Ricky H. Wong

Frequency, magnitude, and distribution of head impacts in Pop Warner football: The cumulative burden

BACKGROUND A growing body of research suggests that subconcussive head impacts or repetitive mild Traumatic Brain Injury (mTBI) can have cumulative and deleterious effects. Several studies have investigated head impacts in football at the professional, collegiate, and high school levels, in an attempt to elucidate the biomechanics of head impacts among football players. Youth football players, generally from 7 to 14 years of age, constitute 70% of all football players, yet burden of, and susceptibility to, head injury in this population is not well known. METHODS A novel impact sensor utilizing binary force switches (Shockbox(®)) was used to follow an entire Pop Warner football team consisting of twenty-two players for six games and five practices. The impact sensor was designed to record impacts with linear accelerations over 30g. In addition, video recording of games and practices were used to further characterize the head impacts by type of position (skilled versus unskilled), field location of impact (open field versus line of scrimmage), type of hit (tackling, tackled, or hold/push), and whether the impact was a head-to-head impact or not. RESULTS We recorded a total of 480 head impacts. An average of 21.8 head impacts occurred per practice, while 61.8 occurred per game. Players had an average of 3.7 head impacts per game and 1.5 impacts per practice (p<0.001). The number of high magnitude head impacts (>80g) was 11. Two concussions were diagnosed over the course of the season. However, due to technical reasons the biomechanics of those hits resulting in concussions were not captured. CONCLUSION Despite smaller players and slower play when compared to high school, collegiate or professional players, those involved in youth football sustain a moderate number of head impacts per season with several high magnitude impacts. Our results suggest that players involved in open-field, tackling plays that have head-to-head contact sustain impacts with the highest linear accelerations. Our data supports previously published data that suggests changes to the rules of play during practice can reduce the burden of hits.

Clinical Outcomes of Microendoscopic Foraminotomy and Decompression in the Cervical Spine

OBJECTIVE Few reports have addressed long-term outcomes, as well as the safety and efficacy of the cervical microendoscopic foraminotomy (CMEF) and cervical microendoscopic diskectomy (CMED) procedures used in modern spine practice to treat degenerative disease of the cervical spine. Accordingly, we present long-term outcomes from a cohort of patients treated for foraminal stenosis or disk herniation with the CMEF or CMED procedure, respectively. METHODS A total of 38 patients were included in the study, with a mean follow-up of 24.47 ± 12.84 months. Patients were monitored prospectively with questionnaires consisting of a visual analog scale for the neck (VASN) and arm (VASA), and a neck disability index (NDI) form. Operative time, estimated blood loss, and hospitalization stay also were collected. Data were analyzed with Microsoft Office Excel 2007. RESULTS The mean 1 year follow-up scores all showed statistically significant improvements: NDI (P = 0.0019), VASN (P = 0.0017), VASA (P ≤ 0.0001). Similar results were seen at 2-year follow-up: NDI (P = 0.0011), VASN (P = 0.0022), and VASA (P ≤ 0.0001); and at 3- to 6-year follow-up: NDI (P = 0.0015), VASN (P = 0.0200), and VASA (P = 0.0034). The average operation time, hospitalization stay, and estimated blood loss were 154.27 ± 26.79 minutes, 21.22 ± 14.23 hours, and 27.92 mL, respectively. There were no statistically significant differences when patients were compared by age (over 50 vs. under 50), operative level (above C6 vs. below C6), or sex. One complication was reported in this study consisting of duratomy, which required no further intervention. CONCLUSION Posterior CMEF and CMED are safe and effective procedures for minimally invasive decompression in the cervical spine.

Microendoscopic decompression for cervical spondylotic myelopathy

OBJECT Cervical spondylotic myelopathy (CSM) is a common cervical degenerative disease that affects the elderly population. Spinal cord decompression is achieved through various anterior and posterior approaches including anterior cervical decompression and fusion, laminectomy, laminoplasty, and combined approaches. The authors describe another option, minimally invasive endoscopically assisted decompression of stenosis (MEDS), which obviates the need for muscle dissection and disruption of the posterior tension band, a cause of postlaminectomy kyphosis. METHODS The authors conducted a retrospective study of 10 patients with CSM who underwent MEDS from January 2002 through July 2012. Data were collected on demographics, preoperative and postoperative Nurick scores, postoperative Odom scores, and preoperative and postoperative Cobb angles. RESULTS The mean patient age (± SD) was 67 ± 7.7 years; 8 patients were male. The average number of disc levels operated on was 2.2 (range 1-4). The mean Nurick score was 1.6 ± 0.7 preoperatively and improved to 0.3 ± 0.7 postoperatively (p < 0.0005). The postoperative Odom scores indicated excellent outcomes for 4 patients, good for 3, fair for 2, and poor for 1. The average preoperative focal Cobb angle at the disc levels operated on was -0.43º ± 1.9º. The average Cobb angle at the last follow-up visit was 0.25° ± 1.6° (p = 0.6). The average follow-up time was 18.9 ± 32.1 months. There were no intraoperative or postoperative complications. CONCLUSIONS For selected patients with CSM, whose pathologic changes are primarily posterior and who have acceptable preoperative lordosis, MEDS is an alternative to open laminectomy and laminoplasty.

