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.

Medical Students Training and Mental Health: An Exploratory Study

Introduction: Medical students are vulnerable to psychological distress and face a number of stressors such as academic pressures, economic concerns, and difficulties in interpersonal relationships. The quality of their educational training may also impact their mental health and subjective well-being. Objective: to describe their perception of subjective well-being and the impact of medical training on their own mental health. Methods: We surveyed 119 medical students and administered the "Perception survey on vocation, living and recreational habits, training and professional attitudes," the CAGE questionnaire, the Generalized Anxiety Disorder-7 (GAD-7) and the Patient Health Questionnaire-2 (PHQ-2). Results: Students' mean age was 22.5±2.28 years old and 59.7 % of participants were women, their lifestyle habits were scored as acceptable, and the employment of cell-phones and social networks ranged 76-99%; 24.1 % recognized a problematic alcohol, 67.2 % reported anxiety according to the GAD-7, and 49.6 % depression according to PHQ-2. Symptoms of anxiety were frequent among females and were higher when the perceived quality of training and student/teacher ratio were lower. Discussion: Students' perceptions of lower quality of training and resources seemed to be associated with higher levels of anxiety, which may suggest that educational policies and resources should be carefully revised and implemented to improve students' health and well-being.

Introducción: los estudiantes de medicina son vulnerables al malestar psicológico y se enfrentan a una serie de factores estresantes como las presiones académicas, las preocupaciones económicas y las dificultades en las relaciones interpersonales. La calidad de su formación educativa también puede influir en su salud mental y bienestar subjetivo. Objetivo: describir su percepción de bienestar subjetivo y el impacto de la formación médica en su propia salud mental. Metodología: se encuestó a 119 estudiantes de medicina y se les administró la "Encuesta de percepción sobre vocación, hábitos de vida y recreación, formación y actitudes profesionales", el cuestionario CAGE, el Trastorno de Ansiedad Generalizada-7 (TAG-7) y el Cuestionario de Salud del Paciente-2 (PHQ-2). Resultados: la edad media de los estudiantes fue de 22,5±2,28 años y el 59,7 % de los participantes eran mujeres; sus hábitos de vida se calificaron como aceptables, y el empleo de teléfonos móviles y redes sociales osciló entre el 76 y el 99 %; el 24,1 % reconoció un consumo problemático de alcohol, el 67,2 % manifestó ansiedad según el TAG-7, y el 49,6 % depresión según el PHQ-2. Los síntomas de ansiedad eran frecuentes entre las mujeres y eran mayores cuando la calidad percibida de la formación y la proporción alumnos/profesor eran menores. Discusión: la percepción por parte de los estudiantes de una menor calidad de la formación y de los recursos parecía estar asociada a mayores niveles de ansiedad, lo que puede sugerir que las políticas y los recursos educativos deberían revisarse y aplicarse cuidadosamente para mejorar la salud y el bienestar de los estudiantes.

Biomechanical Analysis on NiTi Memory Alloy Stent for Lumbar Interbody Fusion / 医用生物力学

Objective To evaluate biomechanical properties of the nickel-titanium (NiTi) memory alloy stent and its in vitro biomechanical properties for lumbar interbody fusion. Methods The mechanical properties of the NiTi memory alloy stent were tested on mechanical testing machine. Moreover, lumbar interbody fusion was simulated on fresh lumbar specimens, and biomechanical properties of the NiTi memory alloy stent with matching bone graft for used for lumbar interbody fusion were analyzed and compared with the traditional box-shape cage. Results The maximum compressive strength of the NiTi memory alloy stent was ( 12 964 ± 962) N. The maximum deformation within the effective range of memory characteristics was (4. 68±0. 03) mm. The recovery rate of the NiTi memory alloy stent was up to 99. 86% . Compared with the intact lumbar model, the stability of the operative segment after the simulated lumbar interbody fusion using NiTi memory alloy stent alone was increased in the direction of anterior flexion, posterior extension, lateral flexion and rotation, which was equivalent to the box shape cage group (P>0. 05). After the combined use of autogenous bone granule and absorbable bone cement the ROM of the operative segment was further reduced (P0. 05). The pull-out strength of the NiTi memory alloy stent with matching bone graft group was significantly stronger than that of the box-shape cage group (P<0. 05). Conclusions The NiTi memory alloy stent in this study was designed with a matched bone granule-absorbable bone cement graft,which provided a new idea for the further optimization and development of lumbar interbody fusion. With excellent support and deformation properties, this NiTi memory alloy stent is biomechanical equivalent to the traditional box shape cage for lumbar interbody fusion, and can greatly improve the stability of surgical segment and the pull-out strength of implants after the combined use of autogenous bone granule and absorbable bone cement.

