bluuebunny/crossref_metadata_2025_split huggingface dataset:
Image Analysis Software as a Strategy to Improve the Radiographic Determination of Fracture Healing
Authors: Duryea Jeffrey , Evans Christopher , Glatt Vaida 
Published: June 2018

Objectives:
To develop and validate an unbiased, accurate, convenient, and inexpensive means of determining when an osseous defect has healed and recovered sufficient strength to allow weight bearing.

Methods:
A novel image processing software algorithm was created to analyze the radiographic images and produce a metric designed to reflect the bone strength. We used a rat femoral segmental defect model that provides a range of healing responses from complete union to nonunion. Femora were examined by x-ray, micro–computed tomography and mechanical testing. Accurate simulated radiographic images at different incident x-ray beam angles were produced from the micro–computed tomography data files.

Results:
The software-generated metric (SC) showed high levels of correlation with both the mechanical strength (τMech) and the polar moment of inertia (pMOI), with the mechanical testing data having the highest association. The optimization analysis yielded optimal oblique angles θB of 125 degrees for τMech and 50 degrees for pMOI. The Pearson R2 values for the optimized model were 0.71 and 0.64 for τMech and pMOI, respectively. Further validation using true radiographs also demonstrated that the metric was accurate and that the simulations were realistic.

Conclusions:
The preliminary findings suggest a very promising methodology to assess bone fracture healing using conventional radiography. With radiographs acquired at appropriate incident angles, it proved possible to accurately calculate the degree of healing and the mechanical strength of the bone. Further research is necessary to refine this approach and determine whether it translates to the human clinical setting.
The Peritubercle Lucency Sign is a Common and Early Radiographic Finding in Slipped Capital Femoral Epiphysis
Authors: Maranho Daniel A. , Miller Patricia E. , Novais Eduardo N. 
Published: June 2018

Background:
A rotational mechanism of slipped capital femoral epiphysis (SCFE) in which the epiphyseal tubercle acts as a fulcrum has been recently described. However, there is limited radiographic evidence supporting this theory. We aimed to investigate whether a radiographic lucency around the epiphyseal tubercle (peritubercle lucency sign) could be observed before or at the diagnosis of a subsequent slip in patients initially presenting with unilateral SCFE.

Methods:
We evaluated 70 patients with unilateral SCFE who were followed until a contralateral slip was diagnosed, and 180 patients with unilateral SCFE who had no contralateral slip until skeletal maturity between 2000 and 2017. We revised anteroposterior and lateral radiographs from the initial presentation, surveillance, and diagnosis of a contralateral SCFE. The presence or absence of the peritubercle lucency sign in the contralateral initially uninvolved hip was recorded for every radiograph. The presence of hip pain, and the presence of classic radiographic parameters for SCFE diagnosis (epiphyseal tilt and Klein’s line) were recorded when the peritubercle lucency sign became noticeable.

Results:
The peritubercle lucency sign was observed in 84% [59/70; 95% confidence interval (CI), 73%-92%] of the patients who developed contralateral slip. Most patients (46/59=78%; 95% CI, 65%-87%; P<0.001) had the peritubercle lucency sign visible within 9 months after the initial diagnosis of unilateral SCFE. The sign preceded the definitive diagnosis of the contralateral slip at a median of 9 weeks (interquartile range, 0 to 10 wk). At the time of first observation of the peritubercle lucency sign, 36% (25/70; 95% CI, 25%-48%) of the patients were asymptomatic and 49% (34/70; 95% CI, 36%-61%) of the hips showed no abnormalities in the tilt angle or the Klein line. Among patients who did not experience a contralateral slip (n=180), the sign was observed in 2 patients (1.1%; 95% CI, 0.2%-4.4%). The sensitivity was 84% and specificity was 99%.

Conclusions:
A peritubercle lucency is an early imaging sign, present in >80% of contralateral slips following an initial presentation of unilateral SCFE. The presence of the peritubercle lucency sign may be helpful for contralateral hip surveillance. Future studies are necessary to establish the clinical validity of the peritubercle lucency sign and whether it may serve as a predictor of contralateral involvement.

Level of Evidence:
Diagnostic level III.
Idiopathic Early-onset Scoliosis: Growing Rods Versus Vertically Expandable Prosthetic Titanium Ribs at 5-year Follow-up
Authors: Bachabi Malick , McClung Anna , Pawelek Jeff B. , El Hawary Ron , Thompson George H. , Smith John T. , Vitale Michael G. , Akbarnia Behrooz A. , Sponseller Paul D. 
Published: June 2018

Background:
Distraction-based techniques allow spinal growth until skeletal maturity while preventing curve progression.

