BACKGROUND: Calcium sulfate (CS) is a good bone conduction material due to its good biocompatibility and degradability. However, simple CS lacks of osteoinductive capability, so it can not satisfy clinical requirements.OBJECTIVE: To verify the potential ofCS/bone matrix gelatin (BMG) composite biomaterial in the repair of segmental bone defects.DESIGN, TIME AND SETTING: An in vivo multi-dimensional observation was performed in the Laboratory Animal Center, Nanfang Hospital, Southern Medical University between December 2004 and April 2006.MATERIALS: Twenty-one healthy adult New Zealand rabbits, weighing 2.5-3.5 kg, were included. The segmental ulnar defects of 15 mm were created bilaterally. CS and BMG were self-prepared.METHODS: CS and BMG were composited at 2:1 and then implanted into 15-mm rabbit ulnar bone defect. The present study consisted of 3 groups: CS/BMG group, defects were filled with CS/BMG; CS group, defects were filled with CS; and blank control group, untreated control defects.MAIN OUTCOME MEASURES: At weeks 4, 8, and 12 post-surgery, repair of bone defect was observed by gross observation, radiographic, histomorphological and tetracycline tracing analysis.RESULTS: Surgical incisions all primarily healed. No inflammatory or foreign reaction was found around all the defects. Both CS/BMG and CS were almost completely absorbed at week 8 post-surgery. In the CS/BMG group, newly formed bone was found throughout the defects after 4 weeks; all defects were repaired with a well-organized trabecular pattern and a thit neocortex after 12 weeks. In the CS group, mass of new bone tissue formed at the periphery of the defect at week 4 post-surgery, but the development of new bone in the center of defect was latter compared with the CS/BMG group: at 12 weeks, all defects were bridged by newly formed bone tissue with little adjacent medullary bone. In the blank control group, slight new bone was found at the periphery of the defect region, and the defects were filled with fibrous tissue.CONCLUSION: CS/BMG composite is totally bioresorbable and biocompatible. The composite can repair bone defects effectively as a bone graft substitute.

Objective To analyze the reasons of early complications in anterior cervical spine surgery and its management. Methods Between Jan 1992 and Dec. 2003, 412 patients underwent anterior cervical surgery. There were 308 males and 104 females with an average age of 45.6 years (18-76). The di-agnosis of these patients included 258 of cervical spondylosis, 138 of cervical injury, 8 of cervical spinal tu-mor and 8 of tuberculosis of cervical spine. The medical history was from 4 hours to 20 years with an aver-age duration of 548 days. Among 412 patients, there were 58 cases (14.1%) with complete paraplegia, 192 cases (46.6%) with incomplete paraplegia and 162 cases without neurological deficits. Anesthesia used in this group of patients were local in 35, cervical plexus block in 52, local associated with cervical plexus block in 6, general in 318 and general associated with cervical plexus block in 1. Three surgical procedures were performed: 1) anterior decompression and interbody fusion with autogenous iliac crest in 33 cases; 2) anterior decompression and interbody fusion with threaded fusion cage in 32 cases; 3) anterior decompres-sion, interbody fusion with autogenous iliac crest and plate fixation in 347 cases. Results Fifty-one early complications occurred in 42 patients and the incidence was 12.37%. 28 patients (6.8%) had complications directly related to the procedure which included superior laryngeal nerve injury in 5, recurrent laryngeal nerve injury in 4, migration of bone graft in 2, infection or haematoma in 4, deterioration of neurological function in 5,nerve root injury in 2, loosening of screw or plate fixation in 2 and esophageal fistula in 1. 23 cases (5.08%) had early complications indirectly related to the procedure. Conclusion In order to reduce the incidence of early complications in anterior cervical spine surgery, make familiarization with anatomy, improvement of surgical skill as well as appropriate perioperative management are essential in anterior cer-vical spine surgery.

Objective To discuss the selection of surgical procedures for the treatment of spinal tu-berculosis according to the status of segmental stability of the spine. Methods One hundred adult patients with spinal tuberculosis were treated surgically between January 1998 and December 2003. There were 57 males and 43 females with an average age of 39.4 years and an average history of 16 months. The lesion ranged from T2 to S 2, and involved single vertebral body in 3 cases, double vertebral bodies in 66 cases, and more than two vertebral bodies in 31 cases. Of 100 cases, 32 were with neurological dysfunctions, and 65 were accompanied by kyphotic deformity with an average Cobb angels of 36.4? (20? to 48?). Preoperative chemotherapy of four drugs lasted more than two weeks. Three surgical procedures were performed according to the status of segmental stability of the spine: 12 cases without spine instability underwent single debride-ment, 8 cases of spine instability with debridement and interbody fusion, and 80 cases of significant insta-bility with debridement, fusion and internal fixation. Results All patients' incision healed without chronic infection and sinus formation. 95 patients were followed up with an average of 2.9 years ranged 1 to 77 years except 5 patients lost at follow up. 68 cases with anterior fusion achieved solid fusion in average 3.5 months. 65 cases with kyphotic deformity had an average correction of 20.2? postoperatively, and 2? to 4? loss during follow-up. 32 cases with neurological deficits had an improvement of neurological function postoperatively. One patient of L 4,5 tuberculosis treated with anterior debridement, fusion and instrumentation recurred at 7 months due to an inadequate postoperative chemotherapy of 6 months, and healed with a continuous chemotherapy for 18 months, However, satisfactory clinical results were obtained in other patients without any recurrence. A left external iliac vein was torn and repaired successfully in 1 case. Conclusion The maintenance of segmental stability has significant effect in the surgical treatment of spinal tuberculosis. Sta-tus of segmental stability of each patient should be evaluated preoperatively. Satisfactory clinical results can be achieved by proper selection of the surgical procedure according to the status of segmental stability.

