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Objective Based on construction and verification of the lumbar finite element model, the simulation calculation and injury prediction on dynamic response of normal lumbar model and L5 unilateral and bilateral spondylolysis models of the pilot were carried out, so as to explore the influence of persistent flight overload on normal and spondylolysis lumbar vertebrae of the pilot. Methods The precise finite element model of lumbavertebrae was established using reverse engineering software and computer-aided engineering (CAE) technology based on CT images. The validity of the lumbar vertebrae model was verified by static and dynamic in vitro experiments. The biomechanical simulation analysis on normal and spondylolysis lumbar vertebrae of the pilotunder persistent overload was carried out, and the spinal injury was predicted and analyzed by dynamic response index (DRI) injury evaluation and prediction method. Results The maximum isthmus stress of L5 vertebra in unilateral and bilateral spondylolysis models were 105. 29 MPa and 126. 32 MPa, respectively, which were significantly higher than those in normal model. The L4-5 and L5-S1 intervertebral discs of the spondylolysis model were more prone to premature degenerative changes than those of normal model. Combined with DRI spinal injury prediction method, the probability of spinal injury in normal lumbar vertebrae, lumbar vertebrae with L5 unilateral and bilateral spondylolysis were 0. 001 4% , 2. 26% and 3. 21% , respectively, and the probability of spinal injury was significantly increased after the occurrence of spondylolysis. Conclusions The spondylolysis increases the load of lumbar isthmus under flight overload. The results provide more accurate data support for the formulation of training programs and the development of protective devices to ensure flight safety
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Objective: Lumbar spondylolysis, caused by stress fracture of the pars interarticularis may lead to a bony defect or spondylolisthesis. In adolescents, its surgical treatment employs the smiley face rod method for direct reduction of pseudoarthrotic spondylolysis and spondylolisthesis. Clinical outcomes of this treatment have been occasionally described; however, implant removal has not been discussed previously. We present a patient with lumbar spondylolysis with grade 1 slip at the 5th lumbar vertebra (L5) per the Meyerding classification.Patient: A 14-year-old boy presented with chronic severe lower back pain. Since conservative therapy did not resolve pain or enable resuming sports activities, the smiley face rod repair was performed 7 months after the initial treatment.Result: Anterior slippage of the L5 was surgically reduced. The patient wore a brace for 3 months postoperatively, and partial bone fusion was noted 6 months postoperatively. He resumed his sports activity 8 months postoperatively, and absolute bone fusion was confirmed 18 months postoperatively. Implant removal was performed 3 years postoperatively. Grade 1 slip was corrected with absolute bone fusion, and long-term follow-up revealed good results in terms of healing and rehabilitation.Conclusion: Smiley face rod method that allows for implant removal after bone fusion is suitable for adolescents.
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Purpose: This study aimed to examine the characteristics of lumbar spondylolysis with acute lumbar spondylolysis on one side and pseudoarthrotic spondylolysis on the other, relative to acute lumbar spondylolysis on one side only.Patients and Methods: Short-tau inversion recovery images obtained through magnetic resonance imaging were used to diagnose 58 patients with acute lumbar spondylolysis with bone marrow edema on one side only. A total of 20 patients who had pars defects on the contralateral side (terminal-stage pseudoarthrotic spondylolysis) were included in the contralateral pseudoarthrosis group (P group). The remaining 38 patients with normal images for the contralateral pars interarticularis were included in the unilateral lesion group, in which the contralateral side was normal (U group). We investigated the union rate, age, sex, lesion laterality, vertebral level, pathological stage, and existing spina bifida occulta in both groups.Results: The P group was characterized by a higher proportion of right-side cases, L5 lesions, more progressed pathological stage, and spina bifida occulta and a significantly lower union rate than the U group.Conclusion: The union rate in patients with lumbar spondylolysis with acute lumbar spondylolysis on one side and pseudoarthrotic spondylolysis on the opposite side was only 15%. We should inform patients with acute unilateral spondylolysis lesions and contralateral pseudoarthrosis about this poor union rate and urge them to choose their therapy accordingly.
