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BACKGROUND: Posterior transarticular screw fixation (Magerl’s) is recommended for atlantoaxial instability. However,some patients do not suit for Magerl’s fixation. OBJECTIVE: To evaluate the clinical outcomes of atlantoaxial pedicle screw system in the treatment of atlantoaxial instability from odontoid fracture. DESIGN,TIME AND SETTING: The retrospective case analysis was performed at the Department of Orthopedics,Sichuan People’s Hospital between July 2004 and June 2007. PARTICIPANTS: Twenty-one cases of atlantoaxial instability from odontoid fracture were selected. According to Anderson and D’Alonzo classification,9 of them belonged to type II odontoid fracture with atlantoaxial instability and 12 to type Ⅲ with severe atlantoaxial dislocation. All cases suffered pain at occipitocervical part and limited activities of cervical spine. According to Frankel classification in function of spinal cord,16 cases of them belonged to Grade E and 5 cases to D. METHODS: All cases were fixed with C1 and C2 pedicle screws system following skull traction and reduction. MAIN OUTCOME MEASURES: Biocompatibility between materials and host; bone graft fusion and functional improvement. RESULTS: No vertebral artery injury or spinal injury was found during operation,neither incision infection was. All cases were followed up for at least 8 months. Postoperative radiograph and CT detection revealed good positions of all screws with no loosening or breakage. All fractures healed within 5 months,and activities of cervical vertebra were not obviously limited except slightly limited rotation function. As for nerve function,5 cases of Grade D recovered up to Grade E. CONCLUSION: Posterior pedicle screw fixation system exhibits no specific biocompatibility responses. It greatly improves atlantoaxial stability and promotes functional recovery of spinal cord but has little influence on cervical function.
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AIM: To evaluate the clinical outcomes and evaluate the application value of pedicle screw system internal fixation in short segment for the treatment of Hangman's fracture. METHODS: A retrospectively analysis was conducted in 17 cases of Hangman's fracture who were treated in Department of Orthopaedics, Sichuan Provincial People's Hospital since 2004. According to Levine-Edwards classification, 4 of them belonged to type II, 6 type IIA, 7 type III. According to Frankel classification in function of spinal cord, 12 cases of them belonged to Grade E and 5 cases D. All cases were fixed with C2,3 pedicle screw system short segment implantation materials (product of Medtronic Sofamor) after skull traction and reduction. RESULTS: No vertebra artery injury or spinal injury was found during operation. Postoperational photograph and CT detection revealed bilateral fracture had no reduction in 1 case and cerebrospinal fluid leaking occurred in 1 case who was cured after conventional therapy. All cases were followed up for 12-24 months (average 14.5 moths). All fractures healed within 6 months, and activities of cervical vertebra were not obviously limited. As for nerve function, 4 cases of Grade D recovered up to Grade E. Ti-alloy implant materials used in this study were well biocompatible to the human body. There were no blood, immune, histology reactions, or the corrosion and abrasion of Ti-alloy appeared. CONCLUSION: Pedicle screw fixation in short segment for the treatment of Hangman's fracture is satisfactory in fracture reduction, fixation and healing. There are little lose in function of cervical vertebrae and it promotes functional recovery of spinal cord.
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@#ObjectiveTo explore the mechanism of estrogen inhibiting osteoblast apoptosis induced with serum hungry.MethodsOsteoblasts of the second or third generation from newly born SD rats calvaria were divided randomly into three groups: control group,serum hungry group,serum hungry with estrogen group.Cells of each group were incubated for 1,2,3,5,7 or 14 d,and then were stained immunohistochemically.The rates of positive cells of each group were analyzed.ResultsThere was a little positive expression of Bax,Bcl2 and Fas in control group.The expression of Bax and Fas were significantly increased(P<0.05)in serum hungry group,peak time was 14 d,but the expression of Bcl-2 were not affected.Compared with that of serum hungry group,the expression of Bax and Fas significantly decreased(P<0.05) in serum hungry and estrogen group,peak time was still 14 d,while that of Bcl-2 increased(P<0.05).ConclusionSerum hungry can increase the expression of Bax and Fas in osteoblast,that can be inhibited by estrogen.Estrogen can also increase the expression of Bcl-2 in osteoblast.All of these may play a role in inhibiting osteoblast apoptosis induced with serum hungry.
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@#ObjectiveTo explore the effect of estrogen on osteoblast apoptosis induced by serum hungry in vitro.MethodsOsteoblasts of second or third generation from newly born SD rats calvaria were divided randomly into the control group, serum hungry group and serum hungry with estrogen group. Cells of each group were incubated for 24 h, 48 h, 72 h, 5 d, 7 d and 14 d, then labeled using TUNEL staining and examined for morphological characteristics of apoptotic cell under light microscopy after incubated for 72 h. The rates of apoptotic cells of each group were examined with flow cytometry.ResultsThe cells of the control group showed normal appears, the serum hungry group had many cells with purple and blue particles in nuclei, but serum hungry with estrogen group had less such cells. The rate of apoptotic cell significantly increased in serum hungry group and decreased in serum hungry with estrogen group compared with the control group examined with flow cytometry (P<0.05).ConclusionEstrogen can repress osteoblasts apoptosis of rats induced by serum hungry.