Background:
Knee laxity in the setting of anterior cruciate ligament (ACL) injury is often assessed through physical examination using the Lachman, pivot shift, and anterior drawer tests. The degree ...of laxity noted on these examinations may influence treatment decisions and prognosis.
Hypothesis:
Increased preoperative knee laxity is associated with increased risk of revision ACL reconstruction, increased risk of contralateral ACL reconstruction, and poorer patient-reported outcomes at 6 years postoperatively.
Study Design:
Cohort study; Level of evidence, 2.
Methods:
2333 patients who underwent primary isolated ACL reconstruction without additional ligament injury were identified. Patients reported by the operating surgeons to have an International Knee Documentation Committee (IKDC) grade D Lachman, anterior drawer, or pivot shift examination were classified as having a high-grade laxity. Multiple logistic regression models were used to evaluate whether having high-grade preoperative laxity was predictive of increased odds of undergoing subsequent revision or contralateral ACL reconstruction within 6 years of the index procedure, controlling for patient age, sex, body mass index, Marx activity level, sport, graft type, medial meniscal treatment, and lateral meniscal treatment. Multiple linear regression modeling was used to evaluate whether having high-grade preoperative laxity was predictive of poorer IKDC or Knee injury and Osteoarthritis Outcome Score Knee-Related Quality of Life (KOOS-QOL) scores at 6 years postoperatively, after controlling for baseline score, patient age, ethnicity, sex, body mass index, marital status, smoking status, sport participation, competition level, Marx activity rating score, graft type, and articular cartilage and meniscal status.
Results:
In total, 743 of 2325 patients (32.0%) were noted to have high-grade laxity on at least 1 physical examination test. High-grade Lachman was noted in 334 patients (14.4%), high-grade pivot shift was noted in 617 patients (26.5%), and high-grade anterior drawer was noted in 233 patients (10.0%). Six-year revision and contralateral ACL reconstruction data were available for 2129 patients (91.6%). High-grade prereconstruction Lachman was associated with significantly increased odds of ACL graft revision (odds ratio OR, 1.76; 95% CI, 1.10-2.80, P = .02) and contralateral ACL reconstruction (OR, 1.68; 95% CI, 1.09-2.69; P = .019). High-grade prereconstruction pivot shift was associated with significantly increased odds of ACL graft revision (OR, 1.75; 95% CI, 1.19-2.54, P = .002) but not with significantly increased odds of contralateral ACL reconstruction (OR, 1.30; 95% CI, 0.89-1.87; P = .16). High-grade prereconstruction laxity was associated with statistically significantly lower 6-year IKDC (β = −2.26, P = .003), KOOS-QOL (β = −2.67, P = .015), and Marx activity scores (β = −0.54, P = .020), but these differences did not approach clinically relevant differences in patient-reported outcomes.
Conclusion:
High-grade preoperative knee laxity is predictive of increased odds of revision ACL reconstruction and contralateral ACL reconstruction 6 years after ACL reconstruction. Poorer patient-reported outcome scores in the high-grade laxity group were also noted, but the difference did not reach a level of clinical relevance.
Fatal cerebrovascular events are often caused by rupture of atherosclerotic plaques. However, rupture-prone plaques are often distinguished by their internal composition rather than degree of luminal ...narrowing, and conventional imaging techniques might thus fail to detect such culprit lesions. In this feasibility study, we investigate the potential of ultrasound shear wave elastography (SWE) to detect vulnerable carotid plaques, evaluating group velocity and frequency-dependent phase velocities as novel biomarkers for plaque vulnerability. In total, 27 carotid plaques from 20 patients were scanned by ultrasound SWE and magnetic resonance imaging (MRI). SWE output was quantified as group velocity and frequency-dependent phase velocities, respectively, with results correlated to intraplaque constituents identified by MRI. Overall, vulnerable lesions graded as American Heart Association (AHA) type VI showed significantly higher group and phase velocity compared to any other AHA type. A selection of correlations with intraplaque components could also be identified with group and phase velocity (lipid-rich necrotic core content, fibrous cap structure, intraplaque hemorrhage), complementing the clinical lesion classification. In conclusion, we demonstrate the ability to detect vulnerable carotid plaques using combined SWE, with group velocity and frequency-dependent phase velocity providing potentially complementary information on plaque characteristics. With such, the method represents a promising non-invasive approach for refined atherosclerotic risk prediction.
