PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Contusions”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources

Early changes and rules of cardiac function and hemodynamics in rabbits with experimental myocardial contusion.

OBJECTIVE: To study changes and rules of the left ventricular functions in rabbits with myocardial contusion through parallel functional analysis by using echocardiography combined with cardiac catheter intervention. METHODS: Thirty healthy rabbits were selected and impacted to make moderate or severe myocardial contusion by BIM-II biomedical impact machine. The changes of hemodynamics and cardiac systolic and diastolic functions were respectively observed before injury and 1, 4, 8 and 24 hours after injury. RESULTS: After myocardial contusion, the heart rate, systolic pressure, diastolic pressure and mean arterial pressure of rabbits decreased remarkably at 1-4 hours. The left ventricular end systolic pressure (LVESP), the maximum increasing rate of the left intraventricular pressure (+dp/dtmax), isovolumic pressure (IP) and the maximum systolic velocity of the left ventricle (Vmax) also decreased markedly. And then these parameters recovered to the level of preinjury at 8-24 hours. The left ventricular end-diastolic pressure (LVEDP), the rate of the left intraventricular pressure (-dp/dtmax) and the decreasing time constant of the left intraventricular pressure (T) increased remarkably 1 hour after myocardial contusion, and did not decrease until 8 hours after myocardial contusion. Detection by echocardiography showed that ejection fraction of the left ventricle markedly decreased at 24 hours after myocardial contusion, while the systolic volume decreased obviously as early as 1 hour after myocardial contusion, at 4-8 hours it recovered a little and again decreased at 24 hours. The end systolic volume and end diastolic volume increased after myocardial contusion, but statistical significance was only seen at 8 hours after myocardial contusion. CONCLUSIONS: Cardiac functions of the left and right ventricles are markedly injured after myocardial contusion with disorders of the left ventricle diastolic function and of the right ventricle systolic function as the dominant injury. While the systolic function of the left ventricle can recover. Echocardiography shows clinical importance in detection of early injuries of cardiac functions.

Animals↗

[Expression of heat shock protein 70 and heat shock protein 27 in lens epithelial cells induced by contusion and thermotolerance in rat model].

OBJECTIVE: To study the dynamic expression of heat shock protein (HSP) 70 and HSP27 in lens epithelial cells (LECs) in contused eyes of rat model and to detect the dynamic change of the expression of HSP70 and HSP27 after thermotolerance. METHODS: Forty-eight Sprague-Dawley (SD) rats were randomized into two groups: contusion group and thermotolerance group. Contusion eyes were induced by dropping a steel ball of 20 g from the height of 20 cm for 100 times. Thermotolerance was induced by raising the core body temperature of rat to 40.5-41.5 degrees C for 8 min, 2-3 h before eyes contusion. HSP70 and HSP27 expression in the LEC were measured using one-tube RT-PCR. RESULTS: Contusion of eyes resulted in increase of HSP70 expression. Expression of HSP70 increased to 4.59 +/- 0.12 at 1 h after contusion, reached the highest level of 7.72 +/- 0.27 at 3 h after contusion, and reduced to the normal level of 1.32 +/- 0.14 at 24 h after contusion. Preconditioning hyperthermia resulted in significantly increase of HSP70 expression. There was no significant change of HSP27 expression in both groups. CONCLUSIONS: Increased expression of HSP70 in LECs of contused eyes possibly protects the proteins of lens against degeneration. Thermal preconditioning might suppress lens injury induced by contusion via increasing the expression of HSP70.

Animals↗

Expression of Hsp70 and Hsp27 in lens epithelial cells in contused eye of rat modulated by thermotolerance or quercetin.

