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OBJECTIVE To analyze characteristics of surgically managed tear drop (TD) fractures of the C2 axis associated with other injuries such as hangman's fracture and C2-3 discoligamentous injury as well as treatment outcomes. METHODS A total of 14 patients (eight men and six women) with TD fractures of the C2 , who were surgically treated at four national trauma centers of tertiary university hospitals from January 2000 to December 2017, were included in this retrospective study. The mean age of the patients was 45.5 years (ranging from 19 to 74 years). The characteristics, surgical treatment methods (anterior fusion vs posterior fusion), and results of 14 TD fractures of the C2 were analyzed retrospectively. And the clinical relevance between C2 TD fracture and hangman's fracture and C2-3 discoligamentous injury was investigated through the co-occurrence between injuries. The mean follow-up time after surgery was 22.6 months (ranging from 12 to 60 months). RESULTS Among 14 patients with TD fracture of the C2 , four patients (28.6%) had anterior TD fracture and 10 patients (71.4%) had posterior TD fracture. All 10 posterior TD fracture patients had anterior C2-3 displacement. While two of four anterior TD fracture patients had posterior C2-3 displacement, the remaining two did not. All 14 patients of TD fracture had at least two or more other associated C2 injuries as well as C2-3 discoligamentous injuries. About 92.9% (13/14) of the patients had typical or atypical hangman's fracture; 100% (10/10) of the posterior TD fracture patients had hangman's fracture, but 75% (3/4) of the anterior TD fracture had hangman's fracture. At admission, 13 patients were neurologically intact. However, the remaining patient had spinal cord injury with American Spinal Injury Association (ASIA) impairment scale B with C2-3 bilateral facet dislocation. All four anterior TD fracture patients underwent posterior C2-3 fusion. While four of 10 posterior TD fracture patients underwent C2-3 anterior fusion, the remaining six underwent posterior fusion. At last follow-up, 100% (14/14) of the patients achieved solid fusion, and visual analog scale for neck pain was significantly improved (5.9 vs 2.2, P

Surgical outcomes of degenerative cervical spinal disease are dependent on the selection of surgical techniques. Although a standardized decision cannot be made in an actual clinical setting, continued education is provided to standardize the medical practice among surgeons. Therefore, it is necessary to supervise and regularly update overall surgical outcomes. This study aimed to compare the rate of additional surgery between anterior and posterior surgeries for degenerative cervical spinal disease using the National Health Insurance Service-National Sample Cohort (NHIS-NSC) nationwide patient database. The NHIS-NSC is a population-based cohort with about a million participants. This retrospective cohort study included 741 adult patients (> 18 years) who underwent their first cervical spinal surgery for degenerative cervical spinal disease. The median follow-up period was 7.3 years. An event was defined as the registration of any type of cervical spinal surgery during the follow-up period. Event-free survival analysis was used for outcome analysis, and the following factors were used as covariates for adjustment: location of disease, sex, age, type of insurance, disability, type of hospital, Charles comorbidity Index, and osteoporosis. Anterior cervical surgery was selected for 75.0% of the patients, and posterior cervical surgery for the remaining 25.0%. Cervical radiculopathy due to foraminal stenosis, hard disc, or soft disc was the primary diagnosis in 78.0% of the patients, and central spinal stenosis was the primary diagnosis in 22.0% of them. Additional surgery was performed for 5.0% of the patients after anterior cervical surgery and 6.5% of the patients after posterior cervical surgery (adjusted subhazard ratio, 0.83; 95% confidence interval, 0.40–1.74). The rates of additional surgery were not different between anterior and posterior cervical surgeries. The results would be helpful in evaluating current practice as a whole and adjusting the health insurance policy.

Objective The demand for treating degenerative lumbar spinal disease has been increasing, leading to increased utilization of medical resources. Thus, we need to understand how the budget of insurance is currently used. The objective of the present study is to overview the utilization of the National Health Insurance Service (NHIS) by providing the direct insured cost between patients receiving surgery and patients receiving nonsurgical treatment for degenerative lumbar disease. Methods The NHIS-National Sample Cohort was utilized to select patients with lumbar disc herniation, spinal stenosis, spondylolisthesis or spondylolysis. A matched cohort study design was used to show direct medical costs of surgery (n = 2,698) and nonsurgical (n = 2,698) cohorts. Non-surgical treatment included medication, physiotherapy, injection, and chiropractic. The monthly costs of the surgery cohort and nonsurgical cohort were presented at initial treatment, posttreatment 1, 3, 6, 9, and 12 months and yearly thereafter for 10 years. Results The characteristics and matching factors were well-balanced between the matched cohorts. Overall, surgery cohort spent $50.84/patient/month, while the nonsurgical cohort spent $29.34/patient/month (p Conclusion Surgical treatment initially led to more government reimbursement than nonsurgical treatment, but the charges during follow-up period were not different. The results of the present study should be interpreted in light of the costs of medical services, indirect costs, societal cost, quality of life and societal willingness to pay in each country. The monetary figures are implied to be actual economic costs but those in the reimbursement system instead reflect reimbursement charges from the government.

