bluuebunny/crossref_metadata_2025 huggingface dataset:
110 Subfascial Lipomatous Tumors
Authors: Einarsdottir H. , Söderlund V. , Larsson O. , Mandahl N. , Bauer H. C. F.
Published: October 2009

Purpose: To evaluate whether liposarcoma, atypical lipomatous tumors and lipoma can be differentiated radiologically.

Material and Methods: We have retrospectively analyzed CT and/or MR images of 110 subfascial lipomatous lesions. the amount of fat within the tumors was visually graded from the images as: none, 1–75%, 75–95% or 95–100%. the structure of non-fatty tumor components was compared. the images were compared to histopathology and in 37 cases to cytogenetic findings.

Results: Only 4 of 20 liposarcomas contained fat. All 4 lesions, histopathologically diagnosed as atypical lipomatous tumors, contained fat but less than 75% of tumor volume. All lesions with more fat than 75% of tumor volume were histologically diagnosed as lipomas. However, one-third of the karyotyped lipomas had ring chromosomes which are considered typical for atypical lipomatous tumors.

Conclusion: When a tumor is composed more or less solely of fat, the diagnosis of a lipoma or atypical lipomatous tumor with a phenotype simulating a lipoma can be assumed. When the fat content is less than 75% of the tumor volume or non-fatty nodules are found, biopsies from different tumor components have to be performed to exclude malignancy. When no fat is found, imaging does not help in differentiating lipoma or liposarcoma from other soft tissue tumors.
MR Assessment of Movement and Morphologic Change in the Menisci during Knee Flexion
Authors: Kawahara Y. , Uetani M. , Fuchi K. , Eguchi H. , Hayashi K.
Published: October 2009

Purpose: To examine movement and morphologic alteration in the menisci during knee flexion.

Material and Methods: Twenty healthy knees were imaged at 0°, 45°, and 90° of passive non-weight-bearing flexion in the sagittal plane with MR. In each meniscus, posterior movement distance during knee flexion and the ratio of anteroposterior (a.p.) diameter at flexion to that at extension were calculated.

Results: Each meniscus moved posteriorly during knee flexion. Movement was greater in the anterior horn than in the posterior horn, and greater in the medial meniscus than in the lateral meniscus (p<0.05). the a.p. diameter of each meniscus was reduced at flexion (p<0.05).

Conclusion: Knee flexion normally leads to posterior movement and shortening of the a.p. diameter of the menisci, which may be related to the positioning and curvature of femoral condyles at the femorotibial contact point at knee flexion.
MR Imaging in Suspected Acute Trauma of Wrist Bones
Authors: Lohman M. , Kivisaari A. , Vehmas T. , Kinnunen J. , Karaharju E. , Kaukonen J.-P. , Kivisaari L.
Published: October 2009

Objective: the purpose of this study was to evaluate the findings of MR imaging compared to plain radiography in acute wrist trauma.

Methods: Radiography and MR imaging (obtained at 1.5 T) of 67 patients (38 female, 29 male, aged 15–80 years) were analysed by three senior radiologists in a blinded random fashion.

Results: One-third (n=13) of the 37 fractures observed on MR images were missed on the radiographs. the McNemar test indicated significant differences in diagnoses between radiography and MR.

Conclusion: We recommend that MR imaging should be considered in the diagnosis of acute wrist trauma when: 1) There is a clear discrepancy between the clinical status and a negative radiography and when splint treatment would increase cost by causing occupational restrictions; and 2) Healing of trauma diagnosed as contusion or distension does not occur within the expected time.
Ultrasonographic Localization of a Displaced Screw in the Carpal Canal
Authors: Grechenig W. , Peicha G. , Clement H. G. , Preidler K. W.
Published: October 2009

We present a case of a 65-year-old patient with a surgically treated distal radius fracture. At 5-month follow-up, conventional radiography revealed breakage of the plate and a screw displaced into the volar soft tissue. Preoperative ultrasonography including dynamic assessment of the tendons showed the screw intratendinously as a hyperechogenic structure with repetitive echoes. This unusual localization was proven by surgery. Dynamic ultrasonography played an important diagnostic role in the localization of the loosened and displaced osteosynthetic material.
Spio-MR Imaging versus Double-Phase Spiral CT in Detecting Malignant Lesions of the Liver
Authors: Müller R.-D. , Vogel K. , Neumann K. , Hirche H. , Barkhausen J. , Stöblen F. , Henrich H. , Langer R.
Published: October 2009

Purpose: To assess the diagnostic performance of superparamagnetic iron oxide MR (SPIO-MR) imaging compared with double-phase spiral CT in detecting liver metastases and hepatocellular carcinoma.

Material and Methods: Thirty-eight patients with a total of 144 malignant lesions of the liver were examined by CT and SPIO-MR. After definition of a gold standard by a panel of experts, the patient images were randomized and presented to a blinded jury of 5 independent observers whose task was to identify as many lesions as possible. the results were tested for statistical significance using multifactorial analysis of variance (α=5%).

Results: SPIO-MR produced the highest detection rate and was significantly superior ( p<0.05) to unenhanced MR imaging and double spiral-phase contrast-enhanced CT (DPS-CECT). Maximum performance in DPS-CECT was obtained during the portal venous contrast phase but was significantly inferior to SPIO-MR imaging. the scores for unenhanced CT and unenhanced MR were significantly lower than for the corresponding enhanced procedures. SPIO-MR imaging produced a higher incidence of false-positive findings (n=39).

