Risk factors for cage retropulsion following transforaminal lumbar interbody fusion / 中国组织工程研究

BACKGROUND:Previous literature reported that the fusion cage moved more than 2 mm from its original position,which means that the fusion cage moved backward.At present,clinical observation has found that the factors leading to the displacement of the fusion cage are complex,and the relationship between these factors and the cage retropulsion is not clear. OBJECTIVE:To explore the risk factors related to cage retropulsion after lumbar interbody fusion. METHODS:Retrospective analysis was conducted in 200 patients who underwent transforaminal lumbar interbody fusion surgery with a polyetheretherketone interbody fusion from February 2020 to February 2022.According to the distance from the posterior edge of the vertebral fusion cage to the posterior edge of the vertebral body after the operation(the second day after the removal of the drainage tube)and 1,3,6 and 12 months after the operation,patients were divided into cage retropulsion group(≥2 mm)and cage non-retropulsion group(<2 mm).The factors that may affect cage retropulsion,such as age,gender,body mass index,bone mineral density,operation time,bleeding,endplate injury,preoperative and postoperative interbody height,cage implantation depth,cage size,and segmental anterior convexity angle,were analyzed by univariate and logistic regression analysis. RESULTS AND CONCLUSION:(1)Posterior displacement of the fusion cage occurred in 15 cases(15/200).The differences in basic information such as age and body mass index between the two groups were not statistically significant.(2)The results of the univariate analysis were that gap height difference,time to wear a brace,segmental anterior convexity angle difference,bone mineral density,and age were related to posterior migration of the cage.(3)The results of logistic regression analysis were that cage size,endplate injury condition,and depth of cage implantation were risk factors for cage retropulsion.(4)These findings suggest that cage retropulsion after lumbar interbody fusion is caused by multiple factors,including segmental anterior convexity angle difference,bone mineral density,cage size,endplate damage,time to wear a brace,and depth of cage implantation.

Finite element analysis of lumbar vertebra biomechanics after transforaminal lumbar interbody fusion combined with bilateral transpedicular transdiscal lumbar screw fixation / 中国组织工程研究

BACKGROUND:Transpedicular transdiscal lumbar screw is a new type of spinal minimally invasive internal fixation technology.Compared with traditional bilateral pedicle screws,only one screw is needed to fix one segment on one side.It has the characteristics of being more economical,less trauma and easy to operate.However,studies on the application of transpedicular transdiscal lumbar screws combined with transforaminal lumbar interbody fusion(TLIF)and fixation are still rare. OBJECTIVE:To evaluate the effect of TLIF combined with various surgery methods on stress distribution of cage,fixation,disc lower and endplate and range of motion of lumbar vertebrae by constructing three kinds of finite element models including modified TLIF(cage alone)model,modified TLIF combined with bilateral pedicle screw(cage+BPS)model and modified TLIF combined with bilateral transpedicular transdiscal lumbar screw(cage+BTPTDS)model. METHODS:The CT images of the adult lumbar spine were used to establish the three kinds of TLIF finite element models:cage alone,cage+BPS and cage+BTPTDS using software Mimics,Geomagic and SolidWorks.ANSYS Workbench was used to simulate the application of six different motion loads of human body flexion and extension,left and right bending,and left and right rotation to calculate stress distribution and the changes in the range of motion of the lumbar spine of the cage,fixation,endplate and disc of the three lumbar spine surgery models and to compare the effects of three surgical options on the biomechanical effects of the lumbar spine. RESULTS AND CONCLUSION:(1)The cage alone model,cage+BPS model and cage+BTPTDS model were constructed successfully.(2)In flexion and lateral bending conditions,the maximum stress of the cage of cage+BTPTDS model was smaller than that of the cage alone model and a little greater than that of the cage+BPS model.In the extension condition,the maximum stress of the cage of the cage+BPS model was obviously smaller than that of the other two models.When it came to rotating condition,the maximum stress of the cage in the cage+BPS model and the cage+BTPTDS model presented no obvious difference,which was both smaller than the cage alone model.(3)The maximum stress of fixation of the cage+BTPTDS model was obviously bigger than the cage+BPS model in flexion and extension conditions,close to the cage+BPS model in lateral bending conditions,and smaller than the cage+BPS model in rotation conditions.(4)The maximum stress of the lower endplate of the fusion segment of the cage+BPS model was between the two other models.(5)In terms of the range of motion,the cage+BTPTDS model presented no obvious difference with that of the cage+BPS model at flexion and extension,left and right bending,and left and right rotation.(6)It is concluded that modified TLIF combined with transpedicular transdiscal lumbar screw provides stable support for the vertebral body of the fusion segment,ensures the motion range of the lumbar spine and has a good biomechanical effect.

Robot-assisted minimally invasive transforaminal lumbar interbody fusion in treatment of lumbar degenerative diseases / 中国组织工程研究