[Objective]To study the biocompatibility of nacre on cultured human osteoblasts in vitro.[Method]The iliac bone of human were added with collagenase-trypsin,a lot of osteoblasts were released out.Then the osteoblasts were purified and cultured.Subsequently,the 3rd generation cultured human osteoblasts were inoculated with the extract of three materials:nacre,hydroxyapatite,and rubber.The appearance of osteoblast was observed under the phase contrast microscope.Microstructure of the osteoblast was observed under transmission electron microscope.Additionally,to determine whether these three materials affect cell proliferation,the numbers of BrdU-labeled cells were examined at three groups.MTT assay was tested to observe the viability of human osteoblasts.[Result]Under the phase contrast microscope,the appearance of the osteoblasts in two groups were spindle or triangle like,and black nodes were seen in confluent cell layer 19 days after cultured.The observation of electron microscopy showed that the nucleus of the osteoblasts in two groups were big and round,and there were a large number of mitochondrion and rough endoplasmic reticulum in two groups.Stereological analyses of the numbers of BrdU-labeled cells revealed that females produced more cells than males in the dentate gyrus but not in the subventricular zone.[Conclusion]The nacre have no harmful effect to character of biology of human osteoblasts in vitro.

[Objective]To study the role of nitric oxide on the degeneration of the cartilage endplate(CEP).[Method]Twenty-four New Zealand rabbits were divided into experiment and control groups.In the experiment group,the model of lumbar CEP degeneration was established by resection of all lumbar supraspinous and interspinous ligaments,excision of parts of zygapophysial joints and detachment of the posterior paravertebral muscles from lumbar vertebraes.Mechanical instability of the lumbar spine could induced the process of CEP degeneration.The X-ray examination of lumbar spine was examined by at 12,24 and 36 weeks with or without operation,respectively.Changes of the ultrastructure of CEP were also observed by scanning electron microscope(SEM) during this process,and the content of IL-1?,IL-6,TNF-? in the CEP were also detected during the periods.[Result]X-ray graph showed that the CEP calcified gradually with time increasing,and those of the experiment groups calcified more obviously than those of the control groups.The SEM showed that collagen fibers became thin,irregular and fissured and the content of proteoglycan decreased severely with the elapse of time.The changes in experiment groups were more obvious than those in control groups.The content of IL-1?,IL-6,TNF-? had a significant difference between the experiment groups and the control groups(P0.05).[Conclusion]It implies that inflammatary cytokin may play an important role in the development and progression of the degeneration of cartilage endplate.

[Objective] To investigate the osteogenetic effect of calcium sulfate(CS)combined with bone matrix gelatin(CS)as bone substitute material in a rabbit ulnar defect model.[Method]Twenty one adult New Zealand White rabbits were used.The segmental ulnar defects of 15 mm were created b/laterally and were divided into tbree groups:Group 1,defects were filled with CS/BMG;Group 2,defects were filled with CS;Group 3,untreated control defects.The samples were harvested at 4,8,12 weeks and were examined by radiographic,histomorphological and tetracycline tracing analysis.[Result]No inflammatory or foreign body reaction was observed around all the defects.Both CS/BMG and CS were almost completely resorbed 8 weeks postoperation.At the group 1,nem bone was found throngbout the defects after 4 weeks.All defects were repaired with a well-organized traheeular pattern and a thin neocortex after 12 weeks.At the group 2,mass of new bone tissue formed at the periphery of the defect 4 weeks postoperatlon,but the development of new bone at the central of the defect was latter than that at the group 1.At 12 weeks,all defects were bridged by new bone tissue with little adjacent medullary bone.At the group 3,slight new bone was observed at the periphery of the defect region,and the defects were filled with fibrous tissue.[Conclusion]Calcium sulfate containing bone matrix gelatin is totally bioresorbable and biocompatible.The compound material can enhance the repair bone defects effectively as a bone graft substitute.