The management of unruptured intracranial aneurysms is controversial. Investigators form the International study of Unrupted intracranial Aneurysms aimed to asses the natural history of unrupted ...Intracranial aneurysms and to measure the risk associalted with the repair.
Centres in the USA, Canada, and Europe enrolled patients for prospective assessment of unruptured aneurysms. Investigators recorded the natural history in patients who did not have surgery, and assessed morbidity and mortality associated with repair of unruptured aneurysms by either open surgery or endo-vascular procedures.
4060 patients were assessed-1692 did not have aneurysmal repair, 1917 had open surgery, and 451 had endovascular procedures. 5-year cumulative rupture rates for patients who did not have a history of subarachnoid haemorrhage with aneurysms located in internal carotid artery, anterior communicating or anterior cerebral artery, or middle cerebral artery were 0%, 2·6%, 14·5%, and 40% for aneurysms less than 7 mm, 7–12 mm, 13–24 mm, and 25 mm or greater, respectively, compared with rates of 2·5%, 14·5%, 18·4%, and 50%, respectively, for the same size categories involving posterior circulation and posterior communicating artery aneurysms. These rates were often equalled or exceeded by the risks associated with surgical or endovascular repair of comparable lesions. Patients' age was a strong predictor of surgical outcome, and the size and location of an aneurysm predict both surgical and endovascular outcomes.
Many factors are involved in management of patients with unruptured intracranial aneurysms. Site, size, and group specific risks of the natural history should be compared with site, size, and age-specific risks of repair for each patient.
The case for episodic memory in animals Dere, E.; Kart-Teke, E.; Huston, J.P. ...
Neuroscience and biobehavioral reviews,
2006, 2006-00-00, 20060101, Letnik:
30, Številka:
8
Journal Article
Recenzirano
The conscious recollection of unique personal experiences in terms of their details (what), their locale (where) and temporal occurrence (when) is known as episodic memory and is thought to require a ...‘self-concept’, autonoetic awareness/conciousness, and the ability to subjectively sense time. It has long been held that episodic memory is unique to humans, because it was accepted that animals lack a ‘self-concept’, ‘autonoetic awareness’, and the ability to ‘subjectively sense time’. These assumptions are now being questioned by behavioral evidence showing that various animal species indeed show behavioral manifestations of different features of episodic memory such as, e.g. ‘metacognition’, ‘conscious recollection’ of past events, ‘temporal order memory’, ‘mental time travel’ and have the capacity to remember personal experiences in terms of what happened, where and when. The aim of this review is to provide a comprehensive overview on the current progress in attempts to model different prerequisites and features of human episodic memory in animals and to identify possible neural substrates of animal episodic memory. The literature covered includes behavioral and physiological studies performed with different animal species, such as non-human primates, rodents, dolphins and birds. The search for episodic memory in animals has forced researchers to define objective behavioral criteria by which different features of episodic memory can be operationalized experimentally and assessed in both animals and humans. This is especially important because the current definition of episodic memory in terms of mentalistic constructs such as ‘self’, ‘autonoetic awareness/consciousness’, and ‘subjectively sensed time’, not only hinders animal research on the neurobiology of episodic memory but also research with healthy human subjects as well as neuropsychiatric patients with impaired language or in children with less-developed verbal abilities.
The relationship between carotid intraplaque hemorrhage and luminal stenosis severity is not well-established. We sought to determine whether intraplaque hemorrhage is related to carotid stenosis and ...at what degree of stenosis intraplaque hemorrhage most likely contributes to ischemic symptoms.