PURPOSE: To investigate the dynamic expression of heat shock protein (Hsp)70 and Hsp27 in lens epithelial cells (LECs) of contused eyes and the effects of heat shock and quercetin. METHODS: Rat eyes were randomized into three groups: contusion, heat shock, and quercetin. Eye contusions were induced by dropping a 20 g steel ball from a height of 20 cm for 100 times. Heat shock was induced by raising the core body temperature to 40.5-41.5 degrees C for 8 min, 2-3 h before eye contusion. Quercetin, an inhibitor of Hsp expression, was given via gavage (100 mg/kg) 2-3 h before eye contusion. Experimental eyes were enucleated at 0, 1, 3, 6, and 24 h following each group treatment for the detection of Hsp70 and Hsp27 expression in LECs using RT-PCR. Lens sections were examined by immunohistochemistry with antibodies to Hsp70. RESULTS: Basic expression of Hsp70 and Hsp27 was observed in LECs. Expression of Hsp70 in LECs was increased after contusion in a time-dependent manner. Preconditioning hyperthemia (45 degrees C, 8 min) resulted in a significant increase of Hsp70 expression compared to the base level, and enhanced the expression in each subgroup in contrast to the corresponding subgroup in the contusion group. However, Hsp70 levels in the 1-6 h subgroup in the quercetin group was significantly lower. There was no notable change of expression of Hsp27 between each group. Immunostaining of Hsp70 was prominent in LECs of contusion eyes and heat shock eyes compared with those in normal eyes. Immunostaining of Hsp70 was faint in LECs of quercetin eyes. CONCLUSIONS: Increased expression of Hsp70 in LECs of contused eyes may play a protective role against degeneration of lens protein. Thermal preconditioning possibly protects against lens injury by increasing the expression of Hsp70. Endogenous protective mechanisms may be important in eye contusion.

Animals↗

CT prediction of contusion evolution after closed head injury: the role of pericontusional edema.

BACKGROUND: Cerebral contusions have a 51% incidence of evolution in the first hours after injury. Evolution is associated with clinical deterioration and is the reason for ICP monitoring or surgical intervention. We sought to define CT features that predict cerebral contusion evolution. METHODS: Patients treated for cerebral contusion who had 2 CT scans within 24 hours after injury were evaluated (n = 21). CT scans were analyzed for area of contusion, hemorrhagic components, and edema. Increase (%) in contusion size was recorded. Contusion evolution was defined as > 5% size increase. Ratios of hemorrhagic components to surrounding edema were calculated. RESULTS: Ten patients (47.6%) showed contusion evolution and 11 (52.4%) did not. Age, sex ratio, or injury severity between the 2 groups did not differ. Eight of 10 patients with evolving contusions had minimal or no perilesional edema on first CT; only 2 of 11 nonevolution patients had perilesional edema (p < 0.005). Mean ratio of area of surrounding edema to area of hemorrhagic products on first CT was 0.770 in evolution group versus 2.22 in non-evolution group (p = 0.055). CONCLUSIONS: A higher proportion of patients without contusion evolution had perilesional edema present on first CT scan. The absence of pericontusional edema on early CT may be a useful marker to predict contusion evolution.

Adult↗

Excitatory amino acid release from contused brain tissue into surrounding brain areas.

The EAA release from contused brain tissue and its effect on the extracellular EAA levels in brain areas surrounding the contusion were investigated with microdialysis technique in the rat. A significant increase in extracellular EAA levels was observed in the contused brain tissue. The EAA increase was significantly greater in the contused brain tissue than in the isolated but non-contused brain tissue. It was further demonstrated that EAAs were released from non-contused brain areas 1-2 mm distant from contused brain tissue. No such EAA release from surrounding brain areas was demonstrated when the cavity was filled with isolated but non-contused brain tissue. The increase in EAAs was attenuated by KYN administered through microdialysis, suggesting that the EAA release from the surrounding brain areas appears to be a consequence that is secondary to the EAA release from the contused brain tissue. Such a diffusion-reaction process is probably mediated by the neurotransmitter actions of EAAs. The results of the present study are of clinical importance, since surgical removal of contused brain tissue and administration of EAA antagonists may serve to protect the surrounding brain areas from EAA neurotoxicity.

Animals↗

The contusion index: a reappraisal in human and experimental non-missile head injury.