BACKGROUND:Minimally invasive surgery is developing rapidly.Robot-assisted minimally invasive transforaminal lumbar interbody fusion and robot-assisted unilateral biportal endoscopic transforaminal/posterior lumbar interbody fusion are important posterior minimally invasive surgical approaches to treat lumbar degenerative diseases.However,it is worth discussing which operation method is more advantageous. OBJECTIVE:To compare the clinical efficacy and imaging examination between different operation groups,and discuss the clinical application value of robot-assisted minimally invasive lumbar posterior fusion technology to treat lumbar degenerative diseases. METHODS:Clinical data of 83 patients with lumbar degenerative diseases from January 2018 to June 2022 at the Department of Orthopedics,Sichuan Academy of Medical Sciences&Sichuan Provincial People's Hospital were retrospectively analyzed.Of them,27 patients received robot-assisted minimally invasive transforaminal lumbar interbody fusion treatment(group A);30 patients received robot-assisted unilateral biportal endoscopic transforaminal/posterior lumbar interbody fusion treatment(group B),and 26 traditional minimally invasive transforaminal lumbar interbody fusion patients were selected as the control group(group C).There were no significant differences in gender,age,body mass index,surgical segment,preoperative visual analog scale score and Oswestry Disability Index among the three groups(P＞0.05).The operation time,intraoperative blood loss,complications,fluoroscopic dose,fluoroscopic time,and fluoroscopic frequency were compared among the three groups.Gertzbein-Robbins'classification was used to evaluate the accuracy of percutaneous pedicle screw.Visual analog scale and Oswestry Disability Index scores were evaluated after surgery.The excellent and good rate of the three surgical options was evaluated using Macnab's criteria. RESULTS AND CONCLUSION:(1)The operation time of group A was significantly shorter than that of groups B and C(P＜0.05),but there was no significant difference between group B and group C(P＞0.05).The intraoperative blood loss in group B was significantly less than that in group A,and that in group A was significantly less than that in group C(P＜0.05).(2)The fluoroscopic dose,fluoroscopic time,and fluoroscopic frequency of group C were significantly higher than those of groups A and B(P＜0.05).(3)Visual analog scale score and Oswestry Disability Index in the three groups significantly improved after operation when compared with that before operation(P＜0.05),but there was no significant difference among the three groups 1 day and 6 months after surgery(P＞0.05).(4)Postoperative imaging showed that the accuracy of percutaneous pedicle screw placement in groups A and B was better than that in group C(P＜0.05).(5)There was no significant difference in the excellent and good rate of MacNab criteria among the three groups(P＞0.05).(6)There was no significant difference in complications among the three groups(P＞0.05).(7)The results indicated that robot-assisted minimally invasive transforaminal lumbar interbody fusion and robot-assisted unilateral biportal endoscopic transforaminal/posterior lumbar interbody fusion are effective surgery methods for lumbar degenerative diseases.Compared with traditional minimally invasive transforaminal lumbar interbody fusion,robot-assisted minimally invasive transforaminal lumbar interbody fusion surgery has higher efficiency,less intraoperative radiation and higher internal fixation accuracy,which has a good clinical application value.

Two lumbar fusion regimens in treatment of single-level lumbar degenerative diseases based on propensity score matching / 中国组织工程研究

BACKGROUND:Unilateral biportal endoscopic technique has been widely used in lumbar interbody fusion in recent years,but there is little comparison between its clinical efficacy and that of minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF)in the treatment of lumbar degenerative disease,whether the unilateral biportal endoscopic technique is a safe and effective lumbar fusion remains to be further demonstrated. OBJECTIVE:To compare the clinical efficacy of unilateral biportal endoscopic lumbar interbody fusion(UBE-LIF)and MIS-TLIF in the treatment of lumbar degenerative diseases and explore a more efficient lumbar fusion procedure. METHODS:Patients with single-level lumbar degenerative disease were enrolled in Affiliated Hospital of Guilin Medical College from October 2020 to February 2022,including 35 patients who underwent UBE-LIF and 286 patients who underwent MIS-TLIF.Propensity score matching was used to eliminate confounders.Four covariates including sex,age,disease type and surgical segment were matched 1:1(caliper value 0.01).After matching,29 patients from each group were included in the study.The perioperative operative time,hemoglobin loss and hospital stay were compared between the two groups.Visual analog scale score and Oswestry disability index were used to evaluate the functional recovery of the two groups before,1,6 months and 1 year after operation.The excellent and good rate of the two groups was evaluated by the modified MacNab standard at the last follow-up.The fusion of the two groups was evaluated by Lenke Dynamic X-ray film. RESULTS AND CONCLUSION:(1)The operative time in the MIS-TLIF group was shorter than that in the UBE-LIF group(P＜0.05).The amount of intraoperative hemoglobin loss in the MIS-TLIF group was higher than that in the UBE-LIF group.The hospital stay in the MIS-TLIF group was longer than that in the UBE-LIF group,and the differences were statistically significant(P＜0.05).(2)The visual analog scale scores for lumbago and leg pain,and Oswestry disability index were significantly reduced in both groups 1,6 months,and 1 year after surgery compared to before surgery(P＜0.05).Except for the visual analog scale score for lumbago at 1 month after surgery,there was no significant difference in the visual analog scale score for lumbago and leg pain,and Oswestry disability index between the two groups at the above time points(P＞0.05).(3)At the last follow-up,the modified MacNab standard efficacy evaluation showed that the excellent and good rates were 93%(27/29)in the UBE-LIF group and 90%(26/29)in the MIS-TLIF group;there was no significant difference between the two groups(P＞0.05).(4)Lenke dynamic radiographic evaluation system evaluation for lumbar fusion exhibited that the fusion rate was 90%(grade A,21 cases;grade B,5 cases;grade C,3 cases)in the UBE-LIF group;the fusion rate was 86%(grade A,20 cases;grade B,5 cases;grade C,4 cases)in the MIS-TLIF group;there was no significant difference between the two groups(P＞0.05).(5)It is indicated that UBE-LIF and MIS-TLIF have similar clinical effects in the treatment of single-level lumbar degenerative disease with the advantages of less trauma,less bleeding and shorter hospital stay.In addition,the early postoperative lumbago was relatively mild and the learning curve was relatively smooth.Although the operative time in the UBE-LIF group was longer than that in the MIS-TLIF group,it was still a safe and effective operation.

Uniaxial endoscopic intervertebral fusion combined with pedicle screw fixation in treatment of lumbar degenerative diseases / 中国组织工程研究

