Kingsley Abode-Iyamah

Complications associated with recombinant human bone morphogenetic protein use in pediatric craniocervical arthrodesis: Clinical article

OBJECT Management of pediatric occipitocervical instability remains especially challenging. The off-label use of recombinant human bone morphogenetic protein (rhBMP)-2 for spinal fusion has increased with a well-documented increase in fusion rate in many case series. Unfortunately, recent reports have documented complications associated with rhBMP use in adult spinal fusions. Complications associated with the use of rhBMP in pediatric spinal surgery is less well understood. In this study the authors report on the fusion rate and complications associated with rhBMP in pediatric occipitocervical arthrodesis. METHODS The authors reviewed the medical records of those patients 18 years old and younger who underwent dorsal occipitocervical fusion from January 2004 to December 2007 at the University of Iowa Hospitals and Clinics. Forty-eight patients were identified who received rhBMP-augmented fusion. The clinical outcome and complications of these fusions were analyzed. RESULTS All 48 patients had fusion confirmed on lateral radiographs within 4-14 months with an average fusion time of 6.7 months. There were 6 complications, 5 of which included seroma formation. Two of 5 patients who developed postoperative seroma presented with symptoms suggesting brainstem compression and obstructive hydrocephalus requiring emergency reoperation. One patient developed heterotopic bone formation causing cervicomedullary compression requiring reoperation. CONCLUSIONS The use of rhBMP to augment autograft in occipitocervical fusion allows for a high rate of successful arthrodesis, but is associated with potentially life-threatening complications in pediatric patients.

Cervical decompression and reconstruction without intraoperative neurophysiological monitoring.

OBJECT The primary goal of this study was to review the immediate postoperative neurological function in patients surgically treated for symptomatic cervical spine disease without intraoperative neurophysiological monitoring. The secondary goal was to assess the economic impact of intraoperative monitoring (IOM) in this patient population. METHODS This study is a retrospective review of 720 consecutively treated patients who underwent cervical spine procedures. The patients were identified and the data were collected by individuals who were not involved in their care. RESULTS A total of 1534 cervical spine levels were treated in 720 patients using anterior, posterior, and combined (360°) approaches. Myelopathy was present preoperatively in 308 patients. There were 185 patients with increased signal intensity within the spinal cord on preoperative T2-weighted MR images, of whom 43 patients had no clinical evidence of myelopathy. Three patients (0.4%) exhibited a new neurological deficit postoperatively. Of these patients, 1 had a preoperative diagnosis of radiculopathy, while the other 2 were treated for myelopathy. The new postoperative deficits completely resolved in all 3 patients and did not require additional treatment. The Current Procedural Terminology (CPT) codes for IOM during cervical decompression include 95925 and 95926 for somatosensory evoked potential monitoring of the upper and lower extremities, respectively, as well as 95928 and 95929 for motor evoked potential monitoring of the upper and lower extremities. In addition to the charge for the baseline [monitoring] study, patients are charged hourly for ongoing electrophysiology testing and monitoring using the CPT code 95920. Based on these codes and assuming an average of 4 hours of monitoring time per surgical case, the savings realized in this group of patients was estimated to be

The role of primary cilia in the pathophysiology of neural tube defects

1,024,754. CONCLUSIONS With the continuing increase in health care costs, it is our responsibility as providers to minimize expenses when possible. This should be accomplished without compromising the quality of care to patients. This study demonstrates that decompression and reconstruction for symptomatic cervical spine disease without IOM may reduce the cost of treatment without adversely impacting patient safety.

Spinal motion and intradiscal pressure measurements before and after lumbar spine instrumentation with titanium or PEEK rods.

Neural tube defects (NTDs) are a set of disorders that occur from perturbation of normal neural development. They occur in open or closed forms anywhere along the craniospinal axis and often result from a complex interaction between environmental and genetic factors. One burgeoning area of genetics research is the effect of cilia signaling on the developing neural tube and how the disruption of primary cilia leads to the development of NTDs. Recent progress has implicated the hedgehog (Hh), wingless-type integration site family (Wnt), and planar cell polarity (PCP) pathways in primary cilia as involved in normal neural tube patterning. A set of disorders involving cilia function, known as ciliopathies, offers insight into abnormal neural development. In this article, the authors discuss the common ciliopathies, such as Meckel-Gruber and Joubert syndromes, that are associated with NTDs, and review cilia-related signaling cascades responsible for mammalian neural tube development. Understanding the contribution of cilia in the formation of NTDs may provide greater insight into this common set of pediatric neurological disorders.