A previously described method of quantifying cerebral contusions in man (the contusion index) caused by non-missile head injury has been modified and applied to a larger series of cases, and used to assess contusions in experimental head injuries. The initial findings in man have been confirmed, viz. that contusions are most severe in the frontal and temporal lobes; that contusions may be entirely absent in a patient dying as a result of a head injury; that there is no correlation between the severity of contusions and the nature of the injury; that the concept of contrecoup must continue to be questioned; that contusions are more severe in patients who have a fracture of the skull in comparison to those who do not; that contusions are more severe in patients who do not experience a lucid interval than in those who do; and that contusions are less severe in patients with diffuse axonal injury than in those who do not have diffuse axonal injury. The distribution of contusions in subhuman primates is similar to that seen in man, and they occur more frequently with short duration than with long duration acceleration.

Adolescent↗

Cerebral blood flow and vasoresponsivity within and around cerebral contusions.

There is increasing evidence that regional ischemia plays a major role in secondary brain injury. Although the cortex underlying subdural hematomas seems particularly vulnerable to ischemia, little is known about the adequacy of cerebral blood flow (CBF) or the vasoresponsivity within the vascular bed of contusions. The authors used the xenon-enhanced computerized tomography (CT) CBF technique to define the CBF and vasoresponsivity of contusions, pericontusional parenchyma, and the remainder of the brain 24 to 48 hours after severe closed head injury in 10 patients: six patients with one contusion and four with two contusions, defined as mixed or high-density lesions on CT scanning. The CBF within the contusions (29.3 +/- 16.4 ml/100 g/minute, mean +/- standard deviation) was significantly lower than both that found in the adjacent 1-cm perimeter of normal-appearing tissue (42.5 +/- 15.8 ml/100 g/minute) and the mean global CBF (52.5 +/- 17.5 ml/100 g/minute) (p < 0.004, repeated-measures analysis of variance). A subset of seven patients (10 contusions) also underwent a second Xe-CT CBF study during mild hyperventilation (a PaCO2 of 24-32 mm Hg). In only two of these 10 contusions was vasoresponsivity less than 1% (range 0%-7.6%); in the rim of normal-appearing pericontusional tissue, it was 0.4% to 9.1%. The authors conclude that CBF within intracerebral contusions is highly variable and is often above 18 ml/100 g/minute, the reported threshold for irreversible ischemia. Intracontusional CBF is significantly reduced relative to surrounding brain parenchyma, and CO2 vasoresponsivity is usually present. In the contusion and the surrounding parenchyma, vasoresponsivity may be nearly three times normal, suggesting hypersensitivity to hyperventilation therapy. Given this possible hypersensitivity and relative hypoperfusion within and around cerebral contusions, these lesions are particularly vulnerable to secondary injury such as that which may be caused by hypotension or aggressive hyperventilation.

Adolescent↗

Effect of cerebral perfusion pressure on contusion volume following impact injury.

OBJECT: Although it is generally acknowledged that a sufficient cerebral perfusion pressure (CPP) is necessary for treatment of severe head injury, the optimum CPP is still a subject of debate. The purpose of this study was to investigate the effect of various levels of blood pressure and, thereby, CPP on posttraumatic contusion volume. METHODS: The left hemispheres of 60 rats were subjected to controlled cortical impact injury (CCII). In one group of animals the mean arterial blood pressure (MABP) was lowered for 30 minutes to 80, 70, 60, 50, or 40 mm Hg 4 hours after contusion by using hypobaric hypotension. In another group of animals the MABP was elevated for 3 hours to 120 or 140 mm Hg 4 hours after contusion by administering dopamine. The MABP was not changed in respective control groups. Intracranial pressure (ICP) was monitored with an ICP microsensor. The rats were killed 28 hours after trauma occurred and contusion volume was assessed using hematoxylin and eosin-stained coronal slices. No significant change in contusion volume was caused by a decrease in MABP from 94 to 80 mm Hg (ICP 12+/-1 mm Hg), but a reduction of MABP to 70 mm Hg (ICP 9+/-1 mm Hg) significantly increased the contusion volume (p < 0.05). A further reduction of MABP led to an even more enlarged contusion volume. Although an elevation of MABP to 120 mm Hg (ICP 16+/-2 mm Hg) did not significantly affect contusion volume, there was a significant increase in the contusion volume at 140 mm Hg MABP (p < 0.05; ICP 18+/-1 mm Hg). CONCLUSION: Under these experimental conditions, CPP should be kept within 70 to 105 mm Hg to minimize posttraumatic contusion volume. A CPP of 60 mm Hg and lower as well as a CPP of 120 mm Hg and higher should be considered detrimental.

