John P. Dormans

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.

Factors distinguishing septic arthritis from transient synovitis of the hip in children: A prospective study

BACKGROUND Distinguishing septic arthritis from transient synovitis of the hip in children can be challenging. Authors of recent retrospective studies have used presenting factors to establish algorithms for predicting septic arthritis of the hip in children. This study differs from previous work in three ways: data were collected prospectively, C-reactive protein levels were recorded, and the focus was on children in whom the findings were so suspicious for septic arthritis that hip aspiration was performed. METHODS Over four years, we prospectively collected data on every child (a total of fifty-three) who underwent hip aspiration because of a suspicion of septic arthritis at our institution. Diagnoses of confirmed septic arthritis, presumed septic arthritis, and transient synovitis were determined on the basis of the results of Gram staining, culture, and a cell count of the hip aspirate. Presenting factors and laboratory values were recorded. To evaluate the strength of predictors, we performed univariate and multivariate analysis on data from forty-eight patients who met the inclusion criteria. RESULTS Univariate analysis showed that fever, the C-reactive protein level, and the erythrocyte sedimentation rate were strongly associated with the final diagnosis (p < 0.05). On multivariate analysis, the C-reactive protein level and erythrocyte sedimentation rate were found to be significant predictors. However, the erythrocyte sedimentation rate was not independent of the C-reactive protein level on backward elimination, and the C-reactive protein level was the only risk factor that was strongly associated with the outcome at a 5% significance level. Patients with five predictive factors had a 98% chance of having septic arthritis, those with four factors had a 93% chance, and those with three factors had an 83% chance. CONCLUSIONS This prospective study of children who presented with findings that were highly suspicious for septic arthritis of the hip builds on the work of previous authors. We found fever (an oral temperature >38.5 degrees C) was the best predictor of septic arthritis followed by an elevated C-reactive protein level, an elevated erythrocyte sedimentation rate, refusal to bear weight, and an elevated serum white blood-cell count. In our study group, a C-reactive protein level of >2.0 mg/dL (>20 mg/L) was a strong independent risk factor and a valuable tool for assessing and diagnosing children suspected of having septic arthritis of the hip.

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.

Complications in children managed with immobilization in a halo vest.

Thirty-seven patients who were three to sixteen years old were managed with immobilization in a halo vest between 1987 and 1993. Twenty-four patients (65 per cent) had the halo vest applied in conjunction with operative arthrodesis of the cervical spine; the remaining thirteen patients (35 per cent) had the halo vest applied to immobilize the cervical spine after trauma. Complications occurred in twenty-five patients (68 per cent). Pin-site infections were the most common complications, developing in twenty-two patients. Grade-II infections (purulent drainage) developed more frequently in children who were eleven years old or more: they were identified in five of fourteen such patients, compared with two of twenty-three patients who were ten years old or less. There was a tendency toward more grade-I infections (non-purulent drainage, with or without erythema) and loosening of the pins in the children who were ten years old or less: eleven of twenty-three such patients had each of those complications, compared with four of fourteen children who were eleven years old or more. Both loosening and infection occurred more frequently at the anterior pin sites. Other complications included one dural penetration, one transient injury of the supraorbital nerve, and three pin-site scars that were considered by the family to be objectionable. There were no complications related to the vest part of the halo vest. Younger patients who had a halo construct with more than four pins (multiple-pin constructs) had a similar rate of complications compared with patients who were managed with a standard four-pin halo construct.(ABSTRACT TRUNCATED AT 250 WORDS)

Genome-wide association studies of adolescent idiopathic scoliosis suggest candidate susceptibility genes

Adolescent idiopathic scoliosis (AIS) is an unexplained and common spinal deformity seen in otherwise healthy children. Its pathophysiology is poorly understood despite intensive investigation. Although genetic underpinnings are clear, replicated susceptibility loci that could provide insight into etiology have not been forthcoming. To address these issues, we performed genome-wide association studies (GWAS) of ∼327 000 single nucleotide polymorphisms (SNPs) in 419 AIS families. We found strongest evidence of association with chromosome 3p26.3 SNPs in the proximity of the CHL1 gene (P < 8 × 10(-8) for rs1400180). We genotyped additional chromosome 3p26.3 SNPs and tested replication in two follow-up case-control cohorts, obtaining strongest results when all three cohorts were combined (rs10510181 odds ratio = 1.49, 95% confidence interval = 1.29-1.73, P = 2.58 × 10(-8)), but these were not confirmed in a separate GWAS. CHL1 is of interest, as it encodes an axon guidance protein related to Robo3. Mutations in the Robo3 protein cause horizontal gaze palsy with progressive scoliosis (HGPPS), a rare disease marked by severe scoliosis. Other top associations in our GWAS were with SNPs in the DSCAM gene encoding an axon guidance protein in the same structural class with Chl1 and Robo3. We additionally found AIS associations with loci in CNTNAP2, supporting a previous study linking this gene with AIS. Cntnap2 is also of functional interest, as it interacts directly with L1 and Robo class proteins and participates in axon pathfinding. Our results suggest the relevance of axon guidance pathways in AIS susceptibility, although these findings require further study, particularly given the apparent genetic heterogeneity in this disease.

Ultrasonographic evaluation of the elbow in infants and young children after suspected trauma.