Management of spinal fractures in patients with ankylosing spondylitis

Spinal instrumentation and fusion have been incriminated as contributing to adjacent segment degeneration (ASD). It has been suggested that ASD results from increased range of motion and intradiscal pressure (IDP) adjacent to instrumentation. Posterior dynamic stabilization with polyetheretherketone (PEEK) rods has been proposed as potentially advantageous compared to rigid instrumentation with titanium (Ti) rods in reducing the incidence of ASD. We evaluated segmental motions in the cadaveric spine instrumented with PEEK or Ti rods from L3 to S1, as well as the adjacent segment motions and IDP at L1-2 and L2-3. Human cadaveric spines were potted at T12-L1 and S1-2. Spinal instrumentation from L3-S1 was accomplished using pedicle screws with either PEEK or Ti rods. Specimens were subjected to displacement controlled testing: 15° flexion, 15° extension, 10° lateral bending, and 5° right axial rotation using the MTS machine (MTS, Minneapolis, MN, USA). Intradiscal pressure was measured by placing pressure transducers into the intervertebral disc at L1-2 and L2-3. Spinal motion of L2 relative to L3, and L3 relative to S1 was tracked using a three dimensional motion analysis system. Instrumentation with PEEK and Ti rods was associated with a decrease in L3-S1 motion compared to the intact state that was significant in flexion (p=0.002), and extension (p=0.0075). Instrumentation with PEEK and Ti rods was associated with an increase in IDP at L1-2 that was significant in flexion (p=0.0028). Instrumentation with either PEEK or Ti rods resulted in decreased motion at the instrumented levels while increasing IDP at the adjacent level.

Nonoperative Management in Neurologically Intact Thoracolumbar Burst Fractures: Clinical and Radiographic Outcomes.

Ankylosing spondlylitis is a seronegative spondyloarthropathy that primarily affects the spinal column and sacroiliac joints. With disease progression autofusion of the spinal column takes place. This combined with the brittle bone quality make patients prone to fractures and spinal cord injury. The typical fracture pattern is extension type and involves all three columns. These fractures and injuries may involve the craniovertebral junction, the subaxial cervical spine, and the thoracolumbar spine. While at times these fractures are challenging to manage especially when they affect the elderly, there is evidence that supports long segment fixation and fusion. This article presents a narrative review on managing spinal fractures in patients with ankylosing spondylitis.

Intraventricular foramen of Monro cavernous malformation

Study Design. Retrospective cohort study. Objective. The identification of factors that lead to the failure of nonoperative management in neurologically intact thoracolumbar burst fractures. Summary of Background Data. The treatment of thoracolumbar burst fractures (TLBF) can be controversial, particularly in the neurologically intact. Surgery for intact burst fractures has been advocated for early mobilization and a shorter hospital stay. These goals, however, have not always been achieved, rejuvenating an interest in nonoperative treatment. Methods. Sixty-eight neurologically intact patients with burst fractures of the thoracolumbar junction (T11-L2), and a thoracolumbar injury classification and severity score (TLICS) of 2, were treated at our institution. Based on CT scans, patients were scored based on the load-sharing classification (LSC) scale. Initial treatment consisted of bracing in clamshell thoracolumbar orthosis and gradual mobilization. Results. Owing to pain limiting mobilization, 18 patients failed nonoperative management and required instrumentation. Those who failed nonsurgical management were significantly more kyphotic (8°±10) and stenotic (52% ± 14%) than those successfully treated nonoperatively (3°±7 and 63 ± 12%, respectively). The LSC score of those undergoing surgery (6.9 ± 1.1) was also greater than those successfully treated nonoperatively (5.8 ± 1.3, P = 0.006). Length of hospitalization was longer, and hospital charges higher in those requiring surgery compared to the nonoperative group. At follow-up there was no difference between groups in the visual analog score for pain (VAS) or the Oswestry disability index. Conclusion. Owing to pain limiting mobilization, a quarter of neurologically intact patients with thoracolumbar burst fractures and a TLICS score of 2 failed nonsurgical management. The greater the kyphosis, stenosis, and fragmentation of the fracture, the more likely patients required surgery. In addition to the TLICS classification, other radiographic and clinical parameters should be included in selecting appropriate treatment strategy. The cost savings with nonoperative treatment of intact burst fractures, when appropriate, are significant. Level of Evidence: 3

Effects of brain derived neurotrophic factor Val66Met polymorphism in patients with cervical spondylotic myelopathy.

