目的:探讨后路椎弓根螺钉固定在地震伤胸腰椎骨折中的应用及优点。方法:对19例胸腰椎骨折的地震伤患者行后路椎弓根螺钉内固定术。结果:本组病例的手术时间70～115分钟,平均出血量约280mL,两例病员术中出血超过400mL进行输血,复位椎体前缘高度由术前平均57.5%恢复到术后平均93.6%,后突角由术前平均21°矫正到术后平均3°,术后3～7天转往外地继续治疗,Frankel分级平均提高0.4。结论:后路椎弓根螺钉固定具有省时、节约医疗资源、提高救治效率、减轻患者痛苦的优点,尤其适用于大批伤病员的紧急救治。
To investigate the shortsegment pedicle screw in treating degenerative L4 spondylolisthesis and the relationship of the preliminarily bending degree of the titanium rod with the lumbar lordosisangle, the slipping angle and the slipping percentage and to evaluate the clinical coincidence and curative effects of the preliminarilybent rod. MethodsFrom September 2005 to March 2007, 31 female patients (age, 40-70 years; average, 58.3 years) were admitted for surgical treatment of their L4 degenerative spondylolisthesis (MeyerdingⅠ°, Ⅱ°)． Their lumbar lordosis angle （x1）, slipping angle (x2), and slipping percentage (x3) were measured in the L4,5 segment before operation. During the operation, the titanium rod bent beforehand according to the corresponding standards was inserted. The angle of the bent rod (Y) was measured, and then the multiple linear regression equation was established. The regression equation was applied to the surgical treatment of the 30 patients.Results According to the criteria in the JOA scoring system, the 31 patients had scores of 8.300± 1.080 and 26.916±1.859 before operation and after operation, respectively. There was a significant difference between before operation and after operation（Plt;0.05）. The established multiple linear regression equation was as follows:Y=0.1390-0.327logx1+0.463x2+0.288x32．The operating time was 51.290±3.408 min in the 30 patients who underwent an insertion of the preliminarilybent rod during the operation; however, the operating time was 102.360±5.004 min in the 31 patients who underwent an insertion of the bent rod that was made based on experience during the previous operations. There was a significant difference in the operating time between the two kinds of the rods （Plt;0.05）. Estimated according to 90%, 95% and 99% of the areas under the normalcurve, the clinical coincidence rates in the preliminarily bending degrees of the titanium rod in the 30 patients were 80.00％，90.00％ and 96.67％, respectively.Conclusion The titanium rod that has been bent into a certain angle before operation according to the established criteria can definitely diminish its strain during operation and efficiently shorten the operating time．Thiskind of the titanium rod has a good coincidence in clinical application and can be effectively used in clinical practice.It is worth reference during the clinical operation.
【摘要】 目的 探讨经后路全脊截骨联合椎弓根螺钉治疗胸腰椎脊柱后凸畸形的手术评估和临床疗效。 方法 2004年4月－2010年6月采用后路脊椎截骨椎弓根螺钉内固定治疗脊柱后凸畸形15例，其中男11例，女4例；年龄16~61岁，平均49岁。陈旧性胸腰椎骨折后凸10例，结核后凸3例，椎体发育不良2例；后凸顶点：胸9椎体1例，胸11椎体3例，胸12椎体4例，腰1椎体5例，腰2椎体2例。脊柱后凸Cobb角35~61°，平均46°。Frankel分级：E级2例，D级8例，C级4例，B级1例。 结果 术中出血800~1 800 mL，平均1 000 mL；术中1例左侧胸神经根损伤；1例术后双下肢肌力感觉减退。15例患者均获随访，随访时间10~30个月，平均12个月。术后6个月Cobb角5~10°，平均矫正率86.5%。术后6~10个月X线片显示截骨平面骨性愈合，术后神经功能恢复情况，除1例B级恢复至D级外，其余为E级。内固定物无松动、断裂和纠正度数丢失等并发症。 结论 经后路脊柱截骨联合椎弓根螺钉内固定具有减压、矫形同时进行，矫正度数大，并发症少，临床效果明显。【Abstract】 Objective To explore the surgery assessment and clinical outcome of the treatment for thoracolumbar kyphosis by whole posterior spinal osteotomy combined with pedicle screw. Methods Fifteen patients including 11 males and 4 females with kyphosis were treated by posterior spinal osteotomy combined with pedicle screw from April 2004 to June 2010. The age of them ranged from 16 to 61 years old averaging at 49. There were 10 cases of old thoracolumbar fracture kyphosis, 3 cases of tuberculosis kyphosis, and 2 cases of poor vertebral growth. As for kyphosis vertices, there were 1 case of T9, 3 cases of T11, 4 cases of T12, 5 cases of L1, and 2 cases of L2. Kyphosis Cobb angle ranged from 35° to 61°, averaging at 46°. Based on Franke Grade, there were 2 grade E cases, 8 grade D cases, 4 grade C cases, and 1 grade B case. Results Intraoperative blood loss was from 800 to 1 800 mL with an average of 1 000 mL; There was 1 case of left thoracic nerve root injury during operation and 1 case of lower extremity muscle strength hypoesthesia after operation. All the 15 patients were followed up for 10 to 30 months with an average time of 12 months. Six months after surgery, Cobb angle ranged from 5° to 10°, with an average correction rate of 86.5%. Six to ten months after osteotomy, X ray showed a good bone healing condition. As for the recovery status of neurological function after surgery, All patients recovered to grade E except 1 patient who returned to grade D from grade B. No such complications as fixation without loosening, fracture or loss of correction degree occurred. Conclusion In posterior spinal osteotomy combined with pedicle screw fixation, decompression and correction can be carried out at the same time to correct a large degree of kyphosis with few complications. The clinical effect is obvious.
ObjectiveTo discuss the security and effectiveness of fixing the unstable region of sagittal injured unit symmetrically with pedicle screws combined with bone graft fusion for treating thoracolumbar fractures.MethodsA series of 65 patients with a single level thoracolumbar fracture between November 2011 and November 2015 were included in the study. There were 41 males and 24 females with an average age of 36.7 years (range, 23-60 years). The fracture segments included T7 1 case, T9 in 2 cases, T10 in 4 cases, T11 in 8 cases, T12 in 14 cases, L1 in 19 cases, L2 in 13 cases, L3 in 3 cases, and L4 in 1 case. According to AO classification, there were 34 cases classified as type A, 27 cases type B, and 4 cases type C. The neurological function was evaluated by American Spinal Injury Association (ASIA) grade score, there were 1 case at grade A, 2 cases grade B, 6 cases grade C, 15 cases grade D, and 41 cases grade E. The thoracolumbar injury severity score (TLICS) was 4 in 9 cases, 5 in 29 cases, 6-8 in 23 cases, 9-10 in 4 cases. The time form injury to operation was 2-12 days (mean, 5.3 days). The fractured vertebra, along with the superior and inferior discs were defined as a injured unit and divided into three parts on the sagittal position: region Ⅰ mainly including the superior disc, cephalic 1/3 of injured vertebra, and posterior ligamentous complex as to oppose; region Ⅱ mainly including the middle 1/3 of injured vertebra, pedicles, lamina, spinous process, and supraspinal ligament; region Ⅲ mainly including the inferior disc, caudal 1/3 of injured vertebra, and posterior ligamentous complex as to oppose. The unstable region was defined as the key injured region of the vertebra. Pedicle screws were fixed symmetrically and correspondingly with bone grafting to treat thoracolumbar fractures. The neurological status, ratio of anterior body height, and sagittal Cobb angle were collected at preoperation, immediate after operation, and last follow-up to evaluate surgical and clinical outcomes.ResultsAll patients accepted operation safely and were followed up 12-24 months (mean, 17.3 months). Cerebrospinal fluid leakage occurred in 3 patients, and cured by symptomatic treatment. There was no complications such as loosening, displacement, and breakage of internal fixator. Bony fusion was achieved in all patients at 10-13 months (mean, 11.4 months) after operation. At last follow-up, according to ASIA grading, 1 case was grade A, 1 grade B, 3 grade C, 9 grade D, and 51 grade E, showing significant difference when compared with preoperative data (Z=–2.963, P=0.014). The ratio of anterior body height at preoperation, immediate after operation, and last follow-up were 53.2%±6.8%, 91.3%±8.3%, 89.5%±6.6% respectively; and the sagittal Cobb angle were (16.3±8.1), (2.6±7.5), (3.2±6.8)° respectively. The ratio of anterior body height and the sagittal Cobb angle at immediate after operation and at last follow-up were significantly improved when compared with preoperative values (P<0.05), but no significant difference was found between at immediate after operation and at last follow-up (P>0.05).ConclusionIt is safe and reliable to treat thoracolumbar fractures under the principle of fixing the unstable region of injured unit symmetrically with pedicle screws combined with bone grafting.
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.
ObjectiveTo investigate the clinical application of three-dimensional (3D) printing technique combined with a new type of thoracic pedicle screw track detector in thoracic pedicle screw placement.MethodsAccording to the characteristics of thoracic pedicle and common clinical screw placement methods, a new type of thoracic pedicle screw track detector was independently developed and designed. The clinical data of 30 patients with thoracic vertebrae related diseases who underwent posterior thoracic pedicle screw fixation between March 2017 and January 2020 were retrospectively analysed. Among them, there were 18 males and 12 females with an average age of 56.3 years (range, 32-76 years). There was 1 case of thoracic disc herniation, 4 cases of thoracic canal stenosis, 2 cases of ossification of posterior longitudinal ligament of thoracic vertebra, 16 cases of thoracic trauma, 2 cases of thoracic infection, and 5 cases of thoracic canal occupation. Three-dimensional CT of the thoracic vertebra was routinely performed preoperatively, and the model of the patient’s thoracic vertebra was reconstructed and printed out. With the assistance of the model, preoperative simulation was performed with the combination of the new type thoracic pedicle screw track detector, and detected no nails after critical cortical damage. During operation, one side was randomly selected to use traditional hand screws placement (control group), and the other side was selected to use 3D printing technique combined with new type thoracic pedicle screw track detector to assist thoracic pedicle screws placement (observation group). The single screw placement time, adjustment times of single screw, and blood loss during screw placement were compared between the two groups. The accuracy of screw placement in the two groups was evaluated according to postoperative CT imaging data.ResultsThe single screw placement time, adjustment times of single screw, and blood loss during screw placement in the observation group were significantly less than those in the control group (P<0.05). Postoperative CT examination showed that the observation group had 87 screws of grade 1, 3 screws of grade 2, and the acceptable screw placement rate was 100% (90/90); the control group had 76 screws of grade 1, 2 screws of grade 2, 11 screws of grade 3, and 1 screw of grade 4, and the acceptable screw placement rate was 86.7% (78/90); showing significant difference in screw placement between the two groups (χ2=12.875, P=0.001). All patients were followed up 6-18 months, with an average of 11.3 months. There was no complication of vascular, nerve, spinal cord, or visceral injury, and screws or rods broken, and no patient was revised.ConclusionThe 3D printing technique combined with the new type of thoracic pedicle screw track detector assisted thoracic pedicle screw placement is convenient, and significantly improves the accuracy and safety of intraoperative screw placement, and overall success rate of the surgery.
Objective To investigating the safety and accuracy of artificial intelligence (AI) assisted automatic planning of pedicle screws parallel to sagittal plane for C1. Methods The subjects who completed cervical CT scan in Zigong Fourth People’s Hospital btween January 2020 and December 2023 were selected. The subjects who completed cervical CT scan were randomly divided into two groups using a random number table method. Among them, 80% were used as the training model (training group), and 20% were used as the validation model (validation group). The original cervical CT data of the training group were imported into ITK-SNAP software to mark the feature points. Four feature points were selected. In order to obtain the weighted function model of the four feature points, training group were trained with the spatial key point location algorithm. pedicle trajectory based on the four key points obtained. Finally, the algorithm was compiled to form a visual interface, and imported into the verification group of annular vertebral CT data to calculate the pedicle screw trajectory. Results A total of 500 patients were included. Among them, there were 400 cases in the training group and 100 cases in the validation group. The average positioning error of spatial key points is (0.47±0.16) mm. The average distance between the planned pedicle screw center line and the internal edge of the pedicle was (2.86±0.12) mm. Pedicle screw placement parallel to the sagittal plane and 3D display can be safely performed for the C1 pedicle that is large enough to accommodate a 3.5 mm diameter screw without cortical breakthrough. Conclusions For pedicle screw planning parallel to the sagittal plane in C1, training based on the spatial positioning algorithm of anterior and posterior tubercles and bilateral tangential points can obtain a safe and accurate pedicle screw trajectory. It provides theoretical basis for orthopedic robot automatic screw placement. For vertebral bodies with narrow or deformed pedicles, further expansion of the training data is needed to expand the adaptive range and improve the accuracy of the algorithm.
ObjectiveTo investigate the distance between the screw-out point and the middle sacral artery, and evaluate the safety when the S1 pedicle screw placed by the three cortical fixation techniques.MethodsFrom March to June 2018, randomized CT scan data of 98 adult pelvic angiography were selected to measure the distance from the middle sacral artery to the anterior edge of the vertebral body (a) and the distance from the middle sacral artery to the midline of the vertebral body (b). S1 screw entry point was set as the intersection of lines where extension of S1 facet joint inferior margin and lateral margin cross over. Introversion angles of 10, 15, 20, and 25° were used; the distance between the screw insertion point and the middle sacral artery (d) was measured.ResultsThe middle sacral artery was usually located on the left side of the upper endplate plane of S1. The distance a was (5.40±2.95) mm in 49 males and (4.43±2.32) mm in 49 females, and the difference between the males and females was not statistically significant (t=1.818, P=0.72). The distance b was (12.07±5.42) mm in 45 males and (14.12±4.88) mm in 48 females, and the difference between the males and females was not statistically significant (t=–1.914, P=0.59). The distance d was (12.67±6.00), (9.40±5.17), (7.50±3.76), and (8.10±3.64) mm when the nail was placed at a common internal inclination of 10, 15, 20, and 25°. The differences in the distance d at a common internal inclination of 10° vs. 15°, 10° vs. 20°, 10° vs. 25°, and 15° vs. 20° were all statistically significant (t=16.828, 11.609, 6.073, 6.254; P<0.008 3); there was no statistically significant difference in that at 15°vs. 25°, or 20° vs. 25° (t=2.034, –1.723; P>0.05).ConclusionBy analyzing the relationship between the middle sacral artery and the upper endplate plane of the S1 vertebra, the risk of middle artery injury is small while the biomechanical stability of the screw is increased when using the Lenham method.
