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K. Anthony Kim, Michael Y. Wang, Pamela M. Griffith, Susan Summers and Michael L. Levy

The authors conducted a study to describe the incidence and types of fall-related head injury observed at a pediatric trauma center.

We performed a retrospective analysis of all patients under 15 years of age treated for fall-related trauma between 1992 and 1998. Falls were classified as low (< 15 feet) and high level (≥ 15 feet).

Seven hundred twenty-nine cases were identified with a mortality rate of 1.7%. A fall of greater than 15 feet (high-level fall) was associated with a higher mortality rate than low-level falls (2.4% compared with 1.0%, respectively). Ninety-eight patients had sustained a calvarial fracture and 93 experienced a basal skull fracture. Twenty-six patients had suffered a cerebral contusion, 25 a sub-arachnoid hemorrhage, 22 a subdural hematoma, and 12 had an epidural hematoma. Forty-nine patients required surgery for traumatic injuries; of these, 10 underwent craniotomy for evacuation of a blood clot. Height was not predictive of the Glasgow Coma Scale (GCS) score. In all four deaths resulting from a low-level fall there was an admission GCS score of 3, and abnormal findings were demonstrated on computerized tomography scanning. Death from high-level falls was attributable to either intracranial injuries (50%) or severe extracranial injuries (50%).

Intracranial injury is the major source of fall-related death in children and, unlike extracranial insults, brain injuries are sustained with equal frequency from low- and high-level falls in this population. The only cause of mortality from low-level falls was intracranial injury. Trauma triage criteria must account for these differences in the pediatric population.

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Paul Khoueir, K. Anthony Kim and Michael Y. Wang

✓Numerous new posterior dynamic stabilization (PDS) devices have been developed for the treatment of disorders of the lumbar spine. In this report the authors provide a classification scheme for these devices and describe several clinical situations in which the instrumentation may be expected to play a role. By using this classification, the PDSs that are now available and those developed in the future can be uniformly categorized.

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K. Anthony Kim, Matthew McDonald, Justin H. T. Pik, Paul Khoueir and Michael Y. Wang

Object

To assess the safety and efficacy of the DIAM implant, the authors compared the mean 12-month outcomes in patients who underwent lumbar surgery with DIAM placement and in those who underwent lumbar surgery only.

Methods

Of 62 patients who underwent simple lumbar surgery (laminectomy and/or microdiscectomy) in a 24-month period, 31 underwent concomitant surgical placement of a DIAM interspinous process spacer (33 devices total). Radiographic imaging, pain scores, and clinical assessments were obtained postoperatively to a mean of 12 months (range 8–25 months). Patients who did not undergo implantation of an interspinous process spacer (Group C) were compared with and stratified against patients who underwent placement of a DIAM implant (Group D).

In Group D, no statistically significant differences were noted in anterior or posterior disc height when comparing patients pre- and postoperatively. Compared with Group C, a relative kyphosis of less than 2° was noted on postoperative images obtained in Group D. No statistically significant differences in visual analog scale (VAS) pain scores or MacNab outcomes were noted between Groups C and D at a mean of 12 months of follow up. Complications in Group D included three intraoperative spinous process fractures and one infection.

Conclusions

After simple lumbar surgery, the placement of a DIAM interspinous process spacer did not alter disc height or sagittal alignment at the mean 12-month follow-up interval. No adverse local or systemic reaction to the DIAM was noted. No difference in VAS or MacNab outcome scores was noted between the groups treated with or without the DIAM implants, particularly when the DIAM was used to alleviate low-back pain.

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Anthony C. Wang, Khoi D. Than, Arnold B. Etame, Frank La Marca and Paul Park

Object

Transcranial motor evoked potential (TcMEP) monitoring is frequently used in complex spinal surgeries to prevent neurological injury. Anesthesia, however, can significantly affect the reliability of TcMEP monitoring. Understanding the impact of various anesthetic agents on neurophysiological monitoring is therefore essential.

Methods

A literature search of the National Library of Medicine database was conducted to identify articles pertaining to anesthesia and TcMEP monitoring during spine surgery. Twenty studies were selected and reviewed.

Results

Inhalational anesthetics and neuromuscular blockade have been shown to limit the ability of TcMEP monitoring to detect significant changes. Hypothermia can also negatively affect monitoring. Opioids, however, have little influence on TcMEPs. Total intravenous anesthesia regimens can minimize the need for inhalational anesthetics.

Conclusions

In general, selecting the appropriate anesthetic regimen with maintenance of a stable concentration of inhalational or intravenous anesthetics optimizes TcMEP monitoring.

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Arnold B. Etame, Anthony C. Wang, Khoi D. Than, Frank La Marca and Paul Park

Object

Symptomatic cervical kyphosis can result from a variety of causes. Symptoms can include pain, neurological deficits, and functional limitation due to loss of horizontal gaze.

Methods

The authors review the long-term functional and radiographic outcomes following surgery for symptomatic cervical kyphosis by performing a PubMed database literature search.

