To evaluate the cl inical effect of pedical screw systems fixed between lumbar and il ium for treatment of sacral fractures. Methods From June 2003 to June 2009, 21 cases of sacral fracture (29 sides including monolateral 13 cases and bilateral 8 cases) were treated with pedical screw systems to have reduction and fixation. There were 12 males and 9 females, aging 23-59 years (38.2 years on average). Fractue was caused by traffic accident in 12 cases, by fall ingfrom height in 7 cases, and by crash in 2 cases. Screws were inserted into lumbar pedicles and il iac crests. Decompression was used in 4 cases compl icated by sacral nerves injury, and reductions and fixations were used in 12 cases compl icated anterior pelvic or acetabulum injury. The preoperative proximal displacement at the injured side of the pelvis was (16.29 ± 6.47) mm compared with contralateral pelvis. Results All incisions healed primarily with no compl ication of infection. Twentyone patients were followed up 6 months to 6 years. Cl inical heal ing time of fracture was 6-9 weeks. In 4 cases compl icated by S1 or S2,3 nerves injury, the function recovered completely after 4-9 weeks. In other 17 patients, no compl ication of intraoperative nerve injury occurred. All patients could walk and squat after 6-12 weeks of operation. No breakage or displacement of implant occurred. The postoperative proximal displacement at the injured side of the pelvis was (3.51 ± 0.68) mm compared with contralateral pelvis, showing significant difference (P lt; 0.01) when compared with preoperative one. Conclusion It is a novel choice to have reduction and internal fixation for sacral fracture with pedical screw systems fixed between lumbar and il ium. The strict regulation of indication and skill is the key to prevent compl ication.
Objective To study the MRI diagnosis of sacral fracture with sacral neurological damage and its cl inical appl ication. Methods From October 1999 to October 2007, 20 cases of sacral fracture (Denis classification, Type II)with sacral neurological damage were examined by obl ique coronal MRI of sacrum to show the whole length of sacral nerve. There were 17 males and 3 females, aged 30-55 years. The time from injury to hospital ization varied from 1 day to 23 months. The injury was caused by traffic accident in 10 cases, smash of heavy object in 8 cases and crush in 2 cases. Eight cases were accompanied by pubis fracture and 4 cases by urethral disruption. All patients accepted the examination of X-ray, CT and spiral CT 3D reconstruction. X-ray showed the displacement of fracture fragment was backwards and upwards, and sacral-hole l ine was vague, asymmetric and distorted. CT showed that sacral neural tube was left-right asymmetry, the displacement of fracture fragment was backwards and upwards, combining with the compression and intruding to sacrum center at different section levels. The cl inical manifestations, international standards for Neurological Classification of Spinal Cord Injury recommended by American Spinal Injury Association International Spinal Cord Society, comparison between normal and abnormal MRI and Gierada’s results were the basis for cl inical diagnose and MRI diagnose, which was confirmed by operation. Results Nerve injury diagnosed by cl inical manifestation were S1 (17 cases), S2 (14 cases), S3 (7 cases), and S4 (6 cases). Nerve injury diagnosedby MRI were S1 (17 cases), S2 (14 cases), S3 (3 cases), and S4 (2 cases). Nerve injury confirmed by operation were S1 (17 cases), S2 (14 cases), S3 (7 cases), and S4 (1 case). Obl ique coronal MRI of sacrum showed the whole length of sacral nerve and its adjacent relationship, detecting bone fragment compression and route alteration of never were evident in 5 cases, the fat disappearance around the site of nerve root injury in 19 cases, narrowness of sacral nerve canal in 17 cases and the abnormally enlarged sacral nerve in 11 cases. Conclusion Obl ique coronal MRI of sacrum is of great value in the local ization and the qual itative diagnosis of sacral neurological damage.
Objective To evaluate the effectiveness of lumbopelvic fixation using the combination of closed multi-axial screws (CMAS) iliosacral fixation system and the posterior segmental spinal fixation for unstable sacral fractures. Methods Between January 2013 and November 2014, 25 patients (39 sides) with unstable sacral fractures were treated with lumbopelvic fixation using the combination of CMAS iliosacral fixation system and the posterior segmental spinal fixation. There were 17 males and 8 females, aged 19-55 years (mean, 33.9 years). The causes were traffic accident injury in 15 cases, falling injury from height in 8 cases, and crushing injury in 2 cases. The interval of injury and operation was 1-13 days (mean, 3.5 days). Fracture was classified as Denis type I in 2 sides, type II in 20 sides, and type III in 17 sides; nerve injury was rated as Gibbons grade I in 2 cases, grade II in 2 cases, grade III in 7 cases, and grade IV in 9 cases. The reduction quality was evaluated by Matta criterion, the clinical function outcome by Majeed, and nerve function by Gibbons criterion. Results The average operation time was 110 minutes (range, 80-150 minutes). The average blood loss was 570 mL (range, 250-1 400 mL). Superficial wound infection occurred in 2 patients, and was cured after debridement and antibiotic therapy. All patients were followed up for an average of 18 months (range, 15-22 months). Postoperative X-ray and CT examination showed clinical healing of sacral fractures at 8-12 weeks after operation (mean, 10 weeks). The mean removal time of internal fixation was 13 months (range, 12-20 months). No screw loosening and fracture, adhesion of internal fixation to surrounding tissue, and obvious electrolysis phenomenon occurred. According to Matta criterion, reduction was rated as excellent in 32 sides, good in 6 sides, fair in 1 side, and the excellent and good rate was 97.5%. According to Majeed functional scoring at last follow-up, the mean score was 84.7 (range, 64-98); the results were excellent in 18 cases, good in 5 cases, and fair in 2 cases, and the excellent and good rate was 92.0%. The nerve function was significantly improved when compared with preoperative one; nerve injury was rated as Gibbons grade I in 8 cases, grade II in 8 cases, grade III in 3 cases, and grade IV in 1 case. Conclusion Lumbopelvic fixation using the combination of CMAS iliosacral fixation system and the posterior segmental spinal fixation is a relatively effective fixation for unstable sacral fractures. Not only is the fracture fixation rigid for early full weight-bearing, but also nerve decompression can be performed which facilitates nerve function recovery.
Finite element method (FEM) was used to investigate the biomechanical properties of three types of surgical fixations of U-shaped sacral fractures. Based on a previously established and validated complete lumbar-pelvic model, three models of surgical fixations of U-shaped sacral fractures were established: ① S1S2 passed through screw (S1S2), ② L4–L5 pedicle screw + screw for wing of ilium (L4L5 + IS), and ③ L4–L5 pedicle screw + S1 passed through screw + screw for wing of ilium (L4L5 + S1 + IS). A 400 N force acting vertically downward, along with torque of 7.5 N·m in different directions (anterior flexion, posterior extension, axial rotation, and axial lateral bending), was exerted on the upper surface of L4. Comparisons were made on differences in separation of the fracture gap and maximum stress in sitting and standing positions among three fixation methods. This study showed that: for values of separation of the fracture gap produced by different operation groups in different positions, L4L5 + S1 + IS was far less than L4L5 + IS and S1S2. For internal fixators, the maximum stress value produced was: L4L5 + IS > L4L5 + S1 + IS > S1S2. For the intervertebral disc, the maximum stress value produced by S1S2 is much larger than that of L4L5 + S1 + IS and L4L5 + IS. In a comprehensive consideration, L4L5 + S1 + IS could be prioritized for fixation of U-shaped sacral fractures. The objective of this research is to compare the biomechanical differences of three different internal fixation methods for U-shaped sacral fractures, for the reference of clinical operation.