Animals↗

Effect of single and periodic contusion on the rat soleus muscle at different stages of regeneration.

This work analyzed the rat soleus muscle after single and recurrent contusions at different stages of regeneration. A noninvasive contusion was produced by a type of drop-mass equipment. The posterior region of the right hind limb received a trauma and both right and left soleus muscles were analyzed 1, 4, and 6 days after a single contusion (1x), and 6 and 30 days after periodic contusions (10x, one trauma per week for 10 weeks). Single contusion: there was no significant difference between right and left soleus muscle weight. All animals showed abundant signs of acute damage in the right soleus. AChE activity was identified in regeneration segments of the right soleus. Periodic contusions: there was an increase in the right soleus muscle weight (alpha = 5%) only in the animals evaluated 6 days after periodic contusions. The right soleus muscle showed a high incidence of chronic signs of damage, such as split fibers and a centralized nucleus, which predominated when compared with the acute signs. Right soleus muscles showed split fibers with AChE activity in both the proximal and middle regions. There was no difference in the incidence of muscle fiber types (I, II, and IIC) between right and left soleus muscles after periodic contusions. Skeletal muscle contusion is common in humans, especially in sport activities, where repetitive traumas are also frequent. The results of this work indicate that despite the regeneration process there is an important change in the morphological aspect of regenerated muscle fibers, which possibly affect muscle performance.

Animals↗

Local and systemic reactions after lung contusion: an experimental study in the pig.

The present study was designed to investigate the consequences of isolated unilateral lung contusion on local alveolar and systemic inflammatory responses in an animal model in the pig. Isolated unilateral lung contusion was induced by bolt shot in eight mechanically ventilated animals under general anesthesia (sham: n=4). Plasma and bronchoalveolar lavage fluid were collected during a period of 8 h following lung contusion. Leukocytes, leukocyte neutral protease inhibitor (LNPI), terminal complement complex (TCC), thrombin-antithrombin-complex (TAT) as well as pulmonary microvascular permeability and surfactant function were determined. Within 30 min, lung contusion was found to cause a significant local and systemic increase in TCC and TAT concentrations and a systemic increase in LNPI concentrations. The latter was accompanied by a sequestration of leukocytes in the contused lung. Complement activation and leukocyte sequestration in the contused lung progressively increased during the investigation period. Although surfactant function decreased in the entire lung 30 min after contusion, TCC, TAT, and leukocyte sequestration was unchanged in the contralateral lung. The first indication of an involvement of the contralateral lung was obtained by an increase in leukocyte sequestration 8 h after lung contusion. Unilateral lung contusion initiates an early systemic activation of humoral and cellular defense systems. Involvement of the contralateral lung appears to be a secondary event caused by a systemic inflammatory reaction.

Animals↗

The effect of contusion and cryotherapy on skeletal muscle microcirculation.

OBJECTIVE: The most common treatment of soft tissue contusions is ice application (cryotherapy). The physiological basis for this therapy is assumed to be cold-mediated vasoconstriction resulting in decreased edema formation and a reduction in overall morbidity. This proposed mechanism has not been tested. The present research examined the hypothesis that cryotherapy following contusion is effective because it reduces microvascular perfusion and subsequent edema formation. EXPERIMENTAL DESIGN: The microcirculatory responses to contusion were studied with and without cryotherapy in a chronically instrumented rat model. Initial studies evaluated the immediate effects of cryotherapy on arteriolar and venular diameters and microvascular perfusion (using laser Doppler floxmetry). Variables were measured before and immediately after 20 minutes of cryotherapy. Two additional studies monitored the same microvascular parameters longitudinally in four sets of chronically instrumented animals. Groups of rats studied had contusion or sham contusion with ice treatment or no ice treatment. Measurements were performed repeatedly before and after treatment for 24 hours or 96 hours after contusion/sham contusion. RESULTS: The acute microvascular effects of cryotherapy were vasoconstriction and decreased perfusion. However, when cryotherapy was used as a treatment following contusion/sham contusion, there were no long-lasting microvascular effects of cryotherapy either in the presence or absence of contusion. CONCLUSIONS: These results indicate that cryotherapy of striated muscle following contusion does not reduce microvascular diameters or decrease microvascular perfusion. Alternate mechanisms of action for cryotherapy treatment need to be investigated.