Biomechanical Study on Atlantoaxial Dislocation Combined with Basilar Invagination by Different Posterior Internal Fixation Methods / 医用生物力学

Objective To investigate biomechanical differences of two posterior occipitocervical internal fixation techniques for treating basilar invagination with atlantoaxial dislocation (BI-AAD). Methods Intra-articular cage + posterior occipital plate+C2 pedicle screw (Cage+C2PS+OP), and intra-articular cage+C1 lateral mass screw+C2PS (Cage+C1LMS+C2PS) models were established based on occipitocervical CT data of the BI-AAD and clinical operation scheme, and the stability of atlantoaxial joint and stress distribution characteristics of C2 endplate and implanted instruments under different motion states were analyzed. Results Compared with the Cage+C1LMS+C2PS model, the atlantoaxial range of motion ( ROM) under flexion, extension, lateral bending and axial rotation in the Cage+C2PS+OP model were reduced by 5. 26% , 33. 33% , 43. 75% , -5. 56% , and stress peak of screw-rod fixation system were reduced by 47. 81% , 60. 90% , 48. 45% , 39. 14% , respectively. Under two internal fixation modes, stresses of C2 endplate and cage were mainly distributed on the compressive side during the motion, and both the screw-bone interface and the caudal side of screw subjected to large loading. Conclusions Two internal fixation methods could provide similar stability. However, the stress concentration of screw-rod system was more obvious and the possibility of screw loosening and fracture was greater under Cage+ C1LMS+C2PS fixation.

Early outcomes of the bird-cage chest wall reconstruction in the Philippine General Hospital

Objective@#To describe the treatment outcomes of patients with chest wall tumors undergoing resection and Birdcage chest wall reconstruction in the local setting. @*Methods@#Data were obtained from 13 patients who underwent chest wall resection and Bird-cage (methylmethacrylate neo-rib, mesh, soft tissue, and skin) reconstruction in the Philippine General Hospital from January 2008 to September 2019. Demographics, operative procedures, 30-day operative morbidity, and mortality were evaluated using means and frequencies.@*Results@#We included 13 (77% female) patients with a mean age of 44.5 years. The most common indication for chest wall resection was recurrent neoplasm (5/13, 38.46%). The most extensive chest wall defect was 600 cm2. The average length of ICU stay was 5.15 days, and two patients had prolonged intubation (>3 days). The graft infection rate was 38%, pneumonia 23%, and the operative mortality rate was zero.@*Conclusion@#Bird-cage reconstruction is a safe, reliable, and cheap method of providing rigid chest wall reconstruction for chest wall tumor resection.

3D-printed vertebral body in anterior spinal reconstruction after total spondylectomy for patients with cervical chordoma / 北京大学学报(医学版)

OBJECTIVE@#To investigate whether 3D-printed artificial vertebral body can reduce prosthesis subsidence rate for patients with cervical chordomas, through comparing the rates of prosthesis subsidence between 3D printing artificial vertebral body and titanium mesh for anterior spinal reconstruction after total spondylectomy.@*METHODS@#This was a retrospective analysis of patients who underwent surgical treatment for cervical chordoma at our hospital from March 2005 to September 2019. There were nine patients in the group of 3D artificial vertebral body (3D group), and 15 patients in the group of titanium mesh cage (Mesh group). The patients' characteristics and treatment data were extracted from the medical records, including age, gender, CT hounsfield unit of cervical vertebra and surgical information, such as the surgical segments, time and blood loss of surgery, frequency and degree of prosthesis subsidence after surgery. Radiographic observations of prosthesis subsidence during the follow-up, including X-rays, CT, and magnetic resonance imaging were also collected. SPSS 22.0 was used to analysis the data.@*RESULTS@#There was no significant difference between the two groups in gender, age, CT hounsfield unit, surgical segments, time of surgery, blood loss of posterior surgery and total blood loss. Blood loss of anterior surgery was 700 (300, 825) mL in 3D group and 1 500 (750, 2 800) mL in Mesh group (P < 0.05). The prosthesis subsidence during the follow-up, 3 months after surgery, there was significant difference between the two groups in mild prosthesis subsidence (P < 0.05). The vertebral height of the 3D group decreased less than 1 mm in eight cases (no prosthesis subsidence) and more than 1 mm in one case (mild prosthesis subsidence). The vertebral height of the Mesh group decreased less than 1 mm in five cases (no prosthesis subsidence), and more than 1 mm in eight cases (mild prosthesis subsidence). Two patients did not have X-rays in 3 months after surgery. There was a statistically significant difference between the two groups in the prosthesis subsidence rate at the end of 12 months (P < 0.01). The vertebral height of eight cases in the 3D group decreased less than 1 mm (no prosthesis subsidence) and one case more than 3 mm (severe prosthesis subsidence). Four of the 15 cases in the Mesh group decreased less than 1 mm (no prosthesis subsidence), two cases more than 1 mm (mild prosthesis subsidence), and nine cases more than 3 mm (severe prosthesis subsidence). There was a statistically significant difference between the two groups in the prosthesis subsidence rate at the end of 24 months (P < 0.01). The vertebral height of seven cases in the 3D group decreased less than 1 mm (no prosthesis subsidence), one case more than 3 mm (severe prosthesis subsidence), and one case died with tumor. One case in the Mesh group decreased less than 1 mm (no prosthesis subsidence), one case more than 1 mm (mild prosthesis subsidence), 11 case more than 3 mm (severe prosthesis subsidence), one case died with tumor and one lost the follow-up. Moreover, at the end of 12 months and 24 months, there was significant difference between the two groups in severe prosthesis subsidence rate (P < 0.01).@*CONCLUSION@#3D-printed artificial vertebral body for anterior spinal reconstruction after total spondylectomy for patients with cervical chordoma can provide reliable spinal stability, and reduce the incidence of prosthesis subsidence after 2-year follow-up.