Conclusion: SPIO-MR produced a significantly better detection rate for malignant focal liver lesions compared with double-phase spiral DPS-CECT but was associated with a higher rate of false-positive findings.
Single-Session Alcohol Sclerotherapy in Symptomatic Benign Hepatic Cysts
Authors: Larssen T. B. , Jensen D. K. , Viste A. , Horn A.
Published: October 2009

Purpose: To evaluate the long-term results of single-session alcohol sclerotherapy of symptomatic benign liver cysts.

Material and Methods: 23 cysts in 19 patients were treated by single-session percutaneous catheterization and injection of 96% ethanol. Evaluation of long-term results was possible in 11 cysts (volume 200–2700 ml, mean 1,317 ml) in 11 patients. Time of observation was 12–67 months, mean 38.3 months.

Results: the reduction of volume was 93–100% (mean 98%). the re-accumulation of fluid after therapy seen in 9 patients proved to be transitory. Except for pain there were no complications.

Conclusion: Single-session sclerotherapy resulted in satisfactory cyst volume reduction in all 11 long-term follow-up patients.
Transcatheter Embolization of a Superior Mesenteric Artery Pseudoaneurysm
Authors: Hama Y. , Kaji T. , Iwasaki Y. , Kyoto Y. , Kawarabayashi N. , Hatsuse K. , Kusano S.
Published: October 2009

A 61-year-old man, with pseudoaneurysm of the superior mesenteric artery presenting with gastrointestinal bleeding, was successfully treated by transcatheter embolization using interlocking detachable coils. During the following observation time of 10 months, the patient had no sign of gastrointestinal bleeding. We underline the importance and feasibility of transcatheter embolization as the first-line treatment in such pseudoaneurysms.
Predicting the Effect of Gonadotropin-Releasing Hormone (GnRH) Analogue Treatment on Uterine Leiomyomas Based on MR Imaging
Authors: Matsuno Y. , Yamashita Y. , Takahashi M. , Katabuchi H. , Okamura H. , Kitano Y. , Shimamura T.
Published: October 2009

Purpose: To test the hypothesis that the simple assessment of signal intensity on T2-weighted MR images is predictive of the effect of hormonal treatment with gonadotropin-releasing hormone (GnRH) analogue.

Material and Methods: The correlation between T2-weighted MR imaging of uterine leiomyomas and histologic findings was evaluated using 85 leiomyomas from 62 females who underwent myomectomy or hysterectomy. We also correlated the pretreatment MR images features obtained in 110 women with 143 leiomyomas with the effect of GnRH analogue treatment. The size (length×width×depth) of the leiomyoma was evaluated before and at 6 months after treatment by ultrasound.

Results: The proportion of leiomyoma cell fascicles and that of extracellular matrix affected signal intensities of uterine leiomyomas on T2-weighted MR images. The amount of extracellular matrix was predominant in hypointense leiomyomas on T2-weighted images, while diffuse intermediate signal leiomyomas were predominantly composed of leiomyoma cell fascicles. Marked degenerative changes were noted in leiomyomas with heterogenous hyperintensity. The homogeneously intermediate signal intensity leiomyomas showed significant size reduction after treatment (size ratio; posttreatment volume/pretreatment volume 0.29±0.11). The size ratio for the hypointense tumors was 0.82±0.14, and 0.82±0.18 for the heterogeneously hyperintense tumors. There was a significant difference in the response to treatment between the homogeneously intermediate signal intensity leiomyomas and the hypointense or heterogeneously hyperintense leiomyomas (both p<0.01).

Conclusion: Signal intensity on T2-weighted MR images depends on the amount of leiomyoma cell fascicles and extracellular matrix. Simple assessment of the MR signal intensity is useful in predicting the effect of GnRH analogue on uterine leiomyomas.
Open Reduction Internal Fixation versus Primary Arthrodesis for Lisfranc Injuries: A Prospective Randomized Study
Authors: Henning Jeffrey A. , Jones Clifford B. , Sietsema Debra L. , Bohay Donald R. , Anderson John G.
Published: October 2009

Background:

Dislocations and fracture-dislocations involving the tarsometatarsal joint are a relatively common injury. These injuries are associated with long-term disability from subsequent painful osteoarthritis and residual deformity. This study evaluated whether performing a primary arthrodesis (PA) resulted in improved functional outcome and fewer subsequent surgeries as compared to primary open reduction and internal fixation (PORIF).

Materials and Methods:

Forty patients with acute tarsometatarsal joint fractures or fracture dislocations were prospectively randomized to undergo either PORIF or PA. Clinical and radiographic examination, in addition to Short Form-36 (SF-36) and Short Musculoskeletal Function Assessment (SMFA) questionnaires, were evaluated at intervals of 3, 6, 12, and 24 months following surgery in 32 patients. A patient satisfaction phone survey was also performed.