Methods:
Two multicenter early-onset scoliosis databases were used to identify patients with idiopathic spine abnormalities treated with traditional growing rods (TGR) or vertically expandable titanium ribs (VEPTR). Patients underwent at least 4 lengthenings and had at least 5-year follow-up. Significance was set at P<0.05.

Results:
In total, 50 patients treated with TGR and 22 treated with VEPTR were included. Mean (±SD) age at surgery was 5.5 (±2.0) years for the TGR group versus 4.3 (±1.9) years for the VEPTR group (P=0.044); other demographic parameters were similar. VEPTR patients had more procedures (mean 15±4.2) than TGR patients (mean 10±4.0) (P=0.001). Unilateral constructs were present in 18% (4 of 22) of VEPTR and 16% (8 of 50) of TGR patients. Bilateral constructs spanned a mean 2.1 additional surgical levels and exposed patients to 1.6 fewer procedures than unilateral constructs. Curve correction was similar between bilateral and unilateral constructs. TGR patients experienced greater curve correction (50%) than VEPTR patients (27%) (P<0.001) and achieved a greater percentage of thoracic height gain (24%) than VEPTR patients (12%) (P=0.024). At latest follow-up, TGR patients had better maintenance of curve correction, less kyphosis, and 15% greater absolute gain in thoracic height versus VEPTR patients. TGR patients had a lower rate of wound complications (14%) than VEPTR patients (41%) (P=0.011).

Conclusions:
In patients with idiopathic early-onset scoliosis, TGRs produced greater initial curve correction, greater thoracic height gains, less kyphosis, and lower incidence of wound complications compared with VEPTR.

Level of Evidence:
Level III.
Spondylolisthesis is Common, Early, and Severe in Loeys-Dietz Syndrome
Authors: Kirby David J. , Dietz Harry C. , Sponseller Paul D. 
Published: June 2018

Background:
We studied the prevalence and treatment outcomes of spondylolisthesis in patients with Loeys-Dietz syndrome (LDS).

Methods:
Clinical data and lumbosacral imaging of 138 patients with LDS were reviewed. Spondylolisthesis (L4-L5 or L5-S1) and spondylolysis were characterized by multimodal imaging and correlated with clinical data. Treatments and outcomes were characterized for patients with spondylolisthesis. Associations were determined using the Fisher exact, Mann-Whitney, and Student t tests (α=0.05).

Results:
Twenty-four patients (17%) had spondylolysis and 23 (17%) had spondylolisthesis. Median age at spondylolisthesis diagnosis was 11 (interquartile range, 9.5) years. In patients in whom measurement was possible (n=20), mean (±SD) slip was 48% (±35%). Nineteen patients had L5-S1 slip and 4 had L4-L5 slip. Of the patients with spondylolisthesis, 5 had no evidence of spondylolysis; of those with spondylolysis, all but 6 had spondylolisthesis. Eleven patients with spondylolisthesis underwent posterior spinal fusion (PSF) to treat slip progression, pain, and/or neurological deficit. Spondylolisthesis recurred in 1 patient who underwent PSF with bone graft arthrodesis alone (no instrumentation). The other 10 patients underwent PSF with instrumentation and fusion. Three patients additionally underwent Bohlman interbody fusion. Two patients developed implant failure. S2 fixation was performed at revision to achieve fusion in these patients. Mean Meyerding grade improved in patients who underwent arthrodesis, from 3.9 (±1.2) to 1.9 (±1.3) (P=0.002). Complications were 2 cerebrospinal fluid leaks, 2 transient postoperative paresthesias, and 1 case each of pseudarthrosis at S1-S2, wound dehiscence, and transient urinary incontinence. No significant associations between LDS type and lumbosacral abnormalities were found.

Conclusions:
High-grade spondylolisthesis is common in LDS and usually associated with spondylolysis. Patients requiring surgery for spondylolisthesis present during childhood and do well after instrumented PSF. Interbody fusion and stabilization of S1 and S2 can prevent physeal deformation. LDS should be considered in patients with high-grade spondylolisthesis. Patients with LDS should be monitored for spondylolisthesis and spondylolysis starting when they are young.