BACKGROUND:With the rapid development of minimally invasive spinal surgery and enhanced recovery after surgery,endoscopic intervertebral fusion techniques have gradually emerged and been widely used in clinical practice in recent years. OBJECTIVE:To analyze the early clinical efficacy of uniaxial spinal endoscopic intervertebral fusion combined with posterior percutaneous pedicle screw fixation in the treatment of lumbar degenerative diseases. METHODS:135 patients with lumbar degenerative diseases treated by uniaxial spinal endoscopic intervertebral fusion combined with posterior percutaneous pedicle screw fixation in the Suining Central Hospital from October 2020 to December 2021 were enrolled in this study.There were 59 males and 76 females,aged 47-79 years.The lower limb and lumbar pain was evaluated by visual analog scale and lumbar function was assessed by Oswestry disability index before the operation,1 week,1,and 6 months after the operation,and at the end of follow-up.The overall pain recovery of patients was evaluated by the scoring criteria for low back pain surgery of Spine Group of Chinese Orthopedic Association and the lumbar physiological curvature and intervertebral fusion were evaluated on lumbar lateral X-ray preoperatively and at the end of follow-up. RESULTS AND CONCLUSION:(1)The 135 patients were followed up for(17.8±3.0)months after surgery.There was 1 case of endplate injury,1 case of cerebrospinal fluid leakage,1 case of nerve root injury,1 case of intervertebral cage subsidence and displacement,1 case of chronic infection,and 1 case of pedicle screw rupture.The complication rate was 5.2%.(2)The lumbar visual analog scale score and Oswestry disability index significantly decreased in the waist and lower limbs at various time points postoperatively compared with those preoperatively in 135 patients(P<0.05).The scoring criteria for low back pain surgery of the Spine Group of the Chinese Orthopedic Association were significantly better at the last follow-up than that preoperatively in 135 patients(P<0.05).(3)At the last follow-up,there was no significant difference in physiological curvature of lumbar vertebra as compared with that preoperatively in 135 patients(P>0.05),with a fusion rate of 95.8%.(4)It is concluded that uniaxial spinal endoscopic intervertebral fusion combined with posterior percutaneous pedicle screw fixation in the treatment of lumbar degenerative diseases has shown satisfactory early clinical results and is a highly safe minimally invasive spinal surgery mode.

Finite element analysis of biomechanical effect of lumbar range of motion on the implants after lumbar fusion / 中国组织工程研究

BACKGROUND:At present,lumbar interbody fusion is widely used in the treatment of a variety of lumbar diseases.However,how to reduce postoperative complications such as pseudarthrosis formation,screw loosening and fracture,and cage failure remains a serious challenge. OBJECTIVE:To analyze the effect of total lumbar range of motion on the stress or strain of bone grafts,cage,and screw-rod system,so as to better guide patients to carry out lumbar activities to reduce the risks of pseudarthrosis formation and instrumentation failure. METHODS:An intact human L1-S1 finite element model was constructed using Mimics,3-Matic,HyperMesh,and Abaqus software and the transforaminal lumbar interbody fusion was simulated.The average strain of the interbody bone grafts and the peak stresses of the cage and screw-rod system were compared before and after applying the bending moment,and the changing trend with the total range of motion was analyzed.The stress nephogram was drawn to observe the stress distribution. RESULTS AND CONCLUSION:(1)Compared with applying the vertical compression load alone,the average strain of the interbody bone grafts,peak stresses of the cage and screw-rod system after applying bending moment increased by 2.6%-55.3%,65.6%-166.8%,and 36.0%-353.4%,respectively.(2)With the increase of total range of motion,the average strain of the interbody bone grafts increased nonlinearly and produced the maximum value under left and right axial rotation,while the peak stresses of the cage and screw-rod system increased linearly and produced the maximum value under left and right lateral bending.(3)The stress distribution of the interbody bone grafts and cage was related to the loading condition.The stress of the screw-rod system was mainly concentrated in the interfaces of the screw-bone and screw-rod.(4)Therefore,increasing axial rotation activity after operation may reduce the risk of pseudarthrosis formation,while reducing lateral bending activity may reduce the failure of the cage and screw-rod system.

Short-term clinical of oblique lateral interbody fusion in the treatment of mild-to-moderate of de-generative lumbar spinal stenosis / 中国脊柱脊髓杂志

Objectives:To investigate the short-term efficacy of oblique lateral interbody fusion(OLIF)in treating mild-to-moderate lumbar spinal stenosis(LSS).Methods:35 patients with mild-o-moderate LSS treated with OLIF between May 2018 and May 2020 were analyzed retrospectively,including 25 males and 10 females,aged 50-74(60.3±10.7)years old.The patients were followed up for 12-28(18.3±3.7)months.The operative time,intraoperative bleeding,and complications were recorded;At preoperation,1 week,and 3,6 and 12 months after surgery,the visual analogue scale(VAS)for lumbar and leg pain and Oswestry disability index(ODI)were compared to evaluate clinical efficacy;And lumbar X-ray,CT,and MRI were performed at the same time to measure and evaluate the height of the intervertebral space,size of intervertebral foramen,area of dural sac and sagittal diameter,lordotic angle of intervertebral space,lordotic angle of lumbar spine,and their respective differences between before and after operation,as well as between each postoperative time point were analyzed;The complications and fusion conditions at each time point were also documented.Results:The operative time was 30-100(70.5±20.3)min,and intraoperative bleeding was 20-120(60.3±20.2)mL.The lumbar and leg pain VAS scores and ODI at postoperative 1 week,and 3,6 and 12 months were signif-icantly improved compared with those before operation,and the differences were statistically significant(P＜0.05),while there was no statistical significance when compared pairwisely between postoperative time points(P＞0.05).At postoperative 1 week,and 3,6 and 12 months,the intervertebral space height,intervertebral lor-dotic angle and lumbar lordotic angle,left and right intervertebral foramina sizes,dural sac areas,and sagittal diameters increased significantly compared with those before operation,with statistically significance(P＜0.05),and no statistical difference was found when compared pairwisely between postoperative time points for each imaging parameter(P＞0.05).According to the CT image evaluation 1 year after operation,the overall fusion rate was 94.2％(33/35 cases).No serious complications such as nerve and vascular injury occurred;3 cases of postoperative hip flexion weakness and anterior thigh numbness were relieved after 1 month of symptomatic treatment with conservative therapy;2 cases of fusion device sinking of end-plate cutting were revised in the second stage and underwent posterior muscular gap approach internal fixation.Conclusions:OLIF has satisfactory short-term clinical efficacy in the treatment of mild-to-moderate LSS.