Results:

The rate of planned and unplanned secondary surgeries, including hardware removal and salvage arthrodesis, between ORIF and PA groups, 78.6% vs. 16.7% was significantly different. No statistically significant differences were found with physical functioning for the PORIF or PA groups with regard to SF-36 or SMFA scores at any followup time interval. However, time from injury had a significant effect with impaired functioning at three months compared to all future intervals. No difference in satisfaction rates were found between PORIF and PA at an average of 53 months in a phone survey.

Conclusion:

PA of tarsometatarsal joint injuries resulted in a significant reduction in the rate of followup surgical procedures if hardware removal is routinely performed with no significant difference in SF-36 and SMFA outcome scores when compared to PORIF. Level of Evidence: I, Prospective Randomized Study
Instability of the First Metatarsal-Cuneiform Joint: Diagnosis and Discussion of an Independent Pain Generator in the Foot
Authors: Cooper Andrew J. , Clifford Paul D. , Parikh Viraj K. , Steinmetz Neil D. , Mizel Mark S.
Published: October 2009

Background:

First metatarsocuneiform (MC) instability is recognized as a pathologic contributor to hallux valgus. There are no studies identifying the first MC joint as an independent pain generator in the foot that may require surgical arthrodesis for its management.

Materials and Methods:

The authors reviewed the records of all patients with this newly described pathology in the first MC joint. There were 61 patients with 85 feet who underwent a fluoroscopically guided local anesthetic injection into the first metatarsocuneiform joint to assess pain relief. Patient's complaints, physical exam findings, treatment decisions, patient characteristics, and radiographic findings were evaluated.

Results:

Seventy-nine percent of patients (67/85) injected had relief of their symptoms. Eight or these 67 patients were eventually treated with first MC arthrodesis with complete relief of symptoms. The average time from onset of symptoms to presentation was 21 (range, 1 to 72) months. Eighty-five percent of feet (72/85) had multiple previous diagnoses. Radiographic plantar widening of the first M-C joint on weightbearing views was inconsistent with pathology.

Conclusion:

The first MC joint is an independent pain generator in the foot that can have variable presentations. Radiographic data can often be helpful, but clinical exam findings are paramount in the diagnosis. Fluoroscopically-guided long acting local anesthetic injections of this joint are helpful in the diagnosis, especially in the patient with multiple possible pain generators in the foot and ankle. Failure to recognize the first MC joint as a source of pain may lead to delay in treatment, misdiagnosis, and mistreatment of foot pathology. Level of Evidence: IV, Retrospective Case Series
Ankle Replacement: Current Practice of Foot & Ankle Surgeons in the United Kingdom
Authors: Goldberg Andrew J. , Sharp Robert J. , Cooke Paul
Published: October 2009

Background:

The main surgical treatments for end stage ankle arthritis are arthrodesis and total ankle replacement (TAR). In Europe, there are now more than 11 different prostheses, most with limited outcome data. This study aimed to determine the number and types of implants used in the United Kingdom.

Materials and Methods:

A questionnaire based survey was sent to all Consultant members of the British Orthopaedic Foot & Ankle Society ( n = 180).

Results:

Sixty-eight percent completed the questionnaires. Thirty percent of respondents were not performing ankle joint replacements at the time of the survey. The mode number of ankle replacements carried out per year by Foot and Ankle Specialists was eight.

Conclusion:

The UK has a population of 60 million and surgeons are implanting at least 800 ankle replacements per year. More surgeons are beginning to perform ankle replacements in small numbers and a UK National Joint Registry for Ankle Replacements is in development. Currently, none of the fixed bearing implants being used in the United States are being used in the United Kingdom and although the number of ankle replacements implanted in the United States is unknown, it is predicted that this type of surgery could have a significant impact on insurers and healthcare providers in the future.
Clinical Evaluation and Radiographic Assessment of Bone Lysis of the AES Total Ankle Replacement
Authors: Besse Jean-Luc , Brito Nuno , Lienhart Christophe
Published: October 2009

Background:

AES mobile-bearing total ankle replacement is evolved from the Buechel Pappas model. We report medium-term results of a prospective study with AES.

Materials and Methods:

All patients who underwent AES TAR for ankle arthritis, by a single surgeon, from 2003 to 2006 were included, excluding neurologic disease, talar osteonecrosis and malalignment more than 20 degrees. All were reviewed at 6 months, 1 year, and at yearly intervals thereafter. X-rays were analyzed by three observers, using a 10-zone protocol. Fifty consecutive AES implants in 47 patients (mean age, 56 years; range, 21 to 79 year) were included, with at least 2 years' followup (mean 40 months). Preoperative diagnosis was mainly post-traumatic (50%) and osteoarthritis secondary to instability (36%). Associated procedures were performed in 38%.

Results:

Eighty-two percent had good functional results. The mean AOFAS score rose from 36.9 ± 1.7 preoperatively to 85.4 ± 12, dorsiflexion from 3 degrees to 7.3 degrees, and plantarflexion from 30.8 degrees to 37.8 degrees. Two ankles underwent secondary arthrodesis for talar subsidence and mechanical dislocation. Ninety-eight percent of implants were well positioned at 90 degrees ±4. Mean prosthesis ROM on X-ray was 22.1 degrees. There were tibia/implant interface cysts (greater than 5 mm) in 62% of cases, and talar/implant interface cysts in 43%.

