This study examined the effects of parathyroid hormone (PTH) on bone augmentation beyond the skeletal envelope within a plastic cap in rat calvaria.The calvaria of 30 rats were exposed, and 2 plastic caps were placed on each. Each of the 10 rats was treated with 35 or 105 μg/kg (PTH-35, PTH-105) PTH 3 times per week. The control group was injected with sterile saline 3 times per week. Micro-computed tomography (CT) imaging was performed every 2 weeks for 12 weeks. Micro-CT and histological sections were used to determine the amount of bone augmentation within the plastic caps. Bone volume (BV) was calculated using BV-measuring software.The histomorphometric and histological analyses showed that the amount of bone augmentation was increased significantly in the PTH groups compared with the controls at 12 weeks. The PTH-105 group showed significantly more bone augmentation and osteoblasts compared with the PTH-35 group.These results indicate that the higher the dose of intermittent PTH administered, the greater the amount of bone formation beyond the skeletal envelop in the rat calvarium.
Sacral fracture is the most frequent posterior injury among unstable pelvic ring fractures and is prone to massive hemorrhage and hemodynamic instability. Contrast extravasation (CE) on computed tomography (CT) is widely used as an indicator of significant arterial bleeding. However, while CE is effective to detect significant arterial bleeding but negative result cannot completely rule out massive bleeding. Therefore, additional factors help to compensate CE for the prediction of early hemodynamically unstable condition.We evaluated the risk factors that predict CE on enhanced computed CT in patients with sacral fractures. Patients were classified into 2 groups: CE positive on enhanced CT of the pelvis [CE(+)] and CE negative [CE(-)]. We compared age, sex, injury severity score (ISS), systolic blood pressure (sBP), type of sacral fracture based on Denis classification, platelet (PLT), base excess, lactate, prothrombin time-international normalized ratio, hemoglobin (Hb), activated partial thromboplastin time, D-dimer, and fibrinogen between the 2 groups.A total of 82 patients were treated for sacral fracture, of whom 69 patients were enrolled. There were 17 patients (10 men and 7 women) in CE(+) and 52 patients (28 men and 24 women) in CE(-). Age, ISS, and blood transfusion within 24 hours were significantly higher in the CE(+) group than in the CE(-) group (P = .023, P < .001, P < .001). sBP, Hb, PLT, fibrinogen were significantly lower in the CE(+) group than in the CE(-) group (P < .001, P < .001, P < .001, P < .001). D-dimer and lactate were higher in the CE(+) group than in the CE(-) group (P = .036, P < .001) with significant differences. On multivariate analysis, the level of fibrinogen was an independent predictor of CE(+). The area under the curve value for fibrinogen was 0.88, and the optimal cut-off value for prediction was 199 mg/dL.The fibrinogen levels on admission can predict contrast extravasation on enhanced CT in patients with sacral fractures. The optimal cut-off value of fibrinogen for CE(+) prediction in sacral fracture was 199 mg/dL. The use of fibrinogen to predict CE(+) could lead to prompt and effective treatment of active arterial hemorrhage in sacral fracture.
Kinetic MRIs of cervical spines were obtained and analyzed according to the amount of motion and the degenerative grade of the intervertebral disc.To define the relationship between the grade of disc degeneration and the motion unit of the cervical spine and elucidate changes in the role of each cervical spine unit during flexion-extension motion caused by degeneration.Degenerative changes in the cervical disc occur with age. The correlation between the degree of cervical disc degeneration and extent of cervical spine mobility has not yet been determined. The effect of degeneration on the overall motion of the functional spinal unit also remains undefined.We studied 164 patients with symptomatic neck pain. The cervical intervertebral discs were graded by spine surgeons according to the degenerative grading system (Grades I to V). All radiologic data from kinetic MRIs were recorded on a computer for subsequent measurements. All measurements and calculations for translational motion and angular variation of each segment were automatically performed by a computer analyzer.The translational motion in discs with Grade II degeneration (mild degeneration) increased to Grade III degeneration (higher degeneration). However, the translational motion and angular variation significantly decreased for the Grade V (severe degeneration). For patients with relatively low grades of degeneration, Grades I and II discs, the C4-C5 and C5-C6 segmental units contributed the majority of total angular mobility of the spine. However, for the severely degenerated segments, Grade V discs, the contributions of the C4-C5 and C5-C6 U significantly decreased.The changes that occur with disc degeneration progress from the normal state to an unstable phase with higher mobility and subsequently to an ankylosed stage. This study evaluated the contribution of different levels to the changes in overall motion that occur with degeneration.
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