Minimally Invasive Transforaminal Lumbar Interbody Fusion (TLIF) for Spondylolisthesis in 282 Patients: In Situ Arthrodesis versus Reduction

OBJECTIVE The benefits of spondylolisthesis reduction via minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) remain poorly understood. The purpose was to compare the complications, perioperative factors, and fusion rates in patients undergoing MI-TLIF for degenerative spondylolisthesis between those in whom reduction was or was not performed. METHODS INCLUSION CRITERIA 1) patients who underwent a 1, 2, or 3 level MI-TLIF and 2) had a preoperative diagnosis of degenerative spondylolisthesis (Meyerding grade >0). EXCLUSION CRITERIA >10° coronal curves, significant sagittal malalignment, infection, and preoperative hardware failure. Patients were grouped on the basis of those who underwent reduction of the spondylolisthesis by at least 1 Meyerding grade (RED) and those who did not (NORED). RESULTS A total of 282 patients were included: RED (162, 57.4%) and NORED (120, 42.6%). Mean ages (61.68 ± 10.43 vs. 61.88 ± 11.76 years, respectively, P > 0.05) and operative times (P > 0.05) were statistically similar. RED had a significantly larger EBL (280.2 ± 24.03 vs. 212.61 ± 17.54, P < 0.05). The length of hospital stay, intraoperative complications, postoperative medical and surgical complications, and disposition were statistically similar between groups (P > 0.05, for all). RED had a significantly higher percentage of patients with a successful fusion at 1 year than NORED (84.50% vs. 70.83%, P < 0.05). CONCLUSION Reduction of spondylolisthesis was not associated with an increase in operative time, length of stay, and perioperative and postoperative complications compared with fusion in situ. Reduction was associated with higher blood loss but also a higher rate of fusion success at 1 year. Overall, reduction did not incur additional risk and had positive perioperative outcomes.

Comparison of open and minimally invasive surgery for intradural-extramedullary spine tumors.

OBJECT Patients with symptomatic intradural-extramedullary (ID-EM) tumors may be successfully treated with resection of the lesion and decompression of associated neural structures. Studies of patients undergoing open resection of these tumors have reported high rates of gross-total resection (GTR) with minimal long-term neurological deficit. Case reports and small case series have suggested that these patients may be successfully treated with minimally invasive surgery (MIS). These studies have been limited by small patient populations. Moreover, there are no studies directly comparing perioperative outcomes between patients treated with open resection and MIS. The objective of this study was to compare perioperative outcomes in patients with ID-EM tumors treated using open resection or MIS. METHODS A retrospective review was performed using data collected from 45 consecutive patients treated by open resection or MIS for ID-EM spine tumors. These patients were treated over a 9-year period between April 2003 and October 2012 at Northwestern University and the University of Chicago. Statistical analysis was performed to compare perioperative outcomes between the two groups. RESULTS Of the 45 patients in the study, 27 were treated with the MIS approach and 18 were treated with the open approach. Operative time was similar between the two groups: 256.3 minutes in the MIS group versus 241.1 minutes in the open group (p = 0.55). Estimated blood loss was significantly lower in the MIS group (133.7 ml) compared with the open group (558.8 ml) (p < 0.01). A GTR was achieved in 94.4% of the open cases and 92.6% of the MIS cases (p = 0.81). The mean hospital stay was significantly shorter in the MIS group (3.9 days) compared with the open group (6.1 days) (p < 0.01). There was no significant difference between the complication rates (p = 0.32) and reoperation rates (p = 0.33) between the two groups. Multivariate analysis demonstrated an increased rate of complications in cervical spine tumors (OR 15, p = 0.05). CONCLUSIONS Thoracolumbar ID-EM tumors may be safely and effectively treated with either the open approach or an MIS approach, with an equivalent rate of GTR, perioperative complication rate, and operative time. Patients treated with an MIS approach may benefit from a decrease in operative blood loss and shorter hospital stays.

Natural history of multiple meningiomas.

Background: Asymptomatic solitary meningiomas are typically managed with clinical and radiographic follow-up. Multiple meningiomas represents a clinical entity distinct from solitary meningiomas and can be sporadic, radiation-induced, associated with neurofibromatosis, or exhibit other familial inheritance. The growth rate for multiple meningiomas is not known and therefore management of these complicated patients can be difficult. Methods: A retrospective chart review was performed on 12 patients with a total of 55 meningiomas. Patients with neurofibromatosis were not included. Serial enhanced magnetic resonance imaging was used to determine tumor growth rates. Treatment history was also reviewed and included for analysis. Results: Analysis of all 55 tumors demonstrated an average rate of growth of 0.46 cm3/year (range: −0.57-2.94 cm3/year). In the 23 tumors that received no treatment, the average rate of growth was 0.34 cm3/year (range: −0.03-1.8 cm3/year). Ten of the 23 tumors that received no treatment had no history of cranial irradiation. This group demonstrated a growth rate of 0.44 cm3/year (range: −0.01-1.8 cm3/year). Linear regression analysis did not yield any significant relationship between tumor burden and rates of growth. Conclusion: Tumor growth rates in patients with multiple meningiomas did not appear to be higher than reported rates for incidentally found solitary meningiomas. As such, asymptomatic multiple meningioma patients should be managed with clinical and radiographic follow-up.