Conclusion:

Although functional outcomes were comparable to the other mobile TAR in the literature, bone lysis with the AES prosthesis was more frequent with risk of subsidence. We therefore stopped implantation of this prosthesis and recommend preventive grafting for severe lysis. Level of Evidence: IV, Retrospective Case Series
Proximal Opening-Wedge Osteotomy of the First Metatarsal for Hallux Valgus Using a Low Profile Plate
Authors: Saragas Nikiforos P.
Published: October 2009

Background:

This retrospective study was conducted to evaluate the results of the proximal (basal) opening-wedge osteotomy of the first metatarsal for correction of symptomatic hallux valgus deformity, using a low profile plate.

Materials and Method:

The procedure was performed by a single surgeon over an 18-month period. Forty-six patients (64 feet) were treated for symptomatic hallux valgus with an average follow up of 20 months. A proximal opening-wedge osteotomy of the first metatarsal and fixation with a low profile plate in combination with a distal soft tissue release with the same postoperative protocol was used in all the patients. Improvement in the hallux valgus angle (HV) and I—II intermetatarsal angle (IM I—II) as well as the AOFAS forefoot score pre and postoperatively (obtained retrospectively from the medical records), were recorded; in particular, the length of the first metatarsal was noted pre- and postoperatively.

Results:

The HV and IM I—II angles improved by a mean of 14.7 degrees and 6.4 degrees, respectively. The AOFAS forefoot score improved from a mean of 51.3 to 86.8. The mean increase in the length of the first metatarsal was 2.3 mm. Of the more significant complications, five patients developed a hallux varus (early in the series), one of which was symptomatic, and there was one non-union requiring bone graft.

Conclusion:

The proximal opening wedge osteotomy of the first metatarsal in combination with a distal soft tissue release and stable fixation of the low profile plate was an effective method for correcting a moderate hallux valgus deformity. Guidance provided by the “First Metatarsal Opening Wedge Angle Reference Chart” was found to be helpful for the IM I–II angle correction. Level of Evidence: IV, Retrospective Case Series
Radiography versus Computed Tomography for Displacement Assessment in Calcaneal Fractures
Authors: Ogawa Brent K. , Charlton Timothy P. , Thordarson David B.
Published: October 2009

Background:

Coronal computed tomography (CT) scans are commonly used in fracture classification systems for calcaneus fractures. However, they may not accurately reflect the amount of fracture displacement. The purpose of this paper was to determine whether lateral radiographs provide superior assessment of the displacement of the posterior facet compared to coronal CT scans.

Materials and Methods:

Lateral radiographs of calcaneus fractures were compared with CT coronal images of the posterior facet in 30 displaced intra-articular calcaneus fractures. The average patient age was 39 years old. Using a Picture Archiving and Communication System (PACS), measurements were obtained to quantify the amount of displacement on the lateral radiograph and compared with the amount of depression on corresponding coronal CT scans.

Results:

On lateral radiographs, the angle of the depressed portion of the posterior facet relative to the undersurface of the calcaneus averaged 28.2 degrees; Bohler's angle averaged 12.7 degrees. These numbers were poorly correlated ( r = 0.25). In corresponding CT images from posterior to anterior, the difference in the amount of displacement of the lateral portion of the displaced articular facet versus the nondisplaced medial, constant fragment, was minimal and consistently underestimated the amount of displacement.

Conclusion:

Underestimation of the amount of depression and rotation of the posterior facet fragment was seen on the coronal CT scan. We attribute this finding to the combined rotation and depression of the posterior facet which may not be measured accurately with the typical semicoronal CT orientation. While sagittal reconstructed images would show this depression better, if they are unavailable we recommend using lateral radiographs to better gauge the amount of fracture displacement. Level of Evidence: IV, Retrospective Case Series
Side-to-Side Difference in Joint Position Sense and Kinesthesia in Unilateral Functional Ankle Instability
Authors: Lim Edwin Choon Wyn , Tan Mann Hong
Published: October 2009

Background:

Impairment in proprioception has been suggested to be one of the causes of FAI. This study aimed to establish intra-session reliability of the Biodex System 2 in assessing joint position sense (JPS) and kinesthesia (K) in addition to determining if there was any side to side difference in JPS and kinesthesia in people with unilateral functional ankle instability.

Materials and Methods:

Both JPS and K were determined by means of the Biodex Systems 2. During evaluation of JPS, participants' ability to actively reproduce ankle joint position was tested three times in each of the two predetermined positions. During evaluation of K, data collection began with the foot placed in a starting position of 0 degrees (neutral position).

Results:

A total of 25 participants (mean age 22.0 years, 95% confidence interval 19.9 to 24.1 years) were recruited into this study. No difference in JPS ( p = 0.162 to 0.764) and K ( p = 0.089 to 0.683) were found between the sprained and uninvolved ankle of subjects with unilateral functional ankle instability. There is moderate to good intra-session reliability in using the Biodex System 2 to assess JPS (ICC = 0.868 to 0.950, p < 0.01) and K (ICC = 0.825 to 0.893, p < 0.01).

Conclusion:

This study suggests that there is perhaps no difference in JPS and K between both ankles in people with unilateral FAI. Proprioceptive deficits may not always be present in every case of FAI.