Estudio comparativo entre la fusión lumbar intersomática por vía oblicua y la fusión lumbar intersomática por vía posterior. Resultados radiográficos y clínicos a corto plazo / Comparison between oblique lumbar interbody fusion (OLIF) and posterior lumbar interbody fusion (PLIF). Short-term radiographic and clinical results

Introducción. La fusión lumbar intersomática posterior (PLIF, "posterior lumbar interbody fusion") es un procedimiento ampliamente utilizado. En los últimos años, la fusión lumbar intersomática por vía oblicua (OLIF, "oblique lumbar interbody fusión") ha ganado cierta popularidad dado su abordaje mini-invasivo y su capacidad de descompresión indirecta. Objetivo. Comparar retrospectivamente los resultados clínicos y radiológicos de pacientes operados por vía oblicua y por vía posterior a corto plazo.Materiales y métodos. Se reunieron los pacientes intervenidos quirúrgicamente por vía OLIF y PLIF entre 2020 y 2021. Se dividieron en dos grupos según la vía utilizada y se compararon los datos demográficos y resultados radiográficos entre el preoperatorio y postoperatorio. Se utilizó el cuestionario de Oswestry (ODI) para evaluar la escala de discapacidad por dolor lumbar y se registraron las complicaciones de ambos grupos. Resultados. Sobre 118 pacientes, 56 corresponden a la vía OLIF y 62 al PLIF. Con respecto al ODI, no se registraron diferencias significativas entre ambos grupos previamente ni posterior a la cirugía. El grupo OLIF mostró mejores resultados radiográficos que el grupo PLIF en el posoperatorio, con una diferencia significativa en la lordosis lumbar total (p 0,017). El grupo PLIF mostró un mayor número de complicaciones posoperatorias. Conclusión. La vía OLIF puede ser un método quirúrgico alternativo a la vía posterior tradicional en pacientes con patología degenerativa lumbar. Esta vía permitiría obtener mejores resultados radiográficos con menos complicaciones comparado con la vía tradiciona

Background. Posterior lumbar interbody fusion (PLIF) is a widely used method. In recent years, oblique lumbar interbody fusion (OLIF) has gained some popularity due to its minimally invasive approach and ability of indirect decompression. Objective. Our objective is to compare retrospectively clinical and radiological results of patients operated by boths techniques in the short term.Materials and methods. Patients who underwent surgery by the OLIF and PLIF between 2020 and 2021 were gathered. They were divided into two groups according to the technique used; and demographic data and radiographic results were compared between the preoperative and postoperative periods. The Oswestry Disability Questionnaire (ODI) was used to assess the low back pain disability; and complications were recorded for both groups. Results. Out of 118 patients, 56 correspond to the OLIF group and 62 to the PLIF group. Regarding the ODI, no significant differences were recorded between the two groups before and after surgery. The OLIF group showed better radiographic results than the PLIF group in the postoperative period, with a significant difference in total lumbar lordosis (p 0.017). The PLIF group showed a higher number of postoperative complications. Conclusion: The OLIF approach can be an alternative surgical method to the traditional posterior approach in patients with lumbar degenerative pathology. This technique would allow obtaining better radiographic results with fewer complications compared to the traditional technique

Comparing perioperative and postoperative outcomes and complications of ALIF and LLIF

Purpose: This paper compares anterior lumbar intercorporeal fusion (ALIF) and lateral lumbar intercorporeal fusion (LLIF). LLIF is an approach through the lateral retroperitoneal corridor, transpsoas. ALIF is a described alternative to interbody fusion with approach variations described as retroperitoneal, transperitoneal, open, and laparoscopic. Our objective is to compare complications can occur in both approaches the ALIF and the LLIF, to see what the advantages and disadvantages are during the perioperative and postoperative. Method: This is a literature review article. A MEDLINE search was conducted through PubMed, google scholar, science direct, and Cochrane to identify articles that reported the differences between ALIF, LLIF and other lumbar interbody fusion approaches focusing the complications, cost and length of surgery, length of hospitalization, narcotic use, sagittal balance and surgical technique. Result: There was no overall significant difference in the postoperative narcotic use, fusion rate, and disc height. However, ALIF was seen to have better postoperative sagittal balance. Although long-term complication rates between ALIF and LLIF are not statistically even though the procedures have procedure-specific complications. Intraoperative blood loss and operative time were relatively higher in ALIF than in LLIF. The risk of injury to the lumbar plexus and iliac vessels is relatively higher than ALIF. Conclusion: ALIF and LLIF they are considered safe, effective and non-invasive. Both procedures present their pearls and pitfalls, but LLIF is associated with more complications than ALIF, although they do not present great differences of clinical outcomes. There is a need more extensive research to determine the best approach.

Propósito: Este trabajo compara la fusión intercorpórea lumbar anterior (ALIF, por sus siglas en inglés) y la fusión intercorpórea lumbar lateral (LLIF, por sus siglas en inglés). LLIF es una aproximación a través del corredor retroperitoneal lateral, con transpsoas. La ALIF es una alternativa a la fusión intercorporal con variaciones de abordaje descritas como retroperitoneal, transperitoneal, abierta y laparoscópica. Nuestro objetivo es comparar las complicaciones que pueden ocurrir en ambos abordajes de la ALIF y la LLIF, para ver cuáles son las ventajas y desventajas durante los procesos perioperatorio y postoperatorio. Método: Este es un artículo de revisión de literatura. Se realizó una búsqueda MEDLINE a través de PubMed, Google Scholar, Science Direct y Cochrane para identificar artículos que reportaron las diferencias entre ALIF, LLIF y otros enfoques de fusión intercorporal lumbar enfocándose en las complicaciones, el costo y la duración de la cirugía, duración de la hospitalización, uso de estupefacientes, equilibrio sagital y técnica quirúrgica. Resultado: No hubo diferencia significativa general en el uso posoperatorio de narcóticos, la tasa de fusión y la altura del disco. Sin embargo, se observó que la ALIF tenía un mejor equilibrio sagital postoperatorio. Aunque las tasas de complicaciones a largo plazo entre ALIF y LLIF no son estadísticamente significativas a pesar de que los procedimientos tienen complicaciones específicas del procedimiento. La pérdida de sangre intraoperatoria y el tiempo operativo fueron relativamente más altos en ALIF que en LLIF. El riesgo de lesión en el plexo lumbar y los vasos ilíacos es relativamente mayor que la ALIF. Conclusiones: ALIF y LLIF se consideran métodos seguros, eficaces y no invasivos. Ambos procedimientos presentan aciertos y desaciertos, pero el LLIF se asocia a más complicaciones que el ALIF, aunque no presentan grandes diferencias en los resultados clínicos. Se necesita una investigación más amplia para determinar el mejor enfoque.

