma Registry database at our institution, we identified sixteen such injuries that had occurred between 1986 and 2003. The hospital charts, clinic notes, and radiographs were reviewed. A careful neurological evaluation was performed for all of the survivors at the time of the latest follow-up. RESULTS: The mean age of the sixteen patients at the time of the injury was 7.6 years. The mechanisms of injury were diverse. The mean Glasgow Coma Scale score was 7.4 points. Eleven of the sixteen patients underwent intubation in the field, two were intubated in the emergency department, and three were not intubated. Eight of the sixteen patients were declared dead on arrival in the emergency department. The eight surviving patients initially were immobilized with either a halo vest or another orthosis. All patients except one received intravenous steroids in the emergency department. Three of the patients who survived the initial injury subsequently died while undergoing neurosurgical procedures for the treatment of extensive intracranial injuries. Four of the remaining five survivors underwent occiput-C2 fusion, and one was managed with a Minerva cast. At the time of the final follow-up, at a mean of 4.2 years after the injury, one patient was neurologically normal, three had mild spastic hemiparesis and were very functional, and one had spastic quadriplegia and was ventilator-dependent. CONCLUSIONS: Prompt recognition and treatment of traumatic atlanto-occipital dislocation in children and adolescents can result in improved survival. Early diagnosis, prompt intubation, early and adequate immobilization of the head and neck, and the use of intravenous steroids appear to facilitate survival. We recommend arthrodesis from the occiput to C2 (or the nearest adjacent intact and stable vertebra caudad to C2) for all children who survive a traumatic atlanto-occipital dislocation, particularly those with an incomplete spinal cord injury.

Radiographic study of the upper cervical spine in the 22q11.2 deletion syndrome.

BACKGROUND: The chromosome abnormality, deletion of 22q11.2, is one of the most common genetic syndromes. The 22q11.2 deletion syndrome encompasses a wide spectrum of abnormalities including cardiac, palate, and immunological anomalies. The purposes of the current study were (1) to define and determine the frequency of variations of the occiput and cervical spine on plain radiographs in patients with the 22q11.2 deletion syndrome and (2) to postulate the potential clinical importance of these variations. METHODS: Seventy-nine consecutive patients with the 22q11.2 deletion underwent clinical and radiographic evaluation of the occiput and cervical spine. Radiographic studies included lateral plain radiographs of the cervical spine in neutral, flexion, and extension; anteroposterior radiographs; and open-mouth odontoid radiographs. RESULTS: At least one developmental variation of the occiput or cervical spine was observed in every patient. The occipital variations were platybasia in fifty-two (91%) of the fifty-seven patients for whom data were available and basilar impression in two (3%) of the seventy-nine patients. The atlas variations were dysmorphic shape in fifty-nine (75%) of the seventy-nine patients, open posterior arch in forty-seven (59%) of the seventy-nine patients, and occipitalization in two (3%) of the seventy-one patients with adequate radiographs. The axis variations were dysmorphic dens in forty-six (58%) and upswept lamina and posterior elements or "C2 swoosh" in forty-seven (59%) of the seventy-nine patients. Of the seventy-one patients with adequate radiographs, twenty-four (34%) had fusion of C2-C3, fifteen (21%) had fusion of the posterior elements only, and nine (13%) had a complete block fusion. Increased segmental motion was observed in forty (56%) of the seventy-one patients. Thirteen (33%) of the forty patients had increased segmental motion at more than one level. Thirty-one patients (44%) had increased occipitoatlantal motion, seven (10%) had increased atlantoaxial motion, and four had increased C2-C3 motion. Eleven (15%) of the seventy-one patients had increased C3-C4 mobility, always adjacent to a fusion of C2-C3. CONCLUSIONS: Variations of the upper cervical spine, including increased segmental motion, are common in the 22q11.2 deletion syndrome. It is premature to predict the clinical implications of these radiographic findings, but advanced imaging and further observation may be needed to clarify their clinical course.

Comparison of titanium elastic nails with traction and a spica cast to treat femoral fractures in children.

