Application of the techniques of pedicle screw fixation in t horacolumbar spine has forcefully promoted the development of spinal surgery. Th e key to the techniques is that the pedicle screw insertion must be located into the sole exact routeway of the three-dimensional-space, that is, into the inn er vertebral body through the pedicle according to the exact arrow plane angle a nd horizontal plane angle. Recently great development has been made in the resea rch on the techniques of pedicle screw insertion in thoracolumbar spine, especia lly in the supervising means during operation. The means have been developed fro m the traditional X-ray perspective or photograph apposition to the application of computer-assisted technique. This paper reviews and discusses the current d evelopment and prospects in the research on the techniques of pedicle screw inse rtion in thoracolumbar spine.

Objective To evaluate the efficacy and safety of balloon kyphoplasty in the treatment of painful multi-vertebral osteoporotic compression fractures. Methods From October 2002 to April 2007, 42 patients (96 vertebrae) with painful multi-vertebral osteoporotic compression fractures underwent kyphoplasty. The group included 14 men and 28 women with an average age of 72.5 years (range 56-91 years). Each pro-cedure included insertion and insertion of balloon, fracture reduction and cement filling under "C"-arm monitoring. Preoperative and postoperative pain level, SF-36 score, vertebral height restoration, local kypho-sis correction and complications were recorded and analysed. Results All 42 patients tolerated the opera-tion well and were followed up for average 31.4 months (range 12-71 months). The mean VAS pain score decreased significantly from 7.1±2.4 preoperatively to 2.7±1.3 postoperatively, the mean height of anterior and medial vertebral body were (1.8±0.5) cm, (1.6±0.6) cm preoperatively and (2.3±0.6) cm, (2.2±0.7) cm postoperatively. No significant change of posterior vertebral height was recorded postoperatively.The mean correction of local kyphosis was 9.2°at each level. 6 of 8 subscahs measured by SF-36, including physical function, role function, bodily pain, vitality, role emotion, mental health, were significantly improved by the operation. Complications were found in 7 patients including 6 cases of cement leakage with no clinical symptoms (intradiscal cement leakage in two cases, paravertebral vessel leakage in two cases, paravertebral leakage in one case and cement leakage into canal in one case), and 1 case of pulmonary embelization with symptoms relieved after conservative treatment. Conclusion Kyphoplasty is effective and relatively safe for multi-vertebral osteoporotic compression fractures.

Objective To investigate the causes and clinical significance of cement leakage into disc space during kyphoplasty. Methods Since 2002, 178 patients with osteoporotic vertebral compression fractures underwent kypboplasty and 15 of them were detected intradiscal cement leakage and followed up more than 2 years (mean 2 years and 8 months). The mean injection of cement in these patients was 4.2ml.The series comprised 10 females and 5 males, with an average of 71.2 years old ( range, 54～84 years old).Visual analog scale was used to score back pain pre- and postoperatively. The height and MRI index of the involved disc were recorded and compared. Results The discs involved were as following: T10-11 for 4 cases,T11-12 for 1, T12L1for 4, L1-2 for 2, L2-3 for 3, L3-4 for 1. Cement leakage was detected in the disc above the fractured vertebrae in 10 cases, and in the disc below the fractured vertebrae in 5 patients. The back pain significantly alleviated and the average visual analog scale (VAS) score was decreased from 8.5±2.1 preoper-atively to 3.3±1.4 postoperatively (P< 0.05). The anterior disc height was (5.1±2.1)mm preoperatively and (4.8±1.9) mm at the final follow-up, the middle disc height was (7.4±3.2) mm preoperatively and (7.3±2.9) mm at the final follow-up, the posterior disc height was (4.9±2.5) mm preoperatively and (5.0±1.8) mm at fi-nal follow-up, the heights of intervertebral space were well maintained. The signal intensity decreased and became inconsistent in some discs, and the preoperative MRI index significantly decreased from 25482.4± 3467.5 to 18927.6±2519.4 at the final follow-up (t=1.967,P< 0.05). Conclusion Pain relief is impressive in patients with intradiseal cement leakage during kyphoplasty. However, cement leakage into disc space may accellerate the process of disc degeneration.

0.05). Conclusion The study of the characteristic of track of percutaneous transpedicular puncture is good for the safe procdure under image guidance. The standard track is safe for transpedicular or parapedicular puncture. The percutaneous transpedicular puncturing sites can be located according to the spinous process.

Objective To modify the posterior procedures for severe thoracolumar fractures. Methods Twenty-one patients of thoracolumbar fractures with over 40% of anterior compression were studied. After reduction and fixation with short-segment pedicle instrumentation was performed, the transpedicular vertebroplasty of the fractured vertebrae with injectable self-setting calcium phosphate cement was carried out under fluoroscopic guidance. All patients were checked with X-ray and CT scanning before and after operation. They were followed up for 4-23 months (average 13 months). Results All patients obtained successful surgery without neurological complications or foreign body response. On CT scanning, the fractured vertebrae were well augmented in 13 cases and insufficiently augmented in 4 cases. Slight extrusion of cement into paravertebral tissue occurred in 4 cases without clinical symptoms. All patients were perfectly recovered without notable correction loss or implant failure during the follow-up. Conclusions Reduction and fixation with short-segment pedicle instrumentation followed by vertebroplasty with injectable self-setting calcium phosphate cement is a promising procedure for severe thoracolumbar fractures.