Objective To evaluate the deviation between actual and simulated screw placement after cervical pedicle screw placement assisted by 3D printed navigation template, and analyze the correlation between screw placement deviation and navigation pipe length. Methods A total of 40 patients undergoing cervical 1-7 pedicle screw insertion assisted by 3D printed navigation template in Zigong Fourth People’s Hospital between February 2018 and August 2020 were included in this prospective study. These patients were divided into 3 groups randomly, including 12 patients with a 5-mm pipe length (5 mm group), 13 patients with a 10-mm pipe length (10 mm group), and 15 patients with a 15-mm pipe length (15 mm group). Three-dimensional modeling was performed on preoperative cervical CT images of these patients and simulated pedicle screw was placed. Individualized pedicle screw navigation templates were designed according to the position and direction of simulated pedicle screws, and 3D printing was performed on the cervical model and navigation templates. Preoperative 3D printed model and navigation templates were used to simulate the surgical process to confirm the safety of screws. During the operation, pedicle screw placement was performed according to the preoperative design and simulated surgical process. The postoperative CT images were registered with the preoperative CT images in 3D model. The safety of screw placement was evaluated by the postoperative screw placement Grade, and the accuracy of screw placement was evaluated by measuring the deviation of screw placement point and the deviation of screw placement direction in horizontal plane (inclination angle) and sagittal plane (head inclination angle). The influence of different navigation pipe lengths on the safety and accuracy of screw placement was analyzed. Results A total of 164 pedicle screws were inserted with navigation template assistance, including 48 screws (38 in Grade 0 and 10 in Grade 1) in the 5 mm group, 52 screws in the 10 mm group (all in Grade 0), and 64 screws (52 in Grade 0 and 12 in Grade 1) in the 15 mm group, and the difference in the grade among the three groups was statistically significant (P<0.05). When the navigation pipe length was 5, 10, and 15 mm, respectively, the screw entry point deviation was (1.87±0.63), (1.44±0.63), and (1.66±0.54) mm, respectively, the inclination angle deviation was (2.72±0.25), (0.90±0.21), and (1.84±0.35)°, respectively, and the head inclination angle deviation was (8.63±1.83), (7.15±1.38), and (8.24±1.52)°, respectively. The deviations in the 10 mm group were all significantly less than those in the other two groups (P<0.05). Conclusions In the cervical pedicle screw placement assisted by navigation template, all the screws were Grade 0 or Grade 1, with high safety. The mean deviation of the screw entry point is within 2 mm, with high accuracy. When the length of navigation pipe is 10 mm, the safety and accuracy of screw placement can be fully guaranteed.
ObjectiveTo explore the feasibility of lumbar puncture models based on 3D printing technology for training junior orthopaedic surgeons to find the optimal pedicle screw insertion points.MethodsMimics software was used to design 3D models of lumbar spine with the optimal channels and alternative channels. Then, the printed lumbar spine models, plasticine, and cloth were used to build lumbar puncture models. From January 2018 to June 2019, 43 orthopedic trainees performed simulated operations to search for the insertion points of pedicle screws base on the models. The operations were performed once a day for 10 consecutive days, and the differences in operation scores and operation durations of the trainees among the 10 days were compared.ResultsAll the trainees completed the surgical training operations successfully, and there were significant differences in the operation scores (13.05±2.45, 14.02±3.96, 17.58±3.46, 21.02±2.04, 23.40±4.08, 25.14±3.72, 27.26±6.09, 33.37±4.23, 35.00±4.15, 38.49±1.70; F=340.604, P<0.001) and operation durations [(22.51±4.28), (19.93±4.28), (18.05±2.89), (17.05±1.76), (16.98±1.97), (15.47±1.74), (13.51±1.42), (12.60±2.17), (12.44±1.71), (11.91±1.87) minutes; F=102.359, P<0.001] among the 10 days.ConclusionThe 3D models of lumbar puncture are feasible and repeatable, which can contribute to surgical training.