Posttraumatic painful hip: sonography as a screening test for occult hip fractures.

OBJECTIVE: Nondisplaced hip fractures may be radiographically occult and require magnetic resonance imaging (MRI) or bone scintigraphy for diagnosis. Both examinations are expensive and are not readily available in many hospitals. Our objective was to evaluate sonography as a screening tool for occult hip fractures in posttraumatic painful hips in elderly patients. METHODS: We prospectively evaluated 30 patients (mean age, 73 years), who were admitted for painful hips after having low-energy trauma with nondiagnostic hip radiographs. After inclusion, patients underwent sonography of both hips for signs of injury. After completion of the sonographic examination and analysis of the results, patients underwent MRI of both hips. The sonographic findings were compared with the MRI findings, which served as the reference standard for accurate detection of a hip fracture. RESULTS: Ten hip fractures were diagnosed by MRI. Sonography showed trauma-related changes in all of those patients and in 7 additional patients, 3 of whom had pubic fractures. Sonography correctly identified 13 patients without hip fractures. The sensitivity of sonography was found to be 100%, whereas the specificity for hip fractures was 65%. CONCLUSIONS: Sonography for posttraumatic hip pain with negative radiographic findings did not result in a single missed hip fracture. Therefore, sonography may serve as an effective screening tool, mandating MRI only for cases with positive findings, whereas patients with negative sonographic findings need no further investigation. Sonography may therefore be very useful in hospitals around the world, where MRI may not be readily affordable or available.

Ultrasound-diagnosed puerperal osteopenia in young primiparas.

OBJECTIVE: To study whether osteopenia occurs following pregnancy and to evaluate its severity in young primiparas. STUDY DESIGN: A prospective case control study. Sixty-one young primigravidae early after birth and 59 nulligravidae matched for age and BMI participated in the study. Bone status was examined using ultrasonic bone transmission velocity over the tibia; Z-score and T-score for bone density were calculated. Serum bone alkaline phosphatase, osteocalcin and urinary N-telopeptide crosslinks were evaluated as bone remodeling biochemical markers. RESULTS: Ultrasonic parameters of bone status following delivery were significantly lower in the puerperal group as compared to the nulligravida group. Serum mean bone alkaline phosphatase levels and urinary N-telopeptide crosslinks secretion were higher by 50% in the puerperal group, while serum osteocalcin levels were significantly lower (by 25%) than in the nulligravida controls. A positive correlation between ultrasonic measurements and biochemical markers was demonstrated in the postpartum group, whereas the control group showed a negative correlation. CONCLUSION: Women at their early puerperium demonstrate a significant cortical bone mass reduction as measured by ultrasonograph and markers of bone turnover. It appears that pregnancy is a state of unbalanced accelerated bone turnover that may be associated with reduced osteoblastic activity.

Finding leading indicators for disease outbreaks: filtering, cross-correlation, and caveats.

Bioterrorism and emerging infectious diseases such as influenza have spurred research into rapid outbreak detection. One primary thrust of this research has been to identify data sources that provide early indication of a disease outbreak by being leading indicators relative to other established data sources. Researchers tend to rely on the sample cross-correlation function (CCF) to quantify the association between two data sources. There has been, however, little consideration by medical informatics researchers of the influence of methodological choices on the ability of the CCF to identify a lead-lag relationship between time series. We draw on experience from the econometric and environmental health communities, and we use simulation to demonstrate that the sample CCF is highly prone to bias. Specifically, long-scale phenomena tend to overwhelm the CCF, obscuring phenomena at shorter wave lengths. Researchers seeking lead-lag relationships in surveillance data must therefore stipulate the scale length of the features of interest (e.g., short-scale spikes versus long-scale seasonal fluctuations) and then filter the data appropriately--to diminish the influence of other features, which may mask the features of interest. Otherwise, conclusions drawn from the sample CCF of bi-variate time-series data will inevitably be ambiguous and often altogether misleading.

A consideration of neonatal resuscitation.

There are currently two major areas of resuscitation of the newborn which have come into question: the use of intermittent positive pressure ventilation and the use of oxygen. There is evolving evidence that volutrauma associated with IPPV, especially in the premature infant, may induce changes in the lung which can lead to chronic lung disease. There is reason to believe that the use of continuous positive airway pressure in premature infants who are making respiratory efforts may be less harmful than the use of IPPV. With regard to the use of oxygen, it is clear that most infants can be successfully resuscitated with room air. Although we can identify markers for oxidative stress in newborns when resuscitated with 100% oxygen, the clinical importance of these markers remain an open issue. If the presence of these markers after resuscitation is shown to relate to clinical problems, then the use of oxygen may need to be considered.

