CT and MRI features of patients with diastematomyelia.

OBJECTIVE: To evaluate computed tomography (CT) and magnetic resonance imaging (MRI) features in patients with diastematomyelia and to investigate clinical characteristics of this lesion. STUDY DESIGN: A retrospectively study. SETTING: The Second Affiliated Hospital, School of Medicine, Xi'an Jiaotong University. METHODS: A total of 82 diastematomyelia cases were retrospectively studied. All the patients underwent neurological examinations as well as MRI and CT of the spine. A self-established neurological functional grading system was used, and posterior tibial nerve somatosensory cortical-evoked potential (PTNSCEP) was measured to assess the neurological status of the patients. Imaging features of symmetry of splitting, presence of septum, location of lesion and number of split segments were studied. The neurological functional grading, PTNSCEP, and imaging findings were then analyzed and compared, and the difference was considered to be significant if P-value was lower than 0.05. RESULTS: Neurological functional grading and latency of PTNSCEP were significantly different but related in terms of symmetry of splitting, presence of septum and location of lesion. Although no significant differences were present in the number of split segments, the severity of the neurological functional grading and PTNSCEP impairment were not related to the number of split segments. CONCLUSION: The imaging features in diastematomyelia are characteristic and relate well with the clinical manifestations according to neurological functional grading and PTNSCEP measurement, except the number of split segments.

Study on the safe range of shortening of the spinal cord in canine models.

STUDY DESIGN: Experimental dog model of spinal cord shortening. OBJECTIVES: To clarify the relationship between the amount of shortening of the spinal cord and the degree of injury it may induce, and to determine the safe range of the shortening. SETTING: Xi'an Jiaotong University, China. METHODS: Thirty adult dogs were randomly allocated to five groups. Dogs in Group A (sham operation control) underwent spondylectomy to have two-thirds of the thirteenth thoracic segment (T13) resected, without bone-to-bone contact of the adjacent vertebral bodies. Those in Group B, C, D and E had one-third, half, two-thirds and total of their T13 resected, respectively, with bone-to-bone contact. Somatosensory-evoked potentials (SEP) and spinal cord blood flow (SCBF) were detected. The histopathologic changes of spinal cord tissue were observed by hematoxylin and eosin stain and electron microscope. RESULTS: The shortening of the spinal cord < half of a vertebral segment height caused a reversible change of SEP. Whereas, the changes resulted from the shortening of more than two-thirds of a vertebral segment height did not return to the normal level. SCBF increased temporarily when the shortening was within two-thirds of a vertebral segment height; whereas, it decreased progressively when the length of the shortening was equal to one vertebral segment height. More serious hemorrhage occurred as the shortening increased. CONCLUSION: Shortening of half of a vertebral segment height will not induce spinal cord injury (SCI), while that between half and two-thirds of a vertebral segment may lead to incomplete SCI.

Treatment of early avascular necrosis of femoral head by small intestinal submucosal matrix with peripheral blood stem cells.

BACKGROUND: Avascular necrosis of the femoral head (ANFH) is a highly mutilating disease. There are no effective ways to treat early femoral head ischemia. Peripheral blood stem cell (PBSC) transplantation may be superior to conventional bone marrow transplantation. Small intestinal submucosae matrix (SIS) is composed of highly conserved collagens, glycoproteins, proteoglycans, and glycoaminoglycans in their natural configuration and concentrations. When implanted in a number of microenvironments in vivo, SIS has been used to induce proliferation, remodeling, and regeneration of host tissues. This study was designed to verify the curative effects of PBSC and SIS transplantation-induced vascular regeneration to improve ischemic femoral head necrosis in rabbits. METHODS: 32 New Zealand white rabbits underwent ischemic femoral head necrosis modeling in both hindlimbs by liquid-nitrogen refrigeration. All rabbits were intraperitoneally injected with grannlocytectomy-stimulating factor (250 µg/kg/d), except for normal control subjects injected with equivalent saline solution. After separation of peripheral blood stem cells (PBSCs), 64 femoral heads in 32 rabbits were randomly divided into 4 groups: group A, cancellous bone and peripheral blood stem cells cultured with small intestinal submucosa; group B, cancellous bone and PBSCs; group C, cancellous bone autografts; and group D, no treatment. The specimens were harvested at 4 and 8 weeks after surgery. All specimens were examined to observe angiogenesis and osteogenesis repairing the avascular necrosis of the femoral head by using gross observation, x-ray, histology, and immunohistochemical staining. RESULTS: In 4 weeks after peripheral stem cell transplantation, the standing ability and activity of the transplanted hindlimbs were improved remarkably, but there were no obvious changes in the control limbs. X-rays showed a greater density of grafts than the host bone in groups A,B, and group C was unchanged at 4 weeks. Histology revealed many osteoprogenitor cells and osteoblasts and no inflammatory cell infiltration at 4 weeks with much new bone formed at 8 weeks in group A and at 4 weeks in group B. The cancellous bone autograft was absorbed completely at 8 weeks in group C. There was little osteoid tissue formed in group D at 8 weeks. The zone of new bone formation in group A was greater than that in group B (P < .05), but there was no significant difference between groups A and C (P > .05). Immunohistochemical staining with CD31 mouse antibody showed greater amounts and zones of new blood vessels in groups A and B at 4 and 8 weeks and little evidence in group D. There was no significant difference between groups A and B (P > .05) and significant differences between groups A and B versus C and D (P < .05). CONCLUSION: Transplantation of PBSCs cultured with SIS effectively improved ischemic femoral head necrosis.

CT evaluation of malformed external and middle ear and its surgical correlation.

This study evaluated the diagnostic value of high resolution CT (HRCT) for atresia of the external auditory meatus (EAM) and isolated middle ear malformation. CT scan of the temporal bone was done in 33 patients with such disorders and 5 patients with otosclerosis etc. were studied in the same way for comparison. Coronal HRCT clearly showed conditions of the atresia plate and malformation of the malleus, incus, abnormal course of facial canal and changes in the vestibular window. The axial HRCT is useful to demonstrate the articulations in between the malleus, incus, stapes and the cochlear window. All the HRCT findings were confirmed during operation. Axial and coronal HRCT for external and middle ear deformation is highly valuable for decision making and surgical planning.