ObjectiveTo investigate the effectiveness of percutaneous double-segment lengthened sacroiliac screws internal fixation assisted by three-dimensional (3D) navigation technology in treatment of Denis type Ⅱ and Ⅲ sacral fractures. Methods A clinical data of 45 patients with the Denis type Ⅱ and Ⅲ sacral fractures admitted between January 2017 and May 2020 was retrospectively analyzed. There were 31 males and 14 females, with an average age of 48.3 years (range, 30-65 years). The pelvic fractures were all high energy injuries. According to the Tile classification standard, there were 24 cases of type C1, 16 cases of type C2, and 5 cases of type C3. The sacral fractures were classified as Denis type Ⅱ in 31 cases and type Ⅲ in 14 cases. The interval between injury and operation was 5-12 days (mean, 7.5 days). The lengthened sacroiliac screws were implanted in S1 and S2 segments respectively under the assistance of 3D navigation technology. The implantation time of each screw, the intraoperative X-ray exposure time, and the occurrence of surgical complications were recorded. After operation, the imaging reexamination was used to evaluate the screw position according to Gras standard and the reduction quality of sacral fractures according to Matta standard. At last follow-up, the pelvic function was scored with Majeed scoring standard. Results The 101 lengthened sacroiliac screws were implanted with the assisting of 3D navigation technology. The implantation time of each screw was 37.3 minutes on average (range, 30-45 minutes), and the X-ray exposure time was 46.2 seconds on average (range, 40-55 seconds). All patients had no neurovascular or organ injury. All incisions healed by first intention. The quality of fracture reduction was evaluated according to Matta standard as excellent in 22 cases, good in 18 cases, and fair in 5 cases, and the excellent and good rate was 88.89%. The screw position was evaluated according to Gras standard as excellent in 77 screws, good in 22 screws, and poor in 2 screws, and the excellent and good rate was 98.02%. All patients were followed up 12-24 months (mean, 14.6 months). All fractures healed and the healing time was 12-16 weeks (mean, 13.5 weeks). Pelvic function was evaluated according to Majeed scoring standard as excellent in 27 cases, good in 16 cases, fair in 2 cases, and the excellent and good rate was 95.56%. Conclusion Percutaneous double-segment lengthened sacroiliac screws internal fixation for the treatment of Denis type Ⅱ and Ⅲ sacral fractures is minimally invasive and effective. With the assistance of 3D navigation technology, the screw implantation is accurate and safe.
Objective To compare the effectiveness of O-arm navigation and C-arm navigation for guiding percutaneous long sacroiliac screws in treatment of Denis type Ⅱ sacral fractures. Methods A retrospective study was conducted on clinical data of the 46 patients with Denis type Ⅱ sacral fractures between April 2021 and October 2022. Among them, 19 patients underwent O-arm navigation assisted percutaneous long sacroiliac screw fixation (O-arm navigation group), and 27 patients underwent C-arm navigation assisted percutaneous long sacroiliac screw fixation (C-arm navigation group). There was no significant difference in gender, age, causes of injuries, Tile classification of pelvic fractures, combined injury, the interval from injury to operation between the two groups (P>0.05). The intraoperative preparation time, the placement time of each screw, the fluoroscopy time of each screw during placement, screw position accuracy, the quality of fracture reduction, and fracture healing time were recorded and compared, postoperative complications were observed. Pelvic function was evaluated by Majeed score at last follow-up. Results All operations were completed successfully, and all incisions healed by first intention. Compared to the C-arm navigation group, the O-arm navigation group had shorter intraoperative preparation time, placement time of each screw, and fluoroscopy time, with significant differences (P<0.05). There was no significant difference in screw position accuracy and the quality of fracture reduction (P>0.05). There was no nerve or vascular injury during screw placed in the two groups. All patients in both groups were followed up, with the follow-up time of 6-21 months (mean, 12.0 months). Imaging re-examination showed that both groups achieved bony healing, and there was no significant difference in fracture healing time between the two groups (P>0.05). During follow-up, there was no postoperative complications, such as screw loosening and breaking or loss of fracture reduction. At last follow-up, there was no significant difference in pelvic function between the two groups (P>0.05). Conclusion Compared with the C-arm navigation, the O-arm navigation assisted percutaneous long sacroiliac screws for the treatment of Denis typeⅡsacral fractures can significantly shorten the intraoperative preparation time, screw placement time, and fluoroscopy time, improve the accuracy of screw placement, and obtain clearer navigation images.