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BACKGROUND: Traditional fluoroscopy-guided pedicle screw fixation is not highly accurate and can lead to serious surgical complications. To reduce surgical complications and improve the success rate of surgery, robotic assistive technology emerges as the times require. OBJECTIVE: To compare the difference of robot-assisted and fluoroscopy-guided pedicle screw placement using meta-analysis. METHODS: The study included clinical controlled trials on robot-assisted and fluoroscopy-guided pedicle screw placement published in and outside China from December 2008 to December 2018. The retrieval was performed in the online databases include Embase, PubMed, Central, CNKI, CQVIP, Wanfang, and CBM. Keywords used for search were robot assisted, fluoroscopy guided, conventional, freehand, pedicle screw in English and Chinese. After the data were extracted, statistical software Review Manager 5.3 was used for data-analysis. RESULTS AND CONCLUSION: (1) Based on the above search strategy, 1 615 studies were retrieved, and 13 were included. (2) Statistical analysis found that placement accuracy in the robot-assisted group was better than that of the fluoroscopy group [95%CI(1.55, 4.06), P=0.000 2]. Radiation intensity in the fluoroscopy group was lower than that in the robot-assisted group [95%CI(0.42, 0.82), P < 0.001], and the difference was statistically significant. (3) However, the incidence of complications [95%CI(0.23, 4.65), P=0.96] and revised surgery [95%CI(0.03, 3.17), P=0.33] were not statistically significant between the robot-assisted group and the fluoroscopy group. Intraoperative fluoroscopy time was similar between the two groups [95%CI(-38.55, 78.26), P=0.51]. Postoperative back pain [95%CI(-0.58, 0.38), P=0.68], leg pain score [95%CI(-0.20, 0.19), P=0.94] and operation time [95%CI(-6.33, 53.02), P=0.12] were also similar between the two groups, and the differences were not statistically significant. (4) Compared with fluoroscopy, robot-assisted technique has higher pedicle screw placement accuracy, especially under percutaneous conditions. Inevitably, the intraoperative radiation intensity is also more than conventional fluoroscopy.
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BACKGROUND: The bone trabecula of the vertebral body cannot be fully recovered, and the mechanical stability of the sagittal position of the spinal column Is affected. The antl-bendlng force and the anti-torsion force of the short-segment fixation of fractured vertebra are obviously Increased. The bearing load of various activities such as flexion, extension, and rotation of the vertebral body is increased. The stability of the injured vertebra is better maintained, and favorable conditions are created for fracture healing. OBJECTIVE: To compare the early- and mid-term follow-up results of trans-injured and cross-injured vertebra pedicle screw fixation in the treatment of thoracolumbar fractures. METHODS: Eighty-eight patients with thoracolumbar vertebrae fracture treated in Affiliated Hospital of Qinghai University from April 2017 to April 2018 were divided into trans-injured vertebra group and cross-injured vertebra group according to the treatment plan. All patients signed the informed consent. This study was approved by the Hospital Ethics Committee. Intraoperative blood loss, operation time, postoperative bed rest time, postoperative site infection, and subcutaneous hematoma were analyzed in both groups. Visual analogue scale score, Oswestry Disability Index, anterior edge height ratio and kyphosis Cobb angle were compared before surgery, 6 and 12 months after surgery between the two groups. RESULTS AND CONCLUSION: (1) The operation time was longer and intraoperative blood loss was higher in the trans-injured group than those in the cross-injured group, but the postoperative bed rest time was shorter in the trans-injured group than that in the cross-injured group (P 0.05). (3) At 6 and 12 months after surgery, visual analogue scale score and Oswestry Disability Index were lower in the trans-injured group than in the cross-injured group; anterior edge height ratio was larger in the trans-injured group than in the cross-injured group; kyphosis Cobb angle was smaller in the trans-injured group than in the cross-injured group (all P < 0.05). (4) Incidence of complications was higher in the cross-injured group (30%) than in the trans-injured group (7%) (P=0.001). (5) The treatment of thoracolumbar fracture with trans-injured pedicle screw can not only effectively restore and maintain the injured vertebral height and kyphosis Cobb angle, restore the physiological height and curvature of vertebral body, but also the incidence of postoperative complications is low, which can effectively improve the prognosis of patients and improve the quality of life of patients.