Results

Fourteen retrospective studies involving a total of 399 patients were identified. Surgical intervention included ventral, dorsal, or circumferential approaches. Analysis of the degree of deformity correction and functional parameters demonstrated significant postsurgical improvement. Overall, patient satisfaction appeared high. Five studies reported mortality with rates ranging from 3.1 to 6.7%. Major medical complications after surgery were reported in 5 studies with rates ranging from 3.1 to 44.4%. The overall neurological complication rate was 13.5%.

Conclusions

Although complications are not insignificant, surgery appears to be an effective option when conservative measures fail to provide relief.

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Oral Presentations

2010 AANS Annual Meeting Philadelphia, Pennsylvania May 1–5, 2010

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Paul Park, Anthony C. Wang, Jaypal Reddy Sangala, Sung Moon Kim, Shawn Hervey-Jumper, Khoi D. Than, Amin Farokhrani and Frank LaMarca

Object

Surgical correction of symptomatic cervical or cervicothoracic kyphosis involves the potential for significant neurological complications. Intraoperative monitoring has been shown to reduce the risk of neurological injury in scoliosis surgery, but it has not been well evaluated during surgery for cervical or cervicothoracic kyphosis. In this article, the authors review a cohort of patients who underwent kyphosis correction with multimodal intraoperative monitoring (MIOM).

Methods

Twenty-nine patients were included in the study. Preoperative and postoperative Cobb angles were measured to determine the extent of correction. Multimodal intraoperative monitoring consisted of somatosensory evoked potentials, transcranial motor evoked potentials (tMEPs), and electromyography activity. Sensitivity, specificity, positive predictive values (PPVs), and negative predictive values (NPVs) were assessed for each monitoring modality.

Results

The mean patient age was 58.0 years, and 20 patients were female. The mean pre- and postoperative sagittal Cobb angles were 41.3° and 7.3°, respectively. A total of 8 intraoperative monitoring alerts were observed. Transcranial MEPs yielded a sensitivity of 75%, specificity of 84%, PPV of 43%, and NPV of 95%. Somatosensory evoked potentials had a sensitivity of 25%, specificity of 96%, PPV of 50%, and NPV of 88%. Electromyography resulted in a sensitivity of 0%, specificity of 93%, PPV of 0%, and NPV of 96%. Changes in tMEPs led to successful intervention in 2 cases. There was 1 case in which a C-8 palsy occurred without any changes in MIOM.

Conclusions

In contrast to sensitivity and PPV, specificity and NPV were generally high in all 3 monitoring modalities. Both false-positive and false-negative results occurred. Transcranial MEP monitoring was the most useful modality and appeared to allow successful intervention in certain cases. Larger, prospective comparative studies are necessary to determine whether MIOM truly decreases the rate of neurological complications and is therefore worth the added economic cost and intraoperative time.

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Khoi D. Than, Anthony C. Wang, Shayan U. Rahman, Thomas J. Wilson, Juan M. Valdivia, Paul Park and Frank La Marca

The goal of this study was to review the literature to compare strategies for avoiding and treating complications from anterior lumbar interbody fusion (ALIF), and thus provide a comprehensive aid for spine surgeons. A thorough review of databases from the US National Library of Medicine and the National Institutes of Health was conducted. The complications of ALIF addressed in this paper include pseudarthrosis and subsidence, vascular injury, retrograde ejaculation, ileus, and lymphocele (chyloretroperitoneum). Strategies identified for improving fusion rates included the use of frozen rather than freeze-dried allograft, cage instrumentation, and bone morphogenetic protein. Lower cage heights appear to reduce the risk of subsidence. The most common vascular injury is venous laceration, which occurs less frequently when using nonthreaded interbody grafts such as iliac crest autograft or femoral ring allograft. Left iliac artery thrombosis is the most common arterial injury, and its occurrence can be minimized by intermittent release of retraction intraoperatively. The risk of retrograde ejaculation is significantly higher with laparoscopic approaches, and thus should be avoided in male patients. Despite precautionary measures, complications from ALIF may occur, but treatment options do exist. Bowel obstruction can be treated conservatively with neostigmine or with decompression. In cases of postoperative lymphocele, resolution can be attained by creating a peritoneal window. By recognizing ways to minimize complications, the spine surgeon can safely use ALIF procedures.

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Anthony C. Wang, Joseph J. Gemmete, Catherine E. Keegan, Cordelie E. Witt, Karin M. Muraszko, Khoi D. Than and Cormac O. Maher

Roberts/SC phocomelia syndrome (RBS) is a rare but distinct genetic disorder with an autosomal recessive inheritance pattern. It has been associated with microcephaly, craniofacial malformation, cavernous hemangioma, encephalocele, and hydrocephalus. There are no previously reported cases of RBS with intracranial aneurysms. The authors report on a patient with a history of RBS who presented with a spontaneous posterior fossa hemorrhage. Multiple small intracranial aneurysms were noted on a preoperative CT angiogram. The patient underwent emergency craniotomy for evacuation of the hemorrhage. A postoperative angiogram confirmed the presence of multiple, distal small intracranial aneurysms.