To compare the effectiveness of the operations in treatment of thoracolumber spine fracture and dislocation with spinal cord injury in different periods. Methods Between June 2003 and June 2008, 80 cases of thoracolumber spine fracture and dislocation with spinal cord injury were treated. There were 52 males and 28 females with an average age of 37.6 years (range, 28-49 years). According to different operative time, they were divided into 2 groups by randomized controlled study: group A (n=39, operation was performed within 24 hours) and group B (n=41, operation was performed at 3-7 days). In group A, there were 23 cases of degree I-II (group A1), 16 cases of degree III-V (group A2) according to Meyerding standard, including 17 cases of grade A, 7 cases of grade B, 9 cases of grade C, and 6 cases of grade D according to Frankel scoring system. In group B, there were 21 cases of degree I-II (group B1) and 20 cases of degree III-V (group B2), including 20 cases of grade A, 7 cases of grade B, 11 cases of grade C, and 3 cases of grade D. All cases were treated with posterior spinal cord decompression and reduction, with internal fixation by pedicle screw-rod system and transforamen lumbar interbody fusion. Results The blood loss was (407.4 ± 24.3) mL in group A1 and (397.4 ± 8.2) mL in group B1, showing no significant difference (t=1.804, P=0.078); the blood loss was (1 046.9 ± 128.6) mL in group A2 and (494.4 ± 97.7) mL in group B2, showing significant difference (t=14.660, P=0.000). All 80 patients were followed up 2 years to 2 years and 6 months (mean, 2 years and 3 months) with satisfactory results in spinal cord decompression and reduction, and bony fusion was achieved at 12 months. There was no significant difference in the vertebral canal volume, vertebral height, and Cobb angle at both pre- and postoperation between 2 groups (P gt; 0.05). No loosening or breakage of screws and rods occurred. At 12 months after operation, the cure rates were 47.83% (11/23) in group A1 and 19.05% (4/21) in group B1, showing significant difference (χ2=4.046, P=0.044); the cure rates were 12.50% (2/16) in group A2 and 10.00% (2/20) in group B2, showing no significant difference (χ2=0.056, P=0.813). There was no significant difference (χ2=0.024, P=0.878) in the cure rates in the patients at grades A and B before operation between group A (12.50%, 3/24) and group B (11.11%, 3/27); but there was significant difference (χ2=5.992, P=0.014) in the cure rates in the patients at grades C and D before operation between group A (66.67%, 10/15) and group B (21.43%, 3/14). Conclusion Emergency operation of posterior pedicle screw-rod system for treatment of thoracolumber spine fracture and dislocation with spinal cord injury can provide good reduction, rigid fixation, and high fusion rate, so it is asafe and effective treatment method.
Objective To evaluate the effectiveness of Confidence high viscosity bone cement system and postural reduction in treating acute severe osteoporotic vertebral compression fracture (OVCF). Methods Between June 2004 and June2009, 34 patients with acute severe OVCF were treated with Confidence high viscosity bone cement system and postural reduction. There were 14 males and 20 females with an average age of 72.6 years (range, 62-88 years). All patients had single thoracolumbar fracture, including 4 cases of T11, 10 of T12, 15 of L1, 4 of L2, and 1 of L3. The bone density measurement showed that T value was less than —2.5. The time from injury to admission was 2-72 hours. All cases were treated with postural reduction preoperatively. The time of reduction in over-extending position was 7-14 days. All patients were injected unilaterally. The injected volume of high viscosity bone cement was 2-6 mL (mean, 3.2 mL). Results Cement leakage was found in 3 cases (8.8%) during operation, including leakage into intervertebral space in 2 cases and into adjacent paravertebral soft tissue in 1 case. No cl inical symptom was observed and no treatment was pearformed. No pulmonary embolism, infection, nerve injury, or other complications occurred in all patients. All patients were followed up 12-38 months (mean, 18.5 months). Postoperatively, complete pain rel ief was achievedin 31 cases and partial pain refief in 3 cases; no re-fracture or loosening at the interface occurred. At 3 days after operation and last follow-up, the anterior and middle vertebral column height, Cobb angle, and visual analogue scale (VAS) score were improved significantly when compared with those before operation (P lt; 0.05)；and there was no significant difference between 3 days and last follow-up (P gt; 0.05). Conclusion Confidence high viscosity bone cement system and postural reduction can be employed safely in treating acute severe OVCF, which has many merits of high viscosity, long time for injection, and easy-to-control directionally.