Monoterpenoids from Paeoniae Radix Rubra based on UPLC-Q-TOF-MS / 中国中药杂志

The ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry(UPLC-Q-TOF-MS) was used to conduct the qualitative analysis of the monoterpene chemical components from Paeoniae Radix Rubra. Gradient elution was performed on C_(18) HD(2.1 mm×100 mm, 2.5 μm) column with a mobile phase of 0.1% formic acid(A) and acetonitrile(B). The flow rate was 0.4 mL·min~(-1) and the column temperature was 30 ℃. MS analysis was conducted in both positive and negative ionization modes using electrospray ionization(ESI) source. Qualitative Analysis 10.0 was used for data processing. The identification of chemical components was realized by the combination of standard compounds, fragmentation patterns, and mass spectra data reported in the literature. Forty-one monoterpenoids in Paeoniae Radix Rubra extract were identified. Among them, 8 compounds were reported in Paeoniae Radix Rubra for the first time and 1 was presumed to be the new compound 5″-O-methyl-galloylpaeoniflorin or its positional isomer. The method in this study realizes the rapid identification of monoterpenoids from Paeoniae Radix Rubra and provides a material and scientific basis for quality control and further study on the pharmaceutical effect of Paeoniae Radix Rubra.

Knowledge of alcohol consumers towards alcoholic liver disease in Afikpo, Ebonyi, Nigeria A community-based cross-sectional study

Background: Daily alcohol consumption above recommended limits is an important cause of Alcoholic Lher Disease. Hence, this study aimed to assess the knowledge of Alcoholic Liver Disease among alcohol consumers and screenfor alcohol misuse, dependence, and disorder. Methods: A community-based cross-sectional survey using simple random sampling technique was conducted on residents ofÅfikpo age 15 and above who consume alcohol using a structured questionnaire to obtain information on alcoholic use disorder and alcohol dependence. The sample size Itas determined Il'ith the aid of a Raosoft sample size calculator. Data obtained was entered into an excel spreadsheetfor data cleaning. The frequency, percentages and mean and Standard deviation was also obtained. Data was exported into IBM SPSS to determine the relationship behre.en knou:ledge of Alcoholic Liver Disease and demographic variables using One-way ANOL4 and Chi-Square Il'here appropriate at P-value <0.05 and 5% significance level. Results: The total number of study participants was 435 with a response rate of 97%. Out of which had a good knowledge of Alcoholic Liver Disease. Adults above the age of 60 had a mean audit score of 12.808 Il'hile male respondents had a mean audit score of 11.395. Adolescents had a mean CAGE test score of 1.89 while adults above 60 scored 2.48. Hou•ever, participants with no education had the highest mean CAGE score of2.27. The males had good knowledge ofAlcoholic Liver Disease. (P 0.006). Conclusion: The residents ofÅfikpo community have a good knowledge ofAlcoholic Lher Disease though there is alcohol use disorder, alcohol misuse and dependence amongst residents in the community. Gender is the only demographic characteristics that influenced the knowledge ofAlcoholic Liver Disease

Desvendando a técnica de compressão torácica em pacientes em ventilação mecânica: uma revisão narrativa / A deep look into the rib cage compression technique in mechanically ventilated patients: a narrative review

RESUMO O manejo deficiente das secreções é uma das complicações mais frequentes em pacientes em ventilação mecânica invasiva. A depuração das secreções por meio da fisioterapia respiratória é um aspecto crítico do tratamento desses pacientes. A compressão torácica manual é uma das técnicas de fisioterapia respiratória mais praticadas em pacientes ventilados, mas seu impacto nos desfechos clínicos permanece controverso devido a questões metodológicas e ao pouco conhecimento sobre sua ação. Nesta revisão, apresenta-se uma análise detalhada dos princípios físicos envolvidos na execução da técnica de compressão torácica. Também investigam-se os efeitos fisiológicos observados em estudos experimentais e clínicos, que mostram que o uso de compressão torácica curta e vigorosa, baseada no aumento de fluxos expiratórios (diferença de fluxo aéreo inspiratório-expiratório > 33L/minuto), pode melhorar o movimento do muco em direção à glote. Por outro lado, o uso de compressão torácica suave e gradual ao longo de toda a fase expiratória não afeta os fluxos expiratórios, resultando em efeitos ineficazes ou indesejados em alguns casos. Mais estudos fisiológicos são necessários para entender os princípios da técnica de compressão torácica em pacientes ventilados. No entanto, de acordo com as evidências, a compressão torácica tem mais benefícios potenciais do que riscos, o que incentiva sua implementação.