Level of Evidence:
Level IV—retrospective study.
Gait Alteration in Cervical Spondylotic Myelopathy Elucidated by Ground Reaction Forces
Authors: Haddas Ram , Ju Kevin L. 
Published: June 2018

Study Design..
Prospective cohort study.

Objective..
Analyze GRF parameters in cervical spondylotic myelopathy (CSM) patients to elucidate gait alterations as compared with healthy controls.

Summary of Background Data..
During the human gait cycle, the magnitude and direction of the force each foot imparts on the ground varies in a controlled fashion to propel the body's center of mass forward. Alterations in GRF patterns can both point to subtle gait disturbances and explain altered gait patterns such as that seen in CSM.

Methods..
Thirty-two patients with symptomatic CSM who have been scheduled for surgery, along with 30 healthy controls (HC), underwent clinical gait analysis a week before surgery. Vertical GRF parameters and force magnitude and timing at various points of the gait cycle (i.e., heel contact, maximum weight acceptance, mid-stance, and push off) were analyzed and compared between groups.

Results..
Increased heel contact (CSM: 60.13% vs. HC: 27.82% of body weight, BW,P = 0.011), maximum weight acceptance (CSM: 120.13% vs. HC: 100.97% of BW, P = 0.016), and diminished push off (CSM: 91.35% vs. HC: 106.54% of BW, P = 0.001) forces were discovered in CSM patients compared with HC. Compared with controls CSM patients had delayed heel contact (CSM: 9.32% vs. HC: 5.12% of gait cycle, P = 0.050) and earlier push off (CSM: 54.96% vs. HC: 59.0% of gait cycle, P = 0.050), resulting in a shorter stance phase.

Conclusion..
This study reinforces how CSM patients commonly exhibit altered gait patterns, but also uniquely demonstrates the increased heel-contract and maximum weight acceptance forces, diminished toe-off forces, and the shorter stance phase to absorb the BW load. When examined from a global perspective, these altered GRF parameters reflect the difficulty CSM patients have with catching their center of mass during heel-contact to avoid falling and with subsequently propelling themselves forward.

Level of Evidence: 3
Whorling-Sclerosing Variant Meningioma of the Spine
Authors: Eghbal Keyvan , Dehghanian Amirreza , Ghaffarpasand Fariborz 
Published: June 2018

Study Design.
Case report

Objective.
To report surgical resection of multiple ventral cervical and thoracic lesion being diagnosed as whorling-sclerosing variant meningioma (WSM) and subsequent stabilization of cervicothoracic spine.

Summary of Background Data.
WSM is a rare histopathology variant of meningioma which is mostly reported in brain and only one case of cervical spine WSM has been reported. Because of the rarity of WSM, there is a paucity of information regarding the clinical, radiological, and histopathologic characteristics.

Methods.
A 57-year-old lady presented with progressive quadriparesis and myelopathy since 10 days. The spine magnetic resonance imaging (MRI) revealed multiple ventral cervical and thoracic lesions which were hypointense in T2-weighted images with heterogeneous and scant enhancement with gadolinium. The patient underwent anterior cervical corpectomy and gross total resection of the lesion along with 360° fixation in the first stage. The thoracic lesions were also resected totally through laminectomy and right lateral extracavitary approach followed by pedicular screw fixation.

Results.
The patient improved muscle powers and spasticity and is not independent (Frankel D). The histopathology examination revealed hypocellular lobulated sclerotic mass with whorling pattern of growth in the sclerotic part suggestive of WSM. Immunohistochemical evaluation demonstrated negative staining for epithelial membrane antigen, cytokeratin, Olig-2 and S-100 and immunoactivity for progesterone receptor (PR) and glial fibrillary acidic protein in the tumoral cells located at the periphery. Ki-67 indexing was low.

Conclusion.
The spine multiple WSM is an extremely rare condition, which has a malignant behavior and it seems that it is spread by cerebrospinal fluid seeding. Surgical removal is hard and requires experience and appropriate equipment.

Level of Evidence: 4
Highly Cited Works in Spinal Disorders
Authors: Badhiwala Jetan H. , Nassiri Farshad , Witiw Christopher D. , Mansouri Alireza , Alotaibi Naif , Eagles Matthew , Almenawer Saleh A. , da Costa Leodante , Wilson Jefferson R. , Fehlings Michael G. 
Published: June 2018

Study Design.
Bibliometric analysis.

Objective.
To identify, and summarize the key findings of, the top 100 most highly cited works published in spinal disorder topic-specific journals.

