ObjectiveThe purpose of this study was to evaluate the different patterns of bone loss between the lumbar spine and the femur after ovariectomy in rats.MethodsTwenty-four female Sprague-Dawley rats underwent a sham operation (the sham group) or bilateral ovariectomy (the ovariectomized group). Four and eight weeks after operation, six rats from each of the two groups were euthanized. Serum biochemical markers of bone turnover including osteocalcin and alkaline phosphatase (ALP), which are sensitive biochemical markers of bone formation, and the telopeptide fragment of type I collagen C-terminus (CTX), which is a sensitive biochemical marker of bone resorption, were analyzed. Bone histomorphometric parameters of the 4th lumbar vertebrae and femur were determined by micro-computed tomography.ResultsOvariectomized rats were found to have higher osteocalcin, ALP and CTX levels than sham controls. Additionally, 8 weeks after ovariectomy in the OVX group, serum levels of osteocalcin, ALP and CTX were significantly higher than those of 4 weeks after ovariectomy. Bone loss after ovariectomy was more extensive in the 4th lumbar spine compared to the femur. Bone loss in the 4th lumbar spine was mainly caused by trabecular thinning, but in the femur, it was mainly caused by trabecular elimination.ConclusionThe present study demonstrates different patterns of bone loss between the 4th lumbar spine and the femur in ovariectomized rats. Therefore, when considering animal models of osteoporosis, it is important that bone sites should be taken into account.
A 79-year-old woman developed neurological deficits 6 weeks after the onset of a thoracic osteoporotic compression fracture. Magnetic resonance (MR) imaging of the thoracic spine revealed an epidural hematoma at the T10-L2 levels. Acute decompressive laminectomy and percutaneous vertebroplasty were performed. Following the surgery, the patient's neurologic deficits improved and follow-up MR imaging showed complete resolution of the hematoma. Spinal epidural hematomas are rare and associated delayed neurological deficits are extremely rare. Conservative treatment may be effective for epidural hematomas in neurologically intact patients, but epidural hematomas can be a cause of neural compression and symptomatic deterioration resulting in delayed neurological deficits during the follow-up period
ObjectiveWe evaluated the efficacy of diffusion-weighted magnetic resonance imaging (DW-MRI) in detecting perioperative cerebral thromboembolic events after anterior cervical discectomy and fusion (ACDF).MethodsThis retrospective case series included 51 consecutive patients that underwent ACDF. To assess baseline presence of plaque or stenosis, all patients were assessed for risk factors of cerebrovascular events and underwent carotid ultrasound preoperatively and cerebral DW-MRI was performed in all patients postoperatively, with areas of high signal intensity interpreted as a cerebral thromboembolic event.
ResultsOne male patient who underwent a C4/5 ACDF had a focal diffusion abnormality on DW-MRI concerning for cerebral thromboembolic events in the right posterior cerebral artery territory. He remained asymptomatic and did not display related neurological symptoms, such as visual deficits.
ConclusionAsymptomatic cerebral thromboembolic events can be detected by DW-MRI after ACDF. The incidence of such events remains very rare despite the direct manipulation and associated alteration of common carotid artery flow dynamics.
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