ABSTRACT Defective management of secretions is one of the most frequent complications in invasive mechanically ventilated patients. Clearance of secretions through chest physiotherapy is a critical aspect of the treatment of these patients. Manual rib cage compression is one of the most practiced chest physiotherapy techniques in ventilated patients; however, its impact on clinical outcomes remains controversial due to methodological issues and poor understanding of its action. In this review, we present a detailed analysis of the physical principles involved in rib cage compression technique performance, as well as the physiological effects observed in experimental and clinical studies, which show that the use of brief and vigorous rib cage compression, based on increased expiratory flows (expiratory-inspiratory airflow difference of > 33L/minute), can improve mucus movement toward the glottis. On the other hand, the use of soft and gradual rib cage compression throughout the whole expiratory phase does not impact the expiratory flows, resulting in ineffective or undesired effects in some cases. More physiological studies are needed to understand the principles of the rib cage compression technique in ventilated humans. However, according to the evidence, rib cage compression has more potential benefits than risks, so its implementation should be promoted.

Effects of posterior pedicle screw internal fixation on early Cage subsidence after oblique lateral lumbar interbody fusion / 西安交通大学学报(医学版)

【Objective】 To investigate the effects of one-stage additional posterior pedicle screws （PPS） internal fixation on early Cage subsidence after oblique lateral interbody fusion （OLIF）. 【Methods】 We made a retrospective analysis of 118 patients with lumbar degenerative diseases treated with OLIF at the Department of Orthopedics， Sir Run Run Shaw Hospital， School of Medicine， Zhejiang University， from January 2016 to December 2019. We divided the patients into OLIF stand-alone group （58 ones） and OLIF with PPS fixation group （60 ones） according to the surgical procedure. All the patients had preoperative frontal and lateral radiographs of the lumbar spine， and CT and MR scans were performed. The clinical outcomes and reoperation rates of the two groups were compared at immediate postoperative follow-up and at 1， 3， 6 and 12 months. X-ray and CT examinations were performed to assess Cage subsidence in both groups at each postoperative follow-up. 【Results】 There was no statistical difference between the two groups in baseline data and surgical segmentation. Of the 118 patients with 141 discs who underwent OLIF surgery， 58 patients with 68 discs received OLIF stand-alone surgery and 60 ones with 73 discs received OLIF with PPS fixation. There were no significant differences in intraoperative bleeding， complications， or postoperative clinical outcomes between the two groups （P>0.05）， and the Cage subsidence rate was 22.4% in OLIF stand-alone group and 5% in OLIF with PPS fixation group， with significant difference between the two groups （P<0.01）. 【Conclusion】 Both OLIF stand-alone and OLIF additional PPS fixation can achieve good early clinical outcomes， and first-stage additional PPS fixation can significantly reduce the occurrence of Cage subsidence in the early postoperative period after OLIF.

Tripodalsporormielones A-C, unprecedented cage-like polyketides with complex polyvdent bridged and fused ring systems

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Research progress on three-dimensional printed interbody fusion cage / 生物医学工程学杂志

Spinal fusion is a standard operation for treating moderate and severe intervertebral disc diseases. In recent years, the proportion of three-dimensional printing interbody fusion cage in spinal fusion surgery has gradually increased. In this paper, the research progress of molding technology and materials used in three-dimensional printing interbody fusion cage at present is summarized. Then, according to structure layout, three-dimensional printing interbody fusion cages are classified into five types: solid-porous-solid (SPS) type, solid-porous-frame (SPF) type, frame-porous-frame (FPF) type, whole porous cage (WPC) type and others. The optimization process of three-dimensional printing interbody fusion cage and the advantages and disadvantages of each type are analyzed and summarized in depth. The clinical application of various types of 3D printed interbody fusion cage was introduced and summarized later. Lastly, combined with the latest research progress and achievements, the future research direction of three-dimensional printing interbody fusion cage in molding technology, application materials and coating materials is prospected in order to provide some reference for scholars engaged in interbody fusion cage research and application.

Recent Advances of Biomechanical Studies on Cervical Spine Anatomy and Titanium Mesh Cage / 医用生物力学

Titanium mesh cage is one of the fusion devices used in anterior cervical corpectomy and fusion (ACCF). It can not only immediately rebuild the stability of cervical spine during the operation, maintain the height and physiological curvature of intervertebral vertebrae, but also avoid the complications of bone donor area caused by autologous bone extraction. Therefore, titanium mesh cage has become the most commonly used internal plant in ACCF. However, there exist many problems in traditional titanium cage, such as stress shielding and titanium cage sinking, which will affect the surgical effect to a certain extent, and even lead to serious postoperative complications requiring revision surgery. At present, a variety of new titanium cages have been invented, which can solve the problems caused by traditional titanium cage to a certain extent. Biomechanical evaluation and its testing methods are an indispensable process for judging whether a new type of spinal fusion cage can be used in clinical practice. This article reviews the biomechanical studies related to cervical spine anatomy, the biomechanical properties of traditional titanium cages and new titanium cages, so as to provide new ideas for the improvement of traditional titanium cages and the development of new titanium cages.

