Sagittal聚焦晶体柔性铰链压弯机构研究

分析了弧矢聚焦晶体弯曲原理及柔性铰链运动方程 ,阐述了弧矢聚焦晶体柔性铰链压弯机构的原理 ,同时提出了抑制子午形变的有效方法。该压弯机构在 5— 2 0keV能量扫描范围内 ,弧矢聚焦比为 3:1,聚焦曲率相对误差 <0 .75 % ,聚焦光斑弥散为 2 5 % ,在 10keV时聚焦面形误差 <2”。

Changes of Transverse Mandibular Width in Set-Back Mandibular Surgery: Sagittal Split versus Intraoral Verticosagittal Osteotomy

Aim: This study was performed to evaluate the movement of the proximal segment following different methods of ramus osteotomy that is one of the side effects of orthognathic surgery. Theoretically, with intraoral verticosagittal ramus osteotomy, it can minimize the movement of the proximal segment. The changes in the intergonal distance of mandible and the angle of the ramus flaring in two methods of osteotomy have been compared in this study. Materials and Methods: In this randomized clinical trial, included 60 patients (32 males) with mandibular prognathism and without any asymmetry were selected and divided into two groups (n = 30). One group underwent bilateral sagittal split ramus osteotomy technique to achieve mandibular setback and the other by the intraoral verticosagittal ramus osteotomy technique. Intergonial width and inner-ramal angle in the transverse plane were measured on radiographs preoperatively and 1 and 12 weeks postoperatively. Data were analyzed using covariance test with the significance level set at P 0.1). Conclusion: Considering our findings, there was no significant difference between two ramus osteotomy techniques regarding changes in mandibular width and inter-ramal flaring angle.

Spinal pedicle subtraction osteotomy for fixed sagittal imbalance patients

In addressing spinal sagittal imbalance through a posterior approach, the surgeon now may choose from among a variety of osteotomy techniques. Posterior column osteotomies such as the facetectomy or Ponte or Smith-Petersen osteotomy provide the least correction, but can be used at multiple levels with minimal blood loss and a lower operative risk. Pedicle subtraction osteotomies provide nearly 3 times the per-level correction of Ponte/Smith-Petersen osteotomies; however, they carry increased technical demands, longer operative time, and greater blood loss and associated significant morbidity, including neurological injury. The literature focusing on pedicle subtraction osteotomy for fixed sagittal imbalance patients is reviewed. The longterm overall outcomes, surgical tips to reduce the complications and suggestions for their proper application are also provided.

The Relationship between Neck and Shoulder Pain and the Sagittal Alignment of the Spine in Standing in Younger Generation

Background: The relationship between chronic neck and shoulder pain and posture remains controversial. The purpose of this study was to investigate the relationship between chronic neck and shoulder pain and spinal sagittal alignment in standing posture in younger generation. Methods: Subjects included 57 females and 32 males (average age, 29.9 ± 5.7 years). All subjects were 20s or 30s. Spinal curvature was assessed using SpinalMouse. The subjects were also divided into a normal group (VAS zero group) and a pain group by VAS results. Statistical analysis was performed by Student’s t-test. Significance was defined as p < 0.05. Results: The normal group and pain group included 29 and 60 subjects, respectively. In terms of location of pain, thirty-one subjects felt neck pain, 50 felt pain above the scapula, and 17 felt pain between the thoracic spine and scapula. Thoracic kyphosis and lumbar lordosis in the pain group were significantly higher than those in the normal group (p = 0.013 and p = 0.020, respectively). Thoracic kyphosis in subjects with neck pain or pain above scapula was significantly higher than that in subjects without pain (p = 0.0075 and p = 0.025, respectively). Lumbar lordosis in subjects with pain above the scapula or interscapula was significantly higher than that in subjects without pain (p = 0.016).