Combined effects modeling of ionizing radiation and biological agent exposures.

A simple two-species population model is used to simulate the interactions of a replicating pathogen and the immune system response. This deterministic model is flexible enough to reproduce the salient population-dynamic features, chiefly the tendency toward an equilibrium state in which the pathogen population is reduced to zero or a negligible level after some finite time. The specific immune system species that can be taken initially at zero increases to a finite equilibrium level that represents an immune system "memory" of a given pathogen. The coefficients in the model equations represent production, interaction, and loss rates. Their relative sizes determine the qualitative behavior of the solution in its phase space. The effect on the immune system of exposure to ionizing radiation is modeled by reducing the production rate coefficients; the reduction is proportional to the level of ionizing radiation. According to the model and based on historical hematopoietic data from retrospective accident studies, exposures to ionizing radiation can cause pathogen levels to rise an order of magnitude or more than the baseline (no radiation exposure) case and, for some simulated levels, escape from the bounded region of the phase space. A means is offered to link the deterministic model of time-varying pathogen level in an individual host to the corresponding probability of lethality (increasing with time) of an individual in a population.

Natural history of nonoperatively treated symptomatic rotator cuff tears in patients 60 years old or younger.

BACKGROUND: Rotator cuff tears are the most frequent tendon injury in the adult population. However, the natural history of nonoperatively treated full-thickness tears is poorly defined. Knowledge of the expected evolution in tear size is important when considering nonoperative versus surgical care, especially in relatively young, active patients. PURPOSE: To evaluate the size change of nonoperatively treated full-thickness rotator cuff tears over 2 to 3 years' follow-up. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The authors prospectively followed patients 60 years old or younger who had a full-thickness rotator cuff tear equal to or larger than 5 mm, as diagnosed by bilateral shoulder ultrasound, and who were treated nonoperatively. At 2 to 3 years after the index ultrasound examination, a repeat ultrasound examination was performed by the same ultrasonographer. Results of the follow-up ultrasound examinations of both shoulders were compared with those of the index ultrasound examinations for change in rotator cuff tear size. The correlations were examined between these changes and age, sex, history of initial trauma, size of tear on the index ultrasound, and current shoulder symptoms. RESULTS: Fifty-one patients with 61 rotator cuff tears were evaluated. At a follow-up of 25 to 39 months (mean, 29), 49% of the tears (30 tears) increased in size, 43% (26 tears) had not changed, and 8% (5 tears) decreased in size. For 25% (10 shoulders ) of initially intact shoulders (41 shoulders), a new full-thickness rotator cuff tear was diagnosed. No correlation was found between the change in tear size and age of the patient (P = .85), sex (P = .93), existence of a prior trauma (P = .63), size of tear at index ultrasound (P = .62), and bilateral tears (P = 1.00). There was a correlation between the existence of considerable pain at the time of the follow-up ultrasound and a clinically significant increase in tear size (P = .002). CONCLUSION: Full-thickness rotator cuff tears tend to increase in size in about half of patients aged 60 years or younger. Surgery should be initially considered in these patients to prevent a probable increase in size tear. Patients treated nonoperatively should be routinely monitored for tear size increase, especially if they remain symptomatic.

Emotional processing deficits in individuals with unilateral brain damage.

This article presents a review of the neural mechanisms underlying emotional processing deficits (EPDs) in individuals with unilateral brain damage. First, key theoretical issues pertaining to the neuropsychology of emotion are presented. These include parameters of emotional processing, the componential approach, emotional domains, and hypotheses regarding hemispheric specialization for emotion. Second, the literature on hemispheric asymmetries for emotion is reviewed in terms of processing mode (perception and expression) and communication channel (facial, prosodic-intonational, and lexical-verbal). Studies involving normal adults and individuals with right- or left-sided brain damage are reviewed. Third, recent findings identifying the role of the right hemisphere in emotional processing are described. The article is concluded by aligning these new data with findings from the general literature, providing added support for the right-hemisphere emotion hypothesis.