Finite Element Analysis of Lumbar Interbody Fusion with Stent-Bone Granule-Absorbable Bone Cement / 医用生物力学

Objective To evaluate the biomechanical properties of lumbar interbody fusion with NiTi memory alloy stent-autogenous bone granule-absorbable bone cement. Methods The normal L3-5 segment finite element model (M0), L4-5 intervertebral fusion model with box fusion cage (M1), L4-5 intervertebral fusion model with NiTi memory alloy stent (M2) and L4-5 interbody fusion model with bone granule-absorbable bone cement for casting bone graft (M3) were constructed, respectively. The models were applied with mechanical loading to analyze the mechanical stability and the peak stress of L4 interior endplate. Results The range of motion (ROM) of L4-5 segment in M1 and M2 models was significantly lower than that of M0 model under flexion, extension, lateral flexion and axial rotation. In M3 model, the stability of the surgical segment was further improved and the peak stress of L4 interior endplate was much smaller than that of M1 and M2 models. Conclusions NiTi memory alloy stent and traditional box fusion cage have biomechanical equivalence when used alone in lumbar interbody fusion, and application of bone granule-absorbable bone cement for casting bone graft can further improve the stability and reduce the stress of endplate.

Optimization Design and Evaluation of Three-Dimensional Printed PEEK Cervical Interbody Fusion Cage with Adjustable Height / 医用生物力学

Objective Aiming at the clinical problem of the low matching degree with the patient’s anatomical morphology for traditional cervical fusion cage, a cervical fusion cage with the function of adjustable height and the shape matched with the vertebral body was established, and its biomechanical properties were evaluated. Methods A cervical C4-5 segment fusion model was established according to anterior cervical discectomy and fusion (ACDF), so as to simulate different motion conditions, i.e. anterior flexion, posterior extension, left/right lateral flexion, left/right rotation, and stress of the fusion cage and vertebral endplate was calculated. After three-dimensional (3D) printing of the fusion cage, an in vitro mechanical experiment was conducted to explore safety and stability of the fusion cage. ResultsThe fusion cage could keep the range of motion (ROM) of cervical vertebrae at the fusion segment with 1°-2.8° and reduce the ROM to 40%-80% of the natural segment. In the in vitro compression test, the yield load of the fusion cage was (2 721.67±209) N, which met the maximum demand of the physiological load in service state. Conclusions The designed fusion device with adjustable height shows better biomechanical properties and can reduce the selection step in operation.

Development of a lumbosacral intervertebral cage prototype for dogs / Desenvolvimento de um protótipo de cage intervertebral lombossacro para cães

Several surgical procedures aim to decompress and/or stabilize the lumbosacral (LS) joint of dogs; however, the lumbar interbody fusion technique, by using a cage combined with a bone graft, is the most indicated and used in human medicine. No specific implant is available for application to the canine lumbosacral joint. Thus, this study measured lumbosacral discs in large dogs, determined whether a human cage model could fit the dogs' L7-S1 intervertebral space, and developed a LS cage prototype for dogs. Ten cadaveric lumbosacral spines from adult dog weighing 20-35kg were used. The dogs had died for reasons unrelated to this study. The vertebral body dimensions and the L7-S1 intervertebral space occupied by the intervertebral disc were measured by lateral and ventrodorsal radiographs and by computed tomography in the dorsal, sagittal, and transverse views. Measurements were also taken of the anatomical specimens in the sagittal and transverse planes. After measuring the intervertebral discs, the following mean measures were obtained for L7-S1 discs: height 12.23mm, dorsal thickness 3.3mm, central thickness 4mm, ventral thickness 5.5mm, and width 24.74mm. The human lumbar cage models from brands LDR, Baumer Orthopedics, Stryker, Synthes, and Vertebral Technologies, Inc. and cervical stabilization cages from the brands B-Braun and Stryker were evaluated and were found to be unsuitable for large dogs. Cervical human cages had measurements similar to those found in this study; however, due to their quadrangular shape, the possibility of being introduced surgically through the surgical accesses available for the articulation between L7-S1 in dogs without injuring the cauda equina or the L7 root is small. A cage model was then developed using 3D modelling software. It was designed for insertion via dorsal laminectomy in the lateral portions of the intervertebral space. To avoid cauda equina lesion, the implant model was developed to be placed laterally to the midline. The cage surface is serrated to prevent using the locking screw to fix it, thus avoiding further injury to nerve structures. The serrated surfaces are also designed to avoid cage migration and promote stability. The prototype allows graft placement in the surrounding intervertebral space, which is fundamental for fusion through integration between the cage and the endplates as well as for bone growth between and around the cage. It was also considered studies on humans showing that the lateral regions of the endplates support a more considerable load. Biomechanical and in vivo studies on the developed model are necessary to evaluate the actual degree of distraction, mobility and the long-term rate of fusion between L7 and S1 and its possible impact on the adjacent motor units, combined or not with dorsal fixation techniques.(AU)

