Analysis of complications in scoliosis surgery / 中国骨伤

<p><b>OBJECTIVE</b>To analyze the complications occurred in scoliosis surgery and evaluate its prevention strategy.</p><p><b>METHODS</b>From June 2002 to May 2007, 86 cases of idiopathic scoliosis were treated. There were 21 male and 65 female with an average age of 17.8 years(range, from 8 to 22 years). According to Lenke classification, 33 cases were type 1, 10 type 2, 18 type 3, 5 type 4, 10 type 5 and 10 type 6. Five cases were Risser 0 to I, 20 cases II to III, 61 cases 1V to V. Cobb angles were from 45 degrees to 85 degrees (mean 60.35 degrees). The pedicle screw technique was used to correct all the scoliasis, and the results and complications were studied.</p><p><b>RESULTS</b>The average operation time was 3.2 hours and average blood loss volume was 1000 ml (800-2400 ml), 924 pedicle screws were inserted and the average postoperative Cobb angle was 18.46 degrees. All the patients were followed up for 5 to 40 months(mean 20.5 months). The complications were as following: 1 case of spinal cord injury; 25 screws misplaced; 2 cases of nerve root injury; 1 case of pleura injury; 1 case of superior mesenteric artery syndrome; 3 cases of wound infection; 2 cases of trunk decompensation; 1 case of junction kyphosis; 3 cases of implant loosening; 2 cases of pseudarthrosis; 1 case of crankshaft phenomenon; 2 cases of flatback syndrome.</p><p><b>CONCLUSION</b>Many kinds of complications may occur in scoliosis surgery. Exactitude procedures of diagnosis and surgery for the scoliosis are the key to decrease and prevent the complications related to the operation.</p>

Biomechanical comparison of cervical transfacet pedicle screws versus pedicle screws / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Transfacet pedicle screws provide another alternative for standard pedicle screw placement for plate fixation in the lumbar spine. However, few studies looking at transfacet pedicle screw fixation in the cervical spine are available. Therefore, cervical transfacet pedicle screw fixation and standard pedicle screw fixation techniques were biomechanically compared in this study.</p><p><b>METHODS</b>Ten fresh human cadaveric cervical spines were harvested. On one side, transfacet pedicle screws were placed at the C3-4, C5-6, and C7-T1 levels. On the other side, pedicle screws were placed at the C3, C5, and C7 levels. The screw insertion technique at each level was randomized for right or left. The starting point for the transfacet pedicle screw insertion was located at the midpoint of the inferolateral quadrant of the lateral mass and the direction of the screw was about 50 degrees caudally in the sagittal plane and about 45 degrees toward the midline in the axial plane. Screws were placed from the inferior articular process, across the facet complex and the pedicle into the body of the caudal vertebra. The entry point for the pedicle screw was located at the midpoint of the superolateral quadrant of the lateral mass, and the direction of the screw was about 45 degrees toward the midline in the axial plane and toward the upper third of the vertebral body in the sagittal plane. After screw placement we performed axial pullout testing.</p><p><b>RESULTS</b>All the cervical transfacet pedicle screws and the pedicle screws were inserted successfully. The mean pullout strength for the transfacet pedicle screws was 694 N, while for the pedicle screws 670 N (P=0.013). In all but six instances (10%), the pedicle screw pullout values exceeded the values for the transfacet pedicle screws; this occurred three times at the C3/C4 level, twice at the C5/C6 level and once at the C7/T1 level. The greatest pullout strength difference at a single level was observed at the C5/C6 level, with a mean difference of 38 N (t=-1.557, P=0.154). The C7/T1 level had a mean difference of 26 N and the C3/C4 level had a mean difference of 14 N.</p><p><b>CONCLUSIONS</b>Cervical transfacet pedicle screws exhibited higher pullout strength than pedicle screws. Posterior transfacet pedicle screw fixation in the cervical spine may afford an alternative to standard screw placement for plate fixation and cervical stabilization.</p>

All pedicle screws technique applied to the treatment of idiopathic scoliosis / 中国骨伤

<p><b>OBJECTIVE</b>To Analyze the therapeutic efficacy of all pedicle screws technique applied to the treatment of idiopathic scoliosis and evaluate its safety.</p><p><b>METHODS</b>From June 2002 to October 2005, 56 patients with idiopathic scoliosis were treated with all pedicle screws technique, including 11 males and 45 females, ranging in age from 8 to 22 years. According to Lenke classification, 29 patients were Type 1, 6 patients were Type 2, 8 patients were Type 3, 2 patients were Type 4, 8 patients were Type 5, and 3 patients were Type 6. Cobb angles ranged from 45 degrees to 85 degrees (mean 62.45 degrees).</p><p><b>RESULTS</b>The mean operation time was 3 hours and 20 minutes, and the average amount of bleeding was 600 ml. There were 425 pedicle screws inserted including 244 in thoracic, and 181 in lumbar, the positions of which were evaluated by CT. Nine screws were inserted with perforating through the medial wall of the pedicles. All the patients were followed up for 5 to 40 months (mean 22.5 months). The mean Cobb angle was corrected from 62 degrees preoperatively to 18 degrees postoperatively,and the average correction rate was 72.5%. No spinal nerves injury was found after operation, and superficial infection occurred in 2 patients but recovered after dressing change. All the patients got satisfactory spinal fusion and remained partly spinal mobility with fewer complications.</p><p><b>CONCLUSION</b>The application of all pedicles screws technique with familar with pedicular anatomy of scoliosis by imaging examination could gain a satisfactory effect of correction with less complications.</p>