Radiological and clinical outcomes of midline lumbar fusion on sagittal lumbar-pelvic parameters for degenerative lumbar diseases

BACKGROUND Improving the sagittal lumbar-pelvic parameters after fusion surgery is important for improving clinical outcomes.The impact of midline lumbar fusion(MIDLF)on sagittal lumbar-pelvic alignment for the management of degenerative lumbar diseases is still unknown.AIM To analyze the effects of short-segment MIDLF and minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF)on sagittal lumbar-pelvic parameters.METHODS We retrospectively analyzed 63 patients with degenerative lumbar diseases who underwent single-segment MIDLF or MIS-TLIF.The imaging data of patients were collected before surgery and at the final follow-up.The radiological sagittal parameters included the lumbar lordosis(LL),lower LL,L4 slope(L4S),L5 slope(L5S),L5 incidence(L5I),L1 axis and S1 distance(LASD),pelvic incidence(PI),pelvic tilt(PT),sacral slope(SS),and PI-LL mismatch(PI-LL).Additionally,the clinical outcomes,including lower back and leg pain visual analog scale(VAS)and Oswestry disability index(ODI)scores,were also analyzed.RESULTS In both groups,LL and Lower LL significantly increased,while L5I and LASD significantly decreased at the final follow-up compared to that recorded prior to operation(P<0.05).In the MIDLF group,L4S significantly decreased compared to that recorded prior to operation(P<0.05),while the mean SS significantly increased and the PT significantly decreased compared to that recorded prior to operation(P<0.05).In the MIS-TLIF group,SS slightly increased and the mean PT value decreased compared to that recorded prior to operation,but without a statistically significant difference(P>0.05).However,the PI-LL in both groups was significantly reduced compared to that recorded prior to operation(P<0.05).There was no significant difference in the sagittal lumbar-pelvic parameters between the two groups prior to operation and at the final follow-up(P>0.05).In addition,the change in sagittal lumbar-pelvic parameters did not differ significantly,except forΔLASD within the two groups(P>0.05).The mean lower back and leg pain VAS and ODI scores in both groups were significantly improved three months after surgery and at the final follow-up.Though the mean ODI score in the MIDLF group three months after surgery was slightly higher than that in the MIS-TLIF group,there was no significant difference between the two groups at the final follow-up.CONCLUSION Short-segment MIDLF and MIS-TLIF can equally improve sagittal lumbar parameters such as LL,Lower LL,L5I,and LASD in the treatment of lumbar degenerative diseases.However,MIDLF had a larger impact on pelvic parameters than MIS-TLIF.

Effects of lumbar sagittal balance remodeling on natural absorption after lumbar disc herniation

Objective:To explore the influence of the changes of sagittal balance index of lumbar spine on the natural absorption after lumbar disc rupture and protrusion.Methods:From August 2016 to August 2017,64 patients with ruptured lumbar disc herniation and treated with natural absorption in our hospital were selected as the research subjects.According to the size of the herniated discs after 2 years,the subjects were divided into the reabsorption lumbar disc herniation group(group 1,2,3,and 4)and the non-reabsorption group(group 0).The pelvic incidence angle(PI),the sacral slope(SS),the pelvic tilting(PT),and the lumbar lordosis(LL)were measured and compared at the time of admission and 2 years after follow-up.Results:There were no significant differences in the PI value and the change of PI value during the entry and re-examination of different groups.There was no significant difference in the PT,SS,and LL values among the patients in each group;At the time of reexamination,the PT had a decreasing trend and the SS and LL had an increasing trend.With the increase of the patient's score,the changes in PT,SS,and LL values showed an increasing trend.Conclusion:The PT,SS and LL values of patients with lumbar intervertebral disc herniation had significant changes before and after treatment.Changes in the sagittal balance index of the lumbar spine were important factors affecting the natural absorption of lumbar disc herniation.

Sagittal abdominal diameter as a marker of visceral obesity in older primary care patients

Background Longevity,combined with a higher prevalence of obesity,particularly visceral obesity,has been associated with an increased risk of cardiovascular diseases.Insulin resistance(IR)is an important link between visceral obesity and cardiovascular diseases.An important association has been found between sagittal abdominal diameter,visceral obesity and IR.The objective of this study is to evaluate sagittal abdominal diameter as a marker of visceral obesity and correlate it with IR in older primary health care patients.Methods A cross-sectional study was performed with 389 patients over 60 years of age(70.6±6.9),of whom 74%were female.Their clinical,anthropometric and metabolic profiles were assessed and their fasting serum insulin level was used to calculate the homeostasis model assessment insulin resistance(HOMA-IR).Sagittal abdominal diameter was measured in the supine position at the midpoint between the iliac crest and the last rib with abdominal calipers.Results Sagittal abdominal diameter was significantly correlated with anthropometric measures of general and visceral obesity and with HOMA-IR in both genders.There was no change in the association between sagittal abdominal diameter and HOMA-IR after adjusting for age,sex,diabetes and hypertension.Conclusion It is feasible to use sagittal abdominal diameter in older primary care patients as a tool to evaluate visceral obesity,which is an indicator of cardiovascular risk.