Biomechanical Evaluation of Oblique Lateral Interbody Fusion Combined with Different Internal Fixation Methods for Treating Degenerative Lumbar Scoliosis:A Finite Element Analysis / 医用生物力学

Objective To verify the biomechanical stability of oblique lateral interbody fusion ( OLIF) combinedwith different fixation methods for treating degenerative lumbar scoliosis (DLS) by three-dimensional (3D) finite element analysis. Methods The L1-S1 3D finite element DLS model ( Model 1) was established, and then the OLIF (L2-5) at 3 contiguous levels of fusion and its combination with different internal fixation methods were simulated, namely, stand-alone OLIF model ( Model 2), vertebral screw fixation model ( Model 3), unilateral pedicle screw fixation model (Model 4) and bilateral pedicle screw fixation model (Model 5) were established,respectively. Under upright, flexion, extension, lateral bending and axial rotation states, range of motion (ROM) of fusion segments, as well as cage stress, internal fixation stress, and stress distribution were recorded and analyzed. Results Under six motion states, the overall ROM of fusion segments in Models 2-5 was smaller than that of Model 1. Compared with Model 1, the overall ROM reduction of Model 3 and Model 4 was larger than that of Model 2 and smaller than that of Model 5. Under flexion and extension, the overall ROM reduction of Model 4 and Model 5 was basically equal. Under left and right lateral bending, the overall ROM reduction of Model 3 and Model 5 was basically equal. Under all motion states, the peak stress of Model 3 and Model 4 fusion cage was larger than that of Model 5 and smaller than that of Model 2. The peak stresses of L2-3, L3-4 and L4-5 fusion cages in Model 3 increased by 5. 52% , 10. 96% and 7. 99% respectively compared with Model 5 under left lateral bending, and the peak stresses of L2-3, L3-4 and L4-5 fusion cages in Model 4 increased by 8. 70% , 7. 00% and 6. 99% respectively under flexion. Under all motion states, the peak stress of screw rod in Model 5 was smaller than that of Model 3 and Model 4, and the peak stresses of screw rod in Models 3-5 were the smallest in upright state. Conclusions The OLIF with unilateral pedicle screw fixation or vertebral screw fixation can provide favorable biomechanical stability of the fusion segment. The results provide some references for clinical application of OLIF technology in the treatment of DLS.

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.

Comparison of clinical effect and muscle injury imaging between oblique lateral lumbar interbody fusion and transforaminal lumbar interbody fusion in the treatment of single-segment degenerative lumbar spinal stenosis / 中国骨伤

OBJECTIVE@#To compare the efficacy and muscle injury imaging between oblique lateral lumbar interbody fusion (OLIF) and transforaminal lumbar interbody fusion (TLIF) in the treatment of single-segment degenerative lumbar spinal stenosis.@*METHODS@#The clinical data of 60 patients with single-segment degenerative lumbar spinal stenosis who underwent surgical treatment from January 2018 to October 2019 was retrospectively analyzed. The patients were divided into OLIF groups and TLIF group according to different surgical methods. The 30 patients in the OLIF group were treated with OLIF plus posterior intermuscular screw rod internal fixation. There were 13 males and 17 females, aged from 52 to 74 years old with an average of (62.6±8.3) years old. And 30 patients in the TLIF group were treated with TLIF via the left approach. There were 14 males and 16 females, aged from 50 to 81 years old with an average of (61.7±10.4) years old. General data including operative time, intraoperative blood loss, postoperative drainage volume, and complications were recorded for both groups. Radiologic data including disc height (DH), the left psoas major muscle, multifidus muscle, longissimus muscle area, T2-weighted image hyperintensity changes and interbody fusion or nonfusion were observed. Laboratory parameters including creatine kinase (CK) values on postoperative 1st and 5th days were analyzed. Visual analogue scale(VAS) and Oswestry disability index(ODI) were used to assess clinical efficacy.@*RESULTS@#There was no significant difference in the operative time between two groups(P>0.05). The OLIF group had significantly less intraoperative blood loss and postoperative drainage volume compared to the TLIF group(P<0.01). The OLIF group also had DH better recovery compared to the TLIF group (P<0.05). There were no significant differences in left psoas major muscle area and the hyperintensity degree before and after the operation in the OLIF group (P>0.05). Postoperativly, the area of the left multifidus muscle and longissimus muscle, as well as the mean of the left multifidus muscle and longissimus muscle in the OLIF group, were lower than those in the TLIF group (P<0.05) .On the 1st day and the 5th day after operation, CK level in the OLIF group was lower than that in the TLIF group(P<0.05). On the 3rd day after operation, the VAS of low back pain and leg pain in the OLIF group were lower than those in the TLIF group (P<0.05). There were no significant differences in the ODI of postoperative 12 months, low back and leg pain VAS at 3, 6, 12 months between the two groups(P>0.05). In the OLIF group, 1 case of left lower extremity skin temperature increased after the operation, and the sympathetic chain was considered to be injured during the operation, and 2 cases of left thigh anterior numbness occurred, which was considered to be related to psoas major muscle stretch, resulting in a complication rate of 10% (3/30). In the TLIF group, one patient had limited ankle dorsiflexion, which was related to nerve root traction, two patients had cerebrospinal fluid leakage, and the dural sac was torn during the operation, and one patient had incision fat liquefaction, which was related to paraspinal muscle dissection injury, resulting in a complication rate of 13% (4/30). All patients achieved interbody fusion without cage collapse during the 6- month follow-up.@*CONCLUSION@#Both OLIF and TLIF are effective in the treatment of single-segment degenerative lumbar spinal stenosis. However, OLIF surgery has obviously advantages, including less intraoperative blood loss, less postoperative pain, and good recovery of intervertebral space height. From the changes in laboratory indexes of CK and the comparison of the left psoas major muscle, multifidus muscle, longissimus muscle area, and high signal intensity of T2 image on imaging, it can be seen that the degree of muscle damage and interference of OLIF surgery is lower than that of TLIF.