BACKGROUND: Titanium elastic nails are commonly used to stabilize femoral fractures in school-aged children, but there have been few studies assessing the risks and benefits of this procedure compared with those of traditional traction and application of a spica cast. This prospective cohort study was designed to evaluate these two methods of treatment, with a specific focus on the first year after injury, the period when the treatment method should have the greatest impact. METHODS: Eighty-three consecutive children, six to sixteen years of age, were studied prospectively. Factors that were analyzed included clinical and radiographic data, complications, hospital charges, and outcome data. Outcome and recovery were assessed both with the American Academy of Orthopaedic Surgeons Pediatric Outcomes Data Collections Instrument, version 2.0, and according to a series of important recovery milestones including the time to walking with aids, time to independent walking, time absent from school, and time until full activity was allowed. RESULTS: Thirty-five children (thirty-five fractures), with a mean age of 8.7 years, were treated with traction and application of a spica cast, and forty-eight children (forty-nine fractures), with a mean age of 10.2 years, were treated with titanium elastic nails. All fractures healed, and no child sustained a complication that was expected to cause permanent disability. At one year after the fracture, eighty of the children had acceptable alignment and no inequality between the lengths of the lower extremities. The remaining three children, who had an unsatisfactory result, had been treated with traction and a spica cast. Twelve patients (34%) treated with traction and a cast had a complication compared with ten patients (21%) treated with titanium elastic nails. Compared with the children treated with traction and a cast, those treated with titanium elastic nails had shorter hospitalization, walked with support sooner, walked independently sooner, and returned to school earlier. These differences were significant (p < 0.0001). We could detect no difference in total hospital charges between the two groups. CONCLUSIONS: The results of this prospective study support the recent empiric observations and published results of retrospective series indicating that a child in whom a femoral fracture is treated with titanium elastic nails achieves recovery milestones significantly faster than a child treated with traction and a spica cast. Hospital charges for the two treatment methods are similar. The complication rate associated with nailing compares favorably with that associated with traction and application of a spica cast.

Adolescent disc dysplasia and back pain.

PURPOSE: Adolescent disc dysplasia can be a cause of significant back pain and functional impairment in patients. We present a case series of patients inflicted with adolescent disc dysplasia (ADD). METHODS: A retrospective search was performed identifying patients presenting with ADD. Radiographic studies and advanced imaging were described. We documented presenting symptoms and clinical course. RESULTS: Six patients were identified. All patients presented with mechanical back pain, which worsened with flexion and extension. Magnetic resonance imaging was most accurate imaging modality. CONCLUSION: Among our patient cohort, treatment for adolescent disc dysplasia consisted of a combination of physical therapy and bracing. Neither approach proved to be very effective, with only one patient asymptomatic at follow-up.

Transcranial electric motor evoked potential monitoring during spine surgery: is it safe?

STUDY DESIGN: Retrospective review. OBJECTIVE: To report on the safety of repetitive transcranial electric stimulation (RTES) for eliciting motor-evoked potentials during spine surgery. SUMMARY OF BACKGROUND DATA: Theoretical concerns over the safety of RTES have hindered broader acceptance of transcranial electric motor-evoked potentials (tceMEP), despite successful implementation of spinal cord monitoring with tceMEPs in many large spine centers, as well as their apparent superiority over mixed-nerve somatosensory-evoked potentials (SSEP) for detection of spinal cord injury. METHODS: The records of 18,862 consecutive patients who met inclusion criteria and underwent spine surgery with tceMEP monitoring were reviewed for RTES-related complications. RESULTS: This large retrospective review identified only 26 (0.14%) cases with RTES-related complications; all but one of these were tongue lacerations, most of which were self-limiting. CONCLUSIONS: The results demonstrate that RTES is a highly safe modality for monitoring spinal cord motor tract function intraoperatively.

Humerus fractures in the pediatric population: an algorithm to identify abuse.