Cervical spine instability from tumoral calcinosis

Dear Editor, In the present case, we describe the clinical presentation, surgical management, and long-term follow-up of a rare case of tumoral calcinosis-induced cervical spine instability. Tumoral calcinosis is a rare disease characterized by the deposition of calcium crystals in peri-articular soft tissue. It can be familial or associated with other conditions, typically metabolic or other illnesses that result in metabolic disturbances [5]. It most commonly affects large joints, such as the hip and shoulders, but has been described in smaller joints including the spine.When tumoral calcinosis occurs, it appears as multiloculated, solid calcifications that generally cause local swelling, pain, and restricted mobility of the adjacent joint. Surgical resection of these calcifications is associated with a variable rate of recurrence. In patients with associated metabolic abnormalities, recurrence rates up to 33 % have been reported [2]. Some reports also suggest that incomplete resection is associated with higher rates of recurrence [3, 4, 6]. While tumoral calcinosis occurs around joints, erosion into adjacent bone or joint is a rare complication. Tumoral calcinosis of the cervical spine with bone erosion and instability has only been reported once in the literature [1]. A uremic patient on chronic dialysis presented with C1-2 instability from tumoral calcinosis. We present a rare case of significant cervical spine instability caused by tumoral calcinosis-induced bone erosion in a patient without any metabolic disturbances or personal/family history of calcific disease. To the best of our knowledge, this represents the first case of cervical spine instability caused by tumoral calcinosis without any of the typical associated conditions.

Interrupted time-series analysis: studying trends in neurosurgery.

OBJECT Neurosurgery studies traditionally have evaluated the effects of interventions on health care outcomes by studying overall changes in measured outcomes over time. Yet, this type of linear analysis is limited due to lack of consideration of the trends effects both pre- and postintervention and the potential for confounding influences. The aim of this study was to illustrate interrupted time-series analysis (ITSA) as applied to an example in the neurosurgical literature and highlight ITSAs potential for future applications. METHODS The methods used in previous neurosurgical studies were analyzed and then compared with the methodology of ITSA. RESULTS The ITSA method was identified in the neurosurgical literature as an important technique for isolating the effect of an intervention (such as a policy change or a quality and safety initiative) on a health outcome independent of other factors driving trends in the outcome. The authors determined that ITSA allows for analysis of the interventions immediate impact on outcome level and on subsequent trends and enables a more careful measure of the causal effects of interventions on health care outcomes. CONCLUSIONS ITSA represents a significant improvement over traditional observational study designs in quantifying the impact of an intervention. ITSA is a useful statistical procedure to understand, consider, and implement as the field of neurosurgery evolves in sophistication in big-data analytics, economics, and health services research.

Marginal zone lymphoma of the thoracic dura causing spinal cord compression

Primary extra-nodal marginal zone B cell lymphoma (Ex-MZBCL) or mucosa-associated lymphoid tissue (MALT) lymphoma of the cranial dura is a rare but well-known entity. We describe a 58-year-old woman with primary MALT lymphoma of the spinal dura causing extreme thickening of the dura and spinal cord compression who initially presented with acute spinal cord compression from a chronic epidural lesion. She was treated with surgery and radiotherapy and diagnosed with a mature B-cell lymphoma based on gene rearrangement studies. Two years following the completion of radiotherapy, she presented with an increase in the size of the residual mass that was suggestive of an epidural lesion. On re-exploration, no epidural lesion was found; however, the dura was extremely thickened causing spinal cord compression. Clinical course, histological evaluation, immunostaining and gene rearrangement studies resulted in a final diagnosis of primary Ex-MZBCL of the spinal dura. To our knowledge, this is the first report of Ex-MZBCL in the spinal dura. This diagnosis should be considered when evaluating spinal cord lesions in patients with primary central nervous system (CNS) lymphoma, especially recurrent lesions, since this group of tumors carries a favorable outcome compared to other primary CNS lymphomas.

Thrombolysis for intraventricular hemorrhage.

Intraventricular hemorrhage is a frequent complication of intracerebral hemorrhage and is independently associated with significant morbidity and mortality. Intraventricular fibrinolytic therapy is used with increasing frequency to accelerate clot clearance. We review the recent evidence and discuss the therapeutic benefits as well as the current concerns and limitations of fibrinolytic use in this setting.