Vários procedimentos cirúrgicos visam descomprimir e/ou estabilizar a articulação lombossacra (LS) de cães; no entanto, a técnica de fusão lombar, usando um cage intersomático combinado com um enxerto ósseo, é a mais indicada e utilizada na medicina humana. Não há implante específico disponível para aplicação na articulação lombossacra canina. Assim, neste estudo foi realizada a mensuração do espaço do disco intervertebral lombossacro de cães de raças grandes, para verificar se algum modelo de cage usado na medicina humana poderia ser usado no espaço intervertebral L7-S1 de cães. O segundo objetivo foi desenvolver um protótipo de cage lombossacro para cães. Foram utilizadas dez colunas lombossacras provenientes de cadáveres de cães adultos com peso entre 20 e 35kg. Os cães vieram a óbito por razões não relacionadas a este estudo. As dimensões do corpo vertebral e o espaço intervertebral L7-S1 ocupado pelo disco intervertebral foram medidos por radiografias laterais e ventrodorsais e por tomografia computadorizada nos cortes dorsal, sagital e transversal. Também foram realizadas mensurações das peças anatômicas nos planos sagital e transversal. Após a mensuração dos discos intervertebrais, foram obtidas as seguintes medidas médias dos discos L7-S1: altura 12,23mm, espessura dorsal 3,3mm, espessura central 4mm, espessura ventral 5,5mm e largura 24,74mm. Os modelos de cage lombar humano das marcas LDR, Baumer Orthopaedics, Stryker, Synthes e Vertebral Technologies, Inc. não possuíam dimensões adequadas para os cães. Cages de estabilização cervical das marcas B-Braun e Stryker também foram avaliados e apresentaram medidas semelhantes às encontradas neste estudo; no entanto, devido à sua forma quadrangular, a possibilidade de serem introduzidos cirurgicamente através das abordagens disponíveis para a articulação entre L7-S1 em cães sem lesionar a cauda equina ou a raiz L7 é pequena. Um modelo de cage foi então desenvolvido usando-se o software de modelagem 3D. Foi projetado para inserção via laminectomia dorsal nas porções laterais do espaço intervertebral. Para evitar a lesão da cauda equina, o modelo de implante foi desenvolvido para ser colocado lateralmente à linha média. A superfície do cage é serrilhada para evitar o uso do parafuso de travamento, evitando-se lesões adicionais às estruturas nervosas. As superfícies serrilhadas também foram projetadas para evitar a migração do cage e promover estabilidade. O protótipo permite a colocação do enxerto no espaço intervertebral circundante, fundamental para a fusão através da integração entre o cage e as placas vertebrais terminais, bem como para o crescimento ósseo entre e ao redor do implante. Também foram considerados estudos em seres humanos que mostraram que as regiões laterais das placas vertebrais terminais suportam uma carga maior. São necessários estudos biomecânicos e in vivo do modelo desenvolvido para avaliar o grau real de distração, mobilidade e a taxa de fusão a longo prazo entre L7 e S1 e seu possível impacto nas unidades motoras adjacentes, quando combinado ou não com técnicas de fixação dorsal.(AU)

Clinical management of dogs with presumptive diagnosis of cervical intervertebral disc disease: 78 cases (2006-2017) / Tratamento clínico de cães com diagnóstico presuntivo de doença do disco intervertebral cervical: 78 casos (2006-2017)

This study aimed to identify dogs with a presumptive diagnosis of cervical intervertebral disc disease (IVDD; C1-C5 or C6-T2) submitted to clinical management and evaluate the outcome. This study also aimed to demonstrate the age, sex, and treatment response according to the neurological degree, and verify whether those factors could potentially influence the outcome. The data were obtained from patients with a neurological dysfunction, admitted at the Veterinary Hospital from January 2006 to March 2017. In addition to patient records, the tutors answered a questionnaire related to the success of therapy. A hundred and seventy-seven neurological records were evaluated, and 78 were included in the study according to the inclusion criteria. The most frequent breeds were Dachshunds, followed by mixed-breed dogs. Regarding the neurological dysfunction degree, 58.97% presented grade I (only neck pain), 25.64% were grade II (ambulatory tetraparesis), and 15.38% grade III (nonambulatory tetraparesis). Absolute and partial space rest were performed in 75.64% and 24.36% of the cases, respectively. The minimum rest time was one week and could come up to four weeks. Most dogs were small-sized (≤15kg). The recovery was satisfactory in 87.17% of dogs and unsatisfactory in 12.83%. Regarding recurrence, we observed that 10.3% of dogs presented satisfactory recovery. The clinical treatment for dogs with cervical IVDD can be indicated with adequate clinical response to dysfunction degrees ranging from I to III, either at rest or in restricted space and with a low rate of relapse.(AU)