Animals↗

Regional cerebral blood flow trends in head injured patients with focal contusions and cerebral edema.

Focal contusions following head injury may be associated with focal or diffuse cerebral edema. Early global hyperemia and perifocal hyperemia may play a role in cerebral edema, although causal relationships have yet to be clearly been defined. We studied 27 patients with head injury (admission GCS 3-12) resulting in focal contusions (without evidence of subarachnoid, intraventricular or intraparenchymal hemorrhage by CT). Patients were studied with ICP monitors, head CTs, and intravenous 133Xenon regional cerebral perfusion studies serially over several days post injury. Low cortical blood flow and a low mean CBF15 flow were evident on the day of the injury. Additionally, F1 analysis indicated significantly (p < 0.05) greater cortical blood flow in the surrounding brain (mean 60 cc/100 g/min) compared to the contusion area (mean 43 cc/100 g/min) on the day of trauma. Mean regional CBF remained below normal in the contused areas (CBF15 < 35 cc/100 g/min), however the cortical flow increased in the first few days post-injury (peak F1 = 95 cc/100 g/min on day 3) then decreased to sub-normal levels. The mean CBF in the surrounding brain was low on the day of injury (CBF15 = 29 cc/100 g/min), although higher than the contused area, and increased to a peak of 45 cc/1009/min on day 3 posttrauma. Cortical flow in the surrounding brain, however, exhibited a different trend. The mean F1 was low on the day of trauma and significantly higher one day after trauma (mean 105 cc/100 g/min). Only 15 of the 27 patients with focal contusions had evidence of cerebral edema. Eleven of these exhibited focal edema and 4 exhibited diffuse edema. Focal edema developed over the first few days posttrauma as seen in followup CT, whereas patients with diffuse edema exhibited edema on the admission CT. Initial oligemia in the contused areas was associated with a subsequent hyperemic rim about the contusion. Focal hyperemia was associated with focal edema in 41% of the patients, whereas diffuse edema appeared to be independent of the hyperemic response in contusions.

Adolescent↗

Regional cerebral blood flow after a localized cerebral contusion in pigs.

Regional cerebral blood flow (rCBF) in anaesthetized pigs is investigated before and after an induced focal cerebral contusion. Mean intracranial pressure increased for a short period following the contusion and reduced perfusion pressure to 60% of control pressure. Forty five minutes later the mean intracranial pressure was still high and different from the control values. Global flow and cerebral production of CO2 increased concomitantly. In the cortical region where the contusion was visible macroscopically the rCBF diminished from 36.5 to 29.1 ml/min/100 g. In the rest of the grey matter the rCBF raised after the contusion with an increase away from the centre of the lesion. CBF of cortical grey matter in the region symmetrically to the contusion increased significantly more than in the traumatized hemisphere. White matter rCBF changed least in the region underlying the contusion, while an increase was observed away from the contusion and on the opposite side of the brain. The correlation between tension of CO2 in arterial blood and regional cerebral blood flow disappeared in the region of the contusion. The correlation between global metabolism and regional cerebral blood flow disappeared after the contusion in all regions. Local flow modulating factors influencing flow in the region of macroscopically visible injury has influence abating with distance from the centre of the injury together with a possible neuronally transmitted drive on flow in the opposite hemisphere.

Animals↗

Synaptic remodeling and free radical formation after brain contusion injury in the rat.