Study Design: Retrospective cohort study. Objectives: Reported incidences and complications of heterotopic ossification (HO) after using recombinant human bone morphogenetic protein–2 (rhBMP-2) in transforaminal lumbar interbody fusion (TLIF) have been inconclusive. This study was designed to evaluate both incidences of radiologic and symptomatic HO in a large series of TLIFs using rhBMP-2. Methods: A total of 996 disc levels in 927 consecutive TLIF patients were retrospectively evaluated at 6-month postoperative follow-up in a single surgical practice. Subjects were separated into the BMP group and the control group. Operative reports, pre- and postoperative medical records were reviewed. Computed tomography (CT) scans were analyzed and graded independently for ossification at each disc level of TLIF. Results: A total of 933 disc levels were in the BMP group, and 63 were in the control group. Six-month fusion rate of interbody was 92.5% in the BMP group, which was significantly higher in contrast to 71.4% in the control group ( P < .001). The incidence of radiologic HO in the BMP group was 13.5%, which was significantly higher than 1.6% in the control group ( P = .006). After controlling for basic demographics and comorbidities, the presence of radiologic HO was significantly associated with the use of rhBMP-2 ( P = .026). However, only one case in the BMP group (0.11%) developed a symptomatic HO (mild-medium left buttock pain, treated nonsurgically) involving left foramen of L5-S1. Conclusions: rhBMP-2 can be safely used in TLIF with regard to HO. There was a low rate of radiologic HO and minimal symptomatic HO, with high fusion rates at 6 months postoperative.

Background: Multiple studies have demonstrated a strong correlation between sagittal malalignment and health-related quality of life measures. Thus, correction of sagittal vertical axis (SVA), pelvic tilt (PT), lumbar lordosis–pelvic incidence (LL-PI), and T1 spinopelvic inclination (T1SPi) have become a primary objective of adult spinal deformity surgery. Anterior column realignment (ACR) has emerged as a less invasive technique and while the addition of posterior osteotomies has shown greater correction in ACR, it is unknown if a pre-ACR posterior release is necessary for optimal correction. The purpose of this study was to determine if pre-ACR posterior release allows for greater sagittal deformity correction. Methods: Seventeen patients were identified that underwent minimum 1-level ACR. Ten patients underwent an anterior-posterior surgical sequence without a pre-ACR posterior release, and 7 underwent a posterior-anterior-posterior (PAP) sequence with a pre-ACR posterior release. Radiographic outcomes at final follow-up and complications were compared. Results: Both groups saw significant improvements in LL, LL-PI, PT, SVA, and T1SPi but the correction was not significantly different between cohorts. With the exception of PT in the PAP group, the improvements in LL-PI, PT, and SVA correlated to improvement in Scoliosis Research Society–Schwab classification. The correction achieved at the ACR level, represented by motion segment angle, was greater in the PAP group by a degree that approached statistical significance. Five patients (29%) had 6 complications. Conclusions: Both techniques achieved meaningful improvements in overall sagittal alignment. Our results suggest that a pre-ACR posterior release may allow for greater correction specifically at the ACR level but may not always be necessary to achieve clinically meaningful correction of sagittal plane deformity. Level of Evidence: 3 Clinical Relevance: We present our experience with and without pre-ACR posterior release. To our knowledge, this is the first study to show that pre-ACR posterior release may achieve greater correction at the ACR level.

Many anterior C2 (2nd cervical vertebra) tear drop (TD) fractures can be successfully managed with conservative treatment. However, due to the occurrence of nonunion, large-sized or complex anterior C2 TD fractures undergo surgical treatment. To date, no surgical treatment guidelines are available about anterior C2 TD fractures. Therefore, we performed this study to investigate the factors that may affect nonunion for anterior C2 TD fractures and to suggest surgical treatment guidelines. Thirty-three patients with anterior C2 TD fractures, who underwent conservative treatment and had a minimum 1-year follow-up, were divided into union (N = 26) and nonunion (N = 7) groups. Their radiological and clinical data were analyzed retrospectively and compared between the two groups. The avulsion fracture ratio (29.5% vs. 43.3%, p &lt, 0.05) and fracture displacement (3.6 mm vs. 5.1 mm, p &lt, 0.05) were higher in the nonunion group compared to the union group. Incidence of associated C2 injury was higher in the nonunion group compared to the union group (15.4% vs. 57.1%, p &lt, 0.05). Union status was negatively correlated with associated C2 injury (correlation coefficient, CC = −0.398, p &lt, 0.05). Our results suggest that surgical treatment could be considered for anterior C2 TD fractures with an avulsion fracture ratio &gt, 43%, fracture displacement &gt, 5 mm, or associated C2 injury.