Child abuse is a serious problem affecting the pediatric population, which has tremendous medical and social implications. There exists no gold standard test to diagnose child abuse, and as a result, clinicians are often in a difficult position of both protecting the child adequately, and respecting the rights and privacy of families. Upper extremity fractures are also common injuries seen in the emergency room, and a need exists to differentiate accidental from nonaccidental etiologies in young children. The purpose of this study was to produce an algorithm-based on statistical analysis that would allow clinicians to differentiate between humerus fractures stemming from abuse versus accidental trauma. We hypothesized that accidental humerus fractures in pediatric patients under the age of 4 years can be accurately distinguished from child abuse using a combination of history, physical exam findings, radiographic findings, and age. We searched our institutions Suspected Child Abuse and Neglect and trauma databases for nearly a decade. We identified 36 (representing 39 humerus fractures) patients in whom the etiology of their humerus fracture was abuse, and compared that group with 95 patients (representing 95 humerus fractures) in whom accidental trauma was the etiology. Univariate and multivariate statistical analysis techniques were applied to determine factors important in the diagnosis of child abuse given a humerus fracture. Univariate analysis found that location of fracture, polytrauma, age, prior injury, and history were factors that are important in the diagnosis of child abuse. Our multivariate analysis found that age above 18 months, physical and/or radiographic evidence of prior injury, and suspicious history were found in greater frequency in the group of patients experiencing abusive humerus fractures. In conclusion, based on our statistical analysis and earlier studies we developed an algorithm that clinicians can use to guide judgment and refer to social services when encountered with a young child presenting to the emergency room with a humerus fracture.

Diminished spinal cord size associated with congenital scoliosis of the thoracic spine.

BACKGROUND: Intraspinal anomalies are common in patients with congenital scoliosis and are a known risk factor for neurological complications. Smaller but normal-appearing spinal cords have not been described in association with congenital scoliosis, nor have they been considered to be an anomaly with a similar neurological risk. We previously reported on small spinal cords associated with Klippel-Feil syndrome. We hypothesized that patients with congenital thoracic scoliosis would similarly have smaller spinal cords as compared with normal controls, with a potentially increased risk for myelopathy. METHODS: We reviewed thirty patients with congenital scoliosis (including fifteen patients with failure of vertebral formation and fifteen with failure of vertebral segmentation). All patients had adequate axial T2-weighted, digitally formatted magnetic resonance imaging scans that were suitable for cross-sectional measurement. Cross-sectional areas of the spinal cord and spinal canal at each of the twelve thoracic levels were calculated three times by a blinded observer, and the average values were compared with measurements from age-matched normal controls. RESULTS: We observed a significantly smaller mean cross-sectional area at all levels of the spinal cord in the study group as compared with the control group (p < 0.01). When the pathological segments were evaluated, both with and without the inclusion of the adjacent normal segments, the spinal cord was smaller for the study group (p < 0.01). Within the study group, small spinal cords were observed in patients with failed vertebral formation as well as in patients with failed vertebral segmentation, but without an identifiable difference between these two subgroups. The spinal canal was also smaller for the patients in the study group, but not in all cases. No patient showed a reduction of, or encroachment on, the space available for the spinal cord. Spinal cord size increased with age in both the study group and the control group but remained consistently smaller in the study group. Within the study group, the presence of intraspinal anomalies did not appear to influence the spinal cord size. CONCLUSIONS: The spinal cord is significantly smaller in patients with congenital thoracic scoliosis than in normal controls. Because small spinal cords have been reported to be associated with neurological sequelae, we advise that the diminished spinal cord size be considered an important component of intraspinal anomalies associated with congenital scoliosis.

The correction of pelvic obliquity in patients with cerebral palsy and neuromuscular scoliosis: is there a benefit of anterior release prior to posterior spinal arthrodesis?

STUDY DESIGN: A retrospective study of 61 patients with cerebral palsy (CP) and neuromuscular scoliosis treated by either a combined anterior-posterior spinal arthrodesis or a posterior-only arthrodesis with the unit rod. OBJECTIVES: Compare coronal and sagittal plane radiographic outcomes in patients undergoing either a combined anterior-posterior spinal fusion (PSF) or a posterior-only fusion with the unit rod for neuromuscular scoliosis in patients with CP. SUMMARY OF BACKGROUND DATA: Although an anterior release before posterior spinal arthrodesis is commonly done for larger and stiffer neuromuscular curves, it is unclear whether or not an all-posterior construct produces similar correction in pelvic obliquity as that seen with an anterior-posterior spinal fusion. METHODS: Sixty-one consecutive children with CP and scoliosis were treated at a single institution between 1991 and 2003 with PSF using the unit rod with an anterior release (group A: 19 patients; average = 14.4 years) or without an anterior release (group B: 42 patients; average = 13.7 years). Side-bending, AP, and lateral radiographs were used to assess various sagittal and coronal plane parameters at baseline, after surgery, and at 2 years. RESULTS.: Before surgery, group A had larger major curves (91 degrees A vs. 72 degrees B; P = 0.001), less flexible major curves (21% A vs. 40% B; P = 0.01), with greater pelvic obliquity (26 degrees A vs. 19 degrees B, P = 0.02) than group B. In the subset of patients with a more severe preoperative pelvic obliquity (>20 degrees ), percent correction in pelvic obliquity was equivalent between groups A (71%) and B (74%, P = 0.91). With respect to coronal and sagittal plane radiographic outcomes, there were no significant group differences in major curve correction (58% A vs. 60% B), but group A trended toward greater % correction from preop bending films. At most recent follow-up, there were no differences with respect to loss of curve correction (7.6 A vs. 8.1 degrees B, P = 0.80). The rate of major complications was 26% for both groups, but group A patients had significantly longer operative times. CONCLUSION: We demonstrate that excellent correction in severe pelvic obliquity can be achieved in smaller, more flexible curves using an all-posterior PSF, and in larger, less flexible curves using an anterior release with PSF.

