Robert H. Rosenwasser
Roukoz B. Chamoun, Michel E. Mawad, William E. Whitehead, Thomas G. Luerssen and Andrew Jea
Currently, no diagnostic or treatment standards exist for extracranial carotid artery dissection (CAD) in children after trauma. The purpose of this study was to review and describe the characteristics, diagnosis, and treatment of this rather uncommon sequelae of pediatric trauma.
A systematic review of the literature was performed to examine the pertinent studies of traumatic extracranial carotid artery (CA) injuries in children.
No randomized trials were identified; however, 19 case reports or small case series consisting of 34 pediatric patients were found in the literature. The diagnosis of CAD was made in 33 of 34 patients only after the onset of ischemic symptomatology. Twenty-four of 34 patients underwent cerebral angiography to confirm diagnosis; MR angiography affirmed the diagnosis in 6 of 34 patients. There was little published experience with CA ultrasonography or CT angiography for diagnosis. Thirty of 34 patients were treated with medical therapy or observation; 2 of 4 patients treated with observation alone died. There was little experience with open surgical treatment of CAD in the pediatric population, and there were no studies on the endovascular treatment of traumatic CAD in children. The literature does not support anticoagulation therapy over antiplatelet therapy.
As a result of this review of the literature, the authors propose the algorithms for the evaluation and treatment of traumatic extracranial CADs in children. These recommendations include utilizing MR angiography as a screening tool in cases in which the clinical suspicion of CAD is high, using conventional cerebral angiography to confirm the diagnosis, implementing antiplatelet therapy as initial medical management, and reserving endovascular stenting in cases of failed medical treatment.
Keyne K. Johnson, Mark J. Dannenbaum, Meenakshi B. Bhattacharjee, Anna Illner, Robert C. Dauser, William E. Whitehead, Andrew Jea and Thomas G. Luerssen
Primary skull lesions, albeit rare in the pediatric population, have been well described and classified. These lesions are usually benign and commonly present as a painless mass. The most common lesions are epidermoid, dermoid, and Langerhans cell histiocytosis. Cranial fasciitis, encountered less frequently, is usually not considered in this differential diagnosis. Given such few cases reported, it is commonly misdiagnosed preoperatively.
The authors retrospectively reviewed data obtained in 4 patients with cranial fasciitis in whom the diagnosis was based on histopathological findings. In 2 patients the onset of the lesion was spontaneous. One patient had a lesion 4 months following a vacuum extraction and subsequent cephalohematoma formation. One patient developed a lesion following a previous craniectomy. Presentation, imaging studies, and histopathological findings were all reviewed and analyzed. All patients presented with a firm nontender mass. Radiological features included a lytic bone lesion with a mildly sclerotic margin, T1 isodensity, T2 heterogeneous hyperdensity, and heterogeneous enhancement. The enhancing portion was not bright on T2-weighted MR images, likely representing the fibrous component; the nonenhancing portion was bright on T2-weighted images, likely representing the myxoid matrix. Histopathological examination revealed proliferating fibroblasts in a myxoid matrix.
Cranial fasciitis is a benign, painless but rapidly growing lesion of the skull mainly limited to the pediatric population. It is histologically similar to nodular fasciitis, a fibroblastic proliferation of varying size. These lesions are often related to trauma but can also be insidious or can develop at a prior craniectomy site. The appropriate clinical picture and distinguishing radiographic features may help to differentiate cranial fasciitis from other lesions of the skull allowing for earlier intervention.
Ashwin Viswanathan, Katherine Relyea, William E. Whitehead, Daniel J. Curry, Thomas G. Luerssen and Andrew Jea
The authors describe a rare case of pneumothorax as a complication of thoracic pedicle screw placement in an 11-year-old girl undergoing posterior segmental instrumentation for a kyphotic deformity. Spontaneous pneumothorax after posterior fusion for adolescent idiopathic scoliosis has been reported in the orthopedic literature; however, to the best of the authors' knowledge, pneumothorax directly related to pedicle screw placement for spinal deformity has not been previously described. The authors discuss the anatomical and technical aspects leading to this complication and the lessons learned from it.
Benjamin D. Fox, Vikram V. Nayar, Keyne K. Johnson, Andrew Jea, Daniel Curry, Thomas G. Luerssen and William E. Whitehead
Andrew Jea, Keyne K. Johnson, William E. Whitehead and Thomas G. Luerssen
The use of spinal instrumentation to stabilize the occipitocervical junction in pediatric patients has increased and evolved in recent years. Wiring techniques have now given way to screw-rod or screw-plate techniques with or without postoperative external immobilization. Although C-2 translaminar screws have been used in these constructs, subaxial translaminar screws have not, to date, been described in either the pediatric or adult patient populations.
The authors describe the feasibility of translaminar screw placement in the C-3 lamina. Rigid fixation with translaminar screws offers an alternative to subaxial fixation with lateral mass screws, allowing for formation of biomechanically sound spinal constructs and minimizing potential neurovascular morbidity. Their use requires careful analysis of preoperative imaging studies, intact posterior elements, and avoidance of violation of the inner laminar wall.
Roukoz B. Chamoun, William E. Whitehead, Daniel J. Curry, Thomas G. Luerssen and Andrew Jea
The use of C-1 lateral mass screws provides an alternative to C1–2 transarticular screws in the pediatric population. However, the confined space of the local anatomy and unfamiliarity with the technique may make the placement of a C-1 lateral mass screw more challenging, especially in the juvenile or growing spine.