Consecutive patients who underwent MR carotid plaque imaging with MPRAGE sequences to identify intraplaque hemorrhage were retrospectively reviewed. Degrees of stenoses were categorized as minimal (<30%), moderate (30%-69%), and severe (>70%). Arteries were categorized into 2 groups: symptomatic (ipsilateral to a cerebral ischemic event) and asymptomatic (from a patient without an ischemic event). Multiple regression analyses were used to determine independent associations between the degree of stenosis and intraplaque hemorrhage and the presence of intraplaque hemorrhage with symptoms among categories of stenosis.
We included 449 patients with 449 carotid arteries: Two hundred twenty-five (50.1%) were symptomatic, and 224 (49.9%) were asymptomatic. An increasing degree of stenosis was independently associated with the presence of intraplaque hemorrhage (OR = 1.02; 95% confidence interval, 1.01-1.03). Intraplaque hemorrhage was independently associated with ischemic events in arteries with <30% stenosis (OR = 5.68; 95% CI, 1.49-21.69). No such association was observed in arteries with >30% stenosis. Of symptomatic arteries with minimal stenosis, 8.7% had intraplaque hemorrhage versus 1.7% of asymptomatic arteries (
= .02). No differences in intraplaque hemorrhage prevalence were found between symptomatic and asymptomatic groups with moderate (
= .18) and severe stenoses (
= .99).
The presence of intraplaque hemorrhage on high-resolution plaque imaging is likely most useful in identifying symptomatic plaques in cases of minimal stenosis.
A recently developed compact 3 T (C3T) MRI scanner with high performance gradients 1, 2 has a dedicated radiofrequency (RF) transmit coil that exposes only the head, neck and a small portion of the ...upper body region during head-first scanning. Due to the unique coil geometry and patient positioning, the established SAR model used for a conventional whole-body scanner cannot be directly translated to the C3T. Here a specific absorption rate (SAR) estimation and validation framework was developed and used to implement a dedicated and accurate SAR prediction model for the C3T. Two different SAR prediction models for the C3T were defined and evaluated: one based on an anatomically derived exposed mass, and one using a fixed anatomical position located caudally to the RF coil to determine the exposed mass. After coil modeling and virtual human body simulation, the designed SAR prediction model was implemented on the C3T and verified with calorimetry and in vivo scan power monitoring. The fixed-demarcation exposed mass model was selected as appropriate exposed mass region to accurately estimate the SAR deposition in the patient on the C3T.
While changes in ventricular and extraventricular CSF spaces have been studied following shunt placement in patients with idiopathic normal pressure hydrocephalus, regional changes in cortical ...volumes have not. These changes are important to better inform disease pathophysiology and evaluation for copathology. The purpose of this work is to investigate changes in ventricular and cortical volumes in patients with idiopathic normal pressure hydrocephalus following ventriculoperitoneal shunt placement.
This is a retrospective cohort study of patients with idiopathic normal pressure hydrocephalus who underwent 3D T1-weighted MR imaging before and after ventriculoperitoneal shunt placement. Images were analyzed using tensor-based morphometry with symmetric normalization to determine the percentage change in ventricular and regional cortical volumes. Ventricular volume changes were assessed using the Wilcoxon signed rank test, and cortical volume changes, using a linear mixed-effects model (
< .05).
The study included 22 patients (5 women/17 men; mean age, 73 SD, 6 years). Ventricular volume decreased after shunt placement with a mean change of -15.4% (
< .001). Measured cortical volume across all participants and cortical ROIs showed a mean percentage increase of 1.4% (
< .001). ROIs near the vertex showed the greatest percentage increase in volume after shunt placement, with smaller decreases in volume in the medial temporal lobes.
Overall, cortical volumes mildly increased after shunt placement in patients with idiopathic normal pressure hydrocephalus with the greatest increases in regions near the vertex, indicating postshunt decompression of the cortex and sulci. Ventricular volumes showed an expected decrease after shunt placement.