Congenital osseous anomalies of the upper cervical spine.

BACKGROUND: The developmental anatomy and biomechanics of the upper cervical spine are unique in children. Congenital osseous anomalies in this region may be associated with an increased risk for subsequent neurological compromise from instability and/or spinal cord encroachment. We performed a double-cohort study evaluating congenital osseous anomalies of the upper cervical spine in children who presented with one or more clinical problems, and we attempted to outline the risk of possible neurological compromise. METHODS: We reviewed the medical records and imaging studies of all children seen and treated for osseous anomalies of the upper cervical spine at our institution between 1988 and 2003. Patients were divided into two cohorts on the basis of the presence or absence of associated syndromes. Parameters reviewed included demographic data, clinical presentation, and imaging features. All anomalies involving the central nervous system, the occipitocervical junction, and the upper cervical osseous canal were included. Complicating sequelae such as canal stenosis, segmental instability, and other anomalies of the central nervous system and spine were identified. RESULTS: Sixty-eight consecutive children were identified. Twenty-one patients had an underlying described syndrome. There were 234 osseous anomalies (average, 3.4 per patient). Three or more anomalies were noted in 79% of the patients. There was no significant difference in the mean number of anomalies (p = 0.80) or in the frequency of any specific anomaly (p > 0.20 for all) between syndromic and nonsyndromic patients. The variety of clinical presentations included neck pain (twenty-six patients), neurological changes (twenty-one patients), and torticollis and/or stiffness (twenty-one patients). Twenty-three patients had more than one complaint. Six patients had isolated spinal instability, twenty-eight had isolated spinal cord encroachment, and six had a combination of both. Forty-four (65%) of the sixty-eight patients underwent surgical decompression and/or arthrodesis principally focused from the foramen magnum to the second cervical vertebra. CONCLUSIONS: As a result of these findings, we recommend a thorough evaluation and advanced imaging of the upper cervical spine in all children who present with symptoms related to the upper cervical spine, to identify associated anomalies and further define the nature of canal encroachment including any potential for neurologic compromise.

Advanced imaging of the cervical spine and spinal cord in 22q11.2 deletion syndrome: age-matched, double-cohort, controlled study.

PURPOSE: The 22q11.2 deletion syndrome is a common genetic syndrome with a wide spectrum of abnormalities. We have previously described multiple anomalies of the upper cervical spine in this disorder. The objective of this study was to use advanced imaging to further define the morphology of the cervical spine and spinal cord in the 22q11.2 deletion syndrome, with a comparison to age-matched controls. METHODS: A total of 32 patients with a 22q11.2 deletion underwent advanced imaging (computed tomography/magnetic resonance imaging; CT/MRI) of the cervical spine. In 27 patients, space available for the cord (SAC); the sagittal diameter of the vertebral body, spinal canal, cerebrospinal fluid (CSF), and spinal cord; and the cross sectional area of the spinal canal, CSF, and spinal cord were measured at each cervical level and compared to 29 age-matched controls. Statistical analysis was performed and potential implications were hypothesized. RESULTS: In 22q11.2 patients, advanced imaging identified 40 pathologies not evident on plain radiographs with potential mechanical and/or neurological implications. These patients also had significantly smaller values (P