Fractures and epiphyseal injuries in the region of the elbow are uncommon in infants and young children, but they can be very difficult to diagnose and delineate accurately. In addition to plain radiography, invasive or costly procedures such as arthrography and magnetic resonance imaging traditionally have been used to evaluate these injuries. We used high-resolution real-time ultrasonography to evaluate a suspected injury of the elbow in seven infants and one ten-year-old child. Three of the infants had a physeal separation, two had a supracondylar fracture, and two had no skeletal injury. The child had an avulsion fracture of the lateral epicondyle of the humerus and an effusion in the joint. The ultrasonographic findings were confirmed by arthrography in three patients, by open reduction in one, and by follow-up radiographs in all. None of the ultrasonographic studies were performed with the patient under general anesthesia. Ultrasonography, a readily available, non-invasive technique, can be used to evaluate the unossified epiphysis about the elbow of infants and young children; to demonstrate dislocations, fractures, and physeal separations; to identify a hinge of soft tissue at the site of a fracture; to identify interposition of soft tissue between fracture fragments; and to aid in the planning of closed and open reductions.

Analysis of the cause, classification, and associated injuries of 166 consecutive pediatric pelvic fractures

Pediatric pelvic fractures are serious injuries. Anatomical differences exist between pediatric and adult populations, leading to different causes and rates of death, fracture patterns, and associated injuries. This study is the largest consecutive series of pediatric pelvic fractures from one institution emphasizing the unique aspects seen in pediatrics. One hundred sixty-six children were included. Plain radiography and computed tomography scans were used to classify pelvic fractures. Multisystem injuries occurred in 60%, and 50% sustained additional skeletal injuries. The death rate was 3.6%. Head and/or visceral injuries were the causes of all deaths. Life-threatening hemorrhage did not occur. Urethral injury was not seen as often as in adults. Anterior ring fractures were the most common type, dominated by pedestrian versus motor vehicle trauma. Anatomical differences and mechanism of injury may play a role in these contrasting findings.

Langerhans cell histiocytosis of the spine in children: Long-term follow-up

BACKGROUND Langerhans cell histiocytosis causes destructive lesions in a childs spine. Few large, long-term studies have evaluated the clinical and radiographic presentation, natural history, outcomes of modern treatment approaches, and maintenance of normal spinal growth and stability after the diagnosis of this disease in children. METHODS Twenty-six children with biopsy-proven Langerhans cell histiocytosis involving the spine were treated at our institution between 1970 and 2003. They had a total of forty-four involved vertebrae (twenty cervical, fourteen thoracic, and ten lumbar). Vertebral body collapse was measured on radiographs and classified as grade I (0% to 50% collapse) or grade II (51% to 100% collapse) and subclassified as A (symmetric collapse) or B (asymmetric collapse). Lesions of the posterior elements of the spine were classified as grade III. Twenty-three children were followed for two years or more (mean, 9.4 years), and the analyses of treatment and long-term outcomes were performed in that group of patients. RESULTS There was a predominance of lesions in the cervical spine (p </= 0.02). Sixteen (62%) of the twenty-six children were found to have multifocal skeletal disease. Cervical and lumbar lesions were more commonly associated with multilevel spinal disease. The extent of the initial collapse seen radiographically was grade IA for twenty vertebrae, IB for three, IIA for ten, IIB for nine, and III for two. Grade-I lesions were more likely to be associated with symmetric collapse than were grade-II lesions. Spinal deformity developed in four children, and two later required spinal fusion. No relationship was observed between the grade of the initial collapse and the subsequent development of spinal deformity. Despite heterogeneous treatment, all patients were alive and well with resolution of all presenting signs and symptoms and no evidence of active disease at the time of the most recent follow-up. CONCLUSIONS We found a particularly high prevalence of lesions in the cervical spine and a high prevalence of multiple skeletal lesions. In contrast to the classic finding of vertebra plana, we found that more severe lesions often led to asymmetric collapse; yet, asymmetric collapse was not found to be associated with the development of subsequent spinal deformity. The natural history of these lesions in the spine in the absence of systemic disease or spinal deformity is such that aggressive surgical management is usually not indicated; only follow-up is necessary to monitor recovery and spinal balance.

The burden of musculoskeletal injury in low and middle-income countries: challenges and opportunities

The global burden of injury is substantial, and injuries are predicted to be a leading cause of death and disability over the next few decades1-6. The majority of this burden will be borne by low and middle-income countries, where preventive strategies are often nonexistent and barriers to the timely and appropriate care of the injured include absent or inefficient systems for the delivery of trauma care, inadequacies in the number and the distribution of health-care facilities and workers, a lack of infrastructure and/or physical resources, and a lack of education and training. Addressing the burden of injury in low and middle-income countries has become a public health priority. So-called essential services, which are low-cost, high-yield, and target major health problems, should be made available to every person in the world7-10. While surgery has been traditionally viewed as a high-cost treatment lying outside the realm of the traditional public health model, evidence is emerging that the burden of surgical diseases such as trauma is substantial, and that essential surgery may be a cost-effective addition to the health system in low and middle-income countries11,12. The goals for this review were (1) to provide a public health perspective on the burden of injury in low and middle-income countries, (2) to discuss the delivery of musculoskeletal trauma care in resource-challenged environments, (3) to highlight deficiencies in physical resources and human resources for health care, (4) to outline approaches to teaching and training, and (5) to describe the information flow between economically developed and underdeveloped regions. ### Background The World Bank classifies countries in July of each year on the basis of per capita gross national income. As of 2005, countries have been classified (in U.S. dollars) as low income (<

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

875 per year), lower-middle income …