[Objective] To assess the outcomes of lumbar spinal pedicle subtraction osteotomy on single segment for correction of kyphosis in ankylosing spindylitis.[Methods]15 patients were treated with L2 or L3 pedicle subtraction osteotomy and internal fixation by pedicle screw system.All the patients underwent X-ray examinations in standing position before and after the operations.The angles in different part of the sagittal planes were measured and the preoperative and postoperative differences were compared.[Results]All the operations were well complete.The mean time of operations was 3h and the mean bleeding was 840 ml.The lumbar lordosis angle increase from(14.5?15.5)?to(48.4?11.9)?,the total spinal kyphosis angle and the thoracolumbar kyphosis angle improve from(36.1?14.7)?and(30.7?9.3)?to(0.2?14.2)?and(23.7?12.3)? respectively,the sacral slope increase from(12.0?12.7)?to(28.9?8.8)?,whereas thoracic kyphosis angle remained relative stable.[Conclusion]Lumbar spinal pedicle subtraction osteotomy on single segment is a satisfactory and reliable technique for correction of kyphosis in ankylosing spindylitis and the average correction of lumbar lordosis was 33.9?.

[Objective]To establish effective and reliable complete spinal cord transection models in rats,and to investigate the effects of micromanipulation used in surgical procedure of transected spinal cord treated with human umbilical cord blood stem cells(UCBSCs) grafts in rats.[Method]Human UCBSCs were obtained from umbilical cord blood of term deliveries.Sixty Sprague-Dawley(SD) female rats were divided randomly into group A(control group),group B(spinal cord transection and PBS injection),group C(spinal cord transection and UCBSCs transplantation) and group D(spinal cord transection and UCBSCs transplantation by using micromanipulation).All groups were operated,and 1 ?l UCBSCs(6?109/L ~7?109/L) were injected into the both ends of the completely transected spinal cord at the groups C and D by two different surgical procedures respectively.From 1 week to 8 week post-operation,a behavioral testing was performed weekly upon each hindlimb for all animals according to the BBB scoring system.At the 8th week,all animals were sacrificed and the spinal cords were taken out for morphological observation.[Result]No changes were observed at group A pre-and post-operation.After 2 weeks post-operation,the hindlimb motor function of groups C and D began to recover.After 3 weeks post-operation,the group D showed more improvement than group C,and the difference between groups D and C were significant in the BBB scores(P

Objective To establish osteoblasts osteoclasts co culture system in vitro for the study of the biological characteristics of osteoblasts and osteoclasts and also to analyze the interactions between osteoblasts and osteoclasts. Methods The osteoblasts and osteoclasts were isolated from cancellous bone in illium. Osteoblasts osteoclasts co culture system was built to prevent these two kinds of cells from contact with each other although with the facility of their medium exchange. The osteogenety of osteoblasts was evaluated by MTT and ALP activity; the resorption activity of osteoclasts was investigated by TRAP activity and the area of absorption lacuna. Results Osteoblasts are full fusiform, ALP stain positive cells, while osteoclasts are multinuclear and TRAP stain positive, with the ability of forming bone lacuna; while in the co culture system, the proliferation of osteoblasts in co culture (0.60?0.08)OD is quicker(P=0.000)than that in mono culture (0.36?0.03)OD, and the ALP activity increased significantly (P=0.000)from (18.33?0.34)u/mg to (23.37?2.48) u/mg; while the average area of bone resorption formed by osteoclasts [(6.55?0.34)?10-2] ?m2 was also increased obviously(P=0.000)from [(5.15?0.17)?10-2] ?m2. Conclusion In co culture system, osteoclasts were able to enhance ossification effects of osteoblasts by accelerating their proliferation and differentiation; at the same time, osteoblasts upregulated the ability of bone resorption of osteoclasts. This implied that osteoblasts and osteoclasts can promote each others function. This study provide reliable model for bone metabolism research.

Objective To study the effect of nitric oxide synthase inhibitors S methylisothiorurea (SMT) on cartilage metabolism after intraarticular injection of interleukin 1? (IL 1?) and lipopolysaccharides (LPS) in rabbits.Methods The experiments were performed in three groups:normal group,control group and SMT group.The effects of SMT on IL 1? and LPS induced iNOS mRNA expression ,NO production and NOS activity in synovium,synovial fluid and cartilage were detected after 8 h.Proteoglycan synthesis was measured by ex vivo incorporation of Na 2 35 SO 4 into cartilage after 48 h.Results IL 1? and LPS induced iNOS mRNA expression and increased NO release;SMT could reduce NO release and inhibit iNOS mRNA expression in synovium,synovial fluid and cartilage,and partly restore proteoglycan synthesis of cartilage.Conclusion iNOS inhibitor SMT can protect IL 1? and LPS induced cartilage damage in high concentration.