Spinal cord dimensions in children with Klippel-Feil syndrome: a controlled, blinded radiographic analysis with implications for neurologic outcomes.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To evaluate the axial cross-sectional dimensions of the spinal cord and cerebrospinal fluid (CSF) column in children with Klippel-Feil Syndrome (KFS) versus an age-matched cohort of control subjects. SUMMARY OF BACKGROUND DATA: Neurologic sequelae and chronic pain are known to occur in KFS and factors implicated include spinal cord compression from canal stenosis, segmental instability, vascular disruption, and central nervous system abnormalities including tethered cord, syrinx, and diastomyelia. No study to date, however, has examined the role of spinal cord size as a contributing factor to neurologic sequelae in KFS. METHODS: We retrospectively reviewed the plain radiographic, magnetic resonance imaging (MRI), and clinical records of 12 consecutive patients between 2 and 18 years with KFS (average age 9.5 +/- 5.3 years) and 14 age-matched controls (average age 8.3 +/- 5.1 year). For each patient, plain film radiography was reviewed to compare Torg ratios at each cervical level, and axial T1-weighted MRI was used to compare spinal cord and CSF column cross-sectional area calculations. RESULTS: The Torg-Pavlov ratios were identical between the 2 groups (0.77 +/- 0.15 vs. 0.77 +/- 0.19). Analysis of axial T1-weighted MRI cross-sectional spinal cord area revealed that the cord was smaller in KFS patients at each level from C2-C7 compared with controls. These differences were statistically significant at C4 (P = 0.016), C5 (P = 0.035), and C6 (P = 0.032). Subset analysis of abnormal (fused) levels compared with controls revealed the same findings, although these differences were not significant due to the limited numbers available at each level. Analysis of the CSF column, however, revealed that overall the canal was slightly larger in KFS patients compared with controls, although this difference was not statistically significant. Four of the 12 KFS patients presented with neurologic symptoms, all of which improved after posterior cervical stabilization. CONCLUSION: In our cohort of patients we have noted statistically significant differences in axial cord dimensions, with no differences in CSF column, suggesting that the cord size is smaller in KFS children compared with age-matched controls.

Analysis of halo-orthoses application in children less than three years old.

PURPOSE: To evaluate the safety and efficacy of halo immobilization in children younger than 3 years. METHODS: All children less than 3 years of age who were placed in a halo-orthosis at a tertiary pediatric center were reviewed to determine the indications, safety, and efficacy of this method. Adequacy of immobilization and correct technique was established considering the chronology of maturation (skull and brain development). The functional outcome was analyzed. RESULTS: Ten patients (<3 years old) were identified from a total of 150 where halo ring/vest immobilization was used. There were six boys and four girls, with an average age of 2 years (range 10 months to 2 years and 10 months). The average time of immobilization in the halo-orthosis was 75 days (range 33-168 days), and the average follow-up time was 5 years and 2 months (range 1-12 years). There were two halo-related problems and four related to the index procedure. Halo-related problems included pin-site infection in one patient, and three pins loosening in another. There were four complications associated with the index procedure, all early in the series, including three cases of pseudarthrosis and one patient that had an insufficient decompression of basilar invagination. Two of the three failed fusions occurred at the occipito-cervical junction, which prompted us to develop new techniques for fusion at this level. CONCLUSIONS: Halo-orthosis is a relatively safe and reliable device for immobilization of the upper cervical spine in children less than 3 years old. Understanding the developmental anatomy and a limited CT scan are helpful in pin placement. We recommend the use of a multiple pin construct, perpendicular insertion, and precise tightening with good pin-site care and frequent follow-up. The benefits seem to outweigh the risks in this population, considering the mechanical advantages of the halo-orthosis.

Neurophysiological detection of impending spinal cord injury during scoliosis surgery.