Objective To explore the failure cause of posterior approach orthopaedic operation of thoracolumbar hemivertebra, and to summary strategies of revision. Methods The cl inical data from 9 cases undergoing posterior approach orthopaedic operation failure of thoracolumbar hemivertebra between June 2003 and June 2008, were retrospectively analyzed. There were 5 males and 4 females with a median age of 12 years (range, 1 year and 10 months to 24 years). All malformations were identified as fully segmented hemivertebra from the original medical records and X-ray films, including 2 cases in thoracic vertebra, 5 cases in thoracolumbar vertebra, and 2 cases in lumbar vertebra. The preoperative scol iotic Cobb angle was (45.4 ± 17.4)°, and kyphotic Cobb angle was (29.8 ± 22.0)°. The reason of primary surgical failure were analyzed and spinal deformity was corrected again with posterior revision. Results All surgeries were finished successfully. The operation time was 3.0-6.5 hours (mean, 4.5 hours), and the perioperative bleeding was 400-2 500 mL (mean, 950 mL). All incisions healed by first intention; no infection or deep venous thrombosis occurred. Numbness occurred in unilateral lower extremity of 1 case postoperatively, and the symptom was rel ieved completely after treatment of detumescence and neural nutrition. All cases were followed up 12-30 months (mean, 18 months). No pseudoarthrosis and implant failure occurred. The X-ray films showed that the bone grafts completely fused within 8-14 months (mean, 11 months) after operation. The Cobb angles of scol iosis and kyphosis at 1 week after operation and the last follow-up were obviously improved when compared with preoperative ones, showing significant differences (P lt; 0.05). No obvious correction loss was observed either in coronal or sagittal plane. Conclusion The failure causes of posterior approach orthopaedic operation are hemivertebra processing, selection of fixation and fusion range, and selection of internal fixation. If the strategies of revision are made after the above-mentioned failure causes are considered, the cl inical results will be satisfactory.
Objective To evaluate the biomechanical stability of a newly-designed Y type pedicle screw (YPS) in osteoporotic synthetic bone. Methods The osteoporotic synthetic bone were randomly divided into 3 groups (n=20). A pilot hole, 3.0 mm in diameter and 30.0 mm in deep, was prepared in these bones with the same method. The YPS, expansive pedicle screw (EPS), and bone cement-injectable cannulated pedicle screw (CICPS) were inserted into these synthetic bone through the pilot hole prepared. X-ray film examination was performed after 12 hours; the biomechanical stability of YPS, EPS, and CICPS groups was tested by the universal testing machine (E10000). The test items included the maximum axial pullout force, the maximum running torque, and the maximum periodical anti-bending. Results X-ray examination showed that in YPS group, the main screw and the core pin were wrapped around the polyurethane material, the core pin was formed from the lower 1/3 of the main screw and formed an angle of 15° with the main screw, and the lowest point of the inserted middle core pin was positioned at the same level with the main screw; in EPS group, the tip of EPS expanded markedly and formed a claw-like structure; in CICPS group, the bone cement was mainly distributed in the front of the screw and was dispersed in the trabecular bone to form a stable screw-bone cement-trabecular complex. The maximum axial pullout force of YPS, EPS, and CICPS groups was (98.43±8.26), (77.41±11.41), and (186.43±23.23) N, respectively; the maximum running torque was (1.42±0.33), (0.96±0.37), and (2.27±0.39) N/m, respectively; and the maximum periodical anti-bending was (67.49±3.02), (66.03±2.88), and (143.48±4.73) N, respectively. The above indexes in CICPS group were significantly higher than those in YPS group and EPS group (P<0.05); the maximum axial pullout force and the maximum running torque in YPS group were significantly higher than those in EPS group (P<0.05), but there was no significant difference in the maximum periodical anti-bending between YPS group and EPS group (P>0.05). Conclusion Compared with EPS, YPS can effectively enhance the maximum axial pullout force and maximum rotation force in the module, which provides a new idea for the design of screws and the choice of different fixation methods under the condition of osteoporosis.