Objective： To prospectively evaluate the feasibility, safety and efficacy of the percutaneous pedicle screw fixation through the pedicle of fractured vertebra in the treatment of type A thoracolumbar fractures using ...Objective： To prospectively evaluate the feasibility, safety and efficacy of the percutaneous pedicle screw fixation through the pedicle of fractured vertebra in the treatment of type A thoracolumbar fractures using Sextant system in the retrospective non-randomized case-control study. Methods： Atotal of 38 consecutive non-randomized patients with type A thoracolumbar fractures, which had been stabilized posteriorly from December 2006 to March 2009, were examined retrospectively more than 9 months after surgery. Twenty-one patients had been treated conventionally with open pedicle screw fixation （OPSF） and 17 patients received minimally invasive treatment with Sextant percutaneous pedicle screw fixation （SPPSF）. As a method of evaluation, the incision size, the intraoperation and post- operative volume of blood loss, operation time, postoperative hospital stay, blood transfusion, the radiological assessment of the sagittal Cobb＇s angle, vertebral body angle and vertebral body height were recorded and compared. Results： All patients were followed up for 8-24 months （average 11.6 months）. There were significant differences in the incision size, surgical blood loss, surgical draining Joss, operation time, hospital stay after operation, blood transfusion, the proportion of antalgic supplement and postoperative incisional VAS between the two groups （P〈0.05）. Mean preoperative kyphotic deformity was 16.0° and improved by 9.3° after surgery in OPSF group, but 15.2° and 10.3° respectively in SPPSF group. Mean preoperative angle of the fractured vertebral body was 15.9°and improved by 7.9° after surgery in OPSF group, but 14.9° and 6.6° respectively in SPPSF group. Mean anterior vertebral body height （% of normal） was 67.3% before surgery and 95.8% after surgery, but 69.1% and 90.1% respectively in SPPSF group. Mean posterior vertebral body height （% of normal） was 93.3% before surgery and 99.5% after surgery, but 88.9% and 93.3% respectively in SPPSF group. Among the patients whose 9-month follow-up films were available, 3.0° ofkyphosis correction was lost in OPSF group, but 3.2° in SPPSF group. And 1.0°of the angle of the fractured vertebral body correction was lost in OPSF group, but 1.5°in SPPSF group. Then 3.0% of the anterior vertebral body height correction was lost in OPSF group, but 2.2% in SPPSF group. And 3.0% of the posterior vertebral body height correction was lost in OPSF group, but 2.5% in SPPSF group. The sagittal Cobb＇s angle, vertebral body angle and anterior height of the fractured vertebra were all significantly different in each group before and after operation （P〈0.05）. There were no significant differences in the postoperative sagittal Cobb＇s angle, vertebral body angle and the improvement of the vertebral body height and the kyphotic deformity correction between OPSF and SPPSF groups （P〉0.05）, but there was significant difference in the postoperative anterior height of the fractured vertebra between the two groups （P〈0.05）. Conclusion： The percutaneous pedicle screw fixation through the pedicle of fractured vertebra using Sextant system is a good minimally-invasive surgical therapeutic choice for patients with type A thoracolumbar fracture except for that the SPPSF has a little insufficiency in resuming the anterior height of the fractured vertebra compared with OPSF.展开更多
Objective: To investigate appropriate ways for screw placement of pedicle of vertebral arch in the horizontal plane. Methods: Fifteen preserved thoracolumbar spine specimens (T 11 L 5) were used and divided into three...Objective: To investigate appropriate ways for screw placement of pedicle of vertebral arch in the horizontal plane. Methods: Fifteen preserved thoracolumbar spine specimens (T 11 L 5) were used and divided into three groups at random. Firstly four anatomic parameters indicating screw positions in the horizontal plane were measured. Secondly the methods of Roy camille, Magerl, and authors’segmental differences were used to place successively the screws of the pedicles with 5 mm, 6 mm, and 7 mm in diameter. Coincidences between the drilling point, drilling direction and pedicle axis, and ruptures of the pedicle as well as the length of the screw in the vertebral body were observed. Results: Four anatomic parameters at various segments showed significant differences (P < 0.05 ). The drilling point by the Roy camille’s method deviated medial to pedicle axis in most segments, and its drilling direction did not coincide well with most E angles of the pedicles. The drilling point by Magerl’s method coincided relatively well with pedicle axis in lumbar vertebrae, but there were still some differences between its drilling direction and E angles of the pedicles. The method of segmental differences coincided the best with the pedicle axis. The lengths of screw in the vertebra were relatively long by both Magerl and segmental difference methods. When 5 mm diametral screw was used by the three methods, the rupture rate was very low. When 6 mm and 7 mm diametral screws were placed, the rupture rate was accordingly increased. Of the three methods, Roy camilles method showed a relatively high rupture rate, while the method of segmental differences a comparatively low rupture rate. Various degrees of rupture of the pedicle of vertebral arch were found at the juncture of the thoracic and lumbar vertebrae when 6 mm or 7 mm diametral screws was used by any screw placement method. In contrast, the rupture was seldom seen at the lower lumbar vertebrae when 7 mm diametral screws were used.Conclusions: The segmental difference method is proved to have the anatomic safety and screw biomechanical stability. It is appropriate to choose different diametral screws, different drilling points and directions according to different segments of the vertebra.展开更多
