Volume 10 · Issue 06 · 2007

Abstract：Objective: To analyze the data of patients with spinal cord injury (SCI) induced by road traffic crashes in southeastern Iran for better understanding the pattern of these injuries and therefore for better designing health system planning.Methods: In this historical cohort study, the patients who had been transferred to Level I trauma center in southeastern Iran due to road traffic accidents with radiographic documented SCI were evaluated.Results: Among 64 patients with SCI, 38 patients (59.4%, 36 males and 2 females, aged 27.42 years ± 9.44 years on average) were injured by road traffic accidents.Car and motorcycle accidents were responsible for 26 cases (68.4%) and 12 cases (31.6%), respectively. And 31 patients (81. 6%) had complete SCI. Conus medularis (T12-L2) was the most affected level.Conclusions: Results are discussed in terms of preventive measures, specifically those concerning the use of restraint and helmet and driving behavior. This study should be extended nationally to gain a larger case series so that the SCI risk of particular vehicle configurations,considering other crash factors, can be more precisely quantified and the characteristics for low occurrence of SCI can be more precisely identified。

Abstract：Objective: To evaluate the biomechanical performance of vertebroplasty using calcium sulfate cement for thoracolumbar burst fractures.Methods: Sixteen bovine thoracolumbar spines (T11-L1 ) were divided into 4 groups (A, B, C and D). After burst-fracture model was created, 12 vertebral bodies in Groups A, B and C were augmented with calcium sulfate cement (CSC), calcium phosphate cement (CPC) and polymethylmethacrylate ( PMMA ) bone cement,respectively. Each anterior vertebral body height was measured with a caliper at 4 time points: intact conditions(HInt), post-fracture (HFr), post-reduction (HRe) and post-vertebroplasty (HVP). The filling volume of 3 different bone cements was also measured. Each vertebral body was compressed at 0.5 mm/s using a hinged plating system on a materials testing machine to 50% of the postvertebroplasty height to determine strength and stiffness.Difference was checked using t test or One-way ANOVA.Results: The average strike energy was 66. 2 J.Vertebroplasty with different cements could sustain vertebral height. The average filling volume of bone cement in 3 groups was 4.35 ml (CSC), 3.72 ml (CPC) and 3.95 ml (PMMA), respectively, and there was no statistically significant difference among them ( P ＞0.05).Vertebroplasty with PMMA completely restored strength(116%) and stiffness (105%). CSC or CPC partly recovered vertebral strength and stiffness. However,greater strength restoration was got with CSC ( 1 659 N) as compared with CPC (1 011N, P＜0.01 ). Regarding stiffness, differences between CSC (140 N/mm ±40 N/mm)and the other two bone cements ( CPC :148 N/mm ±33 N/mm,PMMA:236 N/mm ±97 N/mm) were not significant (P＞0.05).Conclusions: For a burst-fracture of calf spine, useof CSC for vertebroplasty yields similar vertebral stiffnessas compared with PMMA or CPC. Although augmentationwith CSC partly obtains the normal strength, thistreatment still can be applied in thoracolumbar burstfractures with other instrumental devices in light of itsbioactivation。

Abstract：Objective: To evaluate the therapeutic effect of combined reconstruction of anterior cruciate ligament( ACL ) and posterior cruciate ligament ( PCL )simultaneously by using allograft patellar tendon under arthroscopy.Methods: From May 2003 to November 2005, 10 cases of ruptured ACL and PCL were fixated with compressed screws and reconstructed under arthroscopy with allograft patellar tendon simultaneously. The clinical results were evaluated according to IKDC, Lysholm, and Tegner clinical rating scales.Results: All patients were followed up for 12-30 months (mean: 18 months). At the last follow-up, there was no knee extension limitation and knee flexion was between 120° and 135°, with an average of 128.38°. The Lysholm score of the 10 cases was 66. 5 ± 5. 6 before operation and 89.8 ± 3.4 at last follow up. The difference was statistically significant (P ＜ 0.01 ). The average Tegner activity score decreased from 6.9 ± 1.7 ( range: 4-9 ) before injury to 5.5 ± 1. 6 (rang: 2-9 ) at the follow-up(P =0.53 ). At the end of follow-up, IKDC score was graded as A in 4 cases (40.0%), B in 5 (50.0 % ), and C in 1 (10.0%). Of the 10 patients, 8 returned to the same sports level as before injury and 2 were under the level.Conclusion: Arthroscopic combined reconstruction of ACL and PCL with allograft patellar tendon has the advantages of minimal trauma in surgery and reliable satisfactory outcome。