Study Design: Retrospective cohort study. Objectives: Many patients undergoing posterior spinal fusion (PSF) for scoliosis have concurrent cerebral palsy (CP), which is associated with many medical comorbidities and inherent operative risk. We aimed to quantify the contribution of CP to increased cost, length of stay (LOS), and complication rates in patients with scoliosis undergoing PSF. Methods: Using the National Inpatient Sample database, we collected data regarding patient demographics, hospital characteristics, comorbidities, in-hospital complications, and mortality. Primary outcomes included complications, hospital LOS, and total hospital costs. Multivariate regression models assessed the contribution of CP to in-hospital complications, discharge status, and mortality. Linear regression identified the contribution of a diagnosis of CP on hospital LOS and inflation-adjusted cost. Results: Cerebral palsy was an independent predictor of several complications. The most striking differences were seen for mortality (odds ratio [OR]: 3.40, P < .001), a postoperative requirement for total parenteral nutrition (OR: 3.16, P < .001), urinary tract infection (OR: 2.75, P < .001), surgical site infection (OR: 2.67, P < .001), and pneumonia (2.21, P < .001). Patients with CP ultimately cost an additional $13 482 ( P < .001) with a 2.07-day greater LOS ( P < .001) than patients without CP. Conclusion: Most complications were seen in higher rates in the CP cohort, with higher cost and LOS in patients with CP versus those with idiopathic scoliosis (IS). Our findings represent important areas of emphasis during preoperative consultations with patients with CP and their families. Extra care in patient selection and multifaceted treatment protocols should continue to be implemented with further investigation on how to mitigate common complications.

Study Design: Retrospective case series. Objectives: An increasing focus has been placed on removing implicit (unconscious) bias from the surgical selection process. In spine surgery, there is the potential for implicit bias to affect the decision to either operate on a patient or not, given lack of definitive surgical indications for many elective procedures. The objective of this study was to analyze the surgical decision making of a single spine surgeon in an effort to understand surgical decision-making trends based on certain demographic factors. Methods: This was a retrospective study of 484 patients who had undergone a corrective procedure for cervical myelopathy by an orthopedic spine surgeon at our institution. The preoperative modified Japanese Orthopaedic Association score served as the metric of severity of disease for cervical myelopathy. The factors that have been associated with implicit bias that were evaluated were smoking status, narcotic use status, gender, body mass index, and age. Results: Multivariate linear regression analysis showed that even after controlling for comorbidities and confounders, the only variable which predicted likelihood to operate on a patient of a milder symptomology was age (odds ratio [OR] = −0.138; (confidence interval [CI] = −0.034 to −0.006). The other factors (smoking status, narcotic use status, gender, and body mass index) were not associated with surgical decision making. Conclusions: Our study demonstrates absence of association between commonly studied areas of implicit bias and the decision to operate on a patient with milder symptomology at initial presentation of cervical spondylotic myelopathy.

Cervical laminoplasty is a non-fusion, decompression procedure for cervical spondylotic myelopathy (CSM). It is most commonly indicated for patients with multilevel stenosis who have preserved sagittal alignment and minimal to no axial neck pain related to spondylosis. Expansion of the laminar arch can allow for direct and indirect decompression of the spinal canal. Relative contraindications include those patients with significant preoperative neck pain, kyphotic alignment and substantial instability. Potential advantages over laminectomy and fusion include avoiding fusion-related complications, and the preservation of motion. Important technical considerations include meticulous extensor muscle management, with special attention being given to preserving the soft tissue attachments to C2. In the properly selected patient, outcomes are comparable, and in some studies superior, to other operations for CSM.

The cortical bone trajectory (CBT) screw technique yields effective mechanical and clinical results, improving the holding screw strength with a less invasive exposure. Accurate and safe screw placement is crucial. A patient-specific drill template with a preplanned trajectory was considered a promising solution; however, it is critical to assess the efficacy and safety of this technique. This study aims to evaluate the accuracy of patient-specific computed tomography (CT)-based rapid prototype drill guide templates for the CBT technique. CT scanning was performed in 7 cadaveric thoracolumbar spines, and a 3-dimensional reconstruction model was generated. By using computer software, we constructed drill templates that fit onto the posterior surface of thoracolumbar vertebrae with drill guides to match the CBT. In total, 80 guide templates from T11 to L5 were created from the computer models by using rapid prototyping. The drill templates were used to guide the drilling of CBT screws without any fluoroscopic control, and CT images were obtained after fixation. The entry point and direction of the planned and inserted screws were measured and compared. In total, 80 screws were inserted from T11 to L5. No misplacement or bony perforation was observed on postoperative CT scan. The patient-specific prototype template system showed the advantage of safe and accurate cortical screw placement in the thoracolumbar spine. This method showed its ability to customize the patient-specific trajectory of the spine, based on the unique morphology of the spine. The potential use of drill templates to place CBT screws is promising.