Causes of asymptomatic side limb pain after minimally invasive transforaminal lumbar interbody fusion / 中国骨伤

OBJECTIVE@#To investigate possible causes and preventive measures for asymptomatic pain in the limbs after minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF).@*METHODS@#Clinical data from 50 patients with lumbar degenerative disease who underwent MIS-TLIF between January 2019 and September 2020 were retrospectively analyzed. The group included 29 males and 21 females aged from 33 to 72 years old, with an average age of (65.3±7.13) years. Twenty-two patients underwent unilateral decompression, and 28 underwent bilateral decompression. The side(ipsilateral or contralateral) and site(low back, hip, or leg) of the pain were recorded before surgery, 3 days after surgery, and 3 months after surgery. The pain degree was evaluated using the visual analogue scale(VAS) at each time point. The patients were further grouped based on whether contralateral pain occurred postoperatively (8 cases in the contralateral pain group and 42 in the no contralateral pain group), and the causes and preventive measures of pain were analyzed.@*RESULTS@#All surgeries were successful, and the patients were followed up for at least 3 months. Preoperative pain on the symptomatic side improved significantly, with the VAS score decreasing from (7.00±1.79) points preoperatively to (3.38±1.32) points at 3 days postoperatively and (3.98±1.17) points at 3 months postoperatively. Postoperative asymptomatic side pain (contralateral pain) occurred in 8 patients within 3 days after surgery, accounting for 16% (8/50) of the group. The sites of contralateral pain included the lumbar area (1 case), hip(6 cases), and leg (1 case). The contralateral pain was significantly relieved 3 months after surgery.@*CONCLUSION@#More cases of contralateral limb pain occur after unilateral decompression MIS-TLIF, and the reason may include contralateral foramen stenosis, compression of medial branches, and other factors. To reduce this complication, the following procedures are recommended: restoring intervertebral height, inserting a transverse cage, and withdrawing screws minimally.

Effect of neuroelectrophysiological changes on the clinical manifestations and surgical outcomes of lumbar degenerative diseases / 中国骨伤

OBJECTIVE@#To evaluate the effects of electromyography on the clinical manifestations and prognosis after posterior lumbar interbody fusion(PLIF) of degenerative lumbar diseases.@*METHODS@#A retrospective analysis was performed on 68 patients with degenerative lumbar diseases, including 29 males and 39 females, aged 21 to 84 years old, who underwent electromyogram (EMG) from January 2018 to October 2019. The patients were divided into negative and positive groups according to whether theresults of EMG was normal or abnormal, PLIF surgery was performed in both groups. The preoperative duration of illness, postoperative recovery time, operative time, intraoperative blood loss, postoperative ambulation time and length of postoperative hospital stay were recorded. The clinical efficacy was evaluated by visual analogue scale(VAS) of low back and lower limb, the Japanese Orthopedic Association(JOA) score before and after operation.@*RESULTS@#All patients were follow-up from 26 to 39 months. The subjective symptoms, clinical signs, daily activities and JOA total scores after operation in two groups were significantly higher than those before preoperation(P<0.05);the clinical signs score and total JOA score in the negative group at 3 months after operation were higher than those in the positive group(P<0.05). The VAS score of leg pain in the negative group after 1 and 3 months was less than that in the positive group(P<0.05). Patients 's illness time, postoperative recovery time, hospitalization time and implantation time in the negative group were shorter than those in the positive group(P<0.05). At other time points, there was no significant difference in low pain VAS, leg pain VAS, JOA scores in the two groups(P>0.05). There was no significant difference in the operation time and intraoperative bleeding volume between the two groups(P>0.05).@*CONCLUSION@#Patients with normal electromyography had shorter disease duration than ones with abnormal electromyography in lumbar degenerative disease;after PLIF, patients with normal electromyography recovered faster than ones with abnormal electromyography, but the results of electromyography had no effect on the final prognosis of PLIF surgery.

Clinical efficacy of minimally invasive transforaminal lumbar interbody fusion assisted with microscope in treatment of senile degenerative spondylolisthesis / 临床外科杂志

Objective To investigate the clinical efficacy of endoscopic assisted minimally invasive trans foraminal lumbar interbody fusion(MIS-TLIF)and traditional open TLIF in the treatment of senile degenerative spondylolisthesis.Methods From January 2020 to March 2021,100 elderly patients with degenerative spondylolisthesis were selected and divided into MIS-TLIF group and TLIF group according to the surgical method,with 50 cases in each group.The preoperative and postoperative VAS,Japanese Orthopedic Association score(JO A)and Oswestry disability index(ODI),and the rate of interbody fusion and the incidence of complications were compared and analyzed between the two groups.Results In MIS-TLIF group,the operative time,intraoperative blood loss,incision length,postoperative drainage volume and hospital stay were(167.5±54.2)minutes,(173.8±47.1)ml,(3.5±0.7)cm,(69.6±16.3)ml,and(8.3±2.7)days,respectively.In the TLIF group,it was(136.3±38.9)minutes,(281.0±50.3)ml,(10.0±2.1)cm,(148.4±28.2)ml,and(11.2±3.1)days,respectively.The difference between the two groups was statistically significant(P＜0.05).The VAS,JO A and ODI scores of MIS-TLIF group were(2.17±0.62)points,(21.72±3.14)points and(13.22 ±2.43)points,respectively.The results in TLIF group were(3.24±1.06)points,(17.06±2.85)points and(16.83±2.87)points,respectively,and there was statistical significance between the two groups(P＜0.05).There was no significant difference in the rate of interbody fusion between the two groups at 12 months after operation(P＞0.05).The incidence of postoperative complications in MIS-TLIF group(8.00％)was significantly lower than that in TLIF group(24.00％,P＜0.05).Conclusion MIS-TLIF assisted by endoscope has the advantages of less trauma,faster recovery and less postoperative complications,and the short-term curative effect is more satisfactory than TLIF.