Summary of Background Data.
There is an abundance of published articles pertaining to spine surgery and spinal disorders. The number of citations a work receives provides a useful measure of its scientific impact. An understanding of the most cited works in spine surgery can identify literature that surgeons and researchers should be familiar with, point to the most active areas of research, inform the design of educational curricula, and help guide future research efforts.

Methods.
Journals relating to spinal disorders were identified using the Journal Citation Reports database. We then searched the Web of Science database for articles appearing in each of these journals. The top 100 most cited works were selected for analysis.

Results.
The top 100 most cited articles appeared in seven of eight journals dedicated to spinal disorders, with 84 in Spine and seven in the European Spine Journal. The citation count for individual articles ranged from 343 to 1949. Most works (73) were published between 1990 and 2004. The greatest number of articles (22) focused on low back pain, followed by biomechanics (13), degenerative disc disease (12), and lumbar spinal stenosis/lumbar fusion (9). With regard to study design, laboratory investigations were the most common (12), followed by guideline documents (11), reviews (10), and retrospective cohort studies (10).

Conclusion.
The most cited works in spinal disorder journals are guidelines for low back pain, descriptions of quality of life (QOL) metrics, or laboratory investigations into spinal biomechanics. A gap exists for work relating to neck pain or cervical spinal pathology (e.g., cervical myelopathy), representing opportunity for future work. Time of publication, topic of study, study design, and journal are possible determinants of likelihood of citation.

Level of Evidence: N/A
Sagittal Spinopelvic Alignment After Posterior Spinal Fusion in Adolescent Idiopathic Scoliosis
Authors: Pasha Saba , Ilharreborde Brice , Baldwin Keith 
Published: June 2018

Study Design.
A systematic review and meta-analysis.

Objective.
The aim of this study was to determine the differences in the sagittal spinopelvic parameters between the nonscoliotic controls, preoperative, and different time points postoperative in Lenke 1 and 5 adolescent idiopathic scoliosis (AIS).

Summary of Background Data.
The postoperative changes in the sagittal profile of Lenke 1 and 5 AIS at varying time points after posterior spinal fusion (PSF) has not been rigorously demonstrated; studies performed have had conflicting results.

Methods.
Sagittal spinal and pelvic parameters, T5-T12 thoracic kyphosis (TK), L1-S1 lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), and sagittal vertical axis (SVA), for Lenke 1 and 5 preoperatively, at immediate, less than 2-year, and more than 2-year postoperatively, and for nonscoliotic adolescents were searched. Differences in the sagittal spinopelvic parameters between preoperative and the follow-ups and between the nonscoliotic and pre- and postoperative AIS subtypes were calculated through meta-analysis.

Results.
A total of 22 studies on Lenke1 (1229 patients), 13 studies on Lenke5 (437 patients), and 18 studies on controls (1636 patients) were reviewed. Among all the measured variables, only PI in Lenke1 was significantly different between the final follow-up and controls, P < 0.05. In Lenke 1, SVA was significantly more anterior at the immediate postoperative than preoperative, but continued moving posteriorly up to 2-year postoperative resulting in no significant difference in the SVA position between the final follow-up and preoperative, P > 0.05. In Lenke 5, SVA was significantly more posterior at the immediate postoperative and more anterior at the final follow-up than the preoperative measurements, p < 0.05.

Conclusions.
Continuous changes in the sagittal spinal parameters should be expected after PSF. Normalization of the sagittal spinal parameters appears to be the rule after PSF, and watchful waiting appears to be appropriate in this population when viewing the lateral X-ray postoperatively.

Level of Evidence: 4
Associations of Source-apportioned Fine Particles with Cause-specific Mortality in California
Authors: Berger Kimberly , Malig Brian J. , Hasheminassab Sina , Pearson Dharshani L. , Sioutas Constantinos , Ostro Bart , Basu Rupa 
Published: June 2018

Background:
Exposure to ambient fine particulate matter (PM2.5) has been linked with premature mortality, but sources of PM2.5 have been less studied.

Methods:
We evaluated associations between source-specific PM2.5 exposures and cause-specific short-term mortality in eight California locations from 2002 to 2011. Speciated PM2.5 measurements were source-apportioned using Positive Matrix Factorization into eight sources and combined with death certificate data. We used time-stratified case–crossover analysis with conditional logistic regression by location and meta-analysis to calculate pooled estimates.