A standard file format is proposed to store process and event information, primarily output from parton-level event generators for further use by general-purpose ones. The information content is ...identical with what was already defined by the Les Houches Accord five years ago, but then in terms of Fortran commonblocks. This information is embedded in a minimal XML-style structure, for clarity and to simplify parsing.
Purpose To determine which patient and injury factors are associated with the detection of high-grade laxity on examination under anesthesia before anterior cruciate ligament (ACL) reconstruction. ...Methods We identified 2,318 patients who underwent primary ACL reconstruction without associated ligament injuries. Demographic data and information regarding meniscal tears were collected. Patients with high-grade Lachman (difference from contralateral side >10 mm), pivot-shift (International Knee Documentation Committee grade 3+), or anterior drawer (difference from contralateral side >10 mm) tests were identified by physical examination under anesthesia before ACL reconstruction. Logistic regression modeling was used to evaluate whether chronicity of the ACL injury, patient age, sex, body mass index, generalized ligamentous laxity, and presence of meniscal tears were associated with increased odds of high-grade laxity, while we controlled for examining surgeon. Results Patients with chronic tears (>6 months from injury) had greater than twice the odds of having high-grade Lachman, pivot-shift, and anterior drawer tests (all P < .001) relative to patients with acute tears (<3 months from injury). Generalized ligamentous laxity (odds ratio OR, 2.33; P < .001) and the presence of medial (OR, 1.63; P < .001) or lateral (OR, 1.41; P = .013) meniscus tears were associated with increased odds of a high-grade Lachman test. Age younger than 20 years (OR, 1.34; P = .023), female sex (OR, 1.49; P = .001), generalized ligamentous laxity (OR, 3.46; P < .001), and the presence of a medial (OR, 1.53; P < .001) or lateral (OR, 1.27; P = .041) meniscus tear were associated with increased odds of a high-grade pivot-shift test. Generalized ligamentous laxity (OR, 2.27; P < .001) and the presence of a medial (OR, 1.73; P = .001) or lateral (OR, 1.50; P = .010) meniscus tear were associated with increased odds of a high-grade anterior drawer test. Conclusions Chronic ACL tears, generalized ligamentous laxity, and meniscus tears are associated with increased odds of high-grade laxity with all 3 tests. Female patients and age younger than 20 years are associated with increased odds of a high-grade pivot-shift test. Level of Evidence Level II, lesser-quality prospective study.
Primary CNS vasculitis (PCNSV) is an uncommon disease in which lesions are limited to the brain and spinal cord. Our objective was to evaluate the frequency, clinical features, and outcome of spinal ...cord involvement in PCNSV.
We retrospectively identified 101 consecutive patients with PCNSV. Spinal cord involvement was documented for five. Clinical findings, laboratory studies, and outcomes of patients with spinal cord involvement were assessed and compared with those without spinal cord manifestations.
Spinal cord symptoms developed before cerebral symptoms in one patient, concurrently in two, and after cerebral symptoms in two. CNS biopsy specimens showed necrotizing vasculitis in three patients and granulomatous vasculitis in two. MRI of the spinal cord showed enhanced thoracic lesions in all five. Cerebral angiograms from four patients had normal findings. One patient had a fatal clinical course. The other four had relapses during follow-up but responded well to therapy and had favorable overall outcomes. At the last follow-up (median, 19 months after diagnosis), the four patients had recovered with slight or moderate residual disability. No significant differences in clinical and laboratory features were observed when comparing patients with or without spinal cord involvement. Cerebral angiograms with evidence of vasculitis were significantly more frequent for patients without spinal cord involvement (p = 0.002).
Spinal cord involvement was documented in 5% of patients with primary CNS vasculitis. The thoracic cord was the predominantly affected site. Other than myelopathy, clinical characteristics were similar to those of the patients without spinal cord involvement.
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