Clinical Relevance:

Proprioceptive training may not be beneficial in some patients with unilateral FAI.
Portable Image Analysis System for Characterizing Aggregate Morphology
Authors: Wang Linbing , Lane D. Stephen , Lu Yang , Druta Cristian
Published: October 2009

In the past decade, the application of image-based evaluation of particle shape, angularity, and texture has been widely researched to characterize aggregate morphology. Yet the lack of rapid, objective, and quantitative methods for assessment has inhibited its application in the engineering process. However, recent advances in technology have produced pocket computers with as much processing power as some desktop computers. This project takes advantage of these advances to develop an inexpensive portable image analysis system for characterizing aggregate morphology. The system uses an integral pocket computer–high resolution camera but can employ individual components consisting of a digital camera and a laptop or desktop computer. Digital images of coarse aggregate particles are captured with the camera and analyzed within the Matlab software program environment with a macro developed and written for this project to characterize particle morphology with respect to three parameters (shape, angularity, and texture) on the basis of the particle perimeter (outline or edge). For this purpose, several coarse aggregate types from 10 various Virginia sources were analyzed, and the reliability of the image processing was statistically assessed. Asymptotic analysis was performed to determine the number of images needed to obtain a statistically stable value for each aggregate parameter. It was determined that images acquired at close range (2 or 3 in.) were needed to provide sufficient resolution to adequately characterize the aggregates. Also, it was found that statistically valid values for the three aggregate parameters could be obtained from 15 particle images of random but stable orientation, thus making the system efficient in characterizing coarse aggregate morphology.
Predicting Asphalt Mixture Skid Resistance by Aggregate Characteristics and Gradation
Authors: Rezaei Arash , Masad Eyad , Chowdhury Arif , Harris Pat
Published: October 2009

The objective of this study was to investigate the influence of aggregate characteristics and gradation on the skid resistance of various asphalt mixtures. Asphalt mixture slabs with different combinations of aggregate sources and gradations were fabricated in the laboratory. These slabs were polished with a wheel-polishing device developed by the National Center for Asphalt Technology. The frictional characteristics of each slab were then measured by the sand patch method, British pendulum, dynamic friction tester, and circular texture meter. Aggregates used in these mixtures were characterized by petrographic analysis, conventional test methods (acid insolubility, magnesium soundness, Micro-Deval, and British polish value), and the aggregate imaging system (AIMS). In addition, the aggregate gradation of each mixture was described by the two-parameter cumulative Weibull distribution function. Statistical analysis of test results led to the development of a function for predicting the International Friction Index, which is a measure of skid resistance of asphalt mixtures, after different intervals of polishing. The parameters of this function were found to be related to ( a) initial and terminal aggregate texture measured by using AIMS, ( b) rate of change in aggregate texture measured by using AIMS after different polishing intervals in the Micro-Deval, and ( c) the Weibull distribution parameters describing aggregate gradation. This function can be useful for estimating the frictional characteristics of an asphalt mixture surface during the mixture design stage.
Modulus of Rubblized Portland Cement Concrete from Surface Wave Testing
Authors: Gucunski Nenad , Sauber Robert , Maher Ali , Rascoe Carl
Published: October 2009

Several Interstate portland cement concrete (PCC) pavement sections in New Jersey are being rubblized by multihead breaker equipment; the rubblized concrete is later compacted by several passes of vibratory Z-grid and rubber-wheel static rollers. To evaluate the modulus of the rubblized PCC and to compare it to the modulus of a typical dense graded aggregate base material, nondestructive evaluation using surface waves, implemented in a portable seismic property analyzer, was conducted. The elastic modulus is evaluated from the average velocity of surface waves, from the shortest measurable wavelength (about 2 in.) to one equal to an approximate thickness of the rubblized concrete (about 10 in.). In addition to the average velocity (modulus), the variation of the surface wave (phase) velocity with wavelength can be related to the variation of modulus with depth. The modulus obtained from seismic testing is a low-strain modulus, and appropriate corrections (reductions) should be provided to describe it as a resilient modulus. The modulus variation is largely constrained between 550 and 2,800 MPa (80 and 400 ksi), with an average modulus between 1,100 and 1,400 MPa (160 and 200 ksi). Significant modulus variation is attributed to the rubblization process, which provides the highest crushing of concrete near the surface; near the bottom, rubblized concrete appears more like fractured rock and can form an uneven interface between the two zones. In general, the modulus of rubblized PCC is higher than the modulus of a typical granular base.
Comprehensive Laboratory Testing and Performance Evaluation of Recycled Pulverized Hot-Mix Asphalt Material
Authors: Jeon Eung-Jin , Steven Bruce , Harvey John T.
Published: October 2009