We present a 64-year-old woman who was evaluated after being found unresponsive. Imaging revealed a foramen of Monro cavernoma resulting in hydrocephalus. Supratentorial cavernomas are most frequently found in the cerebral cortex, and although ventricular cavernomas do occur, they are rarely located in the foramen of Monro. Foramen of Monro cavernomas are extremely dangerous, requiring aggressive management when identified.

Risk factors and outcomes in thoracic stenosis with myelopathy: A single center experience

Cervical spondylotic myelopathy (CSM) is the leading cause of spinal cord related disability in the elderly. It results from degenerative narrowing of the spinal canal, which causes spinal cord compression. This leads to gait instability, loss of dexterity, weakness, numbness and urinary dysfunction. There has been indirect data that implicates a genetic component to CSM. Such a finding may contribute to the variety in presentation and outcome in this patient population. The Val66Met polymorphism, a mutation in the brain derived neurotrophic factor (BDNF) gene, has been implicated in a number of brain and psychological conditions, and here we investigate its role in CSM. Ten subjects diagnosed with CSM were enrolled in this prospective study. Baseline clinical evaluation using the modified Japanese Orthopaedic Association (mJOA) scale, Nurick and 36-Item Short Form Health Survey (SF-36) were collected. Each subject underwent objective testing with gait kinematics, as well as hand functioning using the Purdue Peg Board. Blood samples were analyzed for the BDNF Val66Met mutation. The prevalence of the Val66Met mutation in this study was 60% amongst CSM patients compared to 32% in the general population. Individuals with abnormal Met allele had worse baseline mJOA and Nurick scores. Moreover, baseline gait kinematics and hand functioning testing were worse compared to their wild type counterpart. BDNF Val66Met mutation has a higher prevalence in CSM compared to the general population. Those with BDNF mutation have a worse clinical presentation compared to the wild type counterpart. These findings suggest implication of the BDNF mutation in the development and severity of CSM.

An ovine model of spinal cord injury.

OBJECTIVE Identify risk factors predisposing to thoracic spinal stenosis and myelopathy (TS) and address treatment options and outcomes. METHODS A retrospective review of our centers experience with TS over 10 years. Clinical and magnetic resonance imaging (MRI) data, surgical intervention and outcomes using Frankel and Japanese Orthopedic Association (JOA) scales were collected. RESULTS A total of 44 patients with TS were identified. There were 30 men and 14 women with a mean age±SD of 66±15years. Neurological performance was evaluated using the Frankel scale (A-E or 1-5), and JOA scale for myelopathy (0-11). Frankel scores (1-5) and JOA scores (0-11) on admission were 3.5±0.9 and 6.8±2.6 respectively. At follow-up, Frankel scores had improved to 4.1±0.8 (p=0.041) and JOA scores had improved to 8.3±2.4 (p=0.021). The presence on admission of increased signal from the cord on T2-weighted MRI was associated with lower Frankel and JOA scores (3.3±0.9, and 6.2±2.5 respectively) than in those with absent increased signal (4.0±0.4 and 8.6±2.1, p=0.02 and p=0.008 respectively). There were 4 complications, requiring exploration and debridement for dehiscence in 3 and an epidural hematoma in the fourth that necessitated evacuation, with a good outcome. A fifth patient underwent reoperation at the same level 18 months later for persistent stenosis. CONCLUSION Thoracic stenosis with myelopathy should be entertained in patients with myelopathy. Over half of our patients with TS were over the age of 70, and men outnumbered women by a ratio of 2:1. Nearly half the patients with TS had concomitant cervical and/or lumbar degenerative disease warranting surgery also. Increased signal intensity on T2-weighted MRI images correlated with lower Frankel and JOA scores compared to those without. Decompression for thoracic stenosis is associated with neurological improvement.