Abstract：Objective: To study the effect of allograft compound vertebra on vertebral reconstruction in rabbits so as to provide biomechanical direction for manufacturing and selecting vertebral reconstruction materials.Methods: Twenty-five healthy New Zealand white rabbits were divided randomly into three groups: normal group ( Group A, n = 5), iliac bone graft group ( Group B,n = 10) and allograft compound vertebra group ( Group C,n = 10). After C4 was resected, iliac bone implantation and allograft bone cage transplantation were fulfilled in Group B and Group C, respectively. Every 5 rabbits from Group B and Group C were selected to test the biomechanical strength and biological activity one and two months postoperatively.Results: No significant statistical difference was found between Group A and Group C one and two months postoperatively (P ＞ 0.05). The biomechanical strength of Group B was much weaker than that of Group A and Group C one month postoperatively ( P ＜ 0.05 ), but at two months postoperatively, no statistical difference was found among the three groups. The biological activity and vertebral moulding ability of Group C were better than those of Group B at one and two months postoperatively.Conclusions: Compound vertebra, which is made up of allograft cortical bone cage and autogenous cancellous bone, shows instantaneous and permanent biomechanical stability and biological activity, therefore, it is an ideal material for vertebral reconstruction。

Abstract：Objective: To study the effect of vascular endothelial growth factor (VEGF) and anti-VEGF on the expression of fracture healing-related factors and observe pathological changes at fractured sites.Methods: Fracture models were established in 105 New Zealand white rabbits and they were randomly divided into control group, VEGF group and anti-VEGF group.The relevant factors expression at fractured sites was assayed and pathological changes were observed in decalcified samples at 8, 24, 72 hours and 1,3,5,8 weeks after fracture.Results: After application of VGEF, the expression of BMP appeared earlier and expression time lasted longer.On the contrary, anti-VEGF completely inhibited the expression of BMP. The fractured sites were filled with fibrous callus, cartilaginous callus and bony callus at the 3rd week and woven bone was constructed at the 5th week.Fracture healing was accomplished at the 8th week in VEGF group. In anti-VEGF polyclonal antibody group,cellular necrosis increased at early period. Continuous focal necrosis was seen in the fractured sites from the 1st week to 5th week. Vascularization reduced obviously at the 3rd week.Conclusions: Fracture healing is a result of mutual regulation and coordination among many factors. VEGF may be an important factor in fracture healing。

Abstract：Objective: To analyze the application of vertebral pedicle screw fixation in the treatment of burst fracture of thoracolumbar vertebrae.Methods: A total of 48 cases (31 males and 17 females, aged from 18-72 years, mean: 41.3 years) with thoracolumbar vertebrae burst fracture were treated by pedicle screw system since January 2004. According to the AO classification of thoracolumbar vertebrae fracture,there are 36 cases of Type A, 9 of Type B and 3 of Type C.Results: All patients were followed up for 6-25 months (average 12 months ), no secondary nerve root injury, spinal cord injury, loosening or breakage of pedicle screw were observed. The nerve function of 29 patients with cauda equina nerve injury was restored to different degrees. The vertebral body height returned to normal level and posterior process angle was rectified after operation.Conclusions: The vertebral pedicle screw internal fixation was technologically applicable, which can efficiently reposition and stablize the bursting fractured vertabrae,indirectly decompress canalis spinalis, maintain spine stablity, scatter stress of screw system, reduce the risk of loosening or breakage of screw and loss of vertebral height,and prevent the formation of posterior convex after operation。

Abstract：Objective: To provide a sound cell source for further ex-vivo gene therapy for chronic pain, we attempt to develop an immortalized rat astrocyte cell line that expresses enkephalin regulated by doxycycline.Methods: Retrovirus infection method was employed to develop an immortalized rat astrocyte cell line that could express enkephalin regulated by doxycycline. The hPPE gene expression level of immoralized astroyte cells (IAC)/hPPE was detected by RT-PCR, indirect immunofiuorescence staining and radioimmunoassay.Results: IAC carrying Tet-on system transfected with preproenkephalin gene could secrete enkephalin that was regulated by doxycycline in a dose-dependent manner and hPPE gene activation could be repeated in on-off-on cycles through administration or removal of doxycycline.Conclusion: An immortalized rat astrocyte cell line that secrete enkephalin under the control of doxycycline is established successfully, which provides a research basis for transgenic cell transplantation for analgesia。