BACKGROUND: Despite the many reports attesting to the efficacy of intraoperative somatosensory evoked potential monitoring in reducing the prevalence of iatrogenic spinal cord injury during corrective scoliosis surgery, these afferent neurophysiological signals can provide only indirect evidence of injury to the motor tracts since they monitor posterior column function. Early reports on the use of transcranial electric motor evoked potentials to monitor the corticospinal motor tracts directly suggested that the method holds great promise for improving detection of emerging spinal cord injury. We sought to compare the efficacy of these two methods of monitoring to detect impending iatrogenic neural injury during scoliosis surgery. METHODS: We reviewed the intraoperative neurophysiological monitoring records of 1121 consecutive patients (834 female and 287 male) with adolescent idiopathic scoliosis (mean age, 13.9 years) treated between 2000 and 2004 at four pediatric spine centers. The same group of experienced surgical neurophysiologists monitored spinal cord function in all patients with use of a standardized multimodality technique with the patient under total intravenous anesthesia. A relevant neurophysiological change (an alert) was defined as a reduction in amplitude (unilateral or bilateral) of at least 50% for somatosensory evoked potentials and at least 65% for transcranial electric motor evoked potentials compared with baseline. RESULTS: Thirty-eight (3.4%) of the 1121 patients had recordings that met the criteria for a relevant signal change (i.e., an alert). Of those thirty-eight patients, seventeen showed suppression of the amplitude of transcranial electric motor evoked potentials in excess of 65% without any evidence of changes in somatosensory evoked potentials. In nine of the thirty-eight patients, the signal change was related to hypotension and was corrected with augmentation of the blood pressure. The remaining twenty-nine patients had an alert that was related directly to a surgical maneuver. Three alerts occurred following segmental vessel clamping, and the remaining twenty-six were related to posterior instrumentation and correction. Nine (35%) of these twenty-six patients with an instrumentation-related alert, or 0.8% of the cohort, awoke with a transient motor and/or sensory deficit. Seven of these nine patients presented solely with a motor deficit, which was detected by intraoperative monitoring of transcranial electric motor evoked potentials in all cases, and two patients had only sensory symptoms. Somatosensory evoked potential monitoring failed to identify a motor deficit in four of the seven patients with a confirmed motor deficit. Furthermore, when changes in somatosensory evoked potentials occurred, they lagged behind the changes in transcranial electric motor evoked potentials by an average of approximately five minutes. With an appropriate response to the alert, the motor or sensory deficit resolved in all nine patients within one to ninety days. CONCLUSIONS: This study underscores the advantage of monitoring the spinal cord motor tracts directly by recording transcranial electric motor evoked potentials in addition to somatosensory evoked potentials. Transcranial electric motor evoked potentials are exquisitely sensitive to altered spinal cord blood flow due to either hypotension or a vascular insult. Moreover, changes in transcranial electric motor evoked potentials are detected earlier than are changes in somatosensory evoked potentials, thereby facilitating more rapid identification of impending spinal cord injury.

Comparison of Cobb angle measurement of scoliosis radiographs with preselected end vertebrae: traditional versus digital acquisition.

STUDY DESIGN: Prospective study. OBJECTIVE: To compare variability in Cobb angle between digitally and traditionally acquired scoliosis radiographs. SUMMARY OF BACKGROUND DATA: Previous studies have shown that the 95% confidence interval for Cobb angle can vary from 2.6 degrees to 8.8 degrees. No study directly comparing Cobb angles measured from traditional and digitally acquired radiographs has been reported. METHODS: A spine model simulating 25 single right thoracic curves (range, 20 degrees-60 degrees) was imaged using traditional and digital techniques. Traditional films and miniaturized printed digital films were each measured twice manually. Digital films were also measured twice using computer imaging software. RESULTS: Overall mean angle and (95% confidence interval) were 41.7 degrees (39.1 degrees-44.3 degrees) for traditional, 40.6 degrees (37.4 degrees-43.8 degrees) for digital, and 39.7 degrees (36.3 degrees-43.1 degrees) for computer measurements. Overall correlation was 0.994 for traditional and digital, 0.987 for traditional and computer, and 0.993 for digital and computer. Fixed effect model analysis demonstrated that, although a statistically significant difference existed between the 3 methods of measuring the Cobb angle (P < 0.0001), the difference between methods was less than 2 degrees. CONCLUSIONS: Any of the 3 evaluated methods of measurement can be used to measure Cobb angles. Additionally, the methods can be used interchangeably.

The Spinal Appearance Questionnaire: results of reliability, validity, and responsiveness testing in patients with idiopathic scoliosis.