A CT morphometric analysis was performed in 76 pediatric atlases imaged at Texas Children's Hospital from October 1, 2007 until April 30, 2008. Critical measurements were determined for potential screw entry points, trajectories, and lengths, with the goal of replicating the operative technique described by Harms and Melcher for adult patients.
The mean height and width for screw entry on the posterior surface of the lateral mass were 2.6 and 8.5 mm, respectively. The mean medially angled screw trajectory from an idealized entry point on the lateral mass was 16° (range 4 to 27°). The mean maximal screw depth from this same ideal entry point was 20.3 mm. The overhang of the posterior arch averaged 6.3 mm (range 2.1–12.4 mm). The measurement between the left- and right-side lateral masses was significantly different for the maximum medially angled screw trajectory (p = 0.003) and the maximum inferiorly directed angle (p = 0.045). Those measurements in children < 8 years of age were statistically significant for the entry point height (p = 0.038) and maximum laterally angled screw trajectory (p = 0.025) compared with older children. The differences between boys and girls were statistically significant for the minimum screw length (p = 0.04) and the anterior lateral mass height (p < 0.001).
A significant variation in the morphological features of C-1 exists, especially between the left and right sides and in younger children. The differences between boys and girls are clinically insignificant. The critical measurement of whether the C-1 lateral mass in a child could accommodate a 3.5-mm-diameter screw is the width of the lateral mass and its proximity to the vertebral artery. Only 1 of 152 lateral masses studied would not have been able to accommodate a lateral mass screw. This study reemphasizes the importance of a preoperative CT scan of the upper cervical spine to assure safe and effective placement of the instrumentation at this level.
Joshua J. Chern, Roukoz B. Chamoun, William E. Whitehead, Daniel J. Curry, Thomas G. Luerssen and Andrew Jea
The management of upper cervical spinal instability in children continues to represent a technical challenge. Traditionally, a number of wiring techniques followed by halo orthosis have been applied; however, they have been associated with a high rate of nonunion and poor tolerance for the halo. Alternatively, C1–2 transarticular screws and C-2 pars/pedicle screws allow more rigid fixation, but their placement is technically demanding and associated with vertebral artery injuries. Recently, C-2 translaminar screws have been added to the armamentarium of the pediatric spine surgeon as a technically simple and biomechanically efficient means of fixation. However, the use of subaxial translaminar screws have not been described in the general pediatric population. There are no published data that describe the anatomical considerations and potential limitations of this technique in the pediatric population.
The cervical vertebrae of 69 pediatric patients were studied on CT scans. Laminar height and thickness were measured. Statistical analysis was performed using unpaired Student t-tests (p < 0.05) and linear regression analysis.
The mean laminar heights at C-2, C-3, C-4, C-5, C-6, and C-7, respectively, were 9.76 ± 2.22 mm, 8.22 ± 2.24 mm, 8.09 ± 2.38 mm, 8.51 ± 2.34 mm, 9.30 ± 2.54 mm, and 11.65 ± 2.65 mm. Mean laminar thickness at C-2, C-3, C-4, C-5, C-6, and C-7, respectively, were 5.07 ± 1.07 mm, 2.67 ± 0.79 mm, 2.18 ± 0.73 mm, 2.04 ± 0.60 mm, 2.52 ± 0.66 mm, and 3.84 ± 0.96 mm. In 50.7% of C-2 laminae, the anatomy could accept at least 1 translaminar screw (laminar thickness ≥ 4 mm).
Overall, the anatomy in 30.4% of patients younger than 16 years old could accept bilateral C-2 translaminar screws. However, the anatomy of the subaxial cervical spine only rarely could accept translaminar screws. This study establishes anatomical guidelines to allow for accurate and safe screw selection and insertion. Preoperative planning with thin-cut CT and sagittal reconstruction is essential for safe screw placement using this technique.
Daniel K. Fahim, Keyne K. Johnson, William E. Whitehead, Daniel J. Curry, Thomas G. Luerssen and Andrew Jea
Periosteal chondromas located in the spine are rare. The authors document an even more infrequent occurrence of a recurrent periosteal chondroma in the cervical spine of a 6-year-old boy. During the operation, a giant (> 7 cm in diameter) periosteal chondroma with involvement of the C-5 and C-6 vertebral bodies was resected. The vertebral column was reconstructed with anterior-posterior instrumentation. The pathological examination revealed that the tumor consisted of chondroid tissue with typical chondrocytes, confirming the diagnosis of periosteal chondroma.
Daniel K. Fahim, Katherine Relyea, Vikram V. Nayar, Benjamin D. Fox, William E. Whitehead, Daniel J. Curry, Thomas G. Luerssen and Andrew Jea
The authors describe the novel use of a table-mounted tubular retractor system (MetRx) originally designed for minimally invasive spine surgery, in the resection of an intraventricular arteriovenous malformation (AVM) in a 12-year-old child. The tubular retractor system may have several advantages over traditional Greenberg or Leyla retractors in selected intracranial procedures. In our case, the low-profile 4 × 22–mm tube and fixed table attachment offered excellent exposure of the trigone of the lateral ventricle where the choroidal AVM was located and from which it was completely resected. Immediate postoperative cerebral angiography confirmed that the entire AVM had been resected. The patient suffered no new neurological deficits as a result of the retractor system or the exposure that it afforded. Although the good clinical results of a single case cannot be directly compared with those obtained using other open techniques of intracranial surgery in larger series, microendoscopic surgery of the brain is an alternative to the other techniques and may be recommended as a time-saving, trauma-reducing procedure with the potential to improve postoperative outcomes.