文摘Objective： To prospectively evaluate the feasibility, safety and efficacy of the percutaneous pedicle screw fixation through the pedicle of fractured vertebra in the treatment of type A thoracolumbar fractures using Sextant system in the retrospective non-randomized case-control study. Methods： Atotal of 38 consecutive non-randomized patients with type A thoracolumbar fractures, which had been stabilized posteriorly from December 2006 to March 2009, were examined retrospectively more than 9 months after surgery. Twenty-one patients had been treated conventionally with open pedicle screw fixation （OPSF） and 17 patients received minimally invasive treatment with Sextant percutaneous pedicle screw fixation （SPPSF）. As a method of evaluation, the incision size, the intraoperation and post- operative volume of blood loss, operation time, postoperative hospital stay, blood transfusion, the radiological assessment of the sagittal Cobb＇s angle, vertebral body angle and vertebral body height were recorded and compared. Results： All patients were followed up for 8-24 months （average 11.6 months）. There were significant differences in the incision size, surgical blood loss, surgical draining Joss, operation time, hospital stay after operation, blood transfusion, the proportion of antalgic supplement and postoperative incisional VAS between the two groups （P〈0.05）. Mean preoperative kyphotic deformity was 16.0° and improved by 9.3° after surgery in OPSF group, but 15.2° and 10.3° respectively in SPPSF group. Mean preoperative angle of the fractured vertebral body was 15.9°and improved by 7.9° after surgery in OPSF group, but 14.9° and 6.6° respectively in SPPSF group. Mean anterior vertebral body height （% of normal） was 67.3% before surgery and 95.8% after surgery, but 69.1% and 90.1% respectively in SPPSF group. Mean posterior vertebral body height （% of normal） was 93.3% before surgery and 99.5% after surgery, but 88.9% and 93.3% respectively in SPPSF group. Among the patients whose 9-month follow-up films were available, 3.0° ofkyphosis correction was lost in OPSF group, but 3.2° in SPPSF group. And 1.0°of the angle of the fractured vertebral body correction was lost in OPSF group, but 1.5°in SPPSF group. Then 3.0% of the anterior vertebral body height correction was lost in OPSF group, but 2.2% in SPPSF group. And 3.0% of the posterior vertebral body height correction was lost in OPSF group, but 2.5% in SPPSF group. The sagittal Cobb＇s angle, vertebral body angle and anterior height of the fractured vertebra were all significantly different in each group before and after operation （P〈0.05）. There were no significant differences in the postoperative sagittal Cobb＇s angle, vertebral body angle and the improvement of the vertebral body height and the kyphotic deformity correction between OPSF and SPPSF groups （P〉0.05）, but there was significant difference in the postoperative anterior height of the fractured vertebra between the two groups （P〈0.05）. Conclusion： The percutaneous pedicle screw fixation through the pedicle of fractured vertebra using Sextant system is a good minimally-invasive surgical therapeutic choice for patients with type A thoracolumbar fracture except for that the SPPSF has a little insufficiency in resuming the anterior height of the fractured vertebra compared with OPSF.
文摘Objective: To investigate appropriate ways for screw placement of pedicle of vertebral arch in the horizontal plane. Methods: Fifteen preserved thoracolumbar spine specimens (T 11 L 5) were used and divided into three groups at random. Firstly four anatomic parameters indicating screw positions in the horizontal plane were measured. Secondly the methods of Roy camille, Magerl, and authors’segmental differences were used to place successively the screws of the pedicles with 5 mm, 6 mm, and 7 mm in diameter. Coincidences between the drilling point, drilling direction and pedicle axis, and ruptures of the pedicle as well as the length of the screw in the vertebral body were observed. Results: Four anatomic parameters at various segments showed significant differences (P < 0.05 ). The drilling point by the Roy camille’s method deviated medial to pedicle axis in most segments, and its drilling direction did not coincide well with most E angles of the pedicles. The drilling point by Magerl’s method coincided relatively well with pedicle axis in lumbar vertebrae, but there were still some differences between its drilling direction and E angles of the pedicles. The method of segmental differences coincided the best with the pedicle axis. The lengths of screw in the vertebra were relatively long by both Magerl and segmental difference methods. When 5 mm diametral screw was used by the three methods, the rupture rate was very low. When 6 mm and 7 mm diametral screws were placed, the rupture rate was accordingly increased. Of the three methods, Roy camilles method showed a relatively high rupture rate, while the method of segmental differences a comparatively low rupture rate. Various degrees of rupture of the pedicle of vertebral arch were found at the juncture of the thoracic and lumbar vertebrae when 6 mm or 7 mm diametral screws was used by any screw placement method. In contrast, the rupture was seldom seen at the lower lumbar vertebrae when 7 mm diametral screws were used.Conclusions: The segmental difference method is proved to have the anatomic safety and screw biomechanical stability. It is appropriate to choose different diametral screws, different drilling points and directions according to different segments of the vertebra.