Modeling Walking with an Inverted Pendulum Not Constrained to the Sagittal Plane. Numerical Simulations and Asymptotic Expansions

Inverted pendulum models are commonly used to study the bio-mechanics of biped walkers. In its simplest form, the inverted pendulum consists of a point mass attached to two straight mass-less legs. Most works constrain the motion of the mass to the sagittal plane, i.e. the plane perpendicular to the ground that contains the direction toward the biped is walking. In this article, we remove this constrain to study the oscillations, the mass experiences in the direction perpendicular to the sagittal plane as the biped walks. While small, these lateral oscillations are unavoidable and of importance in the understanding of balance and stability of walkers, as well as walkers induced oscillations in pedestrian bridges.

Anatomical Studies on Sagittal Sections of Adrenal Glands for MR Imaging Diagnosis

To provide anatomical data for MR imagingdiagnosis, the bilateral adrenal glands wereinvestigated on serial sagittal sections of 30adult male truncal specimens. The largest sa-gittal section of the left adrenal glands main-y have the shape of the letters Y (40.0%)nd I (33.3%) , but that of the right adrenalglands may present a multi-shape. The

Microsurgical Treatment of Meningiomas Invading the Sagittal or Transverse Sinuses

OBJECTIVE To analyze our management strategy and results of treating patients affected by meningiomas invading the sagittal or transverse sinuses.METHOOS Review of data from 35 patients with pathologically confirmed meningiomas（29 of the sagittal sinus and 6 of the transverse sinus） surgically treated between from July 1999 and June 2003, including clinical manifestations, mode of diagnosis and curative effect of microsurgery etc. For our surgical decision-making, meningiomas were classified into six types based on the degree of sinus involvement.RESULTS A Simpson＇s Grade Ⅰ resection was achieved in 27 cases （77.1%）, Grade Ⅱ in 6 （17.1%） and Grade Ⅲ in 2 （5.7%）. No patients died after the operations. The recurrence rate in the study overall was 2.9%, with a follow-up period from 3 to 6 years.CONCLUSION Application of microsurgical techniques, protection of the sinus, avoidance of damages to the cerebral cortex, veins of the central sulcus, as well as other veins from the tumor, are the major factors for increasing the rate of total resection, reducing complications and improving the quality of life for the patients with meningiomas invading the sagittal or transverse sinuses.

Image Findings Following Vertebroplasty in Osteoporotic Vertebral Compression Fractures: Bone Healing and Sagittal Alignment

Purpose: To clarify the effect of percutaneous vertebroplasty for vertebral compression fracture by assessing the changes of radiographic and CT image findings. Materials and Methods: A retrospective radiological analysis comprising 101 vertebrae of 48 patients who underwent percutaneous vertebroplasty for painful osteoporotic vertebral compression fracture was conducted. Whole spine radiographs and CT images were compared in patients preoperatively and 6 months postoperativey. Sagittal Cobb angles in three regions, sagittal vertical axis, and pelvic tilt were measured using whole spine lateral radiographs. CT findings due to the vertebral compression fracture, its healing process, and complications were evaluated. Results: On radiographs, sagittal alignment had an average gain of no more than 2.5° in each region. Sagittal vertical axis and pelvic tilt did not show significant change. Out of 68 vertebrae that demonstrated cortical disruption on preoperative CT, 37 (54%) demonstrated fusion of disrupted cortex on postoperative CT. Conclusion: No significant difference was observed between preoperative and postoperative spinal sagittal alignment on radiographs. However, CT did reveal healing process through fusion of disrupted cortex, intervertebral bridging, and increased density of cancellous bone. It is suggested that cement in the space of fracture may play a role in both mechanical stability and bone union.