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BACKGROUND: Computer navigation system and orthopedic surgery robot have been developed rapidly in spine surgery in recent years, but the operation effect of computer navigation or navigation robot is still questioned. OBJECTIVE: To compare the difference in robot-assisted and fluoroscopy-guided pedicle screw placement. METHODS: The study included clinical trials published in and outside China from August 2008 to August 2019. The retrieval was performed in the online databases including Embase, PubMed, CNKI, and Wanfang Data. Key words in Chinese were: robot assisted, fluoroscopy guided, pedicle screw, pedicle nail, pedicle screw rod, pedicle internal fixation. Search strategy was: pedicle screw AND robot assisted OR fluoroscopy guided. Key words in English were: Robot assisted, Fluoroscopy guided, Pedicle screw, Pedicle stick, Pedicle screw fixation. Search strategy was: “Pedicle screw” OR “Pedicle stick” OR “Pedicle screw fixation” AND “Fluoroscopy guided” OR “Robot assisted”. After data extraction, statistical software Review Manager 5.3 was used for data analysis. RESULTS AND CONCLUSION: (1) Based on the above search strategy, 357 studies were retrieved. A total of 19 trials were included, containing 17 English studies and 2 Chinese studies. (2) Meta-analysis results displayed that the accuracy of placement of the robot-assisted group was superior to that of the fluoroscopy-guided group [95%CI(1.82, 2.52), P < 0.001]. Number of surgical complications [95%CI(0.25, 0.69), P=0.0006] and revision number [95%CI(0.23, 0.71), P=0.002] were less in the robot-assisted group than in the fluoroscopy-guided group. (3) When evaluating pedicle screw placement, robot-assisted has higher pedicle screw placement accuracy, fewer complications and fewer revisions, and is superior to traditional fluoroscopy-guided technique in accuracy and safety. Considering the expensive price and complex operation steps of navigation robot technology, the selection of specific nail placement method should still follow the principle of individualized treatment.
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BACKGROUND: With the development of three-dimensional (3D) printing technology, it has been widely used in spinal surgery. However, whether 3D printing-assisted surgery for lumbar spondylolisthesis has an advantage over traditional surgery is still controversial. OBJECTIVE: To compare the clinical efficacy and safety of 3D printing-assisted versus conventional surgery for the treatment of lumbar spondylolisthesis using system evaluation. METHODS: Randomized controlled trials about 3D printing technology for lumbar spondylolisthesis in CNKI, Wanfang database, CBM, VIP, PubMed, Cochrane Library, Embase, and Web of Science were searched via computer from inception to November 16, 2019. The retrieved literatures were screened according to predefined inclusion and exclusion criteria, and quality evaluation was performed. Then, the available data were extracted and analyzed with the Stata 11. 0 software. RESULTS AND CONCLUSION: (1) Six randomized controlled trials including 394 cases were included. Among them, 201 cases were assigned to the 3D printing-assisted group and 193 cases to the conventional group. (2) Meta-analysis results showed that the 3D printing-assisted group proved significantly superior to the conventional group regrading the operation time [WMD=-38. 17, 95%CI(-43. 93, -32. 41), P=0. 00], intraoperative blood loss [WMD=-61. 61, 95%CI(-69. 19, -54. 03), P=0. 00], the frequency of fluoroscopy [WMD=-4. 89, 95%CI(-6. 38, -3. 41), P=0. 00] and the screw placement accuracy [OR=3. 89, 95%CI(2. 43, 6. 25), P=0. 00]. (3) However, in terms of the postoperative visual analogue scale scores [WMD=-0. 47, 95%CI(-1. 21, 0. 27), P=0. 215], Oswestry disability index [WMD=-1. 41, 95%CI(-2. 87, 0. 05), P=0. 058], Japanese Orthopaedic Association scores [WMD=1. 02, 95%CI(-0. 68, 2. 72), P=0. 240] and the rate of complications [OR=0. 37, 95%CI(0. 12, 1. 11), P=0. 075], no statistically significant differences were found between the two groups. (4) In conclusion, the application of 3D printing technology in the surgical treatment of lumbar spondylolisthesis has the advantage of shortening the operation time, reducing intraoperative blood loss and frequency of fluoroscopy and improving the accuracy of the screw placement.