The California Department of Transportation is studying a pavement rehabilitation strategy that involves the pulverization of failed hot-mix asphalt (HMA) pavements and uses the pulverized material as a granular base material in the reconstruction of the pavement. Advantages of this technique include a reduction in the use of virgin aggregates, a reduction in the amount of construction traffic, and removal of the potential for reflective cracking from the existing pavement layers. The construction and performance of four pilot projects in District 2 in northeastern California were used to evaluate this rehabilitation strategy. The characteristics and performance of the pulverized material were evaluated by comprehensive laboratory and field testing. The laboratory testing covered basic index tests and comprehensive triaxial testing. Multistage repeated-load permanent strain triaxial tests on different material gradations, stress levels, moisture contents, with and without stabilizing agents (lime and cement), and the degree of compaction were used to investigate the resilient and permanent strain characteristics. Testing was conducted on saturated samples to evaluate the effect of saturation on the pulverized material. The effects of the number of load repetitions were also investigated. The performance of the pulverized material was also compared with two typical virgin aggregate base materials from California. A life cycle cost analysis of this rehabilitation technique when compared to a typical HMA overlay showed that the recycling option was cheaper in both the short term and over the life of the pavement.
Validation of Sensitivity of Sulfate-Bearing Soils to Ettringite Growth by Differential Scanning Calorimetry
Authors: Little Dallas , Nair Syam
Published: October 2009

Considerable attention has been given to sulfate-induced heave in soils stabilized with calcium-based stabilizers over the past two decades. Empirical evidence has supported threshold values of water-soluble sulfates that are used as guidelines to define the risk of distress. This study uses two approaches to evaluate these sulfate threshold values as well as to compare the sensitivity of soils with different mineralogies to sulfate-induced damage. Five soils, each belonging to a different soil series and with significantly different chemistries and mineralogies, are evaluated. Differential scanning calorimeter and stoichiometric mass balance calculations based on a thermodynamics-based phase diagram approach are used to evaluate the influence of mineralogy on soil behavior. The variation in sensitivity of different soils to ettringite formation was substantiated and was found to be dependent on reactive clay content in the soil. Although the sensitivity of soils to ettringite formation was observed to change with the availability of reactive clay fractions, no definitive relationship was established between clay content and weight percentage of ettringite formed. The empirical threshold of about 3,000 ppm is generally substantiated as is the efficacy of the concept of extended mellowing periods with homogeneous mixing while adding as much mixing water as possible. Finally, a general agreement between the mass balance predictive approach and the direct measurement by using the differential scanning calorimeter was established.
Combining Geogrid Reinforcement and Lime Treatment to Control Dry Land Longitudinal Cracking
Authors: Luo Rong , Prozzi Jorge A.
Published: October 2009

In Texas, dry land longitudinal cracking on the farm-to-market network is one of the most prevalent pavement distresses caused by the volumetric change of expansive subgrade soils. Geogrid reinforcement and lime treatment are found to be the most effective methods to control dry land cracks. To provide a safer and more conservative approach for the pavement structure over expansive subgrade, it is desirable to combine the two methods to be more effective in controlling dry land cracks. This paper describes how to appropriately integrate geogrid and lime so that both methods can contribute to the prevention of longitudinal cracks due to the shrinkage of expansive subgrade. Finite element modeling shows that the best place to install the geogrid should be at the interface of the lime-treated layer and the untreated soil, which is close to the initiation location of shrinkage cracks. At this location, the geogrid can effectively reduce the stress concentration at the upper crack tip. A geogrid with higher stiffness provides more benefit. Lime treatment can improve the tensile strength and fracture toughness of the expansive soil, which further reduces the possibility of cracks propagating through the lime-treated layer. Therefore, the combination of geogrid reinforcement and lime treatment is efficient for the control of dry land longitudinal cracking. The development of multiple shrinkage cracks helps to decrease stress concentration at the crack tips when the geogrid stiffness is at a low level. If the geogrid has an extremely high stiffness, the effect of additional shrinkage cracks is not significant in the numerical simulation.
Deformation Properties of Untreated and Enzyme-Treated Bottom Ash Waste for Use in Foundations
Authors: Ahmed Abdelkader , Khalid Hussain
Published: October 2009

The use of waste and recycled materials in different construction applications is a widespread approach. In this work, incinerator bottom ash (IBA) waste was mixed with limestone at different levels, namely, 0%, 30%, 50%, and 80%, to produce blends for use as pavement foundation layers. The study focused on evaluating the resistance to permanent deformation of IBA–limestone blends, which is vital to prevent or minimize pavement rutting. An experimental program was undertaken to investigate the influence of plant-based enzyme treatment on the behavior of these blends. Cyclic and static triaxial compression tests were adopted to determine the materials’ mechanical characteristics. Emphasis was on examining the effect of various parameters, such as IBA content, enzyme content, moisture content, curing time, stress level, and number of load applications, on the behavior of the investigated blends. The accumulated permanent strain and strain rate were used to describe the blends’ shakedown stress limits. Results showed that IBA blends gave a favorable performance as foundation layers in comparison with the control limestone blend. Enzyme addition improved the permanent deformation resistance for the control limestone blend; however, it did not have any noticeable effect on the IBA blends. According to the shakedown concept analysis, all blends, at a cyclic stress level of more than 21% of the static failure stress, underwent excessive plastic strain.
Neurosurgical implications of achondroplasia
Authors: King James A. J. , Vachhrajani Shobhan , Drake James M. , Rutka James T.
Published: October 2009

Object

Achondroplasia is the most common form of human short-limbed dwarfism. The pediatric neurosurgeon is frequently required to treat children with achondroplasia who have hydrocephalus, cervicomedullary compression (CMD), and spinal canal stenosis. Accordingly, the authors have reviewed the experience of neurosurgery in children with achondroplasia at The Hospital for Sick Children.