Researchon the Correlativity between SevenCephalometric Indexes for Evaluation of theMaxillomandibular Sagittal Relationship

An analysis of the correlativity between seven cephalometric indexes of SN. FH and OP systems indicates that none of the systems possesses the index which can rule out the effects of other factors to evaluate objectively the sagittal relation between the jaws. In these three systems, owing to more factors affecting indexes of SN system, we suggest to use AXB or A-B/ /FH and Wit's appraisal in comprehensive analysis of the sagittal relation of the jaws, instead of the indexes of SN system. Using indexes of FH or OP system alone in evaluation of not advocated.

A Flat Sagittal Spinal Alignment Is Common among Young Patients with Lumbar Disc Herniation

Background: Recent studies suggest a correlation between spinal sagittal alignment and different types of lumbar pathologies due to different load patterns on the lumbar spine. The main objective of this study was to investigate the preoperative spinal sagittal alignment in young patients (Methods: Information regarding preoperative clinical examinations was collected from the patient medical charts. Preoperative MRI examinations were used to classify lumbar types according to four sagittal spinal alignment groups (1: a long thoracic kyphosis, 2: a flat back, 3: a normal spine and 4: an increased thoracic kyphosis). Other MRI findings were also noted. Classification of lumbar types was performed independently by three spine surgeons. To compare two sample proportions the 2-sample z-test was performed. Results: The distribution of lumbar curve types was: Type 1, 17% (9 patients);Type 2, 62% (33 patients);Type 3, 17% (9 patients) and Type 4, 4% (2 patients). The distribution of operated levels was: L3 - L4, 2% (1 patient);L4 - L5, 47% (25 patients);L5 - S1, 42% (22 patients) and L4 - L5 + L5 - S1, 9% (5 patients). Conclusions: A majority of the young patients (62%) that underwent surgery due to herniated disc in the lumbar spine were classified as Type 2 indicating a flat back. Future studies are needed to increase the knowledge about spinopelvic sagittal alignment and the correlation to spinal pathologies.

A retrospective study of unfavorable fractures during sagittal split osteotomy:A single surgeon’s experience

Background:Unfavorable fractures are among the most common complications of bilateral sagittal split ramus osteotomy(BSSRO).This study aimed to evaluate unfavorable fracture patterns during BSSRO and assess the related risk factors and treatment measures.Methods:The clinical records and radiographs of 679 patients(1358 sides)who underwent BSSRO at Shanghai Ninth People’s Hospital between September 2013 and December 2021 were examined.Results:Patients with unfavorable fractures who underwent surgical restoration were studied.The incidence of unfavorable fractures was 0.8%(n¼11),with the highest rate in the third year.The unfavorable fractures were divided into three types by location and clinical treatment:(1)SSRO could still be completed after buccal/lingual plate unfavorable fracture(0.6%,n=8);(2)condylar/coronoid process fractures/intermaxillary fixation needed(0.1%,n=2);(3)additional osteotomy required(0.07%,n=1).Conclusion:These results suggest that as a surgeon’s experience increases,the rate of unfavorable fractures may decrease.The novel classification of unfavorable fractures for SSRO might be useful for surgeons to make appropriate treatment choices during orthognathic surgery.

The relationship between the spine-pelvis-lower extremity sagittal parameters and disease-related molecules in serum and synovial fluid in patients with knee osteoarthritis

Objective:To study the relationship between spine-pelvis-lower extremities sagittal parameters and disease-related molecules in serum and synovial fluid in patients with knee osteoarthritis. Methods:A total of 65 patients diagnosed with knee osteoarthritis in Dongguan Tangxia Hospital between May 2013 and December 2016 were collected as OA group, and 70 patients with meniscus and cruciate ligament injury undergoing repair surgery during the same period were collected as the control group. Spine-pelvis-lower extremity sagittal parameters were measured by erect whole spine lateral radiographs. The serum was collected and inflammatory factor contents were measured. The synovial fluid was collected to determine inflammatory factor contents and apoptosis molecule expression.Results: Affected-side PFA and SFA levels of OA group were significantly lower than those of healthy side while FI and ST levels were significantly higher than those of healthy side;serum TNF-α, IL-1β, IL-18, MMP1 and MMP3 contents of OA group were significantly higher than those of control group, negatively correlated with PFA and SFA levels, and positively correlated with FI and ST levels;TNF-α, IL-1β, IL-18, MMP1, MMP3, Fas, FasL, Caveolin-1, NO, CHOP and GRP78 contents in synovial fluid of OA group were significantly higher than those of control group, negatively correlated with PFA and SFA levels, and positively correlated with FI and ST levels. Conclusion: Sagittal parameters of spine-pelvis-lower extremity can be used to evaluate the inflammatory response and apoptosis in patients with knee osteoarthritis.