O objetivo desse estudo foi identificar cães com diagnóstico presuntivo de doença do disco intervertebral cervical (DDIV; C1-C5 ou C6-T2) submetidos ao tratamento clínico e avaliar a resposta a terapia instituída e o índice de recidiva. Esse estudo também visou demonstrar a idade, o gênero e a resposta ao tratamento de acordo com o grau neurológico, a fim de verificar se esses parâmetros podem ser utilizados como fatores prognósticos para a evolução clínica desses pacientes. Foram revisados os registros neurológicos do Hospital Veterinário Universitário de janeiro de 2006 a março de 2017. Realizaram coleta de dados a partir dos registros e por meio de um questionário respondido pelos tutores. Avaliaram 177 fichas neurológicas de cães e obtidas informações para inclusão no estudo em 78 delas. As raças mais frequentes foram Dachshunds, seguido dos cães sem raça definida. Quanto ao grau de disfunção neurológica, 58,97% apresentavam grau I (somente dor), 25,64% estavam em grau II (tetraparesia ambulatória) e 15,38% em grau III (tetraparesia não ambulatória). O repouso absoluto e em espaço restrito foram realizados em 75,64% e 24,36% dos casos, respectivamente e com duração de no mínimo uma semana, podendo chegar a mais de quatro semanas. A maioria dos animais era de pequeno porte (≤15kg). A recuperação foi satisfatória em 87,17% dos cães e insatisfatória em 12,83%. Quanto à recidiva, esta foi observada em 10,3% dos pacientes com recuperação satisfatória. O tratamento clínico para cães com DDIV cervical pode ser indicado com adequada resposta clínica para graus de disfunção que variam de I a III, seja em repouso absoluto ou em espaço restrito e com baixo índice de recidiva.(AU)

Effect of zero-profile and self-locking intervertebral cage and plate-cage construct on maintenance of cervical curvature after anterior cervical surgery / 中国修复重建外科杂志

Objective: To compare differences in the maintenance of cervical curvature after anterior cervical surgery between zero-profile and self-locking intervertebral cage and plate-cage construct (PCC). Methods: A clinical data of 100 patients with single-segment cervical disc herniation who were treated with anterior cervical discectomy and fusion were retrospectively analyzed between January 2015 and January 2016. Among them, 50 patients were treated with the zero-profile and self-locking intervertebral cage (group A) and 50 patients with the PCC (group B). There was no significant difference between the two groups in age, gender, bone mineral density, disease duration, operative segment, and preoperative visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score, C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height ( P>0.05). The operation time and intraoperative blood loss were recorded. The postoperative VAS and JOA scores were used to evaluate the clinical efficacy. The C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height were measured on lateral X-ray films, and the interbody fusion was evaluated according to Pitzen's criteria. Results: The operation time in group A was significantly shorter than that in group B ( t=2.442, P=0.021), but there was no significant difference in the intraoperative blood loss between the two groups ( t=0.812, P=0.403). All patients were followed up 24-36 months, with an average of 28.5 months. According to Pitzen's criteria for cervical interbody fusion, bone fusion achieved in both groups. The VAS score, JOA score, C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height of the two groups at 1 and 24 months after operation were significantly improved when compared with those before operation ( P0.05). There were significant differences in C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height between the two groups at 24 months after operation ( P0.05). Conclusion: Compared with the PCC, the zero-profile and self-locking intervertebral cage can significantly shorten the operation time and obtain the same clinical efficacy, but the intervertebral height loss and secondary cervical curvature change after operation is more serious.

Comparison of the effectiveness of oblique lumbar interbody fusion and posterior lumbar interbody fusion for treatment of Cage dislodgement after lumbar surgery / 中国修复重建外科杂志

