Morphometric study and anatomical variation with its incidence of foramina transversaria on the lower cervical vertebrae / Estudio morfométrico y variación anatómica con la incidencia de forámenes transversos en las vértebras cervicales inferiores

SUMMARY: Anatomical variation of the foramina transversaria (FT) is associated with vertebral neurovascular symptoms and can cause complications after lower spine surgery, especially cervical pedicle screw (CPS) insertion. FT variation has been documented and classified in various populations, as this information can help increase cervical stability in subaxial vertebral surgery. Although the morphometry of the upper cervical spine in Thai populations has been reported, there have yet been no studies examining the features of FT. The FT of dried cervical spines (C3-C7; left and right side; n = 107, male = 53 and female = 54) were examined for morphological variation, and their anteroposterior (AP) and transverse (T) diameters were measured using a digital vernier caliper. Morphometric data and variations were compared by sex and lateral side. It was that the C3-C6 FT in both sexes were round, and the C7 FT was elliptical with an oblique right side. FT diameters did not differ significantly by sex except for the AP diameters of C6-C7 and for T diameters of C4 and C7. The left AP diameters of C3-C6 were significantly longer than the right, as were the T diameters of C4 and C7 FT. Additionally, T diameter was significantly longer than that of the AP, except that of the left C6 in male spines, which did not differ from the AP. Most FT examined were round. These findings should be considered in the provisional diagnosis of vertebral neurovascular symptoms caused by FT variation as well as that of neurovascular damage after cervical pedicle screw placement.

La variación anatómica del foramen transverso (FT) se asocia con síntomas neurovasculares vertebrales y puede causar complicaciones después de la cirugía de columna cervical inferior, especialmente la inserción de tornillos pediculares cervicales (TPC). La variación del FT se ha documentado y clasificado en varias poblaciones, ya que esta información puede ayudar a aumentar la estabilidad cervical en la cirugía vertebral subaxial. Aunque se ha informado sobre la morfometría de la columna cervical superior en poblaciones tailandesas, aún no se han realizado estudios que examinen las características de FT. Se examinó la variación morfológica del FT de vértebras cervicales secas (C3-C7; lado izquierdo y derecho; n = 107, hombres = 53 y mujeres = 54), y se midieron sus diámetros anteroposterior (AP) y transverso (T) usando un pie de metro digital. Se compararon datos morfométricos y variaciones por sexo y lado. Los FT de C3-a C6 en ambos sexos eran redondos, y el FT C7 era elíptico con el lado derecho oblicuo. Los diámetros del FT no difirieron significativamente por sexo excepto para los diámetros AP de C6- C7 y para los diámetros transversos de C4 y C7. Los diámetros AP izquierdos de C3-C6 eran significativamente más largos que los del lado derecho, al igual que los diámetros transversos de C4 y C7. Además, el diámetro transverso fue significativamente mayor que el AP, excepto el C6 izquierdo en las vértebras de hombres, que no difirió del AP. La mayoría de los FT examinados eran redondos. Estos hallazgos deben ser considerados en el diagnóstico provisional de síntomas neurovasculares vertebrales causados por la variación del FT, así como en el de daño neurovascular tras la colocación de tornillos pediculares cervicales.

Percutaneous pedicle screw fixation combined expandable tubular retractor in the treatment of spinal metastases / 北京大学学报(医学版)

OBJECTIVE@#To investigate the effectiveness of percutaneous pedicle screw fixation combined expandable tubular retractor in the treatment of patients with spinal metastases.@*METHODS@#In the study, 12 patients of spinal metastases treated with percutaneous pedicle screw fixation combined expandable tubular retractor in our hospital were retrospectively reviewed between June 2017 and October 2019. Among the 12 patients, 9 were males and 3 were females; the median age was 62.5 years [(65.1±2.9) years]. The decompression segment of 7 patients was located at the lower thoracic spine (including 1 patient with incomplete paraplegia) and the decompression segment of 5 patients was located at the lumbar spine; Tomita score was 6.0±0.6. Perioperative data of the patients were reviewed. Visual analog scale (VAS score), Karnofsky score, and Eastern Cooperative Oncology Group (ECOG) score were compared before and after surgery. The patient's survival, adjuvant treatment, and internal fixation failure were observed in the follow-up period.@*RESULTS@#All the 12 patients had a successful operation with percuta-neous pedicle screw fixation combined expandable tubular retractor. The average operative time, blood loss, and blood transfused of the patients were (247.0±14.6) min, (804.2±222.3) mL and (500.0±100.0) mL, respectively. The average amount of drainage was (240.8±79.3) mL. Drainage tubes were pulled out early postoperative [(3.2±0.3) d], allowing early mobilization. The patients discharged (7.8±0.8) d postoperative. All the patients were followed up for 6-30 months, and the average overall survival time was (13.6±2.4) months. During the follow-up period, 2 patients experienced screw displacement, the internal fixation was stable after conservative treatment and no revision surgery was performed. The VAS of the patients was 7.1±0.2 before surgery, which decreased to 2.3±0.1 and 2.8±0.4 at 3 and 6 months after surgery (P < 0.05). The Karnofsky score of the patients was 59.2±1.9 before surgery, which increased to 75.0±1.9 and 74.2±3.1 at 3 and 6 months after surgery (P < 0.05). The ECOG of the patients was 2.3±0.2 before surgery, which decreased to 1.7±0.1 and 1.7±0.2 at 3 and 6 months after surgery (P < 0.05).@*CONCLUSION@#For selected patients with spinal metastases, minimally invasive surgical treatment of spinal metastases (percutaneous pedicle screw internal fixation combined with expandable tubular retractor) can effectively relieve the clinical symptoms and improve the quality of life, with satisfactory clinical outcome.

O-arm real-time guidance in cervical pedicle screw fixation / 中国骨伤

OBJECTIVE@#To explore the technical aspects of the accuracy of cervical pedicle screw placement with O-arm guidance.@*METHODS@#The clinical data of 21 patients who underwent cervical pedicle screw fixation by O-arm real-time guidance from December 2015 to January 2020 were analyzed retrospectively. There were 15 males and 6 females, aged from 29 to 76 years old with an average of (45.3±11.5) years. The postoperative CT scan was utilized to evaluate the placement of the pedicle screw and classified according to the Gertzbein and Robbins classification.@*RESULTS@#A total of 132 pedicle screws were implanted in 21 patients, 116 at C3-C6 and 16 at C1 and C2. According to Gertzbein & Robbins classification, the overall breach rates were found to be 11.36% (15/132) with 73.33% (11 screws) Grade B, 26.67% (4 screws) Grade C, and no Grade D or E screw breaches. There were no pedicle screw placement related complications at final follow-up.@*CONCLUSION@#The application of O-arm real-time guidance technology can make cervical pedicle screw placement reliable. High accuracy and better intra-operative control can increase surgeon's confidence in using cervical pedicle instrumentation. Considering the high-risk nature of anatomical area around cervical pedicle and the possibility of catastrophic complications, the spine surgeon should have sufficient surgical skills, experience, ensures stringent verification of the system, and never relies solely on the navigation system.

Dynamic Fixation versus Static Screw Fixation for Syndesmosis Injuries in Pronation External Rotation Ankle Fractures: A Retrospective Case Control Study

@#Introduction: The current standard treatment for ankle syndesmosis injury is static screw fixation. Dynamic fixation was developed to restore the dynamic function of the syndesmosis. The purpose of this study was to determine that which of static screw fixation and dynamic fixation is better for treatment of ankle syndesmosis injury in pronationexternal rotation fractures. Materials and methods: Thirty patients were treated with dynamic fixation (DF group) and 28 patients with static screw fixation (SF group). The primary outcome was Olerud–Molander Ankle Outcome Score. The secondary outcome were Visual Analogue Scale score and American Orthopedic Foot and Ankle Society score, radiographic outcomes, complications and cost effectiveness. To evaluate the radiographic outcome, the tibiofibular clear space, tibiofibular overlap, and medial clear space were compared using the pre-operative and last follow-up plain radiographs. To evaluate the cost effectiveness, the total hospital cost was compared between the two groups Results: There was no significant difference in primary outcome. Moreover, there were no significant difference in secondary outcome including Visual Analogue Scale score and American Orthopedic Foot and Ankle Society score and radiographic outcome. Two cases of reduction loss and four cases of screw breakage were observed in the SF group. No complication in the DF group was observed. Dynamic fixation was more cost effective than static screw fixation with respect to the total hospital cost. Conclusion: Although dynamic fixation provided similar clinical and radiologic outcome, dynamic fixation is more cost effective with fewer complications than static screw fixation in ankle syndesmosis injury of pronation-external rotation fractures.

Morphometric Assessment of Pedicles of Indian Adult Lumbar Vertebrae: A Cross Sectional Study

Introduction: Lumbar vertebral column is exposed to various kinds of stress during locomotion. In erect posture weight transmitted through posterior part including pedicles. This causes deformities of this region as the age advances in many individuals. Proper correction of deformity is challenging. There have been advances in spinal fusion procedures and interspinous implantation of devices including pedicle screws. Use of unsuitable dimensions of screw may cause problem of destruction of pedicle. Correct metricular data of pedicle is necessary for choice of appropriate screw size. Aims and Objectives: 1) To measure the various dimensions in Indian adult human lumbar vertebral pedicles. 2) To prepare data of lumbar pedicles useful in various surgical procedures. Material and Methods: A Cross-sectional study was done on 45 dry, fully ossified human lumbar vertebral sets. The bones were grouped into typical (L1 to L4) and atypical (L5) lumbar vertebrae. The dimensions measured included pedicle length, height, thickness, axial length, transverse and sagittal angles. ‘Digital Vernier Caliper’ and Protractor were used. The data was analyzed statistically. Results: The mean length, height and thickness of typical vertebral pedicles increases gradually. In atypical (L5), pedicle thickness suddenly increases. The transverse angle of pedicle elevated gradually from L1 to L4 but at L5, it abruptly increased. Conclusions: The study reported significant differences in several dimensions of pedicles of typical as well as atypical lumbar vertebrae. These differences should be considered by neurosurgeons.

Morphometric Analysis of Vertebral Artery Groove in Human Atlas Vertebra in South Indian Population

Introduction: Recent trends like pedicle screws and other instrumentation of cervical vertebra are on the rise. However, proximity of vertebral artery coursing in vertebral artery groove (VAG) on the superior surface of the posterior arch of atlas poses a unique challenge to surgeons performing these procedures. Such vascular injuries though rare, are not uncommon and may pose immediate to delayed complications. Radiological studies of atlas vertebra & VAG are being extensively done with CT and MR Angiography, but morphometric studies of VAG in atlas vertebra in South Indian population is lacking. Aims: To understand the morphology and dimensions of the vertebral artery groove and its variations if any, in dry atlas vertebra of South Indian population. Settings and Design: Descriptive observational study Methods and Material: 50 dried adult human atlas vertebra of unknown age & sex from the Anatomy Department, PSGIMS & R, Coimbatorewere studied. Intact cervical vertebrae without any degenerative or traumatic disorders were included. The morphometry of VAG and its distance from midline were evaluated through six linear measurements.The parameters were inner and outer lengths of the groove, width & thickness of the groove and the distance of its medial most and lateral most edges from the midline on both sides. Statistical analysis used: SPSS software Results: There is no statistically significant difference between mean values on right and left side for inner length, outer length, width and thickness of vertebral artery groove. The mean inner and outer distance of the vertebral artery groove from the midline on the right is higher than the left. Conclusions: The present study provides morphometric data of VAG & recommends a safe zone of 11.82 mm from midline for instrumentation in posterior spinal surgeries to minimize vertebral artery injuries.

TiRobot-assisted biplane double-supported screw fixation for femoral neck fractures in middle-aged and young patients / 中华创伤骨科杂志

Objective:To investigate the efficacy of biplane double-supported screw fixation in the treatment of femoral neck fractures in the middle-aged and young patients with the assistance of TiRobot.Methods:A retrospective analysis was conducted of the 28 young and middle-aged patients with femoral neck fracture who had been treated by biplane double-supported screw fixation at Department of Traumatic Orthopaedics, Puren Hospital from January 2021 to January 2022. According to the intraoperative use of TiRobot-assistance in the nail placement, they were divided into 2 even groups ( n=14). In the observation group where a TiRobot was used to assist nail placement, there were 6 males and 8 females, with an age of (44.1±8.7) years. In the control group where nail placement was monitored by conventional C-arm fluoroscopy, there were 7 males and 7 females, with an age of (48.8±8.0) years. The 2 groups were compared in terms of operation time, intraoperative fluoroscopy times, intraoperative blood loss, hospitalization time, fracture healing time, postoperative complications and hip function 6 months after operation. Results:There was no significant difference in the preoperative general data between the 2 groups, showing comparability ( P>0.05). The operation time, intraoperative fluoroscopy times, intraoperative blood loss and hospitalization time in the observation group were significantly less than those in the control group [(66.5±3.7) min versus (77.1±3.9) min, (12.8±1.6) times versus (18.7±2.5) times, 3.5 (2.8, 4.0) mL versus 26.0 (24.0, 27.3) mL, (9.4±1.2) d versus (11.3±1.2) d] ( P< 0.05). During the follow-up period, the fractures healed well in both groups with no obvious complications. The fracture healing time in the observation group was (6.1±1.2) months, insignificantly shorter than that in the control group [(6.3±1.1) months] ( P>0.5). The Harris hip score 6 months after operation in the observation group (92.6±2.7) was significantly higher than that in the control group (90.6±1.9) ( P< 0.05). Conclusions:In the treatment of young and middle-aged patients with femoral neck fracture, the biplane double-supported screw fixation assisted by a TiRobot can shorten operation time and hospitalization time, and reduce the intraoperative fluoroscopy times and intraoperative blood loss for the patients, more conducive to the functional recovery of the hip joint, leading to better surgical efficacy than the nail placement monitored by conventional C-arm fluoroscopy.

Detección de tornillos prominentes en la articulación radiocarpiana mediante la proyección tangencial del escafoides dorsal / Detection of protruding screws in the radiocarpal joint using the "scaphoid skyline view"

INTRODUCCIÓN: Una de las complicaciones de la osteosíntesis retrógrada del escafoides es la protrusión del tornillo en la articulación radiocarpiana, dada la limitada visualización intraoperatoria del polo proximal del escafoides con las proyecciones tradicionales. OBJETIVO: Evaluar la capacidad de una nueva proyección radiológica, la proyección "tangencial del escafoides dorsal", o TED, para identificar tornillos prominentes radiocarpianos durante la osteosíntesis retrógrada del escafoides con tornillos canulados. MATERIALES Y MÉTODOS: Estudio cadavérico en muñecas frescas congeladas. Se introdujo en el escafoides un tornillo canulado con técnica retrógrada estándar. La proyección TED fue evaluada en 5 muñecas, con angulaciones del antebrazo de 15°, 30° y 45° para definir la mejor visualización del polo proximal del escafoides y del tornillo. Se comparó la capacidad para identificar la prominencia del tornillo en el polo proximal de la proyección TED de 30° con 5 proyecciones tradicionales de escafoides en 9 muñecas. El tornillo se posicionó a nivel de la superficie del escafoides, y luego se avanzó a intervalos de 0,5 mm bajo visualización directa por artrotomía dorsal. Tras cada intervalo, se repitieron todas las proyecciones para determinar su capacidad de detectar tornillos prominentes en el escafoides. RESULTADOS: La mejor visualización del polo proximal del escafoides se logró con la proyección TED de 30°. Al comparar la proyección TED de 30° y las tradicionales, con la TED se logró identificar tornillos prominentes a 0,8 mm promedio, seguida por la proyección posteroanterior con cubitalización y extensión a 1.3 mm (p » 0.014), con una alta precisión y correlación interobservador de estas proyecciones. CONCLUSIÓN: La proyección TED demostró ser la más sensible para detectar tornillos prominentes en la articulación radiocarpiana. Su uso rutinario podría evitar complicaciones durante la osteosíntesis.

INTRODUCTION: One of the complications of the retrograde percutaneous scaphoid fixation is the protrusion of the screw in the radiocarpal joint due to the limited intraoperative visualization of the proximal pole of the scaphoid with the traditional radiographic views. OBJETIVE: To evaluate the sensitivity of a novel radiographic view (the skyline scaphoid view, SSV) to detect screws protruding in the radiocarpal joint during the retrograde fixation of the scaphoid. MATERIALS AND METHODS: We studied nine cadaverous fresh frozen wrists. A retrograde cannulated screw was inserted in the scaphoid. To validate the SSV, 5 wrists were studied, comparing 3 forearm angulations (15°, 30° and 45°) to get the best visualization of the proximal pole and screw. We compared the ability to identify the protrusion of the screw in the proximal pole of the 30° SSV with that of 5 standard scaphoid radiographic views in 9 wrists. The screw was positioned at the level of the surface of the scaphoid, and was sequentially protruded in 0.5 mm increments, with direct visualization of its tip through a dorsal capsulotomy. After each increment, all views were repeated to determine if they were able to detect screws projecting from the scaphoid. RESULTS: The best visualization of the proximal pole of the scaphoid was found with the 30° SSV. In the comparison of the 30° SSV and the standard views, with the SSV we were able to identify the protrusion of the screws at an average of 0.8 mm, followed by the posterior-anterior view with ulnar deviation and extension at 1.3 mm (p » 0.014), with high precision and interobserver agreement regarding these views. CONCLUSION: The SSV was the most sensitive view to detect protruding screws in the proximal pole of the scaphoid. Its routine use could avoid complications during osteosynthesis.

Meta-analysis of the efficacy of platelet-rich plasma combined with cannulated screw fixation for the treatment of femoral neck fracture / 中国组织工程研究

BACKGROUND: Numerous studies have reported the effectiveness of platelet-rich plasma in promoting and improving bone healing. However, due to the limitations of methods, follow-up and study design, many orthopedicians still doubt the clinical effect of platelet-rich plasma combined with cannulated screw fixation in the treatment of fracture and nonunion. OBJECTIVE: To evaluate the difference in efficacy between platelet-rich plasma combined with cannulated screw fixation and simple cannulated screw fixation in the treatment of femoral neck fracture using meta-analysis system. METHODS: The Cochrane Library, PubMed, Wanfang Medical Network, China National Knowledge Infrastructure, and China Journal Full-text Database were used to search and collect clinical randomized controlled trials of platelet-rich plasma combined with cannulated screw fixation and cannulated screw fixation for the treatment of femoral neck fractures. Two reviewers independently evaluated the quality of the included studies, extracted data and checked each other. Meta-analysis was utilized to analyze the collected data with RevMan 5. 3 software. RESULTS AND CONCLUSION: (1) Seven clinical randomized controlled trials were selected for meta-analysis, totally 760 patients. There were 380 cases undergoing platelet-rich plasma combined with cannulated screw fixation and 380 cases undergoing cannulated screw fixation. (2) The meta-analysis showed that compared with the cannulated screw fixation group, fracture healing time was shorter [MD=-1. 86, 95%CI(-2. 97, -0. 75), P=0. 001]; healing rate was higher [OR=6. 51, 95%CI(3. 36, 12. 62), P < 0. 000 01]; necrosis rate was lower [OR=0. 25, 95%CI(0. 15, 0. 44), P < 0. 000 01]; Harris scores at 1, 3, 6, 9, and 12 months postoperatively were higher [MD=4. 95, 95%CI(4. 12, 5. 77), P < 0. 000 01; MD=19. 78, 95%CI(18. 45, 21. 11), P < 0. 000 01; MD=17. 16, 95%CI(10. 39, 23. 92), P < 0. 000 01; MD=12. 66, 95%CI(10. 60, 14. 71), P < 0. 000 01; MD=10. 17, 95%CI(5. 98, 14. 36), P < 0. 000 01] in the platelet-rich plasma combined with cannulated screw fixation group. (3) Platelet-rich plasma combined with cannulated screw fixation for femoral neck fracture is more effective than that of cannulated screw fixation alone. Combined treatment can accelerate the fracture healing of patients, improve the healing rate, reduce necrosis rate, and promote the recovery of postoperative hip joint function.

Comparison of the short-segment and long-segment cement-augmented pedicle screw fixation for osteoporotic thoracolumbar fracture: A finite element study / 中国组织工程研究

BACKGROUND: Pedicle screw fixation combined with cement-augmented is an effective method for the treatment of severe osteoporotic vertebral fractures, but there is no uniform standard. The range of fixed segments is one of the focus of clinical controversy. OBJECTIVE: To establish a three-dimensional finite element model of the short-segment and long-segment cement-augmented pedicle screw fixation for osteoporotic thoracolumbar fracture, and to analyze the biomechanical characteristics of adjacent segment structures, fractured vertebral bodies and internal fixation devices. METHODS: The T 9 -L 5 segment of a volunteer without obvious degenerative disease was selected for CT scan. The CT images of Dicom format were obtained, and the engineering software was imported to establish a finite element geometric model to simulate the thoracolumbar fracture and the short-segment and long-segment cement-augmented pedicle screw fixation models. The relevant material parameters were set and the biomechanical characteristics of the two groups were compared and analyzed. RESULTS AND CONCLUSION: (1) The stress on the vertebrae was mainly concentrated on the periphery of the vertebral body and the small facet of the attachment. In the four directions flexion, extension, left-sided and right-sided curvature, the maximum stress of the proximal and distal adjacent vertebrae in the long-segment group was greater than that in the short-segment group. The stress of the intervertebral disc was mainly concentrated in the peripheral annulus. The maximum stress of the proximal and distal adjacent intervertebral discs was greater in the short -segment than in the long-segment, but the high stress area of the long-segment was larger than that of the short-segment. Therefore, long-segment fixation might accelerate the degeneration of adjacent segments.(2) The vertebral bodies of the long-segment group and the short-segment group were displaced to different extents, and the displacements in the left and right directions were the most obvious. In the six movement directions, the displacement and maximum stress of the injured segment of the short-segment group were greater than those of the long-segment group. So the long-segment fixation could better maintain the stability of the fractured vertebra. (3) The stress on the internal fixing device was mainly concentrated on the screws at both ends and the part of the rod. The maximum stress of the long-segment group was greater than that of the short-segment group, but the main stress area of the screws at both ends was smaller compared with the short- segment group.and the displacements in the left and right directions were the most obvious. In the six movement directions, the displacement and maximum stress of the injured segment of the short-segment group were greater than those of the long-segment group. So the long- segment fixation could better maintain the stability of the fractured vertebra. (3) The stress on the internal fixing device was mainly concentrated on the screws at both ends and the part of the rod. The maximum stress of the long-segment group was greater than that of the short-segment group, but the main stress area of the screws at both ends was smaller compared with the short-segment group.and the displacements in the left and right directions were the most obvious. In the six movement directions, the displacement and maximum stress of the injured segment of the short-segment group were greater than those of the long-segment group. So the long- segment fixation could better maintain the stability of the fractured vertebra. (3) The stress on the internal fixing device was mainly concentrated on the screws at both ends and the part of the rod. The maximum stress of the long-segment group was greater than that of the short-segment group, but the main stress area of the screws at both ends was smaller compared with the short-segment group.So the long-segment fixation could better maintain the stability of the fractured vertebra. (3) The stress on the internal fixing device was mainly concentrated on the screws at both ends and the part of the rod. The maximum stress of the long-segment group was greater than that of the short-segment group, but the main stress area of the screws at both ends was smaller compared with the short-segment group. So the long-segment fixation could better maintain the stability of the fractured vertebra. (3) The stress on the internal fixing device was mainly concentrated on the screws at both ends and the part of the rod. The maximum stress of the long-segment group was greater than that of the short-segment group, but the main stress area of the screws at both ends was smaller compared with the short-segment group.

Computer navigation-assisted surgical treatment with osteotomy for upper thoracic kyphosis / 中国组织工程研究

BACKGROUND: The biomechanical characteristics of kyphosis of the upper thoracic vertebra are unique. Decompression and internal fixation are relatively difficult. Previous relevant studies and case reports are few, and there is a lack of research on correction of kyphosis of the upper thoracic section with the assistance of computer navigation. OBJECTIVE: To explore the clinical effect of computer navigation-assisted surgical treatment of upper thoracic kyphosis by screws and osteotomy. METHODS: Totally 18 patients with kyphotic deformity of the spine (T1-T4) were admitted in Beijing Jishuitan Hospital from June 2011 to June 2018, including 11 males and 7 females, aged 12 to 59 years. They were all treated with computer-assisted surgical treatment with PSO osteotomy. Local Cobb angle of the upper thoracic kyphosis was determined during final follow-up. Cervical visual analogue scale, Nurick grades, EMS scores and satisfaction of the surgery were evaluated. This study was approved by the Ethics Committee of Beijing Jishuitan Hospital (approval No. 201709-23). RESULTS AND CONCLUSION: (1) A total of 18 patients were followed up for 6-90 months at an average time of (33. 73±35. 33) months. (2) The local Cobb angle of 18 patients at the last follow-up was significantly improved [(47. 32±9. 92)°, (24. 01 ±7. 64)°, P < 0. 001]. Cervical visual analogue scale score at the last follow-up was significantly lower than that before surgery (3. 64±2. 16, 0. 73±1. 01, P< 0. 001). Nurick score at the last follow-up was significantly lower than that before surgery (2. 91 ±0. 94, 0. 82±1. 47, P < 0. 001). EMS score at the last follow-up was significantly higher than that before surgery (14. 45±0. 93), 17. 09±1. 45, P< 0. 001). (3) Surgical satisfaction was excellent (n=16) or good (n=2). (4) At the last follow-up, 18 patients had no adverse reactions related to implants, and the wound healed well without screw loosening. (5) The results showed that reasonable osteotomy correction with computer-assisted surgery and PSO osteotomy could effectively treat kyphosis of upper thoracic segment.

Biomechanical characteristics of transforaminal lumbar interbody fusion combined with different pedicle screw fixation methods in single-segment lumbar spine and adjacent segments / 中国组织工程研究

BACKGROUND: Decompression-fixation-fusion is the key to spinal surgery since early effective fixation to achieve intervertebral fusion can restore spinal stability in lumbar degenerative disease. OBJECTIVE: To compare biomechanical stability of fusion segment and adjacent segments of bilateral pedicle screw fixation, unilateral pedicle screw fixation and unilateral pedicle screw combined with contralateral translaminar facet screw fixation under transforaminal lumbar interbody fusion. METHODS: Eighteen fresh calf L3-5 specimens were selected. Different forms of fixation were conducted under transforaminal lumbar interbody fusion. The specimens were divided into group A (complete specimens) and group B (bilateral pedicle screws), group C (unilateral pedicle screws), and group D (unilateral pedicle screw combined with contralateral translaminar facet screw). The range of motion of adjacent segment L3-4 and fusion segment L4-5 in six directions of backward extension, forward bending, left bending, right bending, left rotation and right rotation and the stiffness of fusion segment L4-5 were tested. RESULTS AND CONCLUSION: (1) For the range of motion of fusion segment L4-5, the stability was highest in the group B in six directions, followed by group D, which showed similar results in rotation in the group B (P > 0.05). The stability of right curvature and left rotation in group C was insufficient, and there was no significant difference in range of motion between group A and group C (P > 0.05). The range of motion in group A was largest and the stability was worst in the six motion directions. (2) For the stiffness value of fusion segment L4-5, the stiffness value of group B was largest in six directions, which was significantly different from other groups (P 0.05). There was no significant difference between group C and group A in the range of motion of six directions (P > 0.05). (4) The results showed that the motion ramge of unilateral pedicle screw fixation in the right and left rotation directions was large in the early stage, which was close to that of the complete specimen group. There is a shortage of stability, so we need to use it carefully and grasp the indications strictly. Unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation improves the disadvantages of asymmetric fixation of unilateral pedicle screw, increases the stability of rotation and lateral bending, and avoids the influence of bilateral pedicle screw fixation on adjacent segments, thus becoming an effective clinical surgical treatment.

Percutaneous pedicle screw fixation combined with vertebroplasty for the treatment of Genant Ⅲ degree osteoporotic vertebral compression fractures / 中国骨伤

OBJECTIVE@#To investigate the clinical effect of percutaneous pedicle screw fixation(PPSF) combined with percutaneous vertebroplasty (PVP) in the treatment of Genant Ⅲ degree osteoporotic vertebral compression fractures (OVCFs).@*METHODS@#The hospitalized 83 patients with Genant Ⅲ degree OVCFs treated by PPSF combined with PVP from June 2015 to June 2017 were retrospectively analyzed, and 83 patients treated by PVP alone from January 2013 to June 2016 were randomly selected as the control group. There were 19 males and 64 females with an average age of (73.6±11.0) years in combined group with treatment of PPSF and PVP. There were 15 malesand 68 females with an average age of (75.5±10.6) years in control group. The anterior edge height of the vertebral body and Cobb angle before operation, 1 day, and 6, 12, 24 months after operation were compared between two groups. Visual analogue scale(VAS) and Oswestry Disability Index (ODI) were used to assess the pain level and daily lumbar dysfunction for patients, respectively. The complications were observed.@*RESULTS@#The follow-up time of all patients was more than 2 years. The combined group and control group were (24.3±10.2) months and (27.5±14.8) months, respectively. There were no statistically significant differences in the anterior edge height of the vertebral body and Cobb angle at 1 day after surgery between two groups (>0.05), and there were statistically significant differences at 6, 12, 24 months after surgery between two groups (<0.01). The difference in ODI and VAS scores at 6 and 12 months after operation between two groups was statistically significant (<0.05). Postoperative complications incontrol group were higher than those in the combined group.@*CONCLUSION@#PPSF combined with PVP for the treatment of Genant Ⅲ degree OVCFs is superior to PVP alone in terms of vertebral height loss, patient satisfaction, and complications.

Comparison of Percutaneous versus Open Pedicle Screw Fixation for Treating Unstable Thoracolumbar Fractures

PURPOSE: This study compared the clinical and radiological results between two groups of patients with percutaneous fixation or conventional fixation after hardware removal.MATERIALS AND METHODS: The study analyzed 68 patients (43 open fixation and 43 percutaneous screw fixation [PSF] 25) who had undergone fixation for unstable thoracolumbar fractures. The radiologic results were obtained using the lateral radiographs taken before and after the fixation and at the time of hardware removal. The clinical results included the time of operation, blood loss, time to ambulation, duration of the hospital stay and the visual analogue scale.RESULTS: The percutaneous pedicle screw fixation (PPSF) group showed better results than did the conventional posterior fixation (CPF) group (p<0.05) in regard to the perioperative data such as operation time, blood loss, and duration of the hospital stay. There were no significant differences in wedge angle, local kyphotic angle, and the ΔKyphotic angle on the postoperative plane radiographs between the two groups (p>0.05). There were no significant differences in the wedge angle and local kyphotic angle after implant removal (p>0.05) between the two groups as well. However, there were significant differences in the segmental montion angle (p<0.001), and the PPSF group showed a larger segmental motion angle than did the CPF group (CPF 1.7°±1.2° vs PPSF 5.9°±3.2°, respectively).CONCLUSION: For the treatment of unstable thoracolumbar fractures, the PPSF technique could achieve better clinical results and an improved segmental motion angle after implant removal within a year than that of the conventional fixation method.

Relationship between different cervical curvature and spinal cord posterior movement after laminectomy with lateral mass screw fixation and its influence on the operative effect / 中国综合临床

Objective@#To investigate the relationship between cervical curvature (CC) and spinal drift distance after laminectomy with lateral mass screw fixation and the influence on the operative effect.@*Methods@#From October 2016 to December 2017, a total of 85 patients with cervical spondylotic myelopathy (CSM) underwent laminectomy with lateral mass screw fixation in handan central hospital, and 78 patients were followed up completely.After the operation, according to the Harrison method, they were divided into 2 groups(Group A (43 cases, 0°≤CC≤16.5°); Group B (35 cases, CC>16.5°)). The spinal drift distance, nerve recovery, axial symptoms and C5 palsy in the groups were recorded and analyzed.@*Results@#The CC was 8.5°±3.8° in group A and 19.6°±3.0° in group B (t=14.071, P=0.000). The laminectomy width in group A was (22.1±1.7) mm, in group B was (21.8±1.5) mm, the difference between the two groups was not statistically significant (P>0.05). The distance of spinal cord backward movement was (1.7±0.4) mm in group A and (3.2±0.7) mm in group B. There was significant difference between the two groups (t=11.879, P<0.001). At the end of one year, the improvement rates of nerve function in the two groups were (63.3±13.1)% and (65.1±13.9)% respectively, there was no significant difference between the two groups (t=0.587, P=0.559). The VAS score of group A was (5.2±1.3) at one week and (3.5±0.6) at one month after operation, and that of group B was (3.8±0.8) and (2.4±0.4) respectively.There were statistically significant differences between groups at different time points (t=5.567, P<0.001; t=9.289, P<0.001). The incidence of C5 paralysis was 7.0% (3/43) in group A and 11.4% (4/35) in group B. There was no significant difference between the two groups (P>0.05).@*Conclusion@#The greater the curvature of cervical spine is, the more fully the spinal cord moves backward.The loss of curvature of cervical spine is related to the occurrence of axial symptoms.The curvature of cervical spine is not related to the recovery of nerve function and the occurrence of C5 nerve paralysis.

Relationship between Cervical Curvature and Spinal Drift Distance after Laminectomy with Screw Fixation and Its Effect on Clinical Outcome / 中国康复理论与实践

Objective:To observe the relationship between cervical curvature and spinal drift distance after laminectomy with lateral mass screw fixation, and its effect on clinical outcome. Methods:From January, 2017 to October, 2018, a total of 117 patients with cervical spondylotic myelopathy (CSM) underwent laminectomy with lateral mass screw fixation, and 90 of them completed the follow-up. According to the patients' cervical curvature (CC), they were divided into three groups: those CC between 0° to 5° were in Group A (n = 28), 5° to 16.5° in Group B (n = 36) and CC > 16.5° in Group C (n = 26). The spinal drift distance, nerve recovery, axial symptoms and C5 palsy were recorded and analyzed. Results:There were significant differences in CC and spinal drift distance (F > 152.119,P < 0.001), and no significant difference was found in laminectomy width and incidence of C5 palsy (P > 0.05) among three groups. The Japanese Orthopaedic Association (JOA) score significantly increased in all the groups post operation and at the last follow-up (t > 8.869,P < 0.001), and no significant difference was found among there groups at the same time (P > 0.05), as well as the incidence of C5 palsy (F = 0.472,P = 0.625). There was significant difference in the score of Visual Analogue Scale of axial symptoms among three groups (F > 34.800,P < 0.001), which was lower in groups B and C than in group A (t > 5.845,P< 0.001), and no significant differene was found between group B and group C. Conclusion:On the basis of the same laminectomy width, the greater the CC was, the more favorable the spinal drift went backwards. The loss of CC was related to the occurrence of axial symptoms, but was not correlated with the neurological recovery and C5 palsy.

Biomechanical comparative analysis of screw fixation and cortical endo-button fixation in Latarjet procedure for anterior dislocation of shoulder joint / 中国修复重建外科杂志

Objective: To clarify the value of the cortical endo-button as an internal fixator in Latarjet procedure through biomechanical analysis. Methods: Ten pairs of shoulder joints from 6-7 months old male pigs were selected. Each pair was randomly divided into screw group and endo-button group. A 25% glenoid defect model was created, and the porcine infraspinatus tendon and its associated bone were used to simulate conjoint tendon and coracoid process in human body. The bone grafts were fixed with two 3.5 mm screws and double cortical endo-buttons with high-strength sutures in screw group and endo-button group, respectively. The prepared glenoid defect model was fixed on a biomechanical test bench and optical markers were fixed on the glenoid and the bone block, respectively. Then fatigue test was performed to observe whether the graft or internal fixator would failed. During the test, the standard deviations of the relative displacement between the graft and the glenoid of two groups were measured by optical motion measure system for comparison. Finally the maximum failure load comparison was conducted and the maximum failure loads of the two groups were measured and compared. Results: There was no tendon tear, bone fracture, and other graft or internal fixation failure in the two groups during the fatigue test. The standard deviation of the relative displacement of the screw group was (0.007 87±0.001 44) mm, and that of the endo-button group was (0.034 88±0.011 10) mm, showing significant difference between the two groups ( t=7.682, P=0.000). The maximum failure load was (265±39) N in screw group and (275±52) N in endo-button group, showing no significant difference between the two groups ( t=1.386, P=0.199). There were 3 ways of failure: rupture at bone graft's tunnel (6/10 from screw group, 3/10 from endo-button group), tendon tear at the cramp (2/10 from screw group, 2/10 from endo-button group), and tendon tear at the internal fixator interface (2/10 from screw group, 5/10 from endo-button group), showing no significant difference between the two groups ( P=0.395). Conclusion: Although the endo-button fixation fails to achieve the same strong fixation stability as the screw fixation, its fixation stability can achieve the clinical requirements. The two fixation methods can provide similar fixation strength when being used in Latarjet procedure.

Ct morphometry of typical cervical vertebral pedicles for clinical accuracy in cervical pedicle screw insertion

Background: Pedicle screw fixation for mid- and lower cervical spine reconstruction has a potential risk of injuryto surrounding structures. To achieve optimal surgical outcomes, it is therefore necessary that pertinentanatomical data, especially with regard to pedicles and vertebral bodies be considered prior to surgery.Methods: 63 patients were scanned using axial CT parallel to the upper endplate of the vertebral body (C3–C6)with a helical CT scanner. Foramen width (FW), Foramen height (FH), Pedicle width (PW), Foramen angle (FA),Pedicle transverse angle (PTA), Lateral mass angle (LMA) were measured. Mean value and standard deviation ofeach parameter were calculated.Results: Mean FW ranged from 5.8 to 6.1 mm with non-significant difference from C3 to C6.The mean FH rangedfrom 4.9 to 5.1 mm, with non-significant differences between each vertebra. The mean PW ranged from 5.3 to 5.8mm. There were significant differences between each vertebra, except for the PW between C3 and C4. The FAranged from 17.5 to 18.5. There were significant differences between each vertebra, except for the FA between C3and C6. The mean PTA ranged from 39.8 to 35.8. The mean LMA ranged from 0.9 to 3.1.There were significantdifferences between each vertebra, except for the LMA between C4 and C5. The FW and FH exhibited no correlationswith PW, PTA or LMA. FA was found to be positively correlated with both PTA and LMA. There was also a positivecorrelation between PTA and LMA.Conclusion: Anatomical features of the cervical spine using CT to select safer screw insertion techniques arehighly recommended. In cases in which insertion of pedicle screws is difficult, Lateral Mass Screw (LMS) can beinserted safely. Whereas when insertion of LMS is difficult, insertion of pedicle screws can be performed easily.

Hoffa Fracture of Medial Femoral Condyle in a 9-Year-Old Child: A Case Report

Hoffa fractures are intra-articular fractures of the distal femoral condyles in coronal plane. These fractures may be of either condylebut lateral condyle is most commonly affected and medial condyle is extremely rare. Non-operative treatment of unicondylarfemur fractures, including Hoffa fractures, yields poor result. We present a case of 9-year-old child with Hoffa fracture of medialfemoral condyle with understanding of the mechanism of injury and its further management. He had history of fall from height ofabout 5 feet on his right knee which was in flexed position at around 90°. X-ray of knee showed fracture of medial femoral condylein coronal plane. Three-dimensional (3D) reconstruction of computed tomography (CT) scan confirmed the coronal fracture ofmedial femoral condyle and was classified as Type 33 B3 according to orthopedic trauma association classification and Type 1as per Letenneur classification. Open reduction and internal fixation were performed with partially threaded cancellous screws.The fixation of coronal fracture of medial femoral condyle done through cancellous screws in anterior to posterior direction wasadequate in giving stable fixation and aided in union without disturbing the physis of the child. At 1 year, the child could do fullextension and 130° flexion. There was no posterior or varus, valgus instability of the knee. We believe that a medial condyleHoffa fracture is extremely rare in children, and the diagnosis can be missed. ORIF using partially threaded cancellous screwsin the epiphysis provides stable fixation and can lead to a good functional outcome in the long term. The mechanism of injuryin this fracture pattern was found to be direct impact on the knee in flexed position of 90°.

Clinical evaluation of a bone cement-injectable cannulated pedicle screw augmented with polymethylmethacrylate: 128 osteoporotic patients with 42 months of follow-up

OBJECTIVES: To evaluate the safety and efficacy of a novel bone cement-injectable cannulated pedicle screw augmented with polymethylmethacrylate in osteoporotic spinal surgery. METHODS: This study included 128 patients with osteoporosis (BMD T-score −3.2±1.9; range, −5.4 to -2.5) who underwent spinal decompression and instrumentation with a polymethylmethacrylate-augmented bone cement-injectable cannulated pedicle screw. Postoperative Visual Analogue Scale scores and the Oswestry Disability Index were compared with preoperative values. Postoperative plain radiographs and computed tomography (CT) scans were performed immediately after surgery; at 1, 3, 6, and 12 months; and annually thereafter. RESULTS: The mean follow-up time was 42.4±13.4 months (range, 23 to 71 months). A total of 418 polymethylmethacrylate-augmented bone cement-injectable cannulated pedicle screws were used. Cement extravasations were detected in 27 bone cement-injectable cannulated pedicle screws (6.46%), mainly in cases of vertebral fracture, without any clinical sequela. The postoperative low back and lower limb Visual Analogue Scale scores were significantly reduced compared with the preoperative scores (<0.01), and similar results were noted for the Oswestry Disability Index score (p<0.01). No significant screw migration was noted at the final follow-up relative to immediately after surgery (p<0.01). All cases achieved successful bone fusion, and no case required revision. No infection or blood clots occurred after surgery. CONCLUSIONS: The polymethylmethacrylate-augmented bone cement-injectable cannulated pedicle screw is safe and effective for use in osteoporotic patients who require spinal instrumentation.