STUDY DESIGN: Prospective, sequential enrollment. OBJECTIVE: We report the development and testing of the Spinal Appearance Questionnaire (SAQ) for reliability, validity, and responsiveness in patients with idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: The SAQ was designed to measure patients' and their parents' perception of their spinal deformity's appearance using standardized drawings and questions. This study was designed to test the instrument's psychometric properties. METHODS: The SAQ was administered as a test-retest to idiopathic scoliosis patients and parents for reliability and initial validity assessment (Group I). It was then administered to patients before surgery and 1 year after surgery (Group II) for responsiveness and further validity testing. Finally, both the SAQ and SRS instruments were administered to adolescent idiopathic patients before surgery and 1 year after surgery (Group III) for comparison of the 2 instruments. RESULTS: Group I: The individual scale items had good to excellent reliability (Spearman's rho, 0.57-0.99) and high internal scale consistency (Cronbach's alpha >0.7). The mean scale scores differentiated between curves greater than 30 degrees and lesser curves (P < 0.01). Surgery improved scores compared with those with "surgery recommended." Group II: The domains correlated with clinical and radiographic aspects of the deformity before surgery. All of the domains showed significant difference after surgery (P < 0.0001) and large effect size for all domains except for the patient chest domain. Group III: Both the SAQ and the SRS instruments had significant improvement in all of their domains except for the SRS Activity scale. The relative efficiency of the SAQ domains to the SRS appearance domain (the most responsive SRS domain) was greater for 5 SAQ domains. CONCLUSION: The SAQ is reliable, responsive to curve improvement, and shows strong evidence of validity. It provides more detail than the SRS in the appearance domain, and provides explanation of spinal deformity's concerns and improvements.

Change in lordosis at the occipitocervical junction following posterior occipitocervical fusion in skeletally immature children.

STUDY DESIGN: Retrospective case series. OBJECTIVE: Evaluate the change in lordosis at the occipitocervical junction occurring during growth in skeletally immature children treated with posterior occipitocervical arthrodesis versus patients skeletally mature at arthrodesis. SUMMARY OF BACKGROUND DATA: Posterior occipitocervical arthrodesis is often indicated for children who have instability of the upper cervical spine develop. Theoretically, in skeletally immature children, this approach retards the growth of the posterior spinal elements but allows the anterior spinal column to continue to grow with the risk of excessive lordosis of the cervical spine developing. METHODS: There were 21 children, younger than 11 years (range 1.9-10.9) at surgery and expected to have normal spinal growth, followed radiographically for an average of 6.3 years (range 2.0-12.4). Postoperative lateral neutral radiographs were compared to those at most recent follow-up to measure the change in occipitocervical angle. These results were then compared to a series of control patients who were skeletally mature at surgery. RESULTS: Average overall change in lordosis at the occipitocervical junction was -4.6 degrees (range -12.8 degrees to +6.5 degrees). Average annualized change was -0.28 degrees per vertebral level per year (range -1.13 degrees to +0.67 degrees). This annualized change in angle was statistically significant compared to the average change of +0.01 degrees (range -0.09 degrees to +0.11 degrees) measured in the control series of patients skeletally mature at surgery (P = 0.01). CONCLUSIONS: Increasing lordosis occurs at the occipitocervical junction following fusion in skeletally immature children. If occipitocervical arthrodesis is indicated in a skeletally immature child, fusion in excessive extension and overtightening of posterior wires should be avoided.

Os odontoideum revisited: the case for a multifactorial etiology.

STUDY DESIGN: Retrospective analysis of our experience with os odontoideum at the Children's Hospital of Philadelphia. OBJECTIVE: To review the origin of os odontoideum and provide evidence for two separate etiologies. SUMMARY OF BACKGROUND DATA: The etiology of os odontoideum has been debated in the literature. Most authors support a post-traumatic etiology; however, some evidence exists to support a congenital origin. METHODS: We reviewed all 519 abnormal cervical spine radiographs performed from 1991 to 2004 to identify os odontoideum. Medical records and imaging studies were examined to determine: history of trauma, severity of injury, interval from injury to presentation, coexisting syndromes, and associated congenital cervical spine anomalies. RESULTS: Sixteen of 519 patients (3.1%) had os odontoideum. Only 8 of 16 patients reported previous trauma. Only 3 of these 8 injuries occurred with an interval remote enough to allow remodeling of the dens to an ossicle by the time of presentation. Six of 16 patients had associated congenital anomalies in the cervical spine. Three of 16 had a coexisting genetic syndrome. CONCLUSION: Our data supports two separate etiologies for the os odontoideum: post-traumatic and congenital. The data should raise awareness that some children with preexisting syndromes may develop os odontoideum without previous trauma.