Objective: To compare the clinical and radiological effectiveness of oblique lumbar interbody fusion (OLIF) and posterior lumbar interbody fusion (PLIF) in the treatment of Cage dislodgement after lumbar surgery. Methods: The clinical data of 40 patients who underwent revision surgery due to Cage dislodgement after lumbar surgery betweem April 2013 and March 2017 were retrospectively analyzed. Among them, 18 patients underwent OLIF (OLIF group) and 22 patients underwent PLIF (PLIF group) for revision. There was no significant difference between the two groups in age, gender, body mass index, intervals between primary surgery and revision surgery, number of primary fused levels, disc spaces of Cage dislodgement, and visual analogue scale (VAS) scores of low back pain and leg pain, Oswestry disability index (ODI), the segmental lordosis (SL) and disc height (DH) of the disc space of Cage dislodgement, and the lumbar lordosis (LL) before revision ( P>0.05). The operation time, intraoperative blood loss, hospital stay, and complications of the two groups were recorded and compared. The VAS scores of low back pain and leg pain were evaluated at 3 days, 3, 6, and 12 months after operation, and the ODI scores were evaluated at 3, 6, and 12 months after operation. The SL and DH of the disc space of Cage dislodgement and LL were measured at 12 months after operation and compared with those before operation. CT examination was performed at 12 months after operation, and the fusion of the disc space implanted with new Cage was judged by Bridwell grading standard. Results: The intraoperative blood loss in the OLIF group was significantly less than that in the PLIF group ( t=-12.425, P=0.000); there was no significant difference between the two groups in the operation time and hospital stay ( P>0.05). Both groups were followed up 12-30 months, with an average of 18 months. In the OLIF group, 2 patients (11.1%) had thigh numbness and 1 patient (5.6%) had hip flexor weakness after operation; 2 patients (9.1%) in the PLIF group had intraoperative dural sac tear. The other patients' incisions healed by first intention without early postoperative complications. There was no significant difference in the incidence of complications between the two groups ( χ2=0.519, P=0.642). The VAS scores of low back pain and leg pain, and the ODI score of the two groups at each time point after operation were significantly improved when compared with those before operation ( P0.05). At 12 months after operation, SL, LL, and DH in the two groups were significantly increased when compared with preoperative ones ( P0.05). CT examination at 12 months after operation showed that all the operated disc spaces achieved bony fusion. According to the Bridwell grading standard, 12 cases were grade Ⅰ and 6 cases were grade Ⅱ in the OLIF group, and 13 cases were grade Ⅰ and 9 cases were grade Ⅱ in the PLIF group; there was no significant difference between the two groups ( Z=-0.486, P=0.627). During follow-up, neither re-displacement or sinking of Cage, nor loosening or fracture of internal fixation occurred. Conclusion: OLIF and PLIF can achieve similar effectiveness in the treatment of Cage dislodgement after lumbar surgery. OLIF can further reduce intraoperative blood loss and restore the SL and DH of the disc space of Cage dislodgement better.

Mid-long-term effect of only placed expandable Interbody fusion cage in the treatment of lumbar spinal Stenosis with vertebral instability using micro-endoscopic Discectomy system / 中国组织工程研究

BACKGROUND: The incidence of lumbar spinal stenosis with vertebral instability is increasing year by year, which can cause symptoms such as waist and leg pain, lower limbs feeling numbness and intermittent claudication. In recent years, scholars have tried various minimally invasive treatment methods to further reduce the trauma and complications of surgery. The improvement of the clinical effect of minimally invasive surgery for lumbar spinal stenosis with vertebral instability is an important issue to be solved. OBJECTIVE: To evaluate the mid-long-term effect of only placed expandable interbody fusion cage in the treatment of lumbar spinal stenosis with vertebral instability using micro-endoscopic discectomy system. METHODS: A retrospective, self-control clinical trial was conducted in the First Affiliated Hospital of Zhengzhou University from 2012 to 2014. Totally 35 patients with lumbar spinal stenosis combined with vertebral instability were treated by only placed expandable interbody fusion cage using micro-endoscopic discectomy system. This study was approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University. RESULTS AND CONCLUSION: (1) All 35 patients were followed-up for 60-85 months, mean (70.17±5.40) months. Among these patients, lumbar interbody fusion in 1 segment, 2 segments and 3 segments was performed in 6, 20 and 9 cases, respectively. A total of 73 intervertebral spaces were fused. (2) The mean operation time was 53.49±9.13 minutes (range, 35-75 minutes). The mean blood loss was 114.86±54.23 mL (range, 50-250 mL). (3) Dural rupture occurred in one case during operation and then hypotensive cranial pressure headache occurred after operation. Headache gradually eased after the patient received rehydration and analgesic treatment for 3 days. Poor incision healing occurred in one case after operation and then healed well after one-week vacuum sealing drainage technique. (4) The Visual Analogue Scale scores, Oswestry Disability Index, and height of intervertebral space were significantly decreased at 1 week, 6 months, 1 year, 2 years after surgery and the final follow-up compared to the preoperative ones. At 6 months after the operation, 31(42.5%) intervertebral spaces reached a strong fusion, 25(34.2%) possible fusion, and 17(23.3%) did not reach fusion. At 1 year after surgery, 51(69.9%) intervertebral spaces achieved a strong fusion and 22(30.1%) achieved possible fusion. At 2 years after surgery, 57(78.1%) intervertebral spaces achieved a strong fusion and 16(21.9%) achieved possible fusion. During final follow-up, 62(84.9%) intervertebral spaces achieved a strong fusion and 11(15.1%) achieved possible fusion. (5) At the last follow-up, cage migration was found in one case. The patient was not treated because of symptomless. (6) Unilateral approach only placed expandable interbody fusion cage by using micro-endoscopic discectomy system is a safe and reliable minimally surgical method, which has a good mid-long-term effect on lumbar spinal stenosis with vertebral instability.