Microsurgical treatment of parasagittal meningiomas in central area

Objective To improve the operative outcome of parasagittal meningiomas in central area. Methods Twenty patients with parasagittal meningiomas were treated with microsurgery. Of them, 16 cases were taken DSA examination before operation to evaluate the blood supplies of the tumor, compensation of venus return around the tumor after obstruction of the sagittal sinus. During the operation, the parasagittal blood supplies were blocked first, the tumors were resected piece by piece. Rolandic veins, other compensative venous pathways and normal brains around the tumors were protected, and the involved sagittal sinuses were appropriately treated. Results Total removal of the tumor was reached in 17 cases, nearly total removal in 3 cases, no death. Postoperatively, 1 patient developed hemiparesis, 2 had paresis of both lower extremities. No tumor recurrence was found in 13 patients during the follow-up of 3 - 7 years. Conclusion Using microsurgical techniques in the resection of parasagittal meningioma in

Combined Therapy for Mandibular Prognathism:Sagittal Split Osteotomy with Excision of Tongue

In the evaluation of the beauty and functional integrity of the lower face, the oral cavity, teeth, mandible, maxilla, and the size and position of the tongue are important. The tongue locates forward and is larger than normal in prognathism, in which the jaw protrudes from the skull. It is not clear whether an enlarged tongue causes the open bite, protrusion or dental arch misalignment, or is a result of them. Here, we report two patients with mandibular prognathism and relative macroglossia, which were treated by mandibular setback surgery using a bilateral sagittal split osteotomy (BSSO) and excision of the tongue. This procedure achieved aesthetic improvement of the face and dentition.

CHANGES IN AIRWAY SPACE FOLLOWING MANDIBULAR SETBACK USING SAGITTAL SPLIT OSTEOTOMY AND RIGID INTERNAL FIXATION

The changes in airway space following mandibular setback using sagittal split osteotomy and rigid internal fixation were studied in 28 Japanese patients with mandibular prognathism. The correlation between the amount of mandibular setback and airway space changes,as well as the correlation between the amount of airway space changes and relapse of pognion point during the following-up period were also studied. Lateral cephalometric radiographs were taken immediately before and shortly after surgery as well as 5 to 12 months postoperation. The cephalometric evaluations of airway space width and area were based on stable craniofacial landmarks. The mean setback of mandible was 8.3 mm in the right side,and 8. 2 mm in the left side. The mean amount of relapse of pogonion point during the following-up period was 0. 52 mm horizontally,and 0. 92 mm vertically. A significant decrease in airway space width and area,especially in the lower part of airway space was found following mandibular setback shortly after surgery. Although there was some increase both in airway space width and area during the following-up period,they did not increase to their original values. This suggests that the narrowing of airway space following mandibular setback using sagittal split osteotomy can be permanent. No significant correlation was found between the amount of mandibular setback and airway space changes. Since the relapse of pogonion point during the following-up period was too small,there is no significant correlation between it and the amount of airway space changes.