The purpose of this study was to explore whether bilateral frontal cortex contusion in rats would demonstrate changes relevant for understanding the pathology of frontal lobe injury in humans. Rats were allowed to survive for 3, 7, or 18 days postinjury (dpi). In the contused rats, albumin was trapped in frontal cortices, as well as in other brain areas, showing that neurons were exposed to plasma components. In the sham-operated rats, which had only craniotomy but no penetration of dura, the level of trapped albumin was also increased compared to intact controls, suggesting a partial lesion-like condition. Choline acetyltransferase activity was severely decreased in the frontal cortices of contused rats, compared to the sham-operated controls. The decrease was most pronounced at 3 dpi and less pronounced 18 dpi, suggesting that after the initial damage, regeneration of the cholinergic terminals occurred. The concentration of the mature presynaptic membrane protein D3(SNAP-25) was also decreased in the frontal cortices of contused rats at 3 and 7 dpi, whereas it was normalized at 18 dpi. Previously, we have evaluated changes in the rate of synaptic remodeling in brain injury by calculating the ratio of the neural cell adhesion molecule (NCAM) to D3(SNAP-25). The NCAM/D3(SNAP-25) ratio at 3 dpi was elevated by more than 60% in the frontal cortices of contused rats, suggesting a high initial rate of synaptic remodeling. The ratios were smaller at 7 and 18 dpi, suggesting that after the initial burst, the rate of remodeling leveled off. In contrast, astrocyte activation was less pronounced at 3 dpi than at 7 and 18 dpi, as measured by the levels of glial fibrillary acidic protein and glutamine synthetase immunoactivities. The immunoreactivity of glutamine synthetase more than doubled in the contused brains but its enzymatic activity increased less than 50%, suggesting that many enzymatic centers had been inactivated by free radicals. Calculated as the difference between the relative immunoreactivity and the relative enzymatic activity the "lost glutamine synthetase activity" increased continuously in frontal cortex and striatum from 3 to 18 dpi, indicating the production of free radicals long after the initial contusion event. In conclusion, following frontal cortical contusions the early synaptic damage was partly compensated by synaptic remodeling. We suggest that the continuous production of free radicals may have contributed to the declining remodeling rate and impair functional recovery.

Animals↗

Operative chest wall stabilization in flail chest--outcomes of patients with or without pulmonary contusion.

BACKGROUND: The aim of operative chest wall stabilization in patients with flail chest and respiratory insufficiency is to reduce ventilator time and avoid ventilator associated complications. The purpose of this retrospective study was to analyze the indications and outcomes of operative chest wall stabilization in defined groups of patients sustaining flail chest with and without pulmonary contusion. METHODS: The hospital records of 405 patients with multiple trauma (Injury Severity Score > 17) between 1988 and 1994 were reviewed. Forty-two patients sustained flail chest. Twenty of these underwent operative chest wall stabilization for the following indications: 1) flail chest with indication for thoracotomy due to intrathoracic injury (n = 6); 2) flail chest without pulmonary contusion (n = 9); 3) paradoxical movement of a chest wall segment in the weaning period from the respirator (n = 3); and 4) severe deformity of the chest wall (n = 2). For the purpose of analysis the patients were separated into groups: group 1: operative chest wall stabilization in flail chest without pulmonary contusion (n = 10); group 2: operative chest wall stabilization in flail chest with pulmonary contusion (n = 10); group 3: flail chest without pulmonary contusion and without chest wall stabilization (n = 18); group 4: flail chest with pulmonary contusion and without chest wall stabilization (n = 4). Data were coded for time of operation, duration of ventilatory support, and complications. RESULTS: There were no significant differences in age, severity of injury, and extent of injury between groups 1, 2, and 3 (p < 0.42). Group 4 was excluded for statistical analysis because of the small number of patients. Patients in group 1 required a shorter ventilatory support time compared to patients in group 3 (6.5+/-7.0 versus 26.7+/-29.0 days) and group 2 (p < 0.02). In group 2 (ventilator time 30.8+/-33.7 days) early extubation was only possible in patients being operated on for chest wall instability during weaning from the ventilator. One patient in group 1, three patients in group 2 and five patients in group 3 developed pneumonia with further disturbance of gas exchange. All patients in group 1 survived; deaths in group 2 were attributed to massive hemorrhage in two and septic multiorgan failure in one patient. Four patients in group 3 died of head injury, one of acute respiratory distress syndrome, one of severe hemorrhage, and one of multiple organ failure. CONCLUSIONS: In patients with flail chest and respiratory insufficiency without pulmonary contusion, operative chest wall stabilization permits early extubation. Patients with pulmonary contusion do not benefit from chest wall stabilization. Secondary operative chest wall stabilization in these patients is indicated when progressive collapse of the chest wall is evident during weaning from the ventilator.