Abstract：Objective: To study the emergency management principles of severe trauma in hospital (injury severity score ≥ 16).Methods: We used "ATP principle" to manage severe traumatic patients. The ATP principle is composed of: 1) attending surgeons offering initial management (A);2 ) teamwork commencement immediately after patients admitted to hospital (T);3) parallel principle, ie,emergency resuscitation, evaluation and laboratory test performed simultaneously (P). Clinical effects before and after applying ATP principle were retrospectively analyzed and compared.Results: During January 1, 2002 to December 31,2003, 338 patients were treated without applying ATP principle, in which ISS was 25.9±6.4, 152 cases died with the mortality being 39.2%, and the time stayed in emergency department and the time to operation room after admission were (102.8±16.7) rmin, (140.3 ±20.6) min,respectively. During January 1, 2004 to December 31,2005, 438 patients were treated based on ATP principle, in which ISS was 28.6±7.8, 87 cases died with the mortality being 19.9%, and the time in emergency department and the time to operation room after admission were (69.5 ±11.5) min, (89.6 ±9.3) min, respectively. ISS showed no significant difference between the two groups (P ＞ 0.05),but the mortality, the time stayed in emergency department and the time to operation room after admission were greatly reduced and showed significant difference between the two groups (P ＜0.05).Conclusions: Applying ATP principle to treat severe traumatic patients can shorten emergency treatment time in hospital and decrease mortality。

Abstract：Objective: To study the change and relationship among bone mineral density (BMD), collagen composition and biomechanical properties of the callus in the healing process of osteoporotic fracture.Methods: The osteoporotic rat model and fracture model were established through bilateral ovariectomy(OVX) and osteotomy of the middle shaft of the right hind tibiae, respectively. Ninety female SD rats were randomly divided into OVX group and sham group. With the samples of blood and callus, roentgenoraphic and histological observation were performed for the assessment of the healing progress of the fracture, and the serum concentration of TRAP-5b, proportion of type Ⅰ collagen,BMD and biomechanical properties of the callus were measured.Results: The OVX group experienced a significant delay of fracture healing. The mean serum concentration of TRAP-5b of rats in the OVX group was much higher than that in the sham group after the operation (P ＜ 0.05), but the difference at the same time point after fracture was smaller than that before fracture (P ＜ 0.05 ). The BMD of the callus in both groups reached the peak value at the 6 th week after fracture while the proportion of the type Ⅰ collagen and the biomechanical strength reached the peak at the 8th week.Conclusions: The deficiency of estrogen after the ovariectomy could induce the up-regulation of the osteoclasts activities, whereas the potency of further activation after fracture was depressed. Although the synthesis of collagen together with its mineralization determines the biomechanical properties of new bone, the accumulation of collagen could be assessed as an index in the prediction of biomechanical strength of bones independent of the bone mineral deposition。

Abstract：Objective: To analyze retrospectively the clinical symptoms, signs, radiological findings and results of treatment of posttraumatic syringomyelia.Methods: The data of 7 patients with posttraumatic syringomyelia confirmed by computerized tomography(CT) and magnetic resonance imaging (MRI) in our hospital between 1999 and 2004 were reviewed retrospectively. The patients underwent decompressive laminectomy or syringo-subarachnoid (S-S) shunting with microsurgery. Long-term follow-up was available (range:13-65 months).Results: The major clinical manifestations of posttraumatic syringomyelia usually included the onset of increasing signs and the development of new symptoms after an apparently stable period. The clinical symptoms included pain, sensory disturbance, weakness, and problems in autonomic nerves. Syrinx existed merely at the cervical level in 4 cases and extended downward to the thoracic levels in the other 3 cases. One case underwent decompressive laminectomy, 6 cases were treated by S-S shunting. During the early postoperative period, all the patients showed an improvement of symptoms of syrinx without major complication or death. The decreased size or collapse of the syrinx was demonstrated by postoperative MRI.Conclusions: Posttraumatic syringomyelia is a disabling sequela of spinal cord injury, developing months to years after spinal injury. MRI is the standard diagnostic technique for syringomyelia. The patients with posttraumatic syringomyelia combined with progressive neurological deterioration should be treated with operations. S-S shunting procedure is effective in some patients with posttraumatic syringomyelia. Decompressive procedure may be an alternative primary surgical treatment for patients with kyphosis and cord compression。

In patients who have sustained traumatic brain injury with associated extremity fracture, there is often a clinical perception that the rate of new bone formation around the fracture site increases. 1 An overgrowth of callus is observed and ectopic ossification even occurs in the muscle,2 but the mechanism remains unclear。

Splenosis is ectopic autotransplantation of splenic tissue after splenic trauma or surgery. 1 The most frequent locations are the surface of visceral peritoneum and parietal peritoneum. Liver and retroperitoneum are rarely involved. 1,2 We present here 2 cases of splenosis involving the liver and retroperitoneum with clinical information, imaging findings, and literature review。