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Objective: The aim of this study was to determine the prevalence of curable and pseudoarthrosis stages of adolescent lumbar spondylolysis under high school students complaining of and seeking medical consultation for low back pain.Patients and Methods: We analyzed age, sex, morbidity, presence of spina bifida occulta (SBO), and competitive sport discipline of patients with lumbar spondylolysis. We then stratified their pathological stage using a modified classification system via magnetic resonance imaging and computed tomography.Results: Of 507 patients, 451 lesions in 268 patients were diagnosed with lumbar spondylolysis (average age, 14.7 years; sex ratio, 215:53 male/female). Morbidity levels were as follows: L1, 1 lesion in 1 patient; L2, 9 lesions in 5 patients; L3, 38 lesions in 25 patients; L4, 106 lesions in 74 patients; L5, 297 lesions in 189 patients, and SBO verified in 111 patients. A total of 264 patients played a specific sport: baseball, 93; soccer, 49; volleyball, 21; track and field, 21; basketball, 20; others, 164. The prevalence of curable- and pseudoarthrosis-stage lumbar spondylolysis was 206 lesions in 142 patients, and 141 lesions in 87 patients, respectively.Conclusion: With 59.3% of patients having curable-stage lumbar spondylolysis, adolescent athletes with low back pain are urged to seek consultation. Furthermore, clinicians should perform magnetic resonance imaging to avoid misdiagnosis.
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Objective To investigate the differences in some measured paremeters on spino-pelvic sagittal X-ray films in middle-aged and elderly patients between lumbar spondylolysis and isthmic spondylolisthesis,and to explore the predictors that the spondylolysis at lumbar 5 may develope into spondylolisthesis in order to provide imaging details for the clinical treatment of teenage patients with lumbar spondylolysis.Methods Imaging data of 60 patients with spondylolysis at lumbar 5 and other 60 with isthmic spondylolisthesis in middle or elder age in our hospital were analyzed retrospectively,and a control group with 60 normal volunteers were recruited in this study.Some parameters including the angles of pelvic incidence (PI),pelvic tilt (PT),sacral slope (SS),lumbar-sacral angle (LSA)and lumbar lordosis (LL),and the sagittal vertical axis (SVA)were measured in sagittal radiographs of the spine and pelvis. Differences in sagittal parameters among 3 groups were analyzed by one-way variance analysis and SNK-q test.Results The PI,PT, SS and LL were higher,and LSA was lower in patients with isthmic spondylolisthesis than those in the control group and lumbar spondylolysis one (P0.05).No significant differences in all spino-pelvic sagittal parameters were found between lumbar spondylolysis group and the control (P>0.05).Conclusion Such spino-pelvic sagit-tal parameters as PI,PT,SS,LL and LSA on X-ray film can be regarded as predictors that lumbar 5 spondylolysis may develop into spondylolisthesis and may provide imaging reference for the clinical treatment of teen-age patients with lumbar spondylolysis.
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OBJECTIVES@#To explore the casual relationship and the significance of identification among the injury, disease and damage consequence in the disability evaluation of lumbar spondylolysis by the standard for identifying grading of disability caused by work-related injuries.@*METHODS@#The general data, injury manner, clinical treatment and the imaging examination of 32 lumbar spondylolysis cases were collected and retrospectively analyzed. According to the degree of participation in the injury and damage consequence, the identification and assessment of casual relationship was made, and the grading of disability was assessed.@*RESULTS@#For 32 cases, injury had no effect on damage consequence in 7 cases, slight effect in 5 cases, secondary effect in 13 cases, equivalent effect in 4 cases, and complete effect in 3 cases. According to the related items in the standard for identifying grading of disability caused by work-related injuries, 3 cases were rated level 7, 5 cases were level 8, 6 cases were level 9, 11 cases were level 11 among the cases which existed causal relationship.@*CONCLUSIONS@#The formation of lumbar spondylolysis is connected to the factors of age, anatomy, occupation and injury manner etc. The degree of disability should be accessed comprehensively after the analysis of the casual relationship among the injury, disease and damage consequence.
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Female , Humans , Disability Evaluation , Lumbar Vertebrae/pathology , Retrospective Studies , Spondylolysis/pathologyABSTRACT
Objective To improve the selection of flying cadets of the Air Force of People′s Liberation Army of China ( PLAAF) by analyzing the differences of medical identification of lumbar spondylolysis between PLAAF and the US Air Force ( USAF) .Methods Flight crew who had been checked for lumbar spondylolysis during hospitalization at the Air Force General Hospital between 2013 and 2015 were chosen.The results of their medical identification were compaired according to PLAAF and USAF Medical Standards Directory, and their differences and possible reasons were analyzed accordingly.Results The qualified rate of PLAAF was about 85%, which was very close to the standards of USAF, but the difference was not of any statistical significance(P>0.05).Conclusion The standards of our medical identification of lumbar spondylolysis was similar to those of USAF, suggesting that the selection of flying cadets can be improved.
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Objective To improve and determine the Medical Standards Directory of the Air Force of People′s Libera-tion Army of China( PLAAF) by analyzing the differences in lumbar spondylolysis and scoliosis between PLAAF and the US Air Force( USAF) .Methods All candidates of flying cadets participating in the final radiographic selection between 2013 and 2015 were chosen.They were judged to be qualified or not according to PLAAF and USAF Medical Standards Directory. Results The average morbility of lumbar spondylolysis and scoliosis in PLAAF was 47%and 30.3%respectively.Arnong those who were eliminated in China,86.0%and 92.5%could be regarded as qualified according to the standard of USAF in 2015.The difference was statistically significant (P<0.01).Conclusion Our selection standards for lumbar spondylol-ysis and scoliosis should be improved based on this study.
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Objective: To summarize the cable tension band fixation for the treatment of the clinical effect of lumbar spondylolysis, to explore the feasibility and effectiveness of the cable tension band fixation. Methods: in 2011 May to 2013 May received a total of 12 cases of L4 and L5 in patients with lumbar spondylolysis. 12 cases were male; age 18---22 year old, average age is 19.5 years old. Were not associated with lumbar spondylolisthesis. All the patients were Ai Wentai cable tension band fixation and isthmic bone grafting treatment, after 3, 6, 9, 12 months of follow-up. Results: there were no operation complications and sequelae, no secondary lumbar spondylolisthesis was found. Reached the standard of bone healing in 11 cases, bone healing rate was 91.7%, 9 cases achieved healthy players training intensity. At the last follow-up evaluation of curative effect, excellent in 9 cases, good in 2 cases, 1 cases, the excellent and good rate was 91.7%. Conclusion: the cable tension band fixation for the treatment of lumbar spondylolysis is effective, simple operation, little injury and good biological compatibility method. On the prevention of lumbar spondylolisthesis, promote the local fracture of lumbar spondylolysis Union, has a positive meaning to improve the symptoms of waist.
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Objective To explore the technical advantages and clinical value of dual-source and image re-construction technique application in lumbar spondyloschisis without sliding .Methods 36 cases of patients with LSWS were collected who were examined by dual-source CT scan and diagnosed definitely .18 cases of patients were examined by X-ray( including lumbar vertebrae and double oblique ) .The diagnosis rate of X-ray and CT scanning in diagnosing LSWS were calculated ,which was made statistical analysis .The image of 36 cases patients with LSWS were reconstructed by multi-planar reconstruction ( MPR) ,volume rendering technique ( VR) and curved planar reconstruc-tion( CPR) .The display rate was calculated , which was made statistical analysis according to various image recon-struction in diagnosing LSWS .Results 7 cases of patients with LSWS were found by X-ray examination .36 cases of patients with LSWS were found by dual-source CT examination .The display rate was 38.9%and 100.0%.71 LSWS were found in 36 cases of patients with LSWS ,35 cases were bilateral spondylolysis ,1 case was unilateral spondylolys-is.In several image reconstruction methods ,CPR and cutting VR showed the highest rate in diagnosing LSWS ,which was 100.0%.The symptom of LSWS in X-ray examination:local thinning and structural disorder in lumbar spondylol-ysis,cortical discontinuity .The symptom of LSWS in CT examination were as follows:clear linear low density shadow in lumbar,ends hardening and bone fragments in some case .Conclusion The dual-source CT and its image recon-struction technology have the technological superiority and higher clinical value in diagnosing LSWS ,which is crucial to prevent LSWS misdiagnosed ,and could become the preferred examination in screening and diagnosing LSWS .
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Objective To explore the clinical value of monoenergetic technology of dual-source CT in removing the artifact of me-tallic fixation after the operation of lumbar spondylolysis.Methods 24 cases of patients with metallic fixation after operation of lum-bar spondylolysis were scanned by dual-energy CT.To reconstruct the imaging using monoenergetic and 3D Inspace software,obtain 50,80,110,140,170 keV five groups of images and the multi-planar reconstruction*(MPR),volume vendering(VR),maximum intensity projection(MIP)imaging in different conditions.The five groups image and average weighted 120kev image are evaluate by two senior radiologist.The quality score of five groups of images and the average weighted images are analyzed statistically using Kruskal-Wallis test.The clinical value of images in the optimal condition are evaluated by two senior department of orthopedics phy-sicians.The results of two radiologists and department of orthopedics physician are examined by kappa test to evaluate consistency. Results In all patients after operation,the case of 110keV images above 3 points is 24,the case of 80keV images above 3 points is 14,the case of of 140keV images above 3 points is 13,the case of weighted average 120kev images above 3 points is 8.Images in 110keV have the best quality (F=98.523,P<0.01).MPR,VR,MIP images are reconstructed in 110keV.The ratio of image which are excellent and have high clinical value is 86.1%,especially the ratio of MPR image is 100%.Conclusion Monoenergetic technology of dual-source CT has a higher clinical value in removing the artifact of metallic fixation after the operation of lumbar spondylolysis.Under the condition of 110keV the quality of images are best,the reconstructed images using MPR Technology have the best clinical value.
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Objective To compare the stresses on the end plate of adjacent lumbar vertebrae between intra-segmental fixation and inter-segmental fixation in treating lumbar spondylolysis by three-dimensional finite element analysis. Method Based on the established finite element model of L4 lumbar spondylolysis, the lumbar internal fixation such as rods and trans-pedicle screws were reconstructed to make the finite element models of intra segmental and inter segmental internal fixation with the same constraint and loading conditions. The stresses on endplate of adjacent lumbar vertebrae of finite element models were measured under three mechanical conditions:spondylolysis, intra-segmental fixation and inter-segmental fixation. Results High stresses were observed under two kinds of internal fixation conditions compared with the spondylolysis condition at the lower endplate of L4 under axial loading(P<0.05). The stresses at the lower endplate of L4 under intra segmental fixation condition were similar as that of the spondylolysis condition under flexion, extension and lateral bending loading. With the same loading, higher stresses were observed under inter-segmental fixation condition compared with the spondylolysis condition, and so did the lower stresses at upper endplate of S1(P<0.05). The lower stresses at the upper endplate of S1 under intra-segmental fixation condition were observed compared with the other two conditions under rotating loading (P<0.05). Conclusions The intra segmental fixation can not only provide stability for lumbar spondylolysis under axial, flexion, extension, lateral bending,but also preserve the normal activity at adjacent disc levels, especially under rotating loading.
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[Objective]To analyze the mechanism of shape memory alloy imrasegmental fixator for lumbar spondylolysis(WMAIF)with finite element method.[Method]The three-dimensional model of WMAIF was established by using ANSYS 8.0 software for large finite element analysis.The model was extended with restriction in different parts,and to undertake corresponding mechanics calculation.[Result]The finite element model of WMAIF was set up,which could predict the strength and displacement of every node and element of its own structure in the course of deforming.[Conclusion]WMAIF is strong enough against tensile stress,which is a new and reliable intrasegmental instrument for direct repairing of lumbar spondylolysis.
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[Objective]To establish digitized visible model of the wrist joint.[Method]Coronal sect ional images of a series of 0.2 man-thick cryosecfions of wrist joint specimens were obtained.After registration and segmentation,the three-dimensional computerized reconstruction of the carpal bone and arch-ligament and its adjacent structures were performed on PC.[Result]For reconstructed Successfully 3D the structures model of wrist joint its adjacent 28 structures.This model can be displayed with single structure and its adjacent structures for wrist joint and can be displayed with several structures in different color and hyalinize.And it can be displayed from any direct ion.Moreover all structures can be measured through angle or line from any direction.[Conclusion]Three-dimensional reconstruction model of the wrist joint demonstrate the relation of anatomy between the carpal bone and ligament by poly-point of view and is meaningful for operations of the wrist joints.
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[Objective]To investigate the influence of wing-like memory alloy intrasegmental fixator(WMAIF)on healing of lumbar spondylolysis.[Method]Eighteen healthy hybrid adult dogs were used in the experiment,regardless of gender,the L_6 isthmic portion were injured by operation randomly and equally divided into three groups.Group Ⅰ were fixed with WMAIF,groupⅡ were fixed with steel wire,group Ⅲ were treated with nothing.Every group was examined through CT at 2,4,6,8 and 10 weeks.[Result]In group Ⅰ,the fracture achieved healing at 6 weeks after operation.In group Ⅱ,the fracture achieved healing at 10 weeks after operation,while no repair of fracture was found in group Ⅲ.[Conclusion]Lumber spondylolysis fixation with WMAIF has stable and continued axial stress,WMAIF is beneficial to fracture healing,and is a new and reliable intrasegmental instrument for direct repair of lumbar spondylolysis.
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OBJECTIVE: The authors introduce a technique of direct repair of pars defects in symptomatic lumbar spondylolysis using pedicle screws and universal hooks. METHODS: From March 2001 to September 2001, six patients with symptomatic lumbar spondylolysis and positive pars injection test underwent this procedure. Patients with lumbar instability and discogenic pain were excluded. After posterior midline incision, clearing of fibrous, cartilaginous and sclerotic tissues in and around the defects of pars was done until healthy bone was exposed. Strips of cancellous bone were taken from adjacent laminae and packed into the defects of pars. After insertion of the pedicle screws, universal hooks were placed in the lower margin of the lamina of the involved vertebra. With gentle compression between the head of screw and universal hook, the nut was fixed. Same procedures were done on the contralateral side. RESULTS: Postoperatively, all six patients experienced clinical improvement and there was no complication related with operation. CONCLUSION: This new technique is considered useful for direct repair of the defects in symptomatic lumbar spondylolysis without significant injury in the normal structures.