Adult↗

Comparison of bone contusion seen by MRI in partial and complete tears of the anterior cruciate ligament.

OBJECTIVE: Bone contusions are frequently found in association with complete tears of the anterior cruciate ligament (ACL) and can be a helpful secondary sign in diagnosis. We compare the frequency, location, and significance of bone contusions in complete and partial ACL tears. MATERIALS AND METHODS: Twenty-nine patients with complete and 42 patients with incomplete tears of the ACL were examined by MRI for the presence of accompanying bone contusions within 1 month of injury. RESULTS: Bone contusions were found in 72% of the complete ACL tears but in only 12% of the partial tears. Of the partial ACL tears with accompanying contusions, 80% were high grade injuries that eventually went on to complete rupture within 6 months. Only 16% of the partial ACL injuries without bone contusion progressed to complete rupture at 1-2 year follow-up. There was no difference between the bone contusions of partial and complete tears in terms of general appearance and location. They were predominantly in the lateral compartment (90%) and had a specific predilection for the mid portion of the lateral femoral condyle and the posterior portion of the lateral tibial plateau, often occurring in tandem. CONCLUSION: Bone contusions occur with much less frequency in partial ACL tears than in complete tears but their presence in partial rupture favors a high grade tear that is likely to become complete.

Adolescent↗

Technetium-fibrinogen lung scanning in canine lung contusion.

To detect experimentally induced acute lung contusion in anesthetized dogs, serial radionuclide images of the lung were recorded following intravenous infusion of 99mTc-labelled human fibrinogen (Tc-HF). The accumulation of Tc-HF in canine lungs was serially quantitated for up to 20 hours after lung contusion. A contusion (#1) was produced in one lung, Tc-HF was injected IV after 15 minutes, and 75 minutes later a contralateral lung contusion (#2) was produced in a series of 14 dogs. At autopsy the excised lungs were scanned, sectioned, and counted for radioactivity. Radiolabelled fibrinogen accumulated within 2-4 minutes of contusion #2 and remained stable over the next 20 hours in 14 dogs; contusion #1 was barely visible in four dogs. Lung Tc-HF activity in the central region of contusion #2 remained sixfold higher than in normal lung tissue. These data suggest that following lung contusion, fibrinogen deposition occurs rapidly and remains stable over a 20-hour interval of observation.

Animals↗

Contusion of skeletal muscle increases leukocyte-endothelial cell interactions: an intravital-microscopy study in rats.

OBJECTIVE: To investigate the relationship between secondary muscle damage after contusion and the interactions between leukocytes and endothelial cells, which are essential steps in secondary inflammatory response. METHODS: In a randomized animal study, rats were chronically instrumented with dorsal skinfold microvascular chambers and exposed to standardized contusion or sham contusion. Leukocyte rolling and adherence in postcapillary venules before and after muscle contusion or sham contusion were quantitated using in vivo microscopy. RESULTS: The number of rolling leukocytes in the postcapillary venules before contusion was low. At 300 minutes after contusion, the number of rolling and adherent leukocytes in the striated muscle microvasculature was increased significantly (p < or = 0.05) compared with either the baseline precontusion condition or the control group at the same time. CONCLUSION: In the mid-term to long-term stages of skeletal muscle injury associated with contusion, a significant portion of tissue damage is secondary to leukocyte-endothelial cell interactions.

Animals↗