Effectiveness analysis of posterolateral approach lumbar interbody fusion assisted by one-hole split endoscope for L4, 5 degenerative lumbar spondylolisthesis / 中国修复重建外科杂志

OBJECTIVE@#To compare the effectiveness of posterolateral approach lumbar interbody fusion assisted by one-hole split endoscope (OSE) and traditional posterior lumbar interbody fusion (PLIF) in the treatment of L4, 5 degenerative lumbar spondylolisthesis (DLS).@*METHODS@#The clinical data of 58 patients with DLS who met the selection criteria admitted between February 2020 and March 2022 were retrospectively analyzed, of which 26 were treated with OSE-assisted posterolateral approach lumbar interbody fusion (OSE group) and 32 were treated with PLIF (PLIF group). There was no significant difference between the two groups in terms of gender, age, body mass index, Meyerding grade, lower limb symptom side, decompression side, stenosis type, and preoperative low back pain visual analogue scale (VAS) score, leg pain VAS score, Oswestry disability index (ODI), and the height of the anterior and posterior margins of the intervertebral space (P>0.05). The operation time, intraoperative blood loss, postoperative hospital stay, and complications were compared between the two groups. The low back pain and leg pain VAS scores and ODI before operation, at 1 month, 6 months after operation, and last follow-up, the height of anterior and posterior margins of the intervertebral space before operation, at 6 months after operation, and last follow-up, the modified MacNab criteria at last follow-up after operation were used to evaluate the effectiveness; and the Bridwell method at last follow-up was used to evaluate the interbody fusion.@*RESULTS@#Both groups successfully completed the operation. Compared with the PLIF group, the OSE group showed a decrease in intraoperative blood loss and postoperative hospital stay, but an increase in operation time, with significant differences (P<0.05). In the OSE group, no complication such as nerve root injury and thecal sac tear occurred; in the PLIF group, there were 1 case of thecal sac tear and 1 case of epidural hematoma, which were cured after conservative management. Both groups of patients were followed up 13-20 months with an average of 15.5 months. There was no complication such as loosening, sinking, or displacement of the fusion cage. The low back pain and leg pain VAS scores, ODI, and the height of anterior and posterior margins of the intervertebral space at each time point after operation in both groups were significantly improved when compared with those before operation (P<0.05). Except for the VAS score of lower back pain in the OSE group being significantly better than that in the PLIF group at 1 month after operation (P<0.05), there was no significant difference in all indicators between the two groups at all other time points (P>0.05). At last follow-up, both groups achieved bone fusion, and there was no significant difference in Bridwell interbody fusion and modified MacNab standard evaluation between the two groups (P>0.05).@*CONCLUSION@#OSE-assisted posterolateral approach lumbar interbody fusion for L4, 5 DLS, although the operation time is relatively long, but the postoperative hospitalization stay is short, the complications are few, the operation is safe and effective, and the early effectiveness is satisfactory.

Research progress on the influence of Modic changes on lumbar interbody fusion and its treatment measure / 中国修复重建外科杂志

OBJECTIVE@#To review the research progress of Modic changes and its influence on lumbar interbody fusion.@*METHODS@#The domestic and foreign literature related to Modic changes and its influence on lumbar interbody fusion was extensively reviewed. The etiology of Modic changes was summarized, and the treatment measures of Modic changes on lumbar interbody fusion were discussed.@*RESULTS@#The etiology of Modic changes is not clear, which may be related to mechanical factors, autoimmune factors, low toxic infection factors, and genetic factors. Modic changes may lead to fusion failure and cage subsidence after lumbar interbody fusion. Preoperative evaluation of endplate sclerosis, reduction of iatrogenic endplate injury, fine operating of intervertebral space, management of osteoporosis, and selection of appropriate cage can prevent or reduce fusion failure or cage subsidence.@*CONCLUSION@#Modic changes may lead to fusion failure and cage subsidence after lumbar interbody fusion, and active perioperative intervention of Modic changes is helpful to improve the clinical prognosis.

Comparison of effectiveness between unilateral biportal endoscopic lumbar interbody fusion and endoscopic transforaminal lumbar interbody fusion for lumbar spinal stenosis combined with intervertebral disc herniation / 中国修复重建外科杂志

OBJECTIVE@#To compare the effectiveness between unilateral biportal endoscopic lumbar interbody fusion (ULIF) and endoscopic transforaminal lumbar interbody fusion (Endo-TLIF) in treatment of lumbar spinal stenosis combined with intervertebral disc herniation.@*METHODS@#A clinical data of 64 patients with lumbar spinal stenosis and intervertebral disc herniation, who were admitted between April 2020 and November 2021 and met the selection criteria, was retrospectively analyzed. Among them, 30 patients were treated with ULIF (ULIF group) and 34 patients with Endo-TLIF (Endo-TLIF group). There was no significant difference in baseline data such as gender, age, disease duration, lesion segment, preoperative visual analogue scale (VAS) score of low back pain and leg pain, Oswestry disability index (ODI), spinal canal area, and intervertebral space height between the two groups ( P>0.05). The operation time, intraoperative blood loss, hospital stays, and postoperative complications were compared between the two groups, as well as the VAS scores of low back pain and leg pain, ODI, and imaging measurement indicators (spinal canal area, intervertebral bone graft area, intervertebral space height, and degree of intervertebral fusion according to modified Brantigan score).@*RESULTS@#Compared with the Endo-TLIF group, the ULIF group had shorter operation time, but had more intraoperative blood loss and longer hospital stays, with significant differences ( P<0.05). The cerebrospinal fluid leakage occurred in 2 cases of Endo-TLIF group and 1 case of ULIF group, and no other complication occurred. There was no significant difference in the incidence of complications between the two groups ( P>0.05). All patients in the two groups were followed up 12 months. The VAS scores of lower back pain and leg pain and ODI in the two groups significantly improved when compared with those before operation ( P<0.05), and there was no significant difference between different time points after operation ( P>0.05). And there was no significant difference between the two groups at each time point after operation ( P>0.05). Imaging examination showed that there was no significant difference between the two groups in the change of spinal canal area, the change of intervertebral space height, and intervertebral fusion rate at 6 and 12 months ( P>0.05). The intervertebral bone graft area in the ULIF group was significantly larger than that in the Endo-TLIF group ( P<0.05).@*CONCLUSION@#For the patients with lumbar spinal stenosis combined with intervertebral disc herniation, ULIF not only achieves similar effectiveness as Endo-TLIF, but also has advantages such as higher decompression efficiency, flexible surgical instrument operation, more thorough intraoperative intervertebral space management, and shorter operation time.

Comparison of screw placement guided by O-arm navigation and ultrasound volume navigation in minimally invasive transforaminal lumbar interbody fusion / 中国修复重建外科杂志

OBJECTIVE@#To compare the effectiveness of O-arm navigation and ultrasound volume navigation (UVN) in guiding screw placement during minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) surgery.@*METHODS@#Sixty patients who underwent MIS-TLIF surgery for lumbar disc herniation between June 2022 and June 2023 and met the selection criteria were included in the study. They were randomly assigned to group A (screw placement guided by UVN during MIS-TLIF) or group B (screw placement guided by O-arm navigation during MIS-TLIF), with 30 cases in each group. There was no significant difference in baseline data, including gender, age, body mass index, and surgical segment, between the two groups ( P>0.05). Intraoperative data, including average single screw placement time, total radiation dose, and average single screw effective radiation dose, were recorded and calculated. Postoperatively, X-ray film and CT scans were performed at 10 days to evaluate screw placement accuracy and assess facet joint violation. Pearson correlation and Spearman correlation analyses were used to observe the relationship between the studied parameters (average single screw placement time and screw placement accuracy grading) and BMI.@*RESULTS@#The average single screw placement time in group B was significantly shorter than that in group A, and the total radiation dose of single segment and multi-segment and the average single screw effective radiation dose in group B were significantly higher than those in group A ( P<0.05). There was no significant difference in the total radiation dose between single segment and multiple segments in group B ( P>0.05), while the total radiation dose of multiple segments was significantly higher than that of single segment in group A ( P<0.05). No significant difference was found in the accuracy of screw implantation between the two groups ( P>0.05). In both groups, the grade 1 and grade 2 screws broke through the outer wall of the pedicle, and no screw broke through the inner wall of the pedicle. There was no significant difference in the rate of facet joint violation between the two groups ( P>0.05). In group A, both the average single screw placement time and screw placement accuracy grading were positively correlated with BMI ( r=0.677, P<0.001; r=0.222, P=0.012), while in group B, neither of them was correlated with BMI ( r=0.224, P=0.233; r=0.034, P=0.697).@*CONCLUSION@#UVN-guided screw placement in MIS-TLIF surgery demonstrates comparable efficiency, visualization, and accuracy to O-arm navigation, while significantly reducing radiation exposure. However, it may be influenced by factors such as obesity, which poses certain limitations.

The trend of changes in spine-pelvic sagittal parameters before and after surgery in patients with double-segment lumbar spondylolisthesis and their evaluating for surgery efficacy / 中国骨伤

OBJECTIVE@#To explore the trend of changes in the parameters of the spine-pelvic sagittal plane before and after surgery in patients with double-segment lumbar spondylolisthesis (LSL) and to evaluate the value of the surgical effect.@*METHODS@#A retrospective analysis of 95 double-segment lumbar spondylolisthesis patients treated with posterior lumbar interbody fusion from October 2019 to October 2020 were analyzed, including 31 males and 64 females;age ranging from 41 to 63 years old, with an average of (52.10±4.35) years old;degree of lesion, 47 patients with gradeⅠand 48 patients with gradeⅡ. The surgical efficacy was evaluated according to the Oswestry dysfunction index(ODI) improvement rate at 3 months after operation. ODI improvement rate ≥50% was considered good, and <50% was considered bad. Ninety-five patients were divided into good curative effect group (74 cases) and poor curative effect group (21 cases) according to surgical curative effect. The clinical data, such as gender, age, body mass index, course of disease, degree of disease, operation time, intraoperative blood loss, and comorbidities were compared between two groups were compared. The parameters of spine pelvis sagittal plane were observed before and 3 months after operation, including spine sacral angle (SSA), T1 pelvic angle (TPA), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS). Clinical symptoms were evaluated using visual analogue scale (VAS) and ODI. The correlation between the changes of spine pelvis sagittal plane parameters and the changes of VAS and ODI before and after surgery were analyzed, and the value of spine pelvis sagittal plane parameters in evaluating the surgical efficacy of patients with double level lumbar spondylolisthesis at 3 months after surgery was evaluated.@*RESULTS@#The courses of disease and surgical time in the group with poor efficacy were longer than those in the group with good efficacy, and the degree of lesion was higher in the group with poor efficacy (P<0.05). The SSA, TPA, LL, and SS of the group with good efficacy were higher than those of the group with poor efficacy before and 3 months after surgery, while the PT was lower than that of the group with poor efficacy (P<0.05). The changes in SSA, TPA, LL, PT, and SS before and after surgery in the group with good efficacy were greater than those in the group with poor efficacy (P<0.05). The VAS and ODI of both groups were lower at 3 months after surgery than before, and the group with good efficacy was lower(P<0.05). The changes in VAS and ODI before and after surgery in the group with good efficacy were greater than those in the group with poor efficacy (P<0.05). The changes in SSA, TPA, LL, PT, SS before and after surgery were positively correlated with the changes in VAS and ODI (P<0.05). Three months after surgery, SSA, TPA, LL, PT, and SS were used to evaluate the surgical efficacy of patients with dual level lumbar spondylolisthesis. The area under the curve (AUC) was 0.868, 0.797, 0.875, 0.822, and 0.853, respectively. The combined evaluation of all indicators resulted in the highest AUC, 0.927, and the best sensitivity and specificity were 90.50% and 91.89%, respectively.@*CONCLUSION@#The spine pelvis sagittal plane parameters SSA, TPA, LL, and SS of patients with double level lumbar spondylolisthesis before and after surgery show an upward trend;PT shows a downward trend;PI do not change significantly. And the changes of SSA, TPA, LL, SS, and PT are closely related to the patient's pain level and the improvement of lumbar function, which can be used as parameters to evaluate the surgical efficacy.