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BACKGROUND: Idiopathic scoliosis surgery is difficult and requires a long operation time. Using 3D printing navigation templates to assist in nail placement can reduce the difficulty of surgery, optimize the operation of nail placement, and improve the effect of nail placement, which has significant advantages. OBJECTIVE: To evaluate the application of 3D printing navigation template assisted screw placement in the pedicle screw internal fixation of idiopathic scoliosis. METHODS: Clinical data of 17 cases of idiopathic scoliosis treated by pedicle screw fixation from January 2018 to August 2019 were retrospectively analyzed. Among them, eight patients were treated with 3D printing navigation template assisted screw placement (3D group), while nine patients were treated with conventional screw placement (conventional group). CT scan was used to evaluate the level and acceptability of screw placement after surgery. The time of nail placement, the times of intraoperative X-ray fluoroscopy, the amount of nailing bleeding, the level of nail placement, the acceptable rate of nail placement, the rate of secondary nail placement, the rate of main bending correction and the complications related to nail placement were compared between the two groups. RESULTS AND CONCLUSION: (1) All the 17 patients successfully completed the operation of nail placement, and there were no complications related to nail placement in blood vessel and nerve injury. One case of back pain and one case of lower extremity pain were found in the conventional group, and the symptoms disappeared after symptomatic treatment. (2) The time of nail placement, the times of intraoperative X-ray fluoroscopy and the amount of nailing bleeding in the 3D group were less than those in the conventional group, and the difference was statistically significant (P 0.05). (5) 3D printing navigation template can reduce the difficulty of screw placement and improve the effect of screw placement during pedicle screw internal fixation of idiopathic scoliosis.
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Objective To evaluate the curative effect of selective screw placement of posterior three-dimensional correction for Lenkeadolescent idiopathic scoliosis (AIS), and to compare the effects of different screw densities on the orthopedic parameters. Methods We retrospectively analyzed the clinical data of LenkeAIS patients undergoing posterior correction of scoliosis＋selective fusion and internal fixation surgery in Department of Spine Surgery of Changhai Hospital of Naval Medical University (Second Military Medical University) between Jan. 2013 and Jan. 2017. According to the references, the screw density was defined as the number of nails/(fusion segment×2). The patients were divided into high density group (screw density0.7) and low density group (screw density≤0.7). The general characteristics, surgical correction rates 2 weeks and 2 years after operation, loss of correction rate after 2 years and correction ratio were compared between the two groups. Results A total of 36 eligible patients (11 males and 25 females) with LenkeAIS were included in this study, with an average age of (13.97±1.89) years old. There were 23 cases in the high density group and 13 cases in the low density group, with the screw densities being 0.80±0.04 and 0.64±0.06, respectively, and the difference was significant (t＝10.799，P0.01). There were no significant differences in gender, age, brand of pedicle screw, preoperation coronal main curve Cobb angle, preoperation bending Cobb angle or preoperation scoliosis flexibility between the two groups (all P 0.05). Compared with the high density group, the low density group had no significant disadvantages in coronal main curve Cobb angles 2 weeks and 2 years after operation, surgical correction rate 2 weeks after operation, or loss of correction rate 2 years after operation (all P0.05). Pearson correlation analysis showed that there were no significant correlations between screw density and surgical correction rate 2 weeks after operation, correction ratio and the loss of correction rate (r＝0.149, 0.348, 0.217; P＝0.387, 0.874, 0.177). Conclusion For LenkeAIS patients with better flexibility, appropriate reduction of the nail number in selective screw placement surgery may not adversely affect the short-term and mid-term outcomes.