Functional outcome of surgical management of low mid-grade lumbar spondylolisthesis when considering the sagittal balance parameters preoperatively:a prospective study

Background:Prospective study objectives.A sagittal balance is a good tool to improve the functional outcome of spine spondylolisthesis surgeries,primarily noted that it has a good impact in deformity surgery and then applied to every spine surgery and the aim of this study is to evaluate its functional outcome when considered in preoperative planning for non-dysplastic low-and mid-grade spondylolisthesis surgeries.Method:Forty patients diagnosed as low-or mid-grade non-dysplastic spondylolisthesis had undergone surgery at Cairo University after failed medical treatment had been evaluated preoperatively by measuring the sagittal balance parameters which include SVA,spinopelvic angles,lumbar lordosis,pelvic tilt,sacral slope,and pelvic incidence and then measure it along a follow-up period of 1 year postoperatively started from February 2018 and correlate it with functional outcome using Oswestry score(ODI)and VAS.Correction of parameters has been estimated preoperatively by manual estimation and Surgimap application then applied during the operation.Results:All patients were treated by surgical treatment through posterior transpedicular screw fixation with conventional or reduction screws and fusion±TLIF cages.The mean of lumbar lordosis and mean spinopelvic angles were increased in a statistically significant manner.Pelvis tilt was decreased in a statistically insignificant manner.The mean of pelvic incidence was not changed and statistically insignificant,and this is matching the fact that pelvic incidence is a constant parameter.The sacral slope was increased in a statistically insignificant manner.Final results showed that 37 had a statistically significant improvement in their ODI>20%at the last visit.Three patients had a poor clinical outcome with ODI scorFinal results showed that 37 had a statistically significant improvement in their ODI>20%at the last visit.Three patients had a poor clinical outcome with ODI score of>20%improvement,and we noticed that the level of pathology was at the level of L4L5,SVA was positive and worsen postoperatively,and also,it is accompanied by decreased lumbar lordosis.Change in ODI means statistically significant improvement when considering sagittal parameters preoperation and during operation.Conclusion:Sagittal balance parameters should be considered in the surgical management of low-grade spondylolisthesis cases to improve their functional outcome.

Risk factors and clinical significance of posterior slip of the proximal vertebral body after lower lumbar fusion

BACKGROUND Adjacent segment disease(ASD)after fusion surgery is frequently manifests as a cranial segment instability,disc herniation,spinal canal stenosis,spondylolisthesis or retrolisthesis.The risk factors and mechanisms of ASD have been widely discussed but never clearly defined.AIM To investigate the risk factors and clinical significance of retrograde movement of the proximal vertebral body after lower lumbar fusion.METHODS This was a retrospective analysis of the clinical data of patients who underwent transforaminal lumbar interbody fusion surgery between September 2015 and July 2021 and who were followed up for more than 2 years.Ninety-one patients with degenerative lumbar diseases were included(22 males and 69 females),with an average age of 52.3 years(40-73 years).According to whether there was retrograde movement of the adjacent vertebral body on postoperative X-rays,the patients were divided into retrograde and nonretrograde groups.The sagittal parameters of the spine and pelvis were evaluated before surgery,after surgery,and at the final follow-up.At the same time,the Oswestry Disability Index(ODI)and Visual Analogue Scale(VAS)were used to evaluate the patients’quality of life.RESULTS Nineteen patients(20.9%)who experienced retrograde movement of proximal adjacent segments were included in this study.The pelvic incidence(PI)of the patients in the retrograde group were significantly higher than those of the patients in the nonretrograde group before surgery,after surgery and at the final follow-up(P<0.05).There was no significant difference in lumbar lordosis(LL)between the two groups before the operation,but LL in the retrograde group was significantly greater than that in the nonretrograde group postoperatively and at the final follow-up.No significant differences were detected in terms of the|PI–LL|,and there was no significant difference in the preoperative lordosis distribution index(LDI)between the two groups.The LDIs of the retrograde group were 68.1%±11.5%and 67.2%±11.9%,respectively,which were significantly lower than those of the nonretrograde group(75.7%±10.4%and 74.3%±9.4%,respectively)(P<0.05).Moreover,the patients in the retrograde group had a greater incidence of a LDI<50%than those in the nonretrograde group(P<0.05).There were no significant differences in the ODI or VAS scores between the two groups before the operation,but the ODI and VAS scores in the retrograde group were significantly worse than those in the nonretrograde group after the operation and at the last follow-up,(P<0.05).CONCLUSION The incidence of posterior slippage after lower lumbar fusion was approximately 20.9%.The risk factors are related to a higher PI and distribution of lumbar lordosis.When a patient has a high PI and insufficient reconstruction of the lower lumbar spine,adjacent segment compensation via posterior vertebral body slippage is one of the factors that significantly affects surgical outcomes.