Methods

The medical records and neurosurgery database at The Hospital for Sick Children were searched to identify all children with achondroplasia who underwent at least 1 neurosurgical procedure between 1956 and the present.

Results

Twenty-nine children with achondroplasia underwent 85 surgical procedures: 52 for CSF diversion in 12 patients, 20 for CMD in 18 patients, 8 for spinal disorders in 4 patients, and 5 for miscellaneous purposes in 4 patients. The CSF shunts were placed almost exclusively before 1990 and were associated with a significant number of complications. Patients undergoing CMD did very well, with only 1 patient failing to improve clinically.

Conclusions

This review provides a historical perspective on the evolution of treatment of pediatric patients with achondroplasia. The use of CSF diversion procedures, formerly fraught with complications, is now rare following the realization of the natural history of CSF space enlargement in these patients. Cervicomedullary compression is more commonly recognized due to better imaging. Central apnea is now better detected by routine sleep studies. Spine surgery, although rare, requires evaluation of both spinal stenosis and instability. These patients are best evaluated by a multidisciplinary team.
Passive range of motion functional magnetic resonance imaging localizing sensorimotor cortex in sedated children
Authors: Ogg Robert J. , Laningham Fred H. , Clarke Dave , Einhaus Stephanie , Zou Ping , Tobias Michael E. , Boop Frederick A.
Published: October 2009

Object

In this study, the authors examined whether passive range of motion (ROM) under conscious sedation could be used to localize sensorimotor cortex using functional MR (fMR) imaging in children as part of their presurgical evaluation.

Methods

After obtaining institutional review board approval (for retrospective analysis of imaging data acquired for clinical purposes) and informed consent, 16 children underwent fMR imaging. All 16 had lesions; masses were found in 9 patients and cortical dysplasia was found in 4; the lesions in 3 patients were not diagnosed. Passive ROM was performed during blood oxygen level–dependent MR imaging sequences. Three of the patients also performed active motor tasks during the fMR imaging study. All patients were evaluated using passive ROM of the hand and/or foot; 3 patients were evaluated for passive touch of the face. In 9 cases, intraoperative electrocorticography (ECoG) was used. Five of the patients underwent intraoperative ECoG to evaluate for seizure activity. Four patients had intraoperative ECoG for motor mapping. Five of the patients had subdural grids placed for extraoperative monitoring.

Results

In 3 cases, the active and passive ROMs colocalized. In 4 patients ECoG was used to identify motor cortex, and in all 4 motor ECoG yielded results consistent with the passive ROM localization. Thirteen of 16 children have undergone resection based on passive ROM fMR imaging findings with no unanticipated deficits.

Conclusions

These preliminary data suggest that passive ROM fMR imaging can accurately detect functional hand, leg, and face regions of the sensorimotor cortex in the sedated child. This extends current extraoperative mapping capabilities to patients unable or unwilling to cooperate for active motor tasks.
The posterior petrosal approach: technique and applications in pediatric neurosurgery
Authors: Klimo Paul , Browd Samuel R. , Pravdenkova Svetlana , Couldwell William T. , Walker Marion L. , Al-Mefty Ossama
Published: October 2009

Object

Various lesions occur in deep locations or at the skull base in pediatric patients and require skull base approaches for resection. Skull base surgery confers the advantages of improved line of sight, a wider operative corridor, and reduced brain retraction. The posterior petrosal approach provides simultaneous access to lesions in the posterior middle fossa and posterior fossa from the top of the clivus to the level of the jugular foramen. It allows visualization of the ventrolateral brainstem and may be combined with various other supra- and infratentorial approaches, thus giving the surgeon a wide array of access routes to the lesion.

Methods

The authors conducted a retrospective review of all cases involving pediatric patients undergoing a posterior petrosal approach, either alone or in combination with other cranial approaches. Preoperative and postoperative data were collected, including presentation, neurological examination, imaging findings, pathological condition, operative details, perioperative complications, and postoperative outcomes.

Results

There were 13 patients (6 female, 7 male) with a mean age of 12.6 years (range 14 months–9 years). The posterior petrosal was the sole skull base cranial approach in 4 patients, whereas the posterior petrosal was combined with 1 or more other cranial approaches in 9. A gross-total resection was achieved in 7 patients, subtotal resection in 5, and a biopsy was performed in 1. Complications occurred in 9 patients, including 7 new or worsened cranial neuropathies. There was no perioperative mortality.

Conclusions

Although infrequently used in pediatric neurosurgery, the posterior petrosal approach is a highly versatile approach that can access intra- and extraaxial pathology centered on the petrous bone. The authors believe that patient outcomes are directly related to the degree of experience using this approach. Therefore, if this approach is to be used, they recommend collaboration with a skull base neurosurgeon.
Prioritizing neurosurgical education for pediatricians: results of a survey of pediatric neurosurgeons
Authors: Aldana Philipp R. , Steinbok Paul
Published: October 2009

Object

Pediatricians play a vital role in the diagnosis and initial treatment of children with pediatric neurosurgical disease. Exposure of pediatrics residents to neurosurgical diseases during training is inconsistent and is usually quite limited. After residency, opportunities for pediatricians' education on neurosurgical topics are few and fall mainly on pediatric neurosurgeons. The American Association of Neurological Surgery/Congress of Neurological Surgeons Joint Section on Pediatric Neurological Surgery Committee on Education undertook a survey of practicing pediatric neurosurgeons to determine whether focused education of practicing pediatricians might lead to better patient outcomes for children with a sampling of common pediatric neurosurgical conditions.

Methods

An Internet-based 40-item survey was administered to practicing pediatric neurosurgeons from the US and Canada identified from the roster of the American Association of Neurological Surgeons/Congress of Neurological Surgeons Joint Section of Pediatric Neurological Surgery. Survey topics included craniosynostosis and plagiocephaly, occult spinal dysraphism and tethered cord, hydrocephalus and endoscopic third ventriculostomy, Chiari malformation Type I, mild or minor head injury, spastic cerebral palsy, and brain tumors. Most questions pertained to diagnosis, initial medical treatment, and referral.

Results

One hundred three (38%) of the 273 practicing pediatric neurosurgeons completed the survey. Two-thirds of the respondents had completed a pediatric neurosurgery fellowship, and two-thirds were in academic practice. Eighty-two percent of the respondents agreed that the care of pediatric neurosurgical patients could be improved with further education of pediatricians. In the opinion of the respondents, the 3 disease topics in greatest need of educational effort were craniosynostosis and plagiocephaly, occult spinal dysraphism and tethered cord, and hydrocephalus. Head injury and spasticity were given the lowest priorities.

Conclusions

This survey identified what practicing pediatric neurosurgeons perceive to be the most important knowledge deficits of their colleagues in pediatrics. These perceptions may not necessarily be congruent with the perceptions of practicing pediatricians themselves; nevertheless, the data from this survey may serve to inform conversations between neurosurgeons and planners of continuing medical education for pediatricians, pediatrics residency program directors, and medical school pediatrics faculty.
Pediatric thalamic glioblastoma associated with Ollier disease (multiple enchondromatosis): a rare case of concurrence
Authors: Ranger Adrianna , Szymczak Artur , Hammond Robert R. , Zelcer Shayna
Published: October 2009

Ollier disease and Maffucci syndrome are rare syndromes in which there is deforming dysplasia of cartilage, primarily but not exclusively involving the metaphyses and diaphyses of long bones. In a minority of patients, dysplasia can lead to sarcomatous degeneration, producing chondrosarcomas. There also appears to be an association with other neoplasms. Little has been written about the association between Ollier disease and intracranial tumors, and these papers have largely consisted of case reports in adults. The authors present the case of a 6-year-old girl with left arm osseous changes consistent with Ollier disease and a biopsy-proven thalamic glioblastoma multiforme. They then examine the co-occurrence of brain tumors in conjunction with a dyschondroplasia syndrome in children and adolescents to assess the presentation, treatment offered, and disease course of similar cases.

Eight other such cases were identified, 6 in patients with Ollier disease (ranging in age from 7 to 18 years), and 2 with Maffucci syndrome (both in late adolescence). Including our own patient, 7 of the 9 cases of comorbid dyschondroplasia and intracranial malignancy occurred in girls. Some patients presented soon after the acute onset of symptoms, and others had a more subtle, protracted course over as many as 2 years. Some tumors were deemed resectable and others not. In only 1 instance was follow-up beyond 1 year reported.
Diagnostic value of S100B and neuron-specific enolase in mild pediatric traumatic brain injury
Authors: Geyer Christian , Ulrich Anett , Gräfe Gerd , Stach Barbara , Till Holger
Published: October 2009

Object

During recent years, several biomarkers have been introduced for use in the diagnosis of traumatic brain injury (TBI). The primary objective of this investigation was to determine if S100B (or S100 calcium-binding protein B) and neuron-specific enolase (NSE) serum concentrations can effectively be used to discriminate between symptomatic and asymptomatic children with minor head trauma.

Methods

The authors conducted a prospective clinical study that involved patients age 6 months to 15 years who had sustained minor head trauma. Children with concomitant extracranial injuries were excluded. Blood samples were obtained within 6 hours of injury to measure S100B and NSE levels in serum. The authors defined 2 diagnostic groups: a mild TBI group (patients with Glasgow Coma Scale [GCS] scores of 13–15) in whom there were clinical signs of concussion (short loss of consciousness, amnesia, nausea, vomiting, somnolence, headache, dizziness, or impaired vision) and a head contusion group (patients with a GCS score of 15) in whom symptoms were absent. Both S100B and NSE concentrations were compared between the 2 groups. Secondary end points were defined as follows: correlation of S100B/NSE and a) the presence of scalp lacerations, b) GCS score, c) age, and d) correlation between S100B and NSE.

Results

One hundred forty-eight patients were enrolled (53 in the contusion group, 95 in the mild TBI group). After adjusting for differences in age and time of injury to blood sample withdrawal, there was no significant difference in S100B or NSE between patients in the 2 groups. Scalp lacerations and GCS score had no affect on posttraumatic S100B or NSE concentrations. The correlation between S100B and NSE was significant. Both markers showed a significant negative correlation with age.

Conclusions

The authors demonstrated that S100B and NSE do not discriminate between symptomatic and asymptomatic children with minor head injury. There seem to be limitations in marker sensitivity when investigating pediatric patients with mild TBI.