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Objective: To investigate the anatomical characters of the sustentaculum tali (ST), accurate entry point and direction for the placement of ST screw from posterior subtalar joint facet to the constant fragment (CF) in calcaneal fractures. Methods: A total of 100 patients with calcaneal fractures performed ankle CT scans were enrolled between January 2016 and April 2016. According to the inclusion criteria, the clinical data of 33 patients were analyzed, including 18 males and 15 females, with a median age of 41.0 years (range, 18-60 years). There were 16 cases on left side and 17 cases on the right side. Three-dimensional (3D) calcaneal model was reconstructed by Mimics 17.0 software, and the ST anatomical references were measured, including the length of upper and lower edge, the length and height of the midline, the horizontal angle between the midline and foot plantar surface. The parameters of the optimal entry point position (P' point) and placement angle of the ST screw were determined. The length of ST screw was also measured. The differences between males and females or left and right sides were compared. Results: The length of upper edge of the ST was (16.60±2.23) mm, lower edge (20.65±2.90) mm, midline (20.56±2.62) mm, and the height of midline was (9.61±1.36) mm. The horizontal angle between the midline and foot plantar surface was (23.43±3.36)°. The vertical distance from P' point to the lowest point of the tarsal sinus was (3.09±1.65) mm, while the horizontal distance was (14.29±2.75) mm. The distance from P' point to the apex of the lateral talus, subchondral bone of subtalar joint, calcaneocuboid joint was (11.41±3.22), (6.59±2.22), (34.58±3.75) mm, respectively. The horizontal angle between the ST screw and foot plantar surface was (-1.17±2.07)°. The anteversion angle of ST screw was (16.18±2.05)° and the length was (41.64 ± 3.09) mm. There were significant differences in the length of upper and lower edge, the length and height of the midline, the distance from P' point to the apex of the lateral talus, subchondral bone of subtalar joint, and calcaneocuboid joint, and the anteversion angle and length of the ST screw between males and females ( P0.05). Conclusion: After appropriate reduction of the calcaneal fractures, the entry point of ST screw was recommended at about 14 mm posterior and about 3 mm upper related to the foot horizontal line through the lowest tarsal sinus point; and the direction of ST screw placement was about 17° anteversion for males and 15° anteversion for females.
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Objective To evaluate the accuracy and safety of screw placement position through second sacral alar -iliac(S2AI)with in-teroperative cone beam CT(CBCT)scan.Methods Collected 22 patients who underwent second sacral alar-iliac screw implant surgery in our hospital from June 2015 to June 2017.All the patients had intraoperative CBCT scan and conventional CT scan after operation.Regard the postoperative CT scan imageing as gold standard to assess the accuracy and safety of S 2AI screws position.The S2AI tract parameters were measured with intraoperative CBCT images and postoperative CT images respectively.Results There was no significant difference between the S2AI tract parameters which were measured with intraoperative CBCT images and postoperative CT images(P>0.05).Conclusion The intraoperative CBCT scan could accurately evaluate the position of S 2AI screws,as well as clarify the damage of the inner and outer plate of the iliac bone in the process of fixation.Compared with postoperative conventional CT scan,the intraoperative CBCT scan can potentially re-duce the reoperation rate.
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Abstract: Introduction: The technique of placement of pedicle screws has gradually improved, but even misplacement observed in 1.2 to 20% of cases, have appeared techniques fluoroscopic, tomographic and electromagnetic navigation, which led it to 1.3 to 4.3%, but nevertheless they are expensive and complex technologies. Present technique pedicle screw placement by using templates with a modification in the art, performing tomography and reconstruction in the same surgical position and with the templates of 3 or more levels. Methods: Five cases of idiopathic scoliosis were performed, with correction and instrumentation with pedicular screws, where a three-dimensional model of the spine was performed with a tomography in a surgical position, whose images were exported to a 3D printer to reconstruct the desired trajectory of the screws in a template using cylinders resting on the inverse surface of the vertebrae. The direction of the screw was planned in the center of the pedicle and parallel to the upper platform of the vertebra. Each template was of several levels and transoperative X-rays were not used. Results: Under electrophysiologic monitoring transoperative «red alerts¼ were not reported, the placement of the screws in postoperative CT scan was evaluated, showing a standard deviation in placement of 1.9 and 2.2 mm on the right and left respectively pedicles, with respect to their planning. Discussion: This technique is simple and safe, besides not requiring great technology, its use is suggested in beginner spine surgeons and in severe deformities, it can be performed in any hospital where spinal surgery is performed.
Resumen: Introducción: La técnica de colocación de tornillos transpediculares ha mejorado paulatinamente, a pesar de ello, la mala colocación oscila entre 1.2 al 20% de los casos; han surgido técnicas de navegación asistidas por flouroscopía, tomografía y resonancia magnética mejorando el índice de falla al 1.3-4.3%. La presente técnica de colocación utiliza plantillas con la modificación de que la tomografía y la reconstrucción son realizadas con el paciente en la posición quirúrgica, además que las plantillas abarcan tres o más niveles. Métodos: Se presentan cinco casos de escoliosis idiopática tratados con instrumentación y colocación de tornillos transpediculares donde se generó un modelo tridimensional de la columna en posición quirúrgica; las imágenes fueron exportadas a una impresora 3-D para reconstruir la trayectoria apropiada de los tornillos, la dirección de éstos fue planeada tomando de referencia el centro del pedículo y paralela a la plataforma superior de la vértebra. Cada plantilla consta de diferentes niveles y no se requirió del uso de rayos X transoperatorios. Resultados: Bajo monitoreo electrofisiológico transquirúrgico no se reportó ninguna «alerta roja¼; la evaluación postoperatoria por tomografía de la colocación de los tornillos mostró una desviación estándar de 1.9 y 2.2 mm tanto a la derecha y a la izquierda, respectivamente, de acuerdo con lo planeado. Discusión: La técnica es simple y segura, no requiere de mucho despliegue tecnológico, se sugiere su uso para los cirujanos de columna con poca experiencia y para deformidades severas; consideramos que puede desarrollarse en cualquier hospital donde se realice cirugía de columna.
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Humans , Scoliosis/surgery , Spinal Fusion/methods , Surgery, Computer-Assisted , Pedicle Screws , Thoracic Vertebrae , Radiography , Tomography, X-Ray ComputedABSTRACT
Objective To evaluate the feasibility of the posterior C2 pedicle screw placement (C2 PSP) by MPR techniques of helical CT.Methods Totally 250 patients (500 sides) who underwent head and neck CTA examination were enrolled.The bony parameters and the arterial parameters were measured after MPR.The bony parameters included pedicle diameter (D),isthmus height (T),internal height (H),and the arterial parameters included medial shifting:lateral (L),neutral (N),medial (M);and the degree of riding included below (b),within (w),above (a).The prevalence of narrow pedicles,high-riding vertebral arteries (HRVA) and the subtypes of IAVA in the general population were calculated,and the statistical analysis between narrow pedicles,HRVA,IAVA and C2 vertebral arteries groove (C2 VAG) injury were performed.Results The rate of narrow pedicles and HRVA were 14.40％ (72/500) and 24.60％ (123/500;x2=141.984,P＜0.001).When it came to the simulation of the C2 PSP inserting,the incidence of C2 VAG injuries was 19.40％ (97/500).In narrow pedicle and HRVA patients,the C2 VAG injuries incidence were higher than that of without narrow pedicle and HRVA patients (both P＜0.001).In 58 sides (58/500,11.60 ％),the narrow pedicles and HRVA occurred simultaneously.There were statistical significance differences of narrow pedicles and HRVA and the C2 VAG injuries in different types of IAVA (all P＜0.001),the subtypes of IAVA M-a consisted most common,which account for 55.56％ (40/72),46.34％ (57/123) and 48.45％ (47/97),respectively.Conclusion Most of the C2 VAG injuries happened in narrow pedicles,HRVA or IAVA M-a type patients.MPR can be used to comprehensively evaluate osseous and arterial parameters,which will provide anatomy foundation to the screw placement of C2 pedicles.
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Objective To analyze the operation time,radiation exposure time and the screw placement accuracy of a newly-developed guiding chunnel-assisted percutaneous pedicle screw placement technique for thoracolumbar vertebral fractures not accompanied by nerve injury.Methods The clinical data of 35 patients with thoracolumbar vertebral fractures not accompanied by nerve injury,who were treated with newly-developed guiding chunnel-assisted percutaneous pedicle screw placement technique during the period from July 2010 to October 2012,were retrospectively analyzed.A total of 178 procedures of pedicle screw placement were performed in the 35 patients by the one and the same surgeon.The operation time and radiation exposure time of each pedicle screw placement procedure were recorded,and based on the findings of postoperative consecutive two CT scans of the operated vertebrae the screw placement accuracy was graded and evaluated.Results The technical success rate of screw placement was 100％.The mean time used for a single pedicle screw placement was (11.35±2.82) minutes,the average radiation exposure time was (8.06± 2.15) seconds.Screw placement accuracy of grade A was obtained in 156 screws (87.64％),grade B in 20 screws (11.24％),grade C in one screw (0.56％),and grade D in one screw (0.56％).Conclusion The newly-developed guiding chunnel-assisted percutaneous pedicle screw placement technique is very helpful in localizing the puncture point,in improving the screw placement accuracy,and in reducing both operation time and radiation exposure time.
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Objective To explore the orientation relationships and changing rules of pedicle screw entry point (PSEP) on the posterior bony landmarks in middle-upper thoracic vertebrae in adults by measuring parameters of 3-D reconstruction CT images. Methods CT images of the middle-upper thoracic vertebrae from 30 healthy adults were used for 3-D reconstruction to observe the anatomical characteristics of posterior bony landmarks, including transverse process-lamina concave, superior ridge of transverse process and outer edge of the lamina. The following basic parameters, including PSEP-to-midline distance (PMD), transverse process-lamina concave-to-midline distance (CMD) and half lamina width (HLW), and target parameters, including PSEP-to-transverse process-lamina concave distance (PCD), entry point location ratio (EPLR) and PSEP-to-superior ridge of transverse process distance (PRD) were determined on reconstructed CT images from T1 to T10. The differences of bilateral measurements of all parameters and the differences of basic parameters were analyzed, and the changing rules of target parameters measurements from T1 to T10 were summarized. Results The transverse process-lamina concave, superior ridge of transverse process and outer edge of the lamina of middle-upper thoracic vertebral characterized by obvious and constant anatomical marks with less proliferative. The left and right PMD, CMD, HLW, PCD, EPLR, and PRD were (14.14±2.63) mm and (14.59±2.58) mm, (10.45±2.12) mm and (10.51±2.02) mm, (16.30±1.48) mm and (16.39±1.61) mm, (4.56±1.03) mm and (4.47±0.94) mm, 0.35±0.26 and 0.33±0.30, and (-1.62±1.90) mm and (-1.63±1.44) mm, respectively. There was no significant difference in the measured values between the two sides of the above parameters (P>0.05). Except that the difference between PMD and HLW in T2 was not significant (P>0.05), the differences between basic parameters in the other segments were statistically significant (P<0.05). PCD of T1 to T10 showed a trend of decrease first and then significant increases in T1, T2, T9, and T10 compared with in T3-T8 (P<0.05). EPLR of T1-T10 showed a trend of increase first and then decrease, in which EPLR in T1, T2 and T3 were significantly lower than in the following any segments (P<0.01), and in the T4-T6 and T10 were significantly lower than in T7-T9 (P<0.01). PRD of T1-T10 showed a trend of increase first and then decrease, in which the PRD in T1, T2 and T3 were significantly lower than in the following any segments, and in the T4-T6 were lower than T7-T10 (P<0.01). Conclusion There is constant orientation relationship and changing rules of PSEP in the middle-upper thoracic vertebrae on the posterior bony landmarks, such as transverse process-lamina concave, superior ridge of transverse process and outer edge of the lamina, and it can serve as a new clinical choice.
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<p><b>OBJECTIVE</b>To investigate the skill and evaluate the accuracy for application of guide combined with probing the internal wall of pedicle screw trajectory for subaxial cervical pedicle screw placement.</p><p><b>METHODS</b>Subaxial cervical pedicle screw was inserted in 11 patients by the guide combined with probing the internal wall of pedicle screw trajectory from January 2014 to October 2016, including 7 males and 4 females with an average age of 48.1 years(ranged 32 to 63 years). There were 4 cases with cervical spondylotic myelopathy, 4 with fracture and dislocation of cervical vertebrae, 1 with cervical cord injury without fracture and dislocation, and 2 with atlantoaxialfracture and dislocation. The target pedicle's diameter, optimal entry point, sagittal angle and cross-sectional angle were measured by CT before operation. During operation, the pedicle screw inserted angle was controlled by a guide with a self-designed protractor and probed the internal wall of pedicle screw trajectory as medial safety margin of insertion screw. The accuracy of cervical pedicle screw was evaluated by CT with classification of four grades and assessed whether there was injury of spine cord or vertebral artery postoperatively.</p><p><b>RESULTS</b>Seventy-one cervical pedicle screws were placed among 11 patients, and no one had been found with clinical manifestations of injury of spine cord (or nerve root) or vertebral artery after operation. According to postoperative CT scan for evaluating the grade of screw position, 52 screws were in grade 0, 13 in grade 1, 4 in grade 2, 2 in grade 3, and 91% (65/71) located in good position. In total, 6 screws were incorreted in placement, and 4 cases of them broke medial wall and 2 cases broke lateral wall.</p><p><b>CONCLUSIONS</b>The method of probing the internal wall of pedicle screw trajectory for subaxial cervical pedicle screw placement is safe and reliable, but the studying curve is long. Probing the internal wall of pedicle screw trajectory and controlling the insertion angle by guide with a protractor are key points of this technology.</p>
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Objective To investigate the clinical application of pedicle screw placement technique for pelvic external fixation.Methods A retrospective review was made on 63 patients (37 males and 26 females;23-67 years of age) managed with anterior or combined anterior and posterior external fixation of pelvic fracture between February 2011 and May 2014.According the ways of screw insertion,the study was divided into two groups:observation group (screw was inserted using the pedicle screw placement technique,n =36) and control group (screw was inserted directly,n =27).Tile fracture classification was 11 patients with type B1,7 type B2,7 type B3,5 type C1,3 type C2 and 3 type C3 in observation group,and 9 patients with type B1,7 type B2,4 type B3,4 type C1,2 type C2 and 1 type C3 in control group.Operation time,rate of the penetration,X-ray fluoroscopy times,screw loosening rate,and postoperative complication rate were documented.Radiologic evaluation of the pelvis was detected with the Matta' s criteria.At the final follow-up,functional evaluation of the pelvis was evaluated with the score proposed by Cole et al.Results Period of follow-up was (14.7 ± 3.2)months in observation group and was (13.8 ± 3.1) months in control group.A total of 190 screws were placed in observation group and 138 screws in control group.Better results were found in observation group than in control group with respect to operation time [(18.8 ± 4.1) min vs.(22.6 ± 5.4) min],rate of the penetration (1.6％ vs.8.7％),X-ray fluoroscopy times (1.6 ± 0.8 vs.2.2 ± 0.9),and screw loosening rate (1.6％ vs.6.5％).There were no significant difference between observation and control groups in percentage of good to excellent reduction(89％ vs.85％) and function score [(35.6 ±3.0) points vs.(34.8 ± 3.9) points] (P ＞ 0.05).After operation,3 patients with lateral femoral cutaneous nerve paralysis and none with wouud infection were found in observation group;3 patients with lateral femoral cutaneous nerve paralysis and one patient with wound infection were found in control group.Conclusion Either the pedicle screw placement technique or conventional technique achieves satisfactory clinical effect,but the former owns better results in operation time,screw insertion accuracy,fluoroscopy frequency and rate of screw loosening,suggesting a fast,safe,and effective screw placement method in pelvic external fixation that should be widely applied.
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Pedicle screw fixation is biomechanically most reliable for reconstruction of the cervical spine, which can ef?fectively restore cervical sagittal profiles, provide rigid fixation and higher fusion rate. Because of the large individual differ?ences in cervical pedicle, vertebral artery and nerve root, preoperative evaluation should be individualized. Cervical pedicle screw techniques include freehand technique and the computer-assisted navigation technology developed recently. Although complications associated with cervical pedicle screw fixation cannot be completely obviated, they can be minimized by com?bination of sufficient preoperative imaging studies of the pedicles and meticulous surgical techniques of screw placement. Cervical pedicle screw fixation techniques have been used in the treatment of various cervical disorders, with fewer complica?tions and good clinical efficacy, and a wide range of clinical applications.
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OBJECTIVE: To evaluate the anatomical feasibility of 3.5 mm screw into the cervical spine in the pediatric population and to establish useful guidelines for their placement. METHODS: A total of 37 cervical spine computerized tomography scans (24 boys and 13 girls) were included in this study. All patients were younger than 10 years of age at the time of evaluation for the period of 2007-2011. RESULTS: For the C1 screw placement, entry point height (EPH) was the most restrictive factor (47.3% patients were larger than 3.5 mm). All C2 lamina had a height larger than 3.5 mm and 68.8% (51/74) of C2 lamina had a width thicker than 3.5 mm. For C2 pedicle width, 55.4% (41/74) of cases were larger than 3.5 mm, while 58.1% (43/74) of pedicle heights were larger than 3.5 mm. For pedicle width of subaxial spine, 75.7% (C3), 73% (C4), 82.4% (C5), 89.2% (C6), and 98.1% (C7, 1/54) were greater than 3.5 mm. Mean lamina width of subaxial cervical spine was 3.1 (C3), 2.7 (C4), 2.9 (C5), 3.8 (C6), and 4.0 mm (C7), respectively. Only 34.6% (127/370) of subaxial (C3-7) lamina thickness were greater than 3.5 mm. Mean length of lateral mass for the lateral mass screw placement was 9.28 (C3), 9.08 (C4), 8.81 (C5), 8.98 (C6), and 10.38 mm (C7). CONCLUSION: C1 lateral mass fixation could be limited by the morphometrics of lateral mass height. C2 trans-lamina approach is preferable to C2 pedicle screw fixation. In subaxial spines, pedicle screw placement was preferable to trans-lamina screw placement, except at C7.
Subject(s)
Child , Humans , SpineABSTRACT
OBJECTIVE: A variety of different pedicle screws entry point techniques are used for the lumbar pedicle screws placement. This study reported Kim's entry point of lumbar pedicle screws with free hand technique and the accuracy of this technique. METHODS: We retrospectively reviewed the 584 cases with free hand placed lumbar pedicle screw placement. The diagnosis included 491 cases with degenerative spine, 59 cases with trauma, 29 cases with metastatic disease, and 5 cases with scoliosis. A total of 2601 lumbar pedicle screws were placed, and the entry points of lumbar pedicle screws were the junction of proximal edge of transverse process and lamina. Incidence and extent of cortical breach by misplaced pedicle screw was determined by review of intra-operative and post-operative radiographs and/or computed tomography. RESULTS: Among the total 2601 lumbar free hand placed pedicle screws, 114 screws (4.4%) in 79 patients (13.5%) were repositioned screws with suspected screw malposition during operation, and 37 screws (1.4%) in 31 patients (5.3%) were identified as moderate to severe breaching the pedicle after post-operative imaging studies. Among the patient with malpositioned screws, 3 patients showed nerve irritation sign of the lesion, and 2 cases were symptom improved after nerve block and conservative management, and 1 case was removed the screw after the failure of the treatment. CONCLUSION: Free hand pedicle screw placement based on external landmark with the junction of proximal edge of transverse process and lamina showed acceptable safety and accuracy and avoidance of radiation exposure.
Subject(s)
Humans , Hand , Incidence , Nerve Block , Retrospective Studies , Scoliosis , SpineABSTRACT
Thoracic pedicle screw fixation techniques are still controversial for thoracic deformities because of possible complications including neurologic deficit. Methods to aid the surgeon in appropriate screw placement have included the use of intraoperative fluoroscopy and/or radiography as well as image-guided techniques. We describe our technique for free hand pedicle screw placement in the thoracic spine without any radiographic guidance and present the results of pedicle screw placement analyzed by computed tomographic scan in two human cadavers. This free hand technique of thoracic pedicle screw placement performed in a step-wise, consistent, and compulsive manner is an accurate, reliable, and safe method of insertion to treat a variety of spinal disorders, including spinal deformity.