Results:
Biomass burning was associated with all-cause mortality lagged 2 days after exposure (lag2) (% changelag2 in odds per interquartile range width increase in biomass burning PM2.5 = 0.8, 95% confidence interval [CI] = 0.2, 1.4), cardiovascular (% changelag2 = 1.3, 95% CI = 0.3, 2.4), and ischemic heart disease (% changelag2 = 2.0, 95% CI = 0.6, 3.5). Vehicular emissions were associated with increases in cardiovascular mortality (% changelag0 = 1.4, 95% CI = 0.0, 2.9). Several other sources exhibited positive associations as well. Many findings persisted during the cool season. Warm season biomass burning was associated with respiratory/thoracic cancer mortality (% changelag1 = 5.9, 95% CI = 0.7, 11.3), and warm season traffic was associated with all-cause (% changelag0 = 1.9, 95% CI = 0.1, 3.6) and cardiovascular (% changelag0 = 2.9, 95% CI = 0.1, 5.7) mortality.

Conclusions:
Our results suggest that acute exposures to biomass burning and vehicular emissions are linked with cardiovascular mortality, with additional sources (i.e., soil, secondary nitrate, secondary sulfate, aged sea salt, and chlorine sources) showing associations with other specific mortality types.
Acute Changes in Community Violence and Increases in Hospital Visits and Deaths From Stress-responsive Diseases
Authors: Ahern Jennifer , Matthay Ellicott C. , Goin Dana E. , Farkas Kriszta , Rudolph Kara E. 
Published: June 2018

Background:
Community violence may affect a broad range of health outcomes through physiologic stress responses and changes in health behaviors among residents. However, existing research on the health impacts of community violence suffers from problems with bias.

Methods:
We examined the relations of acute changes in community violence with hospital visits and deaths due to stress-responsive diseases (mental, respiratory, and cardiac conditions) in statewide data from California 2005–2013. The community violence exposure was measured as both binary spikes and continuous acute changes. We applied a combined fixed-effects and time-series design that separates the effects of violence from those of community- and individual-level confounders more effectively than past research. Temporal patterning was removed from community violence rates and disease rates in each place using a Kalman smoother, resulting in residual rates. We used linear regression with place fixed-effects to examine within-place associations of acute changes in community violence with residual rates of each outcome, controlling for local time-varying covariates.

Results:
We found acute increases in hospital visits and deaths due to anxiety disorders (0.31 per 100,000; 95% confidence interval [CI] = 0.02, 0.59), substance use (0.47 per 100,000; 95% CI = 0.14, 0.80), asthma (0.56 per 100,000; 95% CI = 0.16, 0.95), and fatal acute myocardial infarction (0.09 per 100,000; 95% CI = 0.00, 0.18) co-occurring with violence spikes. The pattern of findings was similar for the exposure of continuous acute violence changes.

Conclusions:
Although the associations were small, the identified increases in stress-responsive conditions suggest the possibility of health impacts of acute changes in community violence.
Implantation failure of endometrial origin: what is new?
Authors: Bellver José , Simón Carlos 
Published: June 2018

Purpose of review
To review recent findings related to possible causes of recurrent implantation failure of endometrial origin in normal uterus.

Recent findings
Recent evidences suggest that in apparently normal endometria, RIF may associate with molecular and functional changes in the uterus such as abnormal endometrial microbiota, including the presence of chronic endometritis, poor synchronization between the blastocyst and endometrium, and/or excessive uterine peristalsis. An altered endometrial microbiota detected by molecular techniques has been recently related to poorer embryo implantation, even in apparently normal endometria. The use of the endometrial receptivity analysis test to obtain an objective signature of endometrial receptivity has shown to improve the reproductive performance in RIF patients. The diagnosis of uterine peristalsis, however, remains challenging since the usual evaluation by transvaginal ultrasound is not accurate, and drugs tested to reduce uterine peristalsis and enhance embryo implantation have not been clearly beneficial. Finally, endometrial injury to improve implantation rates remains controversial being definitive well-designed trials needed to assess its benefit, if any.

Summary
In recurrent implantation failure of endometrial origin an altered pattern of the microbial endometrial ecosystem, a displaced window of implantation leading to desynchronization between the blastocyst and the endometrium, or an altered pattern of uterine contractions during embryo transfer may be factors to consider in our attempt to solve this clinical issue. New diagnostics for assessing these conditions and new therapies to improve these dysfunctional situations are currently under investigation to be presumably included in the near future in the work-up of affected patients.