In this editorial,the authors of this paper comment on the article by Bokov et al published in the recent issue of World Journal of Orthopedics.We reviewed a general overview of oblique lumbar interbody fusions(OLIF)a...In this editorial,the authors of this paper comment on the article by Bokov et al published in the recent issue of World Journal of Orthopedics.We reviewed a general overview of oblique lumbar interbody fusions(OLIF)and lateral lumbar interbody fusions(LLIF),their indications and complications as an increasingly popular minimally invasive technique to address several lumbar pathologies.This editorial thoroughly discusses and reviews the literature regarding factors affecting outcomes of indirect decompression utilized through OLIF and LLIF procedures.Several parameters play a critical role in patient outcomes including restoration of disc height,foraminal height,central canal squared,and foraminal area.The indirect decompression allows for unbuckling of the ligamentum flavum which can significantly decompress the neural elements as well as aid in reduction of spondylolisthesis.However,the authors further highlight the limitations of indirect decompression and factors that may predict unsuccessful outcomes including bony foraminal stenosis,severe central canal stenosis,and osteoporosis.As a result,failure of indirect decompression can lead to persistent pain,radiculopathy and unsatisfied patients.Spinal surgeons may be left to reimage patients and consider additional procedures with direct decompression.展开更多
Interbody fusion is recognized as the golden standard of surgical intervention for degenerative disc disease(DDD).Interbody fusion cage made of polyetheretherketone(PEEK)is commonly used in lumbar interbody fusion sur...Interbody fusion is recognized as the golden standard of surgical intervention for degenerative disc disease(DDD).Interbody fusion cage made of polyetheretherketone(PEEK)is commonly used in lumbar interbody fusion surgery in the treatment of DDD worldwide.However,there are some limitations of PEEK including their bio-inert nature and impediment to host bone integration.This study aimed to evaluate the degradation profile and osteoinductive potential of biodegradable Mg-Zn-Nd-Zr cages with/without micro-arc oxidation(MAO)coatings.The Mg-Zn-Nd-Zr alloy cages,whether coated with MAO or not,demonstrated commendable biocompatibility and biomechanical properties.Immersion and electrochemical tests show better corrosion resistance of MAO coatings in vitro.mRNA sequencing,RT-qPCR and Western blotting revealed that Mg-Zn-Nd-Zr and Mg-Zn-Nd-Zr/MAO had a better effectiveness on osteoinductivity.In vivo evaluations in ovine models over 12 weeks and 24 weeks post-implantation revealed radiological and histological evidence of enhanced bone formation adjacent to the Mg-Zn-Nd-Zr alloy cages compared to PEEK counterparts.Moreover,the MAO-coated cages exhibited a reduced propensity for gas formation.The Mg-Zn-Nd-Zr alloy is as a superior osteoinductive material compared with PEEK,with the MAO coating offering an advantage in mitigating gas production.Nonetheless,further research is warranted to refine the alloy's composition or surface treatments,particularly to address the challenges associated with rapid gas evolution during the early post-implantation period.展开更多
BACKGROUND Indirect decompression is one of the potential benefits of anterior reconstruction in patients with spinal stenosis.On the other hand,the reported rate of revision surgery after indirect decompression highl...BACKGROUND Indirect decompression is one of the potential benefits of anterior reconstruction in patients with spinal stenosis.On the other hand,the reported rate of revision surgery after indirect decompression highlights the necessity of working out prediction models for the radiographic results of indirect decompression with assessing their clinical relevance.AIM To assess factors that influence radiographic and clinical results of the indirect decompression in patients with stenosis of the lumbar spine.METHODS This study is a single-center cross-sectional evaluation of 80 consecutive patients(17 males and 63 females)with lumbar spinal stenosis combined with the instability of the lumbar spinal segment.Patients underwent single level or bisegmental spinal instrumentation employing oblique lumbar interbody fusion(OLIF)with percutaneous pedicle screw fixation.Radiographic results of the indirect decompression were assessed using computerized tomography,while MacNab scale was used to assess clinical results.RESULTS After indirect decompression employing anterior reconstruction using OLIF,the statistically significant increase in the disc space height,vertebral canal square,right and left lateral canal depth were detected(Р<0.0001).The median(M)relative vertebral canal square increase came toМ=24.5%with 25%-75%quartile border(16.3%;33.3%)if indirect decompression was achieved by restoration of the segment height.In patients with the reduction of the upper vertebrae slip,the median of the relative increase in vertebral canal square accounted for 49.5%with 25%-75%quartile border(2.35;99.75).Six out of 80 patients(7.5%)presented with unsatisfactory results because of residual nerve root compression.The critical values for lateral recess depth and vertebral canal square that were associated with indirect decompression failure were 3 mm and 80 mm2 respectively.CONCLUSION Indirect decompression employing anterior reconstruction is achieved by the increase in disc height along the posterior boarder and reduction of the slipped vertebrae in patients with degenerative spondylolisthesis.Vertebral canal square below 80 mm2 and lateral recess depth less than 3 mm are associated with indirect decompression failures that require direct microsurgical decompression.展开更多
Objective We aimed to compare the clinical and radiological outcomes of midline lumbar fusion(MIDLF)versus minimally invasive transforaminal lumbar interbody fusion(MI-TLIF)in patients with degenerative spondylolisthe...Objective We aimed to compare the clinical and radiological outcomes of midline lumbar fusion(MIDLF)versus minimally invasive transforaminal lumbar interbody fusion(MI-TLIF)in patients with degenerative spondylolisthesis and/or stenosis in L4-L5 two years after surgery.Methods Consecutively treated patients with lumbar pathology who underwent MIDLF(n=16)and a historical control group who underwent MI-TLIF(n=34)were included.Clinical symptoms were evaluated using Oswestry Disability Index(ODI),the 36-Item Short-Form Health Survey,and visual analog scale(VAS)scores before surgery and 3,6,12,and 24 months after surgery.Results The mean operative time and hematocrit(HCT,Day 1)were significantly shorter and lower in MIDLF cases(174 min vs.229 min,P<0.001;0.34 vs.0.36,P=0.037).The MI-TLIF group showed better improvement than the MIDLF group in ODI and VAS back and leg pain at 3 months postoperatively.VAS leg pain was higher in MIDLF than in MI-TLIF cases at 6 months.At 24 months follow-up,VAS back pain was higher in MI-TLIF than in MIDLF cases(P=0.018).Conclusion MIDLF is comparable to MI-TLIF at L4-5 in clinical outcomes and fusion rates,and the results verified the meaningful advantage of using MIDLF for the elderly with osteoporosis.展开更多
To evaluate the clinical outcome,effectiveness and safety of the surgical management of traumatic lumbar spondylolisthesis with transforaminal lumbar interbody fusion (TLIF) with short segmental instrumentation fixati...To evaluate the clinical outcome,effectiveness and safety of the surgical management of traumatic lumbar spondylolisthesis with transforaminal lumbar interbody fusion (TLIF) with short segmental instrumentation fixation.A retrospective review of a consecutive series of 24 patients with traumatic lumbar spondylolisthesis treated with TLIF procedure was carried out.Intraoperative spinal cord monitoring was used to confirm the peripheral neural function intact during the reduction of the spondylolisthesis.Preoperative clinical and radiographic evaluation of all cases were originally collected prospectively.Data regarding blood loss,operative time,duration of hospital stay,radiographic fusion,instrumentation failure and clinical result were collected and observed at regular follow-up periods.All patients were engaged in high-energy accidents in the lower back and 16 patients had concomitant injuries.The mean operative time was 124 min,mean blood loss was 350 mL,and mean hospital stay was 6.5 days.There were no complications such as incision infection,cerebrospinal fluide (CSF) leakage and nerve root injury and so on.All patients demonstrated a solid lumbar interbody fusion within 4 months,and no evidence of spondylolisthesis correction loss,instrumentation failure and loosing.They all were completely asymptomatic,with normal neurologic findings,and had resumed their previous level of physical activities on the final follow-up.Meticulous clinical examination and careful imaging assessment could assist an early diagonosis in cases of traumatic lumbar spondylolisthesis.Performing open reduction and the TLIF procedure as soon as possible could restore segmental stability and painless function.The TLIF procedure was a safe,effective technique to treat traumatic lumbar spondylolisthesis.展开更多
BACKGROUND Whether it’s better to adopt unilateral pedicle screw(UPS)fixation or to use bilateral pedicle screw(BPS)one for lumbar degenerative diseases is still controversially undetermined.AIM To make a comparison ...BACKGROUND Whether it’s better to adopt unilateral pedicle screw(UPS)fixation or to use bilateral pedicle screw(BPS)one for lumbar degenerative diseases is still controversially undetermined.AIM To make a comparison between UPS and BPS fixation as to how they work efficaciously and safely in patients suffering from lumbar degenerative diseases.METHODS We have searched a lot in the databases through 2020 with index terms such as“unilateral pedicle screw fixation”and“bilateral pedicle screw fixation.”Only randomized controlled trials and some prospective cohort studies could be found,yielding 15 studies.The intervention was unilateral pedicle screw fixation;Primarily We’ve got outcomes of complications and fusion rates.Secondarily,we’ve achieved outcomes regarding total blood loss,operative time,as well as length of stay.Softwares were installed and utilized for subgroup analysis,analyzing forest plots,sensitivity,heterogeneity,forest plots,publication bias,and risk of bias.RESULTS Fifteen previous cases of study including 992 participants have been involved in our meta-analysis.UPS had slightly lower effects on fusion rate[relative risk(RR)=0.949,95%CI:0.910 to 0.990,P=0.015],which contributed mostly to this metaanalysis,and similar complication rates(RR=1.140,95%CI:0.792 to 1.640,P=0.481),Δvisual analog scale[standard mean difference(SMD)=0.178,95%CI:-0.021 to 0.378,P=0.080],andΔOswestry disability index(SMD=-0.254,95%CI:-0.820 to 0.329,P=0.402).In contrast,an obvious difference has been observed inΔJapanese Orthopedic Association(JOA)score(SMD=0.305,95%CI:0.046 to 0.563,P=0.021),total blood loss(SMD=-1.586,95%CI:-2.182 to-0.990,P=0.000),operation time(SMD=-2.831,95%CI:-3.753 to-1.909,P=0.000),and length of hospital stay(SMD=-0.614,95%CI:-1.050 to-0.179,P=0.006).CONCLUSION Bilateral fixation is more effective than unilateral fixation regarding fusion rate after lumbar interbody fusion.However,JOA,operation time,total blood loss,as well as length of stay were improved for unilateral fixation.展开更多
Objectives:To explore the risk factors and nursing measures of early surgical site infection(SSI)after posterior lumbar interbody fusion(PLIF).Methods:A total of 468 patients who received PLIF in our hospital from Jan...Objectives:To explore the risk factors and nursing measures of early surgical site infection(SSI)after posterior lumbar interbody fusion(PLIF).Methods:A total of 468 patients who received PLIF in our hospital from January 2017 to June 2020 were enrolled into this study.According to the occurrence of early SSI,the patients were divided into two groups,and the general data were analyzed by univariate analysis.Multivariate logistic regression analysis was conducted with the dichotomous variable of whether early SSI occurred and other factors as independent variables to identify the risk factors of early SSI and put forward targeted prevention and nursing measures.Results:Among 468 patients with PLIF,18 patients developed early SSI(3.85%).The proportion of female,age,diabetes mellitus and urinary tract infection(UTI),operation segment,operation time,post-operative drainage volume,and drainage time were significantly higher than those in the uninfected group,with statistical significance(P<0.05),whereas the preoperative albumin and hemoglobin in the infected group were significantly lower than those in the uninfected group,with statistical significance(P<0.05).There was no significant difference between the two groups in the American Society of Anesthesiologists(ASA)grading,body mass index(BMI),complications including cardiovascular and cerebrovascular diseases or hypertension(P>0.05).Logistic regression analysis showed that preoperative diabetes mellitus(OR=2.109,P=0.012)/UTI(OR=1.526,P=0.035),prolonged drainage time(OR=1.639,P=0.029)were risk factors for early SSI.Men(OR=0.736,P=0.027)and albumin level(OR=0.526,P=0.004)were protective factors in reducing early SSI.Conclusions:Women,preoperative diabetes/UTI,hypoproteinemia,and prolonged drainage time are risk factors for early SSI after PLIF.Clinical effective preventive measures should be taken in combination with targeted nursing intervention to reduce the risk of early SSI.展开更多
Posterior lumbar interbody fusion (PLIF) is a common surgical procedure and widely used in the treatment of lumbar degenerative disc disorders. Traditionally, posterior lumbar interbody fusion is done by using the tra...Posterior lumbar interbody fusion (PLIF) is a common surgical procedure and widely used in the treatment of lumbar degenerative disc disorders. Traditionally, posterior lumbar interbody fusion is done by using the traditional pedicle screw (PS) which offers great advantages, but at the same time it has some disadvantages which include the risk of superior facet joint violation and muscle damage. Recently, an alternative method of screw insertion via cortical bone trajectory (CBT) has been invented which has less invasive process and can be placed without the drawbacks associated with the traditional pedicle screw. However, it has to remain an interest whether CBT will provide similar or greater clinical outcomes compared to PS in PLIF. So the main aim of this review is to compare the clinical outcomes of cortical bone trajectory and traditional pedicle screw fixation in posterior lumbar interbody fusion based on the articles published on this topic. Compared to the traditional pedicle screw fixation, PLIF with CBT has similar clinical outcome based on pain intensity, ODI status and JOA score, as well as similar fusion rate and radiological evaluated complication such as loosening of screw. In addition PLIF with CBT has advantages of less facet joint violation, less blood loss, less intraoperative muscle damage and perioperative pain. On the basis of this study, we can suggest that PLIF with CBT can be considered as a reasonable alternative to PS in PLIF.展开更多
BACKGROUND Oblique lumbar interbody fusion is a mini-open retroperitoneal approach that uses a wide corridor between the left psoas muscle and the aorta above L5.This approach avoids the limitations of lateral lumbar ...BACKGROUND Oblique lumbar interbody fusion is a mini-open retroperitoneal approach that uses a wide corridor between the left psoas muscle and the aorta above L5.This approach avoids the limitations of lateral lumbar interbody fusion,is considered less invasive than anterior lumbar interbody fusion,and is similarly effective for indirect decompression and improving lordosis while maintaining a low complication profile.Including L5-S1,when required,adds to these advantages,as this allows single-position surgery.However,variations in vascular anatomy can affect the ease of access to the L5-S1 disc.The nuances of three different oblique anterolateral techniques to access L5-S1 for interbody fusion,namely,left-sided intra-bifurcation,left-sided pre-psoas,and right-sided pre-psoas approaches,are illustrated using three representative case studies.CASE SUMMARY Cases of three patients who underwent multilevel oblique lumbar interbody fusion including L5-S1,using one of the three different techniques,are described.All patients presented with symptomatic degenerative lumbar pathology and failed conservative management prior to surgery.The anatomical considerations that affected the decisions to utilize each approach are discussed.The pros and cons of each approach are also discussed.A parasagittal facet line objectively assesses the relationship between the left common iliac vein and the L5-S1 disc and assists in choosing the approach to L5-S1.CONCLUSION Oblique retroperitoneal access to L5-S1 in the lateral decubitus position is possible through three different approaches.The choice of approach to L5-S1 may be individualized based on a patient’s vascular anatomy using preoperative imaging.While most surgeons will rely on their experience and comfort level in choosing the approach,this article elucidates the nuances of each technique.展开更多
Few biomechanical data exist regarding whether the polyetheretherketone (PEEK) spacer or titanium spacer is better for posterior lumbar interbody fusion (PLIF). This study evaluated the biomechanical influence that th...Few biomechanical data exist regarding whether the polyetheretherketone (PEEK) spacer or titanium spacer is better for posterior lumbar interbody fusion (PLIF). This study evaluated the biomechanical influence that these types of spacers with different levels of hardness exert on the vertebra by using finite element analysis including bone strength distribution. To evaluate the risk of spacer subsidence for PLIF, we built a finite element model of the lumbar spine using computed tomography data of osteoporosis patients. Then, we simulated PLIF in L3/4 and built models with the hardness of the interbody spacer set as PEEK and titanium. Bones around the spacer were subjected to different load conditions. Then, fracture elements and some stress states of the two modalities were compared. In both models of PLIF simulation, fracture elements and stress were concentrated in the bones around the spacer. Fracture elements and stress values of the model simulating the PEEK spacer were significantly smaller compared to those of the titanium simulation model. For PLIF of osteoporotic vertebrae, this suggested that the PEEK spacer is in a mechanical environment less susceptible to subsidence caused by microfractures of bone tissue and bone remodeling-related fusion aspects. Therefore, PEEK spacers are bio-mechanically more useful.展开更多
Objective:Many factors affect intraoperative blood loss(BL)in mini-invasive posterior lumbar interbody fusion(PLIF)procedures,but only few has examined.Specifically,the impact of bone mineral density(BMD)levels on int...Objective:Many factors affect intraoperative blood loss(BL)in mini-invasive posterior lumbar interbody fusion(PLIF)procedures,but only few has examined.Specifically,the impact of bone mineral density(BMD)levels on intraoperative BL.This study aims to examine the correlation between these two factors.Methods:Retrospective review of 120 patients with low back disorders who were scheduled to undergo mini-invasive PLIF from October 2018 to October 2019 was performed.Patients were divided into two groups based on BMD of the lumbar spine:normal group and abnormal group(osteoporosis and osteopenia).Comparison of age,gender,BMD,BL,BMI,prothrombin time,activated partial thromboplastin time,haemoglobin concentration,intraoperative mean arterial pressure,platelet count,and operative time(OT)between the two groups,and correlation analysis of BMD and BL were conducted.Results:The mean BL of patients in the abnormal group was remarkably higher than that in the normal group:357.22±152.55 ml and 259.37±125.90 ml respectively(p<0.001).The partial correlation coefficient between BL and BMD was0.45(p<0.001).The results of univariate regression analysis demonstrated that only BMD,gender,and OT were related to BL(BMD,r=0.427,p<0.001;gender,r=0.211,p=0.024;OT,r=0.318,p=0.001).While multivariate linear regression analysis demonstrated that patients with lower BMD and longer OT had a higher amount of intraoperative BL(p<0.001).Conclusions:BMD is an important factor influencing intraoperative BL in mini-invasive PLIF.It should be assessed routinely as a part of the preoperative examination to improve preoperative assessment and ensure patient safety.展开更多
This work focuses on the influence of elastic modulus on biomechanical properties of lumbar interbody fusion cages by selecting two titanium alloys with different elastic modulus. They were made by a new β type alloy...This work focuses on the influence of elastic modulus on biomechanical properties of lumbar interbody fusion cages by selecting two titanium alloys with different elastic modulus. They were made by a new β type alloy with chemical composition of Ti-24Nb-4Zr-7.6Sn having low Young＇s modulus -50 GPa and by a conventional biomedical alloy Ti-6Al-4V having Young＇s modulus -110 GPa. The results showed that the designed cages with low modulus （LMC） and high modulus （HMC） can keep identical compression load -9.8 kN and endure fatigue cycles higher than 5× 10^6 without functional or mechanical failure under 2.0 kN axial compression. The anti-subsidence ability of both group cages were examined by axial compression of thoracic spine specimens （T9-T10） dissected freshly from the calf with averaged age of 6 months. The results showed that the LMC has better anti-subsidence ability than the HMC （p〈0.05）. The above results suggest that the cage with low elastic modulus has great potential for clinical applications.展开更多
BACKGROUND Allograft interbody spacers are utilized during transforaminal lumbar interbody fusion(TLIF) to reestablish anterior column support and disc height. While the TLIF technique offers many improvements over pr...BACKGROUND Allograft interbody spacers are utilized during transforaminal lumbar interbody fusion(TLIF) to reestablish anterior column support and disc height. While the TLIF technique offers many improvements over previous surgical methods,instrumentation and bone graft-related complications such as spacer misplacement or migration, screw fracture or misplacement, or rod breakage continue to be reported. The objective of this manuscript is to report on a fractured allograft interbody spacer that displaced into the neural foramen and resulted in impingement on the exiting nerve root that required revision.CASE SUMMARY A 50-year-old male had two-level TLIF with immediate post-operative right L5 radiculopathy. Computed tomography scan demonstrated a fractured allograft interbody spacer that displaced into the right neural foramen and impinged on the exiting L5 nerve root. Revision surgery was performed to remove the broken allograft fragments from the right L5 foramen and the intact portion of the spacer was left in place. The right leg L5 radicular pain resolved. At the last follow up 12 mo after the index procedure, computed tomography scan confirmed sound interbody and posterolateral fusion.CONCLUSION Displacement of broken allograft interbody spacer following TLIF procedures can result in neurological sequelae that require revision. To avoid such an occurrence,the authors recommend allowing sufficient time for the reconstitution of the graft in saline prior to use to decrease brittleness, to use an impactor size that is as close as possible to the spacer size and meticulous inspection of the cortical allograft spacer for any visible imperfection prior to insertion.展开更多
Objective: To quantify the strength of the grafts from different body sites and determine the optimalselection of corticocancellous allografts for anterior interbody fusion. Methods: Complete sets of paired freshfroze...Objective: To quantify the strength of the grafts from different body sites and determine the optimalselection of corticocancellous allografts for anterior interbody fusion. Methods: Complete sets of paired freshfrozen femurs, humeri, tibias and iliac crests were obtained from 6 individual donors. One centimeter thick slicesstarting from the proximal and distal bone ends were cut from the non--diaphysial portions of the long bones usinga razor saw with a customized miter box. 2. 5 cm× 3. 0 cm × 1. 0 cm unicortical bone blocks were shaped similarlyfor clinical use as a lumbar interbody graft. Multiple 1 cm thick grafts with 1. 5 cm depth were obtained from theiliac crests, to simulate a cervical interbody graft. The left and right sides of each pair were randomized intoperpendicular and parallel cut groups in the long bones or tricortical and bicortical preparations of the iliac graft.The samples were tested on an MTS by applying a compressive load to failure. Results: The failure loads of distaltibia and femoral head grafts were significantly higher than distal femur, proximal tibia and burneral head grafts(PR0. 05). The strength of the grafts prepared by parallel cutting decreased significantly as compared with theperpendicular cutting (P <0. 05). No significant changes were seen in femoral and burneral head grafts for the 2sectioning orientations. The grafts closer to the anterior superior iliac spine had significant higher failure loads andfailure strengths than those closer to the posterior superior iliac spine. After trimming off the lateral cortex, themean strength of the bicortical grafts decreased significantly as compared with the tricortical grafts (P <0. 05).Conclusion: The grafts from femoral head and distal tibia by perpendicular cutting have higher failure load than theload bearing in lumbar spine. The grafts cut close to the anterior superior iliac spine are recommended for cervicalinterbody fusion.展开更多
BACKGROUND Delayed arterial symptomatic epidural hematoma(SEH)on the 14th day after posterior lumbar interbody fusion(PLIF)is rare but it may lead to severe complications if not identified and treated in a timely mann...BACKGROUND Delayed arterial symptomatic epidural hematoma(SEH)on the 14th day after posterior lumbar interbody fusion(PLIF)is rare but it may lead to severe complications if not identified and treated in a timely manner.After diagnosis of the current case,early surgical removal of the hematoma and strict hemostasis treatment was accomplished.This case report highlights the importance of swift diagnosis and treatment in SEH patients.CASE SUMMARY A 41-year-old male patient with a single-segment lumbar disc herniation underwent left-side PLIF.On the 14th post-operative day,the patient complained of lumbar incision pain with sudden onset accompanied by left limb radiation pain and aggravated cauda equina symptoms.Magnetic resonance imaging examination and a puncture blood draw at the incision site confirmed a delayed arterial SEH.Emergency surgical removal of the hematoma and hemostasis was performed.About 70 mL of hematoma was found in the left incision.Continuous bleeding was found in the anterior branch of the transverse process of the 4th lumbar artery in the muscle area about 2 cm below the transverse process of the 4th lumbar vertebra.A blood jet of about 10 cm in height was observed and bipolar electrocoagulation was used to stop the bleeding.Post-operative lumbar incision pain and left lower limb pain were relieved immediately and gradually disappeared.There was no recurrence during the 12-mo follow-up.CONCLUSION For delayed arterial SEH on the 14th day after PLIF,preventive measures including pre-,intra-and post-operative prevention should be implemented.展开更多
Aim: Intervertebral spacers for anterior spine fusion are made of different materials, which can affect the post-fusion MRI scans. Suscep- tibility artifacts specially for implants made of titanium alloys can decrease...Aim: Intervertebral spacers for anterior spine fusion are made of different materials, which can affect the post-fusion MRI scans. Suscep- tibility artifacts specially for implants made of titanium alloys can decrease the image quality. This study focused on the influence of deter-mined implant parameters like shape and implant volume in MRI artifacting independent from se-lected MRI-sequences. Methods: In this study the post-implantation MRI scans of determined cuboids and cylinders were evaluated. All in-terbody test implants were made of titanium alloys. MRI scans were carried out by using T1 TSE sequences. The total artifact volume (TAV) of all examined implants were calculated for sta-tistical t-test correlation and implant volume (IV)/TAV-relation. Results: Considering all ex-amined test implants with an increasing implant size the TAV became significant larger (p<0,001) with simultaneous reduction of the respective IV/TAV-relation. According to an intergroup TAV- correlation for cylinders and cuboids with an equivalent implant volume the cylindric test im-plants demonstrated a significant smaller arti-fact range (p<0,05). Conclusions: Based on these results the MRI artifacts of larger test im-plants were more limited to the to the implant’s direct surroundings. In this connection for im- plants with identical material volumes a cylin- dric shape demonstrated more advantages con- sidering MRI artifacting than cubic forms.展开更多
Interbody disc spacers for anterior spine fusion are made of different materials, such as titanium alloys or carbon fiber reinforced polymers (CFRP). Implant-related susceptibility artifacts can decrease the quality o...Interbody disc spacers for anterior spine fusion are made of different materials, such as titanium alloys or carbon fiber reinforced polymers (CFRP). Implant-related susceptibility artifacts can decrease the quality of MRI scans. This cadaveric study aimed to demonstrate the extent that implant-related MRI artifacting affects the post fusion differentiation of the spinal canal (SC) and intervertebral disc space (IDS). In 6 cadaveric porcine spines, we evaluated the post-im- plantation MRI scans of a titanium and CFRP spacer that differed in shape and surface qualities. A spacer made of human cortical bone was used as a control. A defined evaluation unit was divided into regions of interest (ROI) to characterize the SC and IDS. Considering 15 different MRI sequences read independently by an interobserver-validated team of specialists artifact-affected image quality of the median MRI slice was rated on a modified score of 0-1-2-3. A maximum score of 15 points for the SC and 9 points for the IDS (100%) was possible. Turbo spin echo sequences produced the best scores for both spacers and the control. Only the control achieved a score of 100%. For the IDS the titanium and CFRP spacer maximally scored 0% and 74%, for the SC 80% and 99%, respectively. By using favored T1 TSE sequences the CFRP-spacer represented clear advantages in post fusion spinal imaging. Independent of artifact dimensions the used scoring system allowed us to create an implant-related ranking of MRI scan quality in reference to the bone control.展开更多
Preventing subsidence of intervertebral cages in posterior lumbar interbody fusion (PLIF) requires understanding its mechanism, which is yet to be done. We aimed to describe the mechanism of intervertebral cage subsid...Preventing subsidence of intervertebral cages in posterior lumbar interbody fusion (PLIF) requires understanding its mechanism, which is yet to be done. We aimed to describe the mechanism of intervertebral cage subsidence by using finite element analysis through simulation of the osteoporotic vertebral bodies of an elderly woman. The data from computed tomography scans of L2-L5 vertebrae in a 72-year-old woman with osteoporosis were used to create 2 FE models: one not simulating implant placement (LS-INT) and one simulating L3/4 PLIF using polyetheretherketone (PEEK) cages (LS-PEEK). Loads and moments simulating the living body were applied to these models, and the following analyses were performed: 1) Drucker-Prager equivalent stress distribution at the cage contact surfaces;2) the distribution of damage elements in L2-L5 during incremental loading;and 3) the distribution of equivalent plastic strain at the cage contact surfaces. In analysis 1, the Drucker-Prager equivalent stress on the L3 and L4 vertebral endplates was greater for LS-PEEK than for LS-INT under all loading conditions and tended to be particularly concentrated at the contact surfaces. In analysis 2, compared with LS-INT, LS-PEEK showed more damage elements along the bone around the cages in the L3 vertebral body posterior to the cage contact surfaces, followed by the area of the L4 vertebral body posterior to the cage contact surfaces. In analysis 3, in the L3 inferior surface in LS-PEEK the distribution of equivalent plastic strain was visualized as gradually expanding along the cages from the area posterior to the cages to the area anterior to them with increased loading. These analyses suggested that in PLIF for osteoporotic vertebral bodies, the localized stress concentration generated by the use of PEEK cages may cause accumulation of microscopic damage in the fragile osteoporotic vertebral bodies around the cages, which may result in cage subsidence.展开更多
Objective:To analyze the correlation between the amplitude changes of motor evoked potential(MEP),the 3D volume changes of spinal canal measuring by postoperative CT and the improvement rate of clinical symptoms after...Objective:To analyze the correlation between the amplitude changes of motor evoked potential(MEP),the 3D volume changes of spinal canal measuring by postoperative CT and the improvement rate of clinical symptoms after the spinal canal decompression in minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF),and to explore the predictive value of the changes of both MEP amplitude and spinal canal volume in the assessment of long-term clinical prognosis in MIS-TLIF.Methods:A retrospective study of 68 patients with L4/5 spinal stenosis treated with MIS-TLIF was performed.The changes of both intraoperative MEP amplitude and 3D spinal canal volume during the spinal canal decompression,as well as the visual analogue scale(VAS)and Oswestry dysfunction index(ODI)scores in the long-term follow-up were all recorded.Results:The values of intraoperative MEP amplitude was 159.04%higher in 68 patients with MIS-TLIF after spinal canal decompression(P<0.01).The 3 postoperative 3D spinal canal volume(4.89±1.27)cm increased by 31.22%in comparison 3 with preoperative date(3.78±1.08)cm(P<0.01).The VAS and ODI scores were improved to 78.55%and 80.60%,respectively at the last follow-up(P<0.01).The improvement rate of MEP amplitude on the decompression side was positively correlated with the improvement rate of postoperative spinal canal volume(r=0.272,P=0.025).The improvement rate of postoperative spinal canal volume was positively correlated with the improvement rate of VAS and ODI at the last follow-up(r=0.656,r=0.490,P<0.01).Moreover,the improvement rate of MEP amplitude on the decompression side was also positively correlated with the improvement rate of VAS and ODI at the last follow-up(r=0.322 and 0.235,respectively,P<0.05).Conclusion:The increase of MEP amplitude after spinal canal decompression in patients with lumbar spinal stenosis treated by MIS-TLIF was closely correlated with both of the increase of spinal canal volume and the improvement of clinical symptoms.Therefore,MEP amplitude monitoring was not only the one of the important monitoring methods for predicting the prognosis of MIS-TLIF but also the reliably predictive value in the long-term clinical prognosis in MIS-TLIF.展开更多
Objective: To evaluate the surgical results of posterior lumber interbody fusion with transpedicular fixation with rod screw system in management of spondylolisthesis. Study Design: Retrospective study reviewed all pa...Objective: To evaluate the surgical results of posterior lumber interbody fusion with transpedicular fixation with rod screw system in management of spondylolisthesis. Study Design: Retrospective study reviewed all patient treated by lumber interbody fusion with transpedicular fixation with rod screw system. Patients and Methods: They were 40 patients operated for lumber and lumbosacral spondylolisthesis from Feb 2014 to April 2017 in Al-Azhar university hospital. These patients followed postoperatively clinically for improved neural function and for fusion stability and hardware fixation by radiological investigation. Data about pain intensity (by Visual Analogue Scale) was collected pre- and postoperatively;and outcome was assessed by Oswetry disability index (ODI). Outcome was graded as excellent, good, fair, or poor. Pre- and Post-operative data were statistically compared. Results: The mean age was 45 years (range between 30 - 60 years) with female sex predominance (male:female = 1:3). They had lytic (n = 30) or degenerative (n = 10) spondylolisthesis;and all underwent PLIF (posterior lumbar interbody fusion). In lytic group, the level was L4/L5 in 19 patients and L5/S1 in 11 patients, while in degenerative group the level was L4/L5 in 4 patients, L5/S1 in 3 patients, L2/L3 in 2 and L3/L4 in one patient. The spondylolisthesis grade was grade I among 25 subjects, grade two among 11 subjects and retrolisthesis among 4 subjects. Sensory deficits reported in 22 subjects (19 had lytic and 3 had degenerative spondylolisthesis);while motor deficits reported among 10 subjects and reduced reflexes among 8 subjects. The outcome was excellent, good, and fair among 30, 7, and 3 subjects respectively. The return to previous levels of activity was reported among 32 patients. VAS was 3.5 ± 2.94 at the end of follow up, while ODI was 28% and 36.0% and 3 and 6 months respectively. Conclusion: PLIF associated with transpedicular rod screw fixation system for management of spondylolisthesis is considered a safe and effective surgical intervention in both lytic and degenerative types.展开更多
文摘In this editorial,the authors of this paper comment on the article by Bokov et al published in the recent issue of World Journal of Orthopedics.We reviewed a general overview of oblique lumbar interbody fusions(OLIF)and lateral lumbar interbody fusions(LLIF),their indications and complications as an increasingly popular minimally invasive technique to address several lumbar pathologies.This editorial thoroughly discusses and reviews the literature regarding factors affecting outcomes of indirect decompression utilized through OLIF and LLIF procedures.Several parameters play a critical role in patient outcomes including restoration of disc height,foraminal height,central canal squared,and foraminal area.The indirect decompression allows for unbuckling of the ligamentum flavum which can significantly decompress the neural elements as well as aid in reduction of spondylolisthesis.However,the authors further highlight the limitations of indirect decompression and factors that may predict unsuccessful outcomes including bony foraminal stenosis,severe central canal stenosis,and osteoporosis.As a result,failure of indirect decompression can lead to persistent pain,radiculopathy and unsatisfied patients.Spinal surgeons may be left to reimage patients and consider additional procedures with direct decompression.
基金supported by the National Natural Science Foundation of China(82172392)the National Natural Science Foundation of China(82372401)+1 种基金the Beijing Natural Science Foundation(L202033)the Basic Applied Research Program of Liaoning Province of China(2022020347-JH2/1013)。
文摘Interbody fusion is recognized as the golden standard of surgical intervention for degenerative disc disease(DDD).Interbody fusion cage made of polyetheretherketone(PEEK)is commonly used in lumbar interbody fusion surgery in the treatment of DDD worldwide.However,there are some limitations of PEEK including their bio-inert nature and impediment to host bone integration.This study aimed to evaluate the degradation profile and osteoinductive potential of biodegradable Mg-Zn-Nd-Zr cages with/without micro-arc oxidation(MAO)coatings.The Mg-Zn-Nd-Zr alloy cages,whether coated with MAO or not,demonstrated commendable biocompatibility and biomechanical properties.Immersion and electrochemical tests show better corrosion resistance of MAO coatings in vitro.mRNA sequencing,RT-qPCR and Western blotting revealed that Mg-Zn-Nd-Zr and Mg-Zn-Nd-Zr/MAO had a better effectiveness on osteoinductivity.In vivo evaluations in ovine models over 12 weeks and 24 weeks post-implantation revealed radiological and histological evidence of enhanced bone formation adjacent to the Mg-Zn-Nd-Zr alloy cages compared to PEEK counterparts.Moreover,the MAO-coated cages exhibited a reduced propensity for gas formation.The Mg-Zn-Nd-Zr alloy is as a superior osteoinductive material compared with PEEK,with the MAO coating offering an advantage in mitigating gas production.Nonetheless,further research is warranted to refine the alloy's composition or surface treatments,particularly to address the challenges associated with rapid gas evolution during the early post-implantation period.
文摘BACKGROUND Indirect decompression is one of the potential benefits of anterior reconstruction in patients with spinal stenosis.On the other hand,the reported rate of revision surgery after indirect decompression highlights the necessity of working out prediction models for the radiographic results of indirect decompression with assessing their clinical relevance.AIM To assess factors that influence radiographic and clinical results of the indirect decompression in patients with stenosis of the lumbar spine.METHODS This study is a single-center cross-sectional evaluation of 80 consecutive patients(17 males and 63 females)with lumbar spinal stenosis combined with the instability of the lumbar spinal segment.Patients underwent single level or bisegmental spinal instrumentation employing oblique lumbar interbody fusion(OLIF)with percutaneous pedicle screw fixation.Radiographic results of the indirect decompression were assessed using computerized tomography,while MacNