Feasibility of a novel type of complex anterior cervical fixation by using Mimics software / 中国骨伤

OBJECTIVE@#To investigate the feasibility of mimics software in analyzing a new type of complex anterior cervical fixation -- anterior transpedicular screw fixation+zero notch internal fixation.@*METHODS@#From January 2021 to September 2022, 50 normal pedestrians who underwent cervical spine CT scanning were selected for C1-C7 segment scanning, including 27 males and 23 females, aged from 25 to 65 years old with an average of (46.0 ± 9.0) years old. The dicom format is exported and engraved into the CD, and use the mimics software to perform 3D reconstruction of each segment. A simulated screw is placed on the image according to the critical value of zero notch screw (head and tail angle 44°, internal angle 29°). The position of zero notch screw in each segment is observed to determine the feasibility of anterior transpedicular screw fixation plus zero notch internal fixation.@*RESULTS@#For the upper zero notch screws the three-dimensional images of the cervical spine across all 50 subjects within the C3-C7 segments demonstrated safe position, with no instances of intersection with ATPS. For the lower zero notch screw, in C3-C4 and C4-C5, 4 out of 50 subjects are in the safe position in the three-dimensional images of cervical vertebrae, and 46 cases could achieve secure screw placement when the maximum caudal angle is(32.3±1.9) ° and (36.1±2.2) °, respectively. In C5-C6 and C6-C7 segments, no lower zero notch screws intersected with ATPS, and all screws are in safe positions.@*CONCLUSION@#Lower cervical anterior pedicle screw fixation plus zero notch internal fixation can achieve successful nail placement through the selected entry point and position.

Analysis of the causes of cage subsidence after oblique lateral lumbar interbody fusion / 中国骨伤

OBJECTIVE@#To observe the cage subsidence after oblique lateral interbody fusion (OLIF) for lumbar spondylosis, summarize the characteristics of the cage subsidence, analyze causes, and propose preventive measures.@*METHODS@#The data of 144 patients of lumbar spine lesions admitted to our hospital from October 2015 to December 2018 were retrospectively analyzed. There were 43 males and 101 females, and the age ranged from 20 to 81 years old, with an average of (60.90±10.06) years old. Disease types:17 patients of lumbar intervertebral disc degenerative disease, 12 patients of giant lumbar disc herniation, 5 patients of discogenic low back pain, 33 patients of lumbar spinal stenosis, 26 patients of lumbar degenerative spondylolisthesis, 28 patients of lumbar spondylolisthesis with spondylolisthesis, 11 patients of adjacent vertebral disease after lumbar internal fixation, 7 patients of primary spondylitis in the inflammatory outcome stage, and 5 patients of lumbar degenerative scoliosis. Preoperative dual-energy X-ray bone mineral density examination showed 57 patients of osteopenia or osteoporosis, and 87 patients of normal bone density. The number of fusion segments:124 patients of single-segment, 11 patients of two-segment, 8 patients of three-segment, four-segment 1 patient. There were 40 patients treated by stand-alone OLIF, and 104 patients by OLIF combined with posterior pedicle screw. Observed the occurrence of fusion cage settlement after operation, conducted monofactor analysis on possible risk factors, and observed the influence of fusion cage settlement on clinical results.@*RESULTS@#All operations were successfully completed, the median operation time was 99 min, and the median intraoperative blood loss was 106 ml. Intraoperative endplate injury occurred in 30 patients and vertebral fracture occurred in 5 patients. The mean follow-up was (14.57±7.14) months from 6 to 30 months. During the follow-up, except for the patients of primary lumbar interstitial inflammation and some patients of lumbar spondylolisthesis with spondylolisthesis, the others all had different degrees of cage subsidence. Cage subsidence classification:119 patients were normal subsidence, and 25 patients were abnormal subsidence (23 patients were gradeⅠ, and 2 patients were gradeⅡ). There was no loosening or rupture of the pedicle screw system. The height of the intervertebral space recovered from the preoperative average (9.48±1.84) mm to the postoperative average (12.65±2.03) mm, and the average (10.51±1.81) mm at the last follow-up. There were statistical differences between postoperative and preoperative, and between the last follow-up and postoperative. The interbody fusion rate was 94.4%. The low back pain VAS decreased from the preoperative average (6.55±2.2 9) to the last follow-up (1.40±0.82), and there was statistically significant different. The leg pain VAS decreased from the preoperative average (4.72±1.49) to the final follow-up (0.60±0.03), and the difference was statistically significant (t=9.13, P<0.000 1). The ODI index recovered from the preoperative average (38.50±6.98)% to the latest follow-up (11.30±3.27)%, and there was statistically significant different. The complication rate was 31.3%(45/144), and the reoperation rate was 9.72%(14/144). Among them, 8 patients were reoperated due to fusion cage subsidence or displacement, accounting for 57.14%(8/14) of reoperation. The fusion cage subsidence in this group had obvious characteristics. The monofactor analysis showed that the number of abnormal subsidence patients in the osteopenia or osteoporosis group, Stand-alone OLIF group, 2 or more segments fusion group, and endplate injury group was higher than that in the normal bone mass group, OLIF combined with pedicle screw fixation group, single segment fusion group, and no endplate injury group, and the comparison had statistical differences.@*CONCLUSION@#Cage subsidence is a common phenomenon after OLIF surgery. Preoperative osteopenia or osteoporosis, Stand-alone OLIF, 2 or more segments of fusion and intraoperative endplate injury may be important factors for postoperative fusion cage subsidence. Although there is no significant correlation between the degree of cage subsidence and clinical symptoms, there is a risk of cage migration, and prevention needs to be strengthened to reduce serious complications caused by fusion of cage subsidence, including reoperation.

Morphometrics of T11-L5 Vertebrae in Jordanian Population: CT Scan-Based Study / Morfometría de las Vértebras T11-L5 en una Población Jordana: Estudio Basado en Tomografía Computarizada

SUMMARY: The study will provide information on the morphometrics of the vertebrae, which can be used to guide clinicians on the appropriate size of transpedicular screws to use in spine interventions among the Jordanian population and for comparative studies with other races. A retrospective analysis of normal CT scans of the lumbar and thoracolumbar areas was done. Linear and angular measurements of 336 vertebrae were collected for 25 males and 23 females. The results were compared between right and left and between both sexes. The L5 has the longest AVBH and the shortest PVBH in both sexes, it also, had the shortest and widest pedicle in both males and females. ratio of the AVBH to PVBH showed progressive increase in both sexes from T11 to L5. Similarly, the VBW increased progressively from the top to the bottom in both sexes, but it was significantly different between both sexes. The L1 was the most cranially oriented vertebrae in males while the L2 showed the most cranial orientation in females. Both sexes L5 was the most caudally oriented vertebrae. This study provides a database for vertebral morphometrics in the Jordanian population, there are slight differences between the right and left side in the upper studied vertebrae (T11-L2) and some measurement showed significant differences between males and females. These findings need to be taken into consideration when inserting pedicle screws.

Este estudio proporciona información sobre la morfometría de las vértebras, la cual puede ser utilizada por los médicos oara determinar el tamaño adecuado de los tornillos transpediculares a utilizar en intervenciones de columna en la población jordana y para estudios comparativos con otras grupos. Se realizó un análisis retrospectivo de tomografías computarizadas normales de las áreas lumbar y toracolumbar. Se recogieron medidas lineales y angulares de 336 vértebras de 25 hombres y 23 mujeres. Los resultados se compararon entre vértebras derechas e izquierdas y entre ambos sexos. La L5 tiene el AVBH más largo y el PVBH más corto en ambos sexos, también tenía el pedículo más corto y más ancho tanto en hombres como en mujeres. La relación de AVBH a PVBH mostró un aumento progresivo en ambos sexos de T11 a L5. De manera similar, el VBW aumentó progresivamente de arriba hacia abajo en ambos sexos, pero fue significativamente diferente entre ambos sexos. La L1 fue la vértebra más orientada cranealmente en los hombres, mientras que la L2 mostró la orientación más craneal en las mujeres. En ambos sexos L5 fue la vértebra más orientada caudalmente. Este estudio proporciona una base de datos para la morfometría vertebral en la población jordana, donde existen ligeras diferencias entre el lado derecho e izquierdo en las vértebras superiores estudiadas (T11-L2). Algunas mediciones mostraron diferencias significativas entre hombres y mujeres. Estos hallazgos deben tenerse en cuenta al insertar tornillos pediculares.

Morphometric Study of Atlas Vertebra In Relation to Sulcus Arteriae Vertebralis

Background: Atlas(C1) is an atypical cervical vertebra shaped like a ring. Important structures like the vertebral artery, suboccipital plexus of veins and first cervical nerve pass through it. Knowledge of the variability of C1 is important for neurosurgeons, orthopaedicians, otorhynologists and other physicians who in everyday practice are in contact with disorders of the spine and their consequences. So, this study was undertaken to assess the various dimensions of the C1 in relation to the vertebral artery groove. Methods and materials: Fifty dried human atlas vertebrae were studied. Various measurements were done and statistically analysed. Results: Antero-posterior diameter (APD) of Foramen transversarium(FT) was measured as 7.73 ± 1.04mm on the right and 7.62 ± 0.90mm on left side. Transverse Diameter(TD) of FT was observed as 6.12 ± 0.97mm on the right side and 6.02 ± 0.97mm on the left side. Outer Distance of Vertebral Artery Groove(VAG) was measured as 26.22 ± 2.32mm and 25.84 ± 1.85mm on the right and left sides, respectively. Inner Distance of VAG was observed as 13.10 ± 1.66mm on right and 13.17 ± 1.57mm on the left side. APD of Superior Articular Facet(SAF) was 21.52 ± 2.36mm on right and 21.51 ± 2.07mm on left side.TD of SAF was 11.21 ± 1.47mm on right and 11.32 ± 1.53mm on left side. APD of Inferior Articular Facet(IAF) was observed as 17.54 ± 1.50mm on right and 17.70±1.60mm on left side. TD of IAF was observed as 14.99 ± 1.65mm on the right side and 14.94 ± 1.51mm on left side. Distance between lateral-most edge of both Foramen Transversaria was measured as 56.37 ± 4.11mm and distance between medial-most edge of both Foramen Transversaria was 44.78 ± 3.67mm. MaximumTD of Atlas was measured as 72.09± 5.59mm. Conclusion: The study will generate information that would be useful for geometric modelling of vertebrae and give necessary morphometric data on human atlas vertebra in Indian population.

Study of Incidence of Ponticulus Posterior In Dry Human Atlas Vertebra and Its Clinical Significance

Background: Atlas is the first cervical vertebra. The vertebral artery lies in the groove on posterior arch of the atlas. The vertebral artery groove may sometimes get converted into a foramen. This is commonly known as ponticulus posterior (ponticulus posticus) or arcuate foramen of the atlas. These foramina may be complete or incomplete. This can lead to compression of the vertebral artery and produce symptoms like headache, syncope, altered consciousness etc. It can also complicate manipulations of the cervical spine by reducing the blood flow during extreme rotations of head and neck. It is also associated with vertebrobasilar artery stroke So, neurosurgeons or orthopaedic surgeons who operate in this area should have a detailed knowledge of variations of groove for the vertebral artery. Materials and Methods: The present study was conducted on 50 dried and fully ossified adult human atlas of unknown age and sex collected from the department of Anatomy, Government Medical college, Nagpur. Each atlas vertebra was carefully observed for the presence or absence of complete or incomplete ponticuli on superior surface of posterior arch of atlas. Results: Out of the 50 vertebra studied 7(14%) showed the presence of Ponticuli. Ponticuli were incomplete in all 7 atlas vertebras. Complete ring was not observed in any of the atlas vertebra .Out of the 7 ponticuli 6(12%) were found to be unilateral and in only 1 (2%) case it was found to be bilateral. Out of the 6 ponticuli 4(8%) were noticed on the Left side and 2(4%) were present on the right side. Conclusion: Presence of incomplete ponticulus posterior might cause cervical pain and even cerebrovascular disorders due to pressure on third part of vertebral artery present in the vertebral artery groove. This anatomical knowledge is important for neurosurgeons, orthopaedic surgeons, radiologists and clinicians while dealing with this region.

Posterior Atlantoaxial Screw Placement in a Portuguese Population: A Morphometric Analysis Based on Computed Tomography Scan Measurements / Colocação de parafusos atlantoaxiais posteriores em uma população portuguesa: Uma análise morfométrica baseada em medidas de tomografia computadorizada

Abstract Objective The present study aims to evaluate the screw length and trajectory angles for posterior atlantoaxial fixation in a Portuguese population, through the study of cervical computed tomography (CT) scans. Methods Cervical CT scans of 50 adults were measured according to predefined screw trajectories of C1-C2 transarticular (C1C2TA), C1 lateral mass (C1LM), C2 pedicle (C2P), C2 pars and C2 laminar (C2L) screws. For each of these trajectories, screw length and angles were measured and compared between males and females. Results For the C1C2TA screw trajectory, the mean length, medial, and cranial angles were 34.12 ± 3.19 mm, 6.24° ± 3.06, and 59.25° ± 5.68, respectively, and for the C1LM screw trajectory, they were 27.12 ± 2.15 mm, 15.82° ± 5.07, and 13.53° ± 4.80, respectively. The mean length, medial, and cranial angles for the C2P screw trajectory were 23.44 ± 2.49 mm, 27.40° ± 4.88, and 30.41° ± 7.27, respectively; and for the C2 pars screw trajectory, they were 16.84 ± 2.08 mm, 20.09° ± 6.83, and 47.53° ± 6,97. The mean length, lateral, and cranial angles for the C2L screw trajectory were 29.10 ± 2.48 mm, 49.80° ± 4.71, and 21.56° ± 7.76, respectively. There were no gender differences except for the lengths of the C1C2TA (p= 0,020) and C2L (p= 0,001) screws, which were greater in males than in females. Conclusion The present study provides anatomical references for the posterior atlantoaxial fixation in a Portuguese population. These detailed data are essential to aid spine surgeons to achieve safe and effective screw placement.

Resumo Objetivo O presente estudo tem como objetivo avaliar o comprimento e os ângulos de trajetória do parafuso para fixação atlantoaxial posterior em uma população portuguesa por meio do estudo de tomografia computadorizada (TC) cervical. Métodos Tomografias computadorizadas cervicais de 50 adultos foram analisadas quanto às trajetórias pré-definidas dos parafusos transarticulares C1-C2 (C1C2TA), na massa lateral de C1 (C1LM), no pedículo de C2 (C2P) e na pars de C2 e C2 laminar (C2L). O comprimento e os ângulos dos parafusos em cada uma destas trajetórias foram medidos e comparados entre homens e mulheres. Resultados O comprimento médio e ângulos medial e cranial da trajetória do parafuso C1C2TA foram de 34,12 ± 3,19 mm, 6,24° ± 3,06 e 59,25° ± 5,68, respectivamente; as medidas da trajetória do parafuso C1LM foram 27,12 ± 2,15 mm, 15,82° ± 5,07 e 13,53° ± 4,80. O comprimento médio e os ângulos medial e cranial da trajetória do parafuso C2P foram de 23,44 ± 2,49 mm, 27,40° ± 4,88 e 30,41° ± 7,27, respectivamente; as medidas da trajetória do parafuso da pars de C2 foram 16,84 ± 2,08 mm, 20,09° ± 6,83 e 47,53° ± 6,97. O comprimento médio e ângulos lateral e cranial da trajetória do parafuso C2L foram de 29,10 ± 2,48 mm, 49,80° ± 4,71 e 21,56° ± 7,76, respectivamente. Não houve diferenças entre os gêneros, à exceção do comprimento dos parafusos C1C2TA (p= 0,020) e C2L (p= 0,001), que foi maior no sexo masculino do que no feminino. Conclusão O presente estudo fornece referências anatômicas para a fixação atlantoaxial posterior em uma população portuguesa. Estes dados detalhados são essenciais para ajudar os cirurgiões de coluna a colocar os parafusos de maneira segura e eficaz.

Biomechanical evaluation of four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs

ABSTRACT Purpose: This study compared, through biomechanical evaluation under ventral flexion load, four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs. Methods: In total, 28 identical atlantoaxial joint models were created by digital printing from computed tomography images of a dog, and the specimens were divided into four groups of seven. In each group, a different technique for ventral stabilization of the atlantoaxial joint was performed: transarticular lag screws, polyaxial screws, multiple screws and bone cement (polymethylmethacrylate-PMMA), and atlantoaxial plate. After the stabilization technique, biomechanical evaluation was performed under ventral flexion load, both with a predefined constant load and with a gradually increasing load until stabilization failure. Results: All specimens, regardless of stabilization technique, were able to support the predefined load without failing. However, the PMMA method provided significant more rigidity (p ≤ 0.05) and also best resisted the gradual increase in load, supporting a significantly higher maximum force (p ≤ 0.05). There was no statistical difference in flexural strength between the transarticular lag screws and plate groups. The polyaxial screws method was significantly less resistant to loading (p ≤ 0.05) than the other groups. Conclusions: The PMMA technique had biomechanical advantages in ventral atlantoaxial stabilization over the other evaluated methods.

Posterior cervical pedicle screw rod short-segment internal fixation for the treatment of atlantoaxial fracture and dislocation / 中国骨伤

OBJECTIVE@#To investigate the clinical efficacy of posterior cervical pedicle screw short-segment internal fixation for the treatment of atlantoaxial fracture and dislocation.@*METHODS@#The clinical data of 60 patients with atlantoaxial vertebral fracture and dislocation underwent surgery between January 2015 and January 2018 were retrospectively analyzed. The patients were divided into study group and control group according to different surgical methods. There were 30 patients in study group, including 13 males and 17 females, with an average age of (39.32±2.85) years old, were underwent short-segment internal fixation with posterior cervical pedicle screws. There were 30 patients in control group, including 12 males and 18 females, with an average age of (39.57±2.90) years old, were underwent posterior lamina clip internal fixation of the atlas. The operation time, intraoperative blood loss, postoperative ambulation time, hospitalization time and complications between two groups were recorded and compared. The pain visual analogue scale(VAS), Japanese Orthopedic Association(JOA) score of neurological function, and fusion status were evaluated between two groups.@*RESULTS@#All patients were followed up for at least 12 months. The study group was better than control group in operation time, intraoperative blood loss, postoperative off-bed activity time, and hospital stay (P=0.000). One case of respiratory tract injury occurred in study group. In control group, 2 cases occurred incision infection, 3 cases occurred respiratory tract injury, and 3 cases occurred adjacent segmental joint degeneration. The incidence of complications in study group was lower than that in control group (χ2=4.705, P=0.030). At 1, 3, 7 days after operation, VAS of study group was lower than that of control group(P=0.000). At 1, 3 months after operation, JOA score of study group was higher than that of control group(P=0.000). At 12 months after operation, all the patients in the study group achieved bony fusion. In control group, there were 3 cases of poor bony fusion and 3 cases of internal fixation fracture, the incidence rate was 20.00%(6/30). The difference between two groups was statistically significant (χ2=4.629, P=0.031).@*CONCLUSION@#Posterior cervical short-segment pedicle screw fixation for atlantoaxial fracture and dislocation has the advantages of less trauma, shorter operation time, fewer complications, and less pain, and can promote the recovery of nerve function as soon as possible.

Clinical outcomes of selecting the vertebra above sagittal stable vertebra as distal fusion level for Scheuermann's thoracic kyphosis / 中华骨科杂志

Objective:To investigate the clinical outcome and complications associated with utilizing sagittal plane stable vertebra-1 (SSV-1) as the distal instrumented vertebra (LIV) in posterior fusion of thoracic kyphosis with Scheuermann's Disease kyphosis (STK).Methods:A longitudinal study on patients with STK who underwent posterior correction and fusion surgery from January 2018 to June 2021 were conducted. All participants had a follow-up duration over two years. Patients were divided into two groups according to the segment of LIV: the SSV group, where LIV was located in SSV; and the SSV-1 group, where LIV was located in the vertebral body above SSV. The radiographic parameters, including global kyphosis (GK), lumbar lordosis (LL), and sagittal plane (SVA), LIV offset distance (LIV translation), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS), were compared between the two groups. The SRS-22 scale was used to evaluate health-related quality of life at pre-operation and last follow-up, and the incidence of postoperative distal junctional kyphosis (DJK) was also recorded. Analytical techniques, such as Analysis of Variance and Mann-Whitney tests, were employed to compare inter-group differences.Results:A total of 57 patients were included in the study, 36 in the SSV group and 21 in the SSV-1 group. The average age for patients were 16.1±2.3 years (range 13-20 years), and the average follow-up time was 32.8±6.8 months (range 24-53 months). There were no statistically significant differences between the two groups in terms of gender, age, follow-up time, surgical time, intraoperative bleeding volume, and fusion level. Before surgery, the LIV deviation distance in the SSV group was significantly lower than that in the SSV-1 group (-7.9±11.0 mm vs. 31.5±11.5 mm, t=7.64, P<0.001). In the SSV group, the preoperative GK was 79.3°±10.5°, and the last follow-up GK was 44.4°±8.5°, which was significantly improved compared to preoperative value ( t=28.28, P<0.001); in the SSV-1 group, the preoperative GK was 81.1°±10.6°, and the value at 1-week post-operative was 44.9°±7.8°, which was significantly improved compared to pre-operative value ( t=22.23, P<0.001). At the last follow-up, it was 45.1°±8.7°, with a correction rate of 44.3%±8.5%. No significant difference was observed between the two groups in terms of GK, LL, SVA, PI, PT and SS at pre-operative, 1-week post-operative and last follow-up ( P>0.05). All patients had no intraoperative complications of nerve injury. During the follow-up period, one patient (1/21, 4.8%) developed DJK without complications such as proximal kyphosis, pseudarthrosis, or failed internal fixation. At the last follow-up, the functional score of SRS-22 in SSV-1 group improved from preoperative (3.5±0.54) to postoperative (4.1±0.62), with an average improvement rate of 19.2%±3.2%, and the difference was statistically significant ( t=3.74, P=0.001). These results indicating that the surgical treatment was effective in relieving the symptoms of the patients. Conclusion:Selecting SSV-1 as LIV in corrective surgeries for STK appears to produce commendable clinical results with minimal implant-associated complications over a two-year observation period.

Diagnosis and treatment of atlantoaxial dislocation / 中华骨科杂志

Atlantoaxial dislocation is a pathological anatomical condition caused by the loss of stability between the atlantoaxial joints, which is a serious disabling disease in spine surgery, and may even endanger the patient's life. The causes of atlantoaxial dislocation include traumatic, congenital, inflammatory, degenerative, tumor, and other factors. Since the symptoms and signs are not specific in clinic, imaging examination is particularly important. Atlantoaxial dislocation is mainly classified according to the etiology, the relative position of atlas and axis, and the difficulty of reduction. Accurate classification is of great significance for the selection of treatment options. There is no popular guideline for surgical indications of atlantoaxial dislocation. Patients presenting with related symptoms or spinal cord dysfunction are generally recognized surgical indications in clinical practice. With the continuous improvement and optimization of atlantoaxial screw placement, reduction and fusion technology, supplemented by new equipment in spine surgery, the surgery-related risks and complications have been greatly reduced, and the surgical treatment of atlantoaxial dislocation can obtain good reduction and fusion results. This tutorial summariz the etiology, diagnosis, classification, treatment, complications, and prognosis of atlantoaxial dislocation, in order to provide a more complete and refined reference for clinical diagnosis and treatment.

Anterior cervical release and posterior fixation for the treatment of irreducible atlantoaxial dislocation with retropharyngeal internal carotid artery / 中华骨科杂志

Objective:To investigate the clinical effect of anterior cervical release and posterior fixation in the treatment of irreducible atlantoaxial dislocation with retropharyngeal internal carotid artery.Methods:Thirteen patients with irreducible atlantoaxial dislocation of retropharyngeal internal carotid artery from January 2015 to July 2019 were treated with anterior cervical release and posterior fixation. There were 8 males and 5 females, aged from 34 to 65 years with an average of 46.1±12.6 years. Positive, lateral and dynamic X-ray films, MR and CTA were performed before operation. There were 4 cases with bilateral retropharyngeal internal carotid artery and 9 cases with unilateral retropharyngeal internal pharyngeal artery. The time of operation, the amount of bleeding and intraoperative and postoperative complications were recorded. The main observations were Japanese Orthopaedic Association (JOA) score, atlantodental interval (ADI), Chamberlain line (CL), and changes in the morphology of the retropharyngeal internal carotid artery and implant fusion.Results:All the operations completed successfully. The operation time was 210-260 min, the average was 245±21 min; the blood loss was 350-600 ml, the average blood loss was 490±107 ml. There was no injury of internal carotid artery, vertebral artery, spinal cord or nerve root during the operation. All patients were followed up for 9 to 24 months, with an average of 15.1±6.2 months. Preoperative JOA score was 6.9±2.3 points, 1 month after operation was 13.5±2.5 points, and the last follow-up was 14.3±2.1 points. The difference was statistically significant ( F=30.91, P<0.001). The difference between 1 month after operation and before operation was statistically significant ( P<0.001), and the improvement rate of JOA score was 75.6%±15.2%. There was no significant difference between the last follow-up and 1 month after operation ( P>0.05). The preoperative ADI was 8.9±2.2 mm, 1 month after operation was 1.1±0.8 mm, and the last follow-up was 1.2±0.9 mm. The difference was statistically significant ( F=114.69, P<0.001). The difference between 1 month after operation and before operation was statistically significant ( P<0.001), and ADI had returned to normal level. There was no significant difference between the last follow-up and 1 month after operation ( P>0.05). The preoperative CL was 11.7±4.8 mm, 1 month after operation was 1.6±2.1 mm, and the last follow-up was 1.8±2.3 mm. The difference was statistically significant ( F=34.19, P<0.001). The difference between 1 month after operation and before operation was statistically significant ( P<0.001), and the position of odontoid process returned to normal level. There was no significant difference between the last follow-up and 1 month after operation ( P>0.05). Bone graft fusion was received at 6 to 12 months after operation, with an average of 10.2 months. Conclusion:CTA examination should be performed before anterior release of atlantoaxial dislocation to understand the position and shape of internal carotid artery. Anterior cervical release combined with posterior bone graft fusion is an effective method for the treatment of irreducible atlantoaxial dislocation with retropharyngeal internal carotid artery without increasing the risk of internal carotid artery injury.

The clinical characteristics and treatment of "sandwich" atlantoaxial dislocation / 中华骨科杂志

Objective:To evaluate the specialty of the clinical features, treatment procedure, clinical outcome, and prognosis in the patients with "sandwich" atlantoaxial dislocation (AAD).Methods:From 2008 to 2018, 160 cases with "sandwich" AAD were retrospectively selected from the case series of AAD in Peking University Third Hospital. The case series had 80 males and 80 females. The mean age at the initial visit was 35.5±14.6 years (range, 5-77). The clinical courses, treatment methodology and prognosis were reviewed. And the surgical approach, posterior fixation segment and the recovery of neurological function were mainly summarized. The atlantodental interval (ADI), the distance by which the odontoid exceeded the Chamberlain line and the cervical-medullary angle were analyzed.Results:The most common symptoms included weakness or numbness of the limbs (67.5%, 108/160), unstable gait (30%, 48/160) and vertigo (20%, 32/160). Among all, 130 cases (81.3%, 130/160) had myelopathy, with the Japanese Orthopaedic Association (JOA) scores from 4 to 16 (mean JOA scores 13.5±2.5). Cranial neuropathy was involved in 20 cases (12.5%). Radiological findings showed brainstem and/or cervical-medullar in 130 cases (81.3%), syringomyelia in 37 cases (23.1%) and Chiari malformation in 30 cases (18.8%). Computed tomography angiography (CTA) was performed in 90 cases, which showed vertebral artery anomalies in 55 cases (61.0%) and excessive medialized internal carotid artery in 5 cases (5.6%). All cases had no spinal cord or vertebral artery injury. The surgery included posterior occipito-cervical fusion (reducible dislocation, 145 cases), and transoral release followed by posterior fusion (irreducible dislocation, 15 cases). Fifty-seven cases were treated using alternative fixation technique. The average follow-up time was 50.5±22.4 months (range, 24 to 120 months). All of 152 cases (95.0%) achieved solid atlantoaxial fusion; there was no obvious osseous fusion formation on postoperative images in 6 cases (3.8%), but no atlantoaxial instability was found on dynamic radiographs; screw loosening happened in 2 patients (1.2%). Nine patients (5.6%) suffered complications, including 4 cases with recurrent dislocation, 2 screw loosening, 2 cases with bulbar paralysis and 1 wound infection. The mean postoperative JOA was 15.1±1.8 (range, 5-17), and the mean neurological improvement rate was 42.9%±33.3% in the patients with myelopathy.Conclusion:"Sandwich" AAD, a subgroup of AAD, has unique clinical features: earlier onset age and more severe myelopathy. The incidence of bone and vascular malformation is higher. So alternative surgical plan and hybrid fixation should be prepared for this subgroup of AAD.

Subclassification and clinical treatment options of refractory atlantoaxial dislocation / 中华骨科杂志

Objective:To subdivide clinical classification of refractory atlantoaxial dislocation, and evaluate the reliability of new subdivide clinical classification of refractory atlantoaxial dislocation.Methods:From January 2010 to December 2018, 48 patients with refractory atlantoaxial dislocation were treated, including 19 males and 29 females, aged 16 to 65 years, with an average of 39.2±13.3 years. According to the changes of relative anatomical position of C 1 and C 2 under general anesthesia with heavy traction of 1/6 body weight, subdivide clinical classification of refractory atlantoaxial dislocation were proposed, and refractory atlantoaxial dislocation was divided into traction loosening type (atlantoaxial angle≥5°) and traction stabilization type (atlantoaxial angle<5°). The traction loosening type was directly reduced by posterior atlantoaxial screw-rod fixation and fusion without anterior or posterior soft tissue release. For traction stabilization type, transoral soft tissue release was performed first, and then transoral anterior reduction plate fixation and fusion or posterior atlantoaxial screw-rod fixation and fusion were performed. Atlantodental interval (ADI) and atlantoaxial angle (AAA) were measured and collected before and after surgery to evaluate atlantoaxial reduction. The space available for the spinal cord (SAC) were measured to evaluate spinal cord compression. Visual analogue score (VAS) was used to evaluate the neck pain levels, and Japanese Orthopaedic Association (JOA) scores was used to evaluate the neurological function. American Spinal Cord Injury Association impairment scale (AIS) was used to evaluate the degree of spinal cord injury. One week, 3, 6, 12 months postoperatively and the annual review of the X-ray and CT scan were checked, in order to evaluate the reduction, internal fixation and bone graft fusion. Results:Among all 48 cases, 22 cases were traction loosening type, of which posterior atlantoaxial screw-rod fixation and fusion were performed in 16 cases and occipitocervical fixation and fusion in 6 cases. 26 cases were traction stabilization type, and they all underwent anterior transoral release, and then, anterior TARP fixation and fusion were performed in 24 cases and posterior screw-rod fixation and fusion in the other 2 cases. X-ray, CT and MRI images and of all patients 1 week after surgery showed good atlantoaxial reduction and decompression of spinal cord. In each of the two types, there was one case lost to follow-up. For 46 cases in follow-up, the follow-up time ranged from 6 to 72 months, with an average of 38.0±17.2 months. Among 46 cases, 21 cases of traction loosening type showed that, ADI reduced from preoperative 9.9±2.2 mm to 2.3±0.9 mm at 3 months after surgery and 2.3±1.0 mm at the last follow-up, AAA increased from preoperative 57.9°±12.3° to 91.0°±2.2° at 3 months after surgery and 90.9°±2.2° at the last follow-up, SAC increased from preoperative 9.8±1.3 mm to 15.1±0.7 mm at 3 months after surgery and 14.9±0.7 mm at the last follow-up, VAS score reduced from preoperative 1.5±2.1 to 0.7±1.0 at 3 months after surgery and 0.3±0.6 at the last follow-up, and JOA score increased from preoperative 10.2±1.7 to 13.3±1.3 at 3 months after surgery and 14.9±1.5 at the last follow-up. Twenty-five cases of traction stabilization type presented that, ADI reduced from preoperative 9.7±2.0 mm to 2.1±1.4 mm at 3 months after surgery and 2.1±1.3 mm at the last follow-up, AAA increased from preoperative 55.8°±9.2° to 90.9°±1.4° at 3 months after surgery and 90.9°±1.3° at the last follow-up, SAC increased from preoperative 10.5±1.0 mm to 15.4±0.5 mm at 3 months after surgery and 14.8±2.8 mm at the last follow-up, VAS score reduced from preoperative 1.7±2.1 to 0.7±0.9 at 3 months after surgery and 0.3±0.5 at the last follow-up, and JOA score increased from preoperative 10.1±1.3 to 12.9±1.5 at 3 months after surgery and 14.4±1.3 at the last follow-up. In the traction loosening type, all the 10 grade D patients were improved to grade E at the last follow-up. In the 2 grade C patients of traction stabilization type before surgery, 1 patient was improved to grade E, 1 patient was improved to grade D, and all 11 patients with grade D were improved to grade E at the last follow-up. Bony fusion was obtained in all patients from 3 to 6 months, with an average of 4.4±1.5 months. During follow-up period, no looseness of internal fixation or redislocation happened.Conclusion:Refractory atlantoaxial dislocation can be divided into traction loosening type and traction stabilization type. For traction loosening type, satisfactory reduction can be achieved by using posterior atlantoaxial screw-rod system without soft tissue release. For traction stabilization type, anterior release is preferable, and then anterior TARP or posterior screw-rod can be used to achieve satisfactory reduction.

An anatomical study of the external bone graft axis from the pedicle to the endplate from T10 to L5 in compression healing fractures of the anterior vertebral column / 中华创伤骨科杂志

Objective:To anatomically study the external bone graft axis from the pedicle (canal) to the endplate designed for compression healing fractures of the anterior vertebral column in freshly dried vertebral specimens from T10 to L5.Methods:Eight groups of freshly dried vertebral specimens from T10 to L5 (128 vertebral bodies and 256 lateral pedicles and lateral vertebral bodies) were used to observe the vertebral axis of the pedicle (canal), the internal sagittal diameter of the pedicle (canal), and the sagittal diameter of the vertebral body, and the position of vertebral pedicle (canal) axis (f-angle) before design of the external bone graft axis from the pedicle (canal) to the endplate of the compression healing vertebral body. (1) The internal sagittal diameter of the pedicle (canal) was divided into 3 segments. The lateral segment of the vertebral plate was wide, the middle segment of the isthmus of the vertebral arch was narrow and the medial segment of the terminal segment of the vertebral arch was wide. The narrow isthmus of the middle arch (canal) was used as a transposition axis in the design of the axis of the bone graft from the vertebral arch (canal) to the endplate of the compression healing vertebral body. (2) The axis of the vertebral body of the pedicle (canal) was located medial to the transposition axis, parallel to the f-angle at 0° as described by Saillant G. (3) The compression degree of the vertebral body was measured at the outer edge of the lateral anterior column, with Ⅰ° for less than 1/4 compression of the anterior column of the vertebral body, Ⅱ° for 1/4 to 2/4, Ⅲ° for 2/4 to 3/4 and Ⅳ° for more than 3/4 of the compression. (4) The f-angle described by Salliant G at the entry end which was corresponding to the endplate of the compression healing vertebral body was used to design the pedicle (canal) to the outer implant axis of the endplate of the compression healing vertebral body.Results:At an f-angle of 8° to 10°, the bone graft axis was aligned with the Ⅱ° compression healing vertebral endplate on the superior endplate side of the vertebral body axis of the arch; at an f-angle of 16° to 18°, the bone graft axis corresponded to the superior endplate of the Ⅰ° compression healing vertebral body. At an f-angle of -10°~-8°, the bone graft axis corresponded to the Ⅲ° compression healing vertebral endplate on the inferior endplate side of the vertebral body axis of the arch; at an f-angle of -18°~-16°, the bone graft axis corresponded to the inferior endplate of the Ⅳ° compression healing vertebral body.Conclusions:The external axis from the pedicle (canal) to the endplate designed in the present anatomic study for compression healing fractures of the anterior vertebral column allows for safe and easy granular bone implantation due to the toughness of the cortical bone around the arch root (canal) in addition to the precise design of the bone graft axis from the pedicle to the endplate from T10 to L5.

A clinical study of a novel manual screw placement based on anatomical study of the 7th cervical vertebra / 中华创伤骨科杂志

Objective:To evaluate the feasibility, accuracy, effectiveness and safety of a novel manual placement of cervical 7 pedicle screws via the posterior approach of cervicothoracic junction.Methods:A retrospective case series study was conducted to analyze the 35 patients with injury to the lower cervical spine or cervicothoracic junction who had been treated by a novel manual placement of cervical 7 pedicle screws at Department of Orthopedics, The First Affiliated Hospital of Zhengzhou University from March 2015 to July 2021. There were 16 males and 19 females, with an age of (52.7±13.2) years. The core of this placement was to determine the entry point of cervical 7 pedicle screws. After the intersection of the upper edge of the cervical 7 lamina and the medial edge of the superior articular process was recorded as point A while the intersection of the lateral edge of the inferior articular process and the lower edge of the transverse process as point B, the intersection of the outer and middle 1/3 of the AB line was taken as the screw entry point, with the screw placement angle perpendicular to the lamina line or slightly inclined from 30° to 40° to the head side and outward. The length, diameter and placement angle of the cervical 7 pedicle screws were recorded and compared postoperatively between the left and right sides to explore the feasibility of this novel manual placement. According to the Rampersaud method, the screw positions were graded 1 week and 6 months after operation to evaluate the accuracy of this manual placement. The visual analogue scale (VAS) and the Japanese Orthopaedic Association (JOA) score were compared between preoperation, 1 week and 6 months after operation to evaluate the effectiveness of this placement. The postoperative complications were counted to evaluate the safety of this method. Loosening, displacement and breakage of the screws were observed by CT scanning at 6 months after operation.Results:This case series was followed up for (9.8±1.7) months. There was no significant difference in the length, diameter or placement angle of the screws between the left and right sides ( P>0.05). A total of 66 cervical 7 pedicle screws were placed. There was no change in the screw position grading at 1 week or 6 months after surgery. Grade A was achieved in 64 screws, Grade B in 2 screws, and Grade C or D in none. The VAS scores before operation, 1 week and 6 months after operation were respectively 4.4±1.7, 3.8±1.0 and 1.1±1.1, and the JOA scores respectively 6.7±2.2, 13.2±1.5 and 15.3±1.2. The VAS and JOA scores at 1 week and 6 months after operation were significantly improved compared with the preoperative values ( P<0.05). The improvement rates in JOA at 1 week and 6 months after operation were 62.7%±13.3 % and 83.9%±11.6%, respectively. There were no complications related to the placement of cervical 7 pedicle screws; there was no wound hematoma or infection. No loosening, displacement or breakage of the screws was observed by the 6-month follow-up. Conclusion:The novel manual placement of cervical 7 pedicle screws via the posterior approach of cervicothoracic junction is feasible, accurate, effective and safe.

Evidence-based guideline for clinical diagnosis and treatment of acute combination fractures of the atlas and axis in adults (version 2023) / 中华创伤杂志

The acute combination fractures of the atlas and axis in adults have a higher rate of neurological injury and early death compared with atlas or axial fractures alone. Currently, the diagnosis and treatment choices of acute combination fractures of the atlas and axis in adults are controversial because of the lack of standards for implementation. Non-operative treatments have a high incidence of bone nonunion and complications, while surgeries may easily lead to the injury of the vertebral artery, spinal cord and nerve root. At present, there are no evidence-based Chinese guidelines for the diagnosis and treatment of acute combination fractures of the atlas and axis in adults. To provide orthopedic surgeons with the most up-to-date and effective information in treating acute combination fractures of the atlas and axis in adults, the Spinal Trauma Group of Orthopedic Branch of Chinese Medical Doctor Association organized experts in the field of spinal trauma to develop the Evidence-based guideline for clinical diagnosis and treatment of acute combination fractures of the atlas and axis in adults ( version 2023) by referring to the "Management of acute combination fractures of the atlas and axis in adults" published by American Association of Neurological Surgeons (AANS)/Congress of Neurological Surgeons (CNS) in 2013 and the relevant Chinese and English literatures. Ten recommendations were made concerning the radiological diagnosis, stability judgment, treatment rules, treatment options and complications based on medical evidence, aiming to provide a reference for the diagnosis and treatment of acute combination fractures of the atlas and axis in adults.

Application value of 3D print navigation module in the precise placement of thoracic and lumbar vertebral arch screws / 解剖学报

[ Abstract ] Objective To explore the effect of 3D print-based navigation module assisted placement of thoracolumbar pedicle screws. Methods From January 2019 to May 2021, we received 70 thoracic and lumbar fracture patients, divided into 3D technical group and conventional method group according to the surgical method, with 35 patients in each group. In the 3D technology group, pedicle screws were placed under the sight of the navigation module, while in the conventional group, pedicle screws were placed under the conventional C-arm fluoroscopy. The amount of intraoperative bleeding and time of C arm were counted in each patient. According to the different number of pedicle screw implantation in each patient, the average amount of blood loss, time and C-arm fluoroscopy times of each screw implantation were compared between the two groups. Ideal screw angles were designed for patients in both groups before surgery. Compared with the preoperative design, the difference between preoperative and postoperative screw angle and head angle was calculated and set as the deviation value. Two sets of data were compared. Visual analogue score(VAS), Japanese Orthopaedic Association (JOA) score, Oswestry disability index(ODI), vertebral height recovery ratio and Cobb’ s angle were compared between the two groups. Results The amount of blood loss, required time and exposure times of C-arm in 3D screw implantation group were significantly lower than those in conventional screw implantation group(P0. 05); In terms of Cobb’s angle and vertebral height recovery ratio, the 3D technique group was better than the conventional method group (P<0. 05). Conclusion The 3D printed navigation module can assist the precise placement of thoracolumbar pedicle screws, shorten the operation time, reduce intraoperative bleeding and c-arm exposure times, facilitate the recovery of the injured vertebral height, improve the efficacy.

Robot-assisted PVP for the treatment of osteoporotic fractures of the upper thoracic vertebra / 中国骨伤

OBJECTIVE@#To investigate the clinical effect of "Tianji" orthopedic robot-assisted percutaneous vertebro plasty(PVP) surgery in the treatment of upper thoracic osteoporotic fracture.@*METHODS@#A retrospective analysis was performed on 32 patients with upper thoracic osteoporotic fracture who underwent PVP surgery in Shenzhen Hospital of Traditional Chinese Medicine from August 2016 to June 2022. There were 8 males and 24 females, ranging in age from 58 to 90 years old, with a mean of (67.75±12.27) years old. Fifteen patients were treated with robot-assisted PVP surgery (robot group), including 3 males and 12 females, with an average age of (68.5±10.3) years. Fracture location:1 case of T2 fracture, 1 case of T3 fracture, 3 cases of T4 fracture, 3 cases of T5 fracture, and 7 cases of T6 fracture. The follow-up period ranged from 1.0 to 3.0 months, with a mean of (1.6±0.7) months. Seventeen patients underwent routine PVP surgery (conventional group), including 5 males and 12 females, with an average age of (66.8±11.6) years old. Fracture location:1 case of T1 fracture, 5 cases of T4 fracture, 2 cases of T5 fracture and 9 cases of T6 fracture. The follow-up period ranged from 0.5 to 4.0 months, with a mean of (1.5±0.6) months. Preoperative and postoperative visual analogue scale(VAS) and Oswestry disability index(ODI) scores were compared between the two groups, and the number of punctures, perspective times, operation time, intraoperative blood loss, bone cement distribution, bone cement leakage, and intraoperative radiation dose were compared between the two groups.@*RESULTS@#Number of punctures times, perspective times, operation time, intraoperative blood loss, bone cement distribution, bone cement leakage and intraoperative radiation dose in the robot group were all significantly better than those in the conventional group(P<0.05). VAS of 2.03±0.05 and ODI of (22.16±4.03) % in the robot group were significantly better than those of the robot group before surgery, which were (8.67±0.25) score and (79.40±7.72)%(t=100.869, P<0.001;t=25.456, P<0.001). VAS of 2.17±0.13 and ODI of (23.88±6.15)% in the conventional group were significantly better than those before surgery, which were (8.73±0.18) score and (80.01±7.59)%(t=121.816, P<0.001;t=23.691, P<0.001). There was no significant difference in VAS and ODI between the two groups after operation (t=-3.917, P=0.476;t=-0.922, P=0.364).@*CONCLUSION@#Robot-assisted PVP in the treatment of upper thoracic osteoporotic fractures can further improve surgical safety, reduce bone cement leakage, and achieve satisfactory clinical efficacy.

Preliminary observation on the clinical application of rehabilitation support for lumbar disc herniation based on 3D printing technology / 中国骨伤

OBJECTIVE@#To analyze the important effect of 3D printing personalized lumbar support on lumbar pain and lumbar function in patients with lumbar disc herniation.@*METHODS@#From October 2018 to May 2021, 60 patients initially diagnosed with lumbar disc herniation were selected and divided into an observation group and a control group, with 30 patients in each group. Among them, there were 18 males and 12 females in the observation group;the age ranged from 24 to 56 years old, with an average of (45.23±6.07) years old. The course of disease ranged from 1 to 24 months, with an average of(6.25±0.82) months, and rehabilitation treatment was carried out by wearing 3D printed personalized lumbar support. There were 19 males and 11 females in the control group;the age ranged from 25 to 57 years old, with an average of (42.78±7.58) years old. The course of disease ranged from 1 to 24 months, with an average of (6.72±1.36) months, and rehabilitation treatment is carried out by wearing traditional lumbar protective equipment. The Japanese Orthopaedic Association (JOA) scores, lumbar Oswestry dysfunction index (ODI) and visual analogue scale (VAS) were evaluated and compared between the two groups before and 1 course after treatment (3 weeks).@*RESULTS@#There was no statistically significant difference in JOA, ODI, and VAS between two groups before treatment (P>0.05). After one course of treatment (3 weeks), JOA scores of both groups was increased compared to before treatment (P<0.05), while ODI and VAS decreased compared to before treatment (P<0.05). After treatment, JOA score of observation group was higher than that of control group (P<0.05), while ODI and VAS scores were lower than those of control group. No adverse events occurred in both groups.@*CONCLUSION@#The application of 3D printing personalized lumbar support can effectively alleviate the pain of patients with lumbar disc herniation and improve their lumbar function of patients.

Effectiveness of sagittal top compression reduction technique in treatment of thoracolumbar vertebral fractures / 中国修复重建外科杂志

OBJECTIVE@#To investigate the effectiveness of sagittal top compression reduction technique in the treatment of thoracolumbar vertebral fractures.@*METHODS@#A retrospective analysis was conducted on the clinical data of 59 patients with thoracolumbar vertebral fractures who met the selection criteria and were admitted between November 2018 and January 2022. Among them, 34 patients were treated with sagittal top compression reduction technique (top pressure group), and 25 patients were treated with traditional reduction technique (traditional group). There was no significant difference in baseline data between the two groups ( P>0.05), including gender, age, fracture segment, cause of injury, AO classification of thoracolumbar vertebral fractures, thoracolumbar injury classification and severity (TLICS) score, American Spinal Injury Association (ASIA) grading, surgical approach, preoperative vertebral body index, height ratio of the anterior margin of injured vertebra, injured vertebra angle, segmental kyphosis angle, visual analogue scale (VAS) score, and Oswestry disability index (ODI). The operation time, intraoperative blood loss, and incidence of complications between the two groups were recorded and compared. After operation, VAS score and ODI were used to evaluate effectiveness, and X-ray and CT examinations were performed to measure imaging indicators such as vertebral body index, height ratio of the anterior margin of injured vertebra, injured vertebra angle, and segmental kyphosis angle.@*RESULTS@#There was no significant difference in operation time and intraoperative blood loss between the two groups ( P>0.05). No complication such as dural sac, nerve root, or vascular injury was found during operation, and all incisions healed by first intention. Patients in both groups were followed up 6-48 months, with an average of 20.6 months. No loosening, breakage, or failure of internal fixation occurred during follow-up. The imaging indicators, VAS score, and ODI of the two groups significantly improved at 1 week and last follow-up when compared to preoperative ones ( P<0.05). At last follow-up, the VAS score and ODI further significantly improved when compared to 1 week after operation ( P<0.05). At 1 week after operation and last follow-up, the vertebral body index, segmental kyphosis angle, injured vertebra angle, and ODI in the top pressure group were significantly better than those in the traditional group ( P<0.05). There was no significant difference in VAS score and height ratio of the anterior margin of injured vertebra between the two groups at 1 week after operation ( P>0.05), but the two indicators in the top pressure group were significantly better than those in the traditional group at last follow-up ( P<0.05).@*CONCLUSION@#The treatment of thoracolumbar vertebral fractures with sagittal top compression reduction technique can significantly improve the quality of vertebral reduction, and is superior to traditional reduction techniques in relieving pain and improving spinal function.