Study Design: Systematic review. Objectives: The objective of this study was to conduct a systematic review to determine (1) change in function, pain, and quality of life following structured nonoperative treatment for degenerative cervical myelopathy (DCM); (2) variability of change in function, pain, and quality of life following different types of structured nonoperative treatment; (3) differences in outcomes observed between certain subgroups (eg, baseline severity score, duration of symptoms); and (4) negative outcomes and harms resulting from structured nonoperative treatment. Methods: A systematic search was conducted in Embase, PubMed, and the Cochrane Collaboration for articles published between January 1, 1950, and February 9, 2015. Studies were included if they evaluated outcomes following structured nonoperative treatment, including therapeutic exercise, manual therapy, cervical bracing, and/or traction. The quality of each study was evaluated using the Newcastle-Ottawa Scale, and strength of the overall body of evidence was rated using guidelines outlined by the Grading of Recommendation Assessment, Development and Evaluation Working Group. Results: Of the 570 retrieved citations, 8 met inclusion criteria and were summarized in this review. Based on our results, there is very low evidence to suggest that structured nonoperative treatment for DCM results in either a positive or negative change in function as evaluated by the Japanese Orthopaedic Association score. Conclusion: There is a lack of evidence to determine the role of nonoperative treatment in patients with DCM. However, in the majority of studies, patients did not achieve clinically significant gains in function following structured nonoperative treatment. Furthermore, 23% to 54% of patients managed nonoperatively subsequently underwent surgical treatment.

Study Design: Retrospective radiographic study. Objective: The optimal radiographic modality for assessing cervical foraminal stenosis is unclear. Determination on conventional axial cuts is made difficult due in part to the complex, oblique orientation of the cervical neuroforamen. The utility of 3-dimensonal (3D) computed tomography (CT) reconstruction in improving neuroforaminal assessment is not well understood. The objective of this study is to determine inter-rater variability in grading cervical foraminal stenosis using 3 different CT imaging modalities: 3D CT surface reconstructions (3DSR), 2D sagittal oblique multiplanar reformations (2D-SOMPR), and conventional 2D axial CT imaging. Methods: Pretreatment CT scans of 25 patients undergoing surgery for cervical spondylotic radiculopathy were analyzed at 2 levels: C5-C6 and C6-C7. Simple interrater agreement and kappa-Fleiss coefficients were calculated for each imaging modality and stenosis grade. Image reviewers (attending spine surgeon, attending neuroradiologist, spine fellow) interpreted each CT scan in 3 different formats: axial, 2D-SOMPR, and 3DSR. Four cervical foramina at 2 spinal levels were graded as normal (no stenosis), mild (≤25% stenosis), moderate (25%-50% stenosis), or severe (>50% stenosis). Results: Across all imaging modalities, interrater reliability was fair when grading foraminal stenosis (κ < 0.4). Agreement was lowest for the axial images (κ = 0.119) and highest for the 3D CT reconstructions (κ = 0.334). 2D-SOMPR images also led to improved interrater reliability when compared with axial images (κ = 0.255). Conclusion: Grading cervical foraminal stenosis using conventional axial CT imaging is difficult with low interrater reliability. CT modalities that provide a circumferential view of the cervical foramen, such as 2D-SOMPR and 3D CT reconstruction, had higher rates of interobserver reliability in grading foraminal stenosis than conventional axial cuts, with 3D having the highest. As these 3D reconstructions can be obtained at no additional cost or radiation exposure over a conventional CT scan, and because they can provide useful information in determining levels being considered for surgical decompression, we recommend they be utilized when evaluating cervical foramina.

Background: The objective of this study is to demonstrate the epidemiology and trends in management of patients with central cord syndrome (CCS) who present to the emergency department. Recent literature has reported that surgical treatment for CCS have increased over the previous decades. Methods: The National Emergency Department Sample (NEDS) was queried from 2009 through 2012 to generate national estimates of patients who presented to the emergency department in the United States and were diagnosed with CCS. Results: From 2009 through 2012, there were 11,975 emergency room visits for CCS (mean age 60 years). The two most common injury mechanisms were: fall (55%) and motor vehicle accident (15%). Concomitant cervical fractures were found in 10% patients. Ninety-three percent of patients were admitted to the hospital directly or after transfer to another facility, and 7% were discharged home. Fifty-five percent of patients were treated non-operatively, 39% were treated with cervical fusion surgery and 6% were treated with laminoplasty. Of patients who underwent cervical fusion, 62% received anterior decompression and fusion, 32% received posterior decompression and fusion, and 6% received combined anterior-posterior decompression and fusion. The incidence of in-hospital mortality was 2.6%. Mortality was associated with older patient age (OR 1.06, P Conclusions: Majority of patients who presented to the emergency room for CCS in the United States were treated non-operatively. Advanced age and greater comorbidities were the factors that were most associated with increased risk of in-hospital mortality in patients with CCS.

Background Context The diagnosis of generalized anxiety disorder (GAD) and major depressive disorder (MDD) amongst adolescents is rising worldwide. Rates of these disorders are higher in those with adolescent idiopathic scoliosis. Purpose To elucidate whether or not depression and anxiety are associated with increased length of stay and total cost after posterior spinal fusion for adolescent idiopathic scoliosis. Study Design/Setting, Patient Sample This study utilized the Nationwide Inpatient Sample (NIS) to obtain a sample of n = 564 in the depression and anxiety cohort and n = 5,185 in the cohort without concomitant diagnosis of depression and anxiety. Outcome Measures Length of stay and total cost after posterior spinal fusion for adolescent idiopathic scoliosis. Methods The Nationwide Inpatient Sample (NIS) was queried for patients undergoing posterior spinal fusion (PSF) for adolescent idiopathic scoliosis with either the concomitant diagnosis of major depressive disorder or generalized anxiety disorder. Comorbidities and other confounders were controlled for using multivariate regression analysis to determine the effect of having either mood disorder on cost and length of stay (LOS) after PSF. Results We determined that after controlling for confounding variables and comorbidities through multivariate regression analysis, patients with either depression or anxiety had increased odds ratios for increased LOS but not for cost. Conclusions The emergence of adolescent MDD and GAD may have significant implications on the inpatient stay for patients undergoing major surgery, including PSF for adolescent idiopathic scoliosis.

Study Design: Systematic review (update). Objective: Degenerative cervical myelopathy (DCM) is a progressive degenerative spine disease that is increasingly managed surgically. The objective of this study is to determine the role of nonoperative treatment in the management of DCM by updating a systematic review published by Rhee and colleagues in 2013. The specific aims of this review were (1) to determine the comparative efficacy, effectiveness, and safety of nonoperative and surgical treatment; (2) to assess whether myelopathy severity differentially affects outcomes of nonoperative treatment; and (3) to evaluate whether activities or minor injuries are associated with neurological deterioration. Methods: Methods from the original review were used to search for new literature published between July 20, 2012, and February 12, 2015. Results: The updated search yielded 2 additional citations that met inclusion criteria and compared the efficacy of conservative management and surgical treatment. Based on a single retrospective cohort, there were no significant differences in posttreatment Japanese Orthopaedic Association (JOA) or Neck Disability Index scores or JOA recovery ratios between patients treated nonoperatively versus operatively. A second retrospective study indicated that the incidence rate of hospitalization for spinal cord injury was 13.9 per 1000 person-years in a nonoperative group compared with 9.4 per 1000 person-years in a surgical group (adjusted hazard ratio = 1.57; 95% confidence interval = 1.11-2.22; P = .011). Conclusion: Nonoperative management results in similar outcomes as surgical treatment in patients with a modified JOA ≥ 13, single-level myelopathy and intramedullary signal change on T2-weighted magnetic resonance imaging. Furthermore, patients managed nonoperatively for DCM have higher rates of hospitalization for spinal cord injury than those treated surgically. The overall level of evidence for these findings was rated as low.

Study Design: Guideline development. Objectives: The objective of this study is to develop guidelines that outline how to best manage (1) patients with mild, moderate, and severe myelopathy and (2) nonmyelopathic patients with evidence of cord compression with or without clinical symptoms of radiculopathy. Methods: Five systematic reviews of the literature were conducted to synthesize evidence on disease natural history; risk factors of disease progression; the efficacy, effectiveness, and safety of nonoperative and surgical management; the impact of preoperative duration of symptoms and myelopathy severity on treatment outcomes; and the frequency, timing, and predictors of symptom development. A multidisciplinary guideline development group used this information, and their clinical expertise, to develop recommendations for the management of degenerative cervical myelopathy (DCM). Results: Our recommendations were as follows: (1) “We recommend surgical intervention for patients with moderate and severe DCM.” (2) “We suggest offering surgical intervention or a supervised trial of structured rehabilitation for patients with mild DCM. If initial nonoperative management is pursued, we recommend operative intervention if there is neurological deterioration and suggest operative intervention if the patient fails to improve.” (3) “We suggest not offering prophylactic surgery for non-myelopathic patients with evidence of cervical cord compression without signs or symptoms of radiculopathy. We suggest that these patients be counseled as to potential risks of progression, educated about relevant signs and symptoms of myelopathy, and be followed clinically.” (4) “Non-myelopathic patients with cord compression and clinical evidence of radiculopathy with or without electrophysiological confirmation are at a higher risk of developing myelopathy and should be counselled about this risk. We suggest offering either surgical intervention or nonoperative treatment consisting of close serial follow-up or a supervised trial of structured rehabilitation. In the event of myelopathic development, the patient should be managed according to the recommendations above.” Conclusions: These guidelines will promote standardization of care for patients with DCM, decrease the heterogeneity of management strategies and encourage clinicians to make evidence-informed decisions.

Anterior cervical discectomy and fusion can be performed for a variety of pathologies but is most commonly used for the treatment of cervical radiculopathy or myelopathy. The procedure involves an anterior decompression of the disc space followed by interbody grafting and fusion. Supplemental anterior plating is commonly performed, and in certain circumstances, posterior instrumentation may provide additional fixation. The procedure includes the following steps: (1) The use of an anterior approach to the cervical spine, most commonly the Smith-Robinson approach medial to the sternocleidomastoid muscle and the carotid sheath. (2) Confirmation of the proper spinal level. (3) Elevation of the longus colli muscle, which acts as a cuff for the placement of retractors. (4) Removal of the involved disc and decompression of the spinal cord and nerve roots. This is facilitated by disc space distraction, most commonly via distraction pins. Osteophytes along the floor of the spinal canal impinging on the spinal cord are removed with a burr. Soft disc and anular material are also removed, usually with curets and rongeurs. Uncovertebral osteophyte resection and foraminotomies are completed to decompress the exiting nerve roots. (5) Carpentry and decortication of the end plates in preparation for fusion. (6) Sizing of the disc space followed by insertion of an interbody graft. (7) Anterior fixation, most commonly via application of a plate-and-screw construct. (8) Hemostasis and closure.

Study design: Cross-sectional survey. Objectives: To obtain information from the global community regarding cervical artificial disc replacement (C-ADR) use and trends before and after US Food and Drug Administration (FDA) approval of devices in 2007 and summarize available information on utilization and government approval for devices. Methods: Data on utilization and approval were sought from PubMed, Google, FDA, and manufacturers’ websites. The 6195 members of AOSpine International were invited to participate in a survey to assess global C-ADR use and trends. Results: Publically available data on utilization, trends, and approval outside of the US and Europe is limited. No studies of utilization were found. Of 1479 professionals responding to the survey, 50% had C-ADR specific training and reported ever performing C-ADR. Most respondents believed that C-ADR was safe and effective, but approximately one quarter responded that they did not know. Of those who had done C-ADR, 49% reported performing ≥ 1 before December compared with 92% after January 2008 and 51.3% indicated that all their C-ADRs were placed in a single level; 27% reported ≥ 1 failures that required revision. The majority foresee that C-ADR use will increase in the next 5 years. Most respondents believed that the best indication is radiculopathy from soft-disc pathology rather than myelopathy or disorders arising from spondylotic (hard-disc) pathology. Conclusion: More C-ADR has been performed after January 2008. Most respondents expect the number to increase. There may be differences in failure rates when performed inside or outside of a sponsored research trial.

Poly(trimethylene terephthalate)/acrylonitrile–butadiene–styrene (PTT/ABS) blends were prepared by melt processing with and without epoxy or styrene–butadiene–maleic anhydride copolymer (SBM) as a reactive compatibilizer. The miscibility and compatibilization of the PTT/ABS blends were investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), capillary rheometer and scanning electron microscopy (SEM). The existence of two separate composition-dependent glass transition temperatures (Tgs) indicates that PTT is partially miscible with ABS over the entire composition range. In the presence of the compatibilizer, both the cold crystallization and glass transition temperatures of the PTT phase shifted to higher temperatures, indicating their compatibilization effects on the blends. The PTT/ABS blends exhibited typical pseudoplastic flow behavior. The rheological behavior of the epoxy compatibilized PTT/ABS blends showed an epoxy content-dependence. In contrast, when the SBM content was increased from 1 wt% to 5 wt%, the shear viscosities of the PTT/ABS blends increased and exhibited much clearer shear thinning behavior at higher shear rates. The SEM micrographs of the epoxy or SBM compatibilized PTT/ABS blends showed a finer morphology and better adhesion between the phases.

The influences of various carbonization temperatures on electrical resistivity and morphologies of polyacrylonitrile (PAN)-based nanofiber webs were studied. The diameter size distribution and morphologies of the nanofiber webs were observed by a scanning electron microscope. The electrical resistivity behaviors of the webs were evaluated by a volume resistivity tester. From the results, the volume resistivity of the carbon webs was ranged from to , and the average diameter of the fiber webs was varied in the range of 310 to 160 nm with increasing the carbonization temperature. These results could be explained that the graphitic region of carbon webs was formed after carbonization at high temperatures. And the amorphous structure of polymeric fiber webs was significantly changed to the graphitic crystalline, resulting in shrinking the size of fiber diameters.

Ibuprofen (IBU), is a non-steroidal anti-inflammatory drug, used to treat rheumatoid arthritis, removal of fever and mild to moderate pain. Because of small dosage and very low accumulation in the body, IBU has been used to heal children's fever. However, IBU was very low solubility in a low pH and water (in water mg/ml). A nanoemulsion containing IBU by means of self-microemulsion drug delver system (SMEDDS) was prepared in order to enhance the solubility of IBU. The SMEDDS was composed of cosurfactant, oil and surfactant The solubility of IBU in various components such as cosurfactant, oil and surfactant was examined. as a cosurfactant, M1944CS as an oil and RH-40 as a surfactant were used in this study for preparing SMEDDS. Optimized formulation of SMEDDS was obtained by phase diagram which express the section of nanoemulsion formation. The SMEDDS containing IBU had higher dissolution rate than conventional IBU sirups. Thus the SMEDDS was a potential candidate of stable conventional and effective oral dosage form for IBU.

The pathway producing imide ring closure during the thermal imidization of poly(amic acid) (PAA) was investigated in detail using a new analytical method, two-dimensional (2D) Raman correlation spectroscopy. The signs of the cross peaks in synchronous spectra provided evidence of the thermal imidization of PAA into PI as the heating temperature increased. The signs of the cross peaks in asynchronous spectra suggested that the imide-related modes changed prior to the amide or carboxylic mode, which indicates that cyclization occurred before the amide proton was abstracted.

Polymer Science and Technology, Chonbuk National University, Chonju, Chonbuk 561-756, KoreaDepartment of Chemistry, Kunsan National University, Kunsan, Chonbuk 573-701, KoreaReceived November 27, 2001Keywords : Raman, Liquid crystal, Intermolecular interaction, Coil effect, Hydrogen bonding.IntroductionLiquid crystalline polymers (LCPs) have been intensivelystudied for their scientific and technological interests. AmongLCPs, rod-coil types have recently drawn attention, parti-cularly in relation to their likelihood to form various kinds ofsupramolecules depending on chain lengths. The LCPs basedon a biphenyl ester moiety can have different microscopicstructures. Most poly(ethylene oxide)s (PEO)-based LCPsresult in a layered smectic mesophase

Macroreticular copolymer beads were prepared by suspension polymerization of 4-vinylbenzyl chloride (VBC), divinylbenzene (DVB) and monomers with carboxylic ester groups like dibutyl maleate (DBM), dibutyl fumarate (DBF) and dibutyl itaconate (DBI) in the presence of toluene as diluent. The copolymer beads were phosphorylated at the chloromethylated phenyl rings with triethyl phosphite and hydrolyzed by an aqueous sodium hydroxide solution; the hydrolysis on the bead surface converted carboxylic ester/phosphonate groups into carboxylic acid/phosphono groups, respectively. The investigations on the metal ion chelation characteristics of the H-form copolymer beads revealed that they have good adsorptivity toward heavy metal ions like Pb2+, Cd2+ and Cu2+, and poor adsorptivity toward ions like Hg2+ and UO22+. The adsorptivity caused by the three carboxylic ester monomer derivatives was in the order DBM > DBI > DBF. Especially, the Na-form copolymer beads neutralized by alkali treatment were very available for the adsorption of all the metal ions under investigation. Makroretikulare Copolymerperlen wurden durch Suspensionspolymerisation von 4-Vinylbenzylchlorid (VBC), Divinylbenzol (DVB) und mehreren Monomeren mit Carboxylestergruppen wie Dibutylmaleat (DBM), Dibutylfumarat (DBF) und Dibutylitaconat (DBI) in Toluol hergestellt. Die Copolymerperlen wurden an den chlormethylierten Phenylringen mit Triethylphosphit phosphoryliert und mit wasriger Natriumhydroxid-Losung hydrolysiert; durch die Hydrolyse auf der Oberflache der Perlen wurden Carboxylat- bzw. Phosphonatgruppen in Carboxylsaure- bzw. Phosphonogruppen umgewandelt. Die Copolymerperlen in der H-Form zeigten gute Adsorptionsfahigkeit gegenuber Schwermetallionen wie Pb2+, Cd2+ und Cu2+ und schlechte Adsorptionsfahigkeit gegenuber Ionen wie Hg2+ und UO22+. Die Adsorptionsfahigkeit der drei Monomerderivate mit Carboxylestergruppen verlauft in der Reihe DBM > DBI > DBF. Besonders die durch alkalische Behandlung neutralisierten Copolymerperlen in der Na-Form waren sehr gut fur die Adsorption aller untersuchten Metallionen geeignet.

Introduction Debate continues about the relative merits of anterior versus posterior surgery for multilevel cervical stenosis causing myelopathy. Conclusions from previous studies were limited because one- or two-level anterior surgeries have been compared with multilevel posterior cases. The objective of this study was to compare outcomes and complications of anterior versus posterior-based cervical procedures (≥ 4 levels) for patients with multilevel disease. Material and Methods Data from the AOSpine North America Cervical Spondylotic Myelopathy Study, a prospective, multicenter study, were analyzed. A subset of patients with myelopathy involving four or five vertebrae was analyzed in this study. The outcome measures included NDI, modified-Japanese Orthopaedic Association scores, SF36v2, and Nurick grades. Adverse events were also collected in a standardized manner and externally monitored. Rates of perioperative complications (within 30 days of surgery) and delayed complications (31 days–2 years following surgery) were tabulated and stratified based on clinical factors. Results Of the 264 patients in the main study, 113 patients (42.8%) had four or more levels of surgery. There were 49 patients who underwent anterior cervical surgery (ACS, combination of anterior cervical decompression fusion ± corpectomy) and 64 patients who underwent posterior-based cervical surgeries (PCS, 45 laminectomy + fusion, 19 laminoplasty). There were statistically significant differences in age, cardiovascular comorbidities, and source of stenosis between these two groups. There was a statistically significant difference in baseline Nurick grades between groups (2.8 ACS vs. 3.3 PCS, p = 0.0075). There was no difference in any outcome measures at baseline. Outcome scores improved in both the ACS and PCS groups from baseline over a period of 2 years. There were no statistically significant differences between the anterior and posterior surgical procedures in terms of outcomes at 2 years ( p > 0.05). This was true for NDI, mJOA, SF36v2, and Nurick scores for both unadjusted and adjusted analyses. There was no significant difference in complication rates between ACS and PCS groups. Each group had 14 reported complications (total 28). Both the groups reported two postoperative C5 radiculopathies. There was one reoperation in the ACS group. Worsening of neck pain was reported in one patient who had an anterior corpectomy/fusion procedure and there was one case of infection in the PCS group. Two patients in the ACS group had worsening of myelopathy. Conclusion In patients with four or five involved vertebral levels of pathology that require surgical intervention for cervical myelopathy, both anterior and posterior surgical procedures demonstrate improved outcomes. With this dataset, we found no evidence of difference between anterior versus posterior surgical procedures in outcomes or associated complication rates. Surgical decision-making related to approach and technique to address issues in these patients can be made by surgeons based on their judgment and experience with these procedures. The limitations of this study include (1) a nonrandomized study design and (2) the grouping together of different subtypes of anterior or posterior procedures.

Study Design: Retrospective comparative study. Purpose: To assess differences in computed tomography (CT) imaging parameters between patients with cervical myelopathy and controls. Overview of Literature: There is a lack of information regarding the best predictor of symptomatic stenosis based on osseous canal dimensions. We postulate that smaller osseous canal dimensions increase the risk of symptomatic central stenosis. Methods: CT images and medical records of patients with cervical myelopathy (19 patients, 8 males; average age, 64.4±13.4 years) and controls (18 patients, 14 males; average age, 60.4±11.0 years) were collected. A new measure called the laminar roof pitch angle (=angle between the lamina) was conducted along with linear measures, ratios and surrogates of canal perimeter and area at each level C2–C7 (222 levels). Receiver-operator curves were used to assess the diagnostic value of each. Rater reliability was assessed for the measures. Results: The medial-lateral (ML) diameter (at mid-pedicle level) and calculated canal area (=anterior-posterior.×ML diameters) were the most accurate and highly reliable. ML diameter below 23.5 mm and calculated canal area below 300 mm 2 generated 82% to 84% sensitivity and 67% to 68% sensitivity. No significant correlations were identified between age, height, weight, body mass in dex and gender for each of the CT measures. Conclusions: CT measures including ML dimensions were most predictive. This study is the first to identify an important role for the ML dimension in cases of slowly progressive compressive myelopathy. A ML reserve may be protective when the canal is progressively compromised in the anterior-posterior dimension.

Anterior cervical plating is commonly performed to stabilize anterior cervical fusions. Modern plating options include dynamic plates, with screws that can either toggle within fixed holes or translate within slotted holes. Regardless of the plating system used, paramount to success and avoidance of complications with plated anterior cervical fusions are meticulous plating techniques, exacting graft carpentry, and understanding the biomechanical limitations of plating in certain situations, such as multilevel corpectomies reconstructed with a single-strut graft. In order to prevent graft-related complications associated with long-strut grafts, additional posterior fixation and fusion, or alternative corpectomy constructs, such as multilevel anterior cervical discectomy and fusion, corpectomy-discectomy, and corpectomy-corpectomy, should be considered instead if the pattern of stenosis allows.

Background To date, there has been no adequate biomechanical model that would allow a quantitative comparison in terms of stability/stiffness between a corpectomy with the posterior column preserved and a total spondylectomy with the posterior column sacrificed. The objective of this study was to perform a biomechanical comparison of 360° stabilizations for corpectomy and total spondylectomy, using the human thoracolumbar spine. Methods Five human cadaveric thoracolumbar spines (T8-L2) were tested according to the following loading protocol: axial compression, flexion, extension, lateral bending to the right and left, and axial rotation to the right and left. This loading protocol was applied three times. Each specimen was tested intact, after corpectomy, and after total spondylectomy. The relative stiffness of each motion segment was determined for each test. Results There was no significant difference in stiffness after reconstruction of total spondylectomy versus corpectomy in our thoracolumbar model. Our construct consisted of an anterior cage and four-level pedicle screw instrumentation (two above and two below) and provided similar stiffness in both models. Despite the additional bone resection in a total spondylectomy versus corpectomy, the constructs did not differ biomechanically. Additionally, there was no significant difference in stiffness between the intact specimen and either reconstruction model. Conclusions A classic corpectomy, which leaves the posterior column intact, is no better in terms of stability/stiffness than a total spondylectomy carried out using a shorter cage, followed by compression using posterior instrumentation.