Objective To investigate the clinical results of percutaneous vertebroplasty(PVP) for symptomatic vertebral hemangioma. Methods Eleven patients(2 males and 9 females) suffered from symptomatic vertebral hemangioma(11 thoracic segment levels and 3 lumbar segment levels) were treated with PVP under DSA or CT guidance. The main goal of this procedure was to relieve hemangioma related pain. All patients were examined with CT scan after intervention and were followed up from 3 to 34 months (average, 15.2 months). Results The procedure was technically successful in all patients, with an average injection amount of 6.3 ml cement per vertebral body. No clinically significant complications were found. There was no epidural leakage, and the 2 paravertebral leakages detected with CT had no clinical importance. Partial or complete pain relief was achieved in all patients associated with improved mobility, and 1 patient experienced transitory worsening of pain followed by significant pain relief. Patients were discharged in 1-4 days (average, 1.5 days) after the procedure. Pain relief was sustained in all patients at the last following-up. Conclusion PVP is a valuable minimal invasive alternative procedure in treatment of symptomatic vertebral hemangioma and provides satisfactory pain relief with less complications.

Objective To evaluate the effects of nutritional status on wound healing after hip fracture in the elderly. Methods From July 2002 to December 2004, 127 patients with hip fracture who were older than 65 years were treated surgically in our department. Their preoperative nutritional status was reviewed. There were 69 males and 58 females, with an average age of 72.7 years (from 65 to 99 years). 60 cases had femoral neck fractures, and 67 cases had intertrochanteric fractures. The parameters indicative of nutritional status (serum albumin, serum transferrin and total lymphocyte count levels) at the time of admission were assessed, along with Rainey McDonald nutritional index and age. Suture removal was performed on postoperative day 14. Results Delayed wound healing complicated 31 of the 127 cases. The preoperative serum transferrin levels were significantly lower in patients who subsequently had delayed wound healing. Only preoperative serum transferrin levels( P

Objective To discuss the necessity of cervical spinal plating after single-level anterior decompression and fusion on mono-segmental cervical disc herniation and cervical spondylosis without obvious kyphotic deformity and segmental lability. Methods The ranges of motion of the two groups with and without plating were tested under the load of 2.0 Nm on cervical spine specimens taken from 16 fresh cadavers. Finite element method was used to calculate the strength of bony callus and the average stress of the parts adjacent to the fused segments at various time intervals. 45 cases after single-level anterior decompression and fusion with and without cervical plating were followed-up at least 3 years, and 33 ones without cervical plating, more than 10 years. Results The test of specimens showed a higher stability of the group with plating just after operation (P

Objective To apply cervical pedicle screw system (CPSS) to treat cervical disorders and discuss its surgical indications, techniques and clinical effectiveness. Methods A total of 52 patients with middle and lower cervical spine lesions who underwent cervical transpedicular fixation were analyzed retrospectively. There were 41 males and 11 females aging from 16 to 62 years. The diagnosis of the patients were fractures and dislocations of cervical spine accompanied by complete paralysis (28 cases) or incomplete paralysis (19 cases) in 47 cases, and metastatic bone tumor in 5 cases. Prior to surgery, anteroposterior and lateral radiographs, CT scan through bone windows, and/or magnetic resonance images were carried out in all patients. During surgery, all screws were inserted into the pedicle under the guidance of lateral or oblique image intensifier to confirm the direction and insertion depth of screws. In 7 to 14 days after surgery, physical examination and roentgenograms evaluations were performed in all patients, and CT scans were obtained in 31 patients, the location of screws were evaluated with the radiographic examinations and CT scan. The follow-up period averaged 13 months (range, 1 to 36 months) in 38 patients. The authors experiences in achieving accurate pedicle screw insertion was introduced, the clinical value of using cervical pedicle screw system to manage cervical lesions was summarized, the possible complications of CPSS were analyzed, the candidates of using CPSS were discussed as well. Results Pedicle screws were inserted successfully in all cases, 9 cases were found to have nerve irritating symptoms by 10 pedicle screws when which were introduced into pedicles, however, by changing the direction of the screws, all symptoms disappeared and screws were successfully inserted. Postoperative radiographic evaluation confirmed proper insertion of screws except 2 screws perforating the lateral pedicle wall but without injury of the vertebral artery demonstrated on CT scans. In the followed-up, no screw breakage and loosening was observed. By applying distractive force between the screws placed into pedicles, the space between the affected vertebrae and discs could be increased, displaced anterior fragments of bone or disc could also be indirectly reduced from the spinal canal, and additional anterior decompression interventions might be avoided. Conclusion CPSS can be considered as one of alternative in posterior cervical internal fixation systems. However, specific caution must be taken. The candidates of utilizing CPSS should be properly selected.

Objective To observe the expression changes of heme oxygenase-1(HO-1) and its mRNA after spinal cord injury (SCI). Methods SD rats were randomly divided into normal (n=5), control (n=5) and experimental group (n=10). The rats were given no operation in the normal group, laminectomy only in the control and both laminectomy and traumatic injury in the experimental group. The SCI animal models were made by using a modified Allen's weight-drop device (50 g.cm) on T 12 . Rats were sacrificed at 1 and 3 days after injury. The distribution and content changes of HO-1 and its mRNA in spinal cord segments were observed by means of immunohistochemistry and in situ hybridization. Results Expression of HO-1 was mainly in neurons in the normal spinal cord. After injury, HO-1 expressed primarily in astrocytes and microglia and the distribution of positive cells closely correlated with intraparenchymal hemorrhage. Protein began to increase at the first day after injury. The expression intensity and the area of positive cells were (148.26?11.39) and (90.50?8.70)?10 3 ?m 2 respectively. At the third day, protein expressed more significantly with expression intensity of (128.03? 12.59) and area of (112.99?10.01)?10 3 ?m 2. The expression intensity and area of positive cells expressed by mRNA were (106.02?9.10) and (70.05?9.26)?10 3 ?m 2 respectively at the first day after injury, (85.82?9.07) and (87.37?10.95)?10 3 ?m 2 respectively at the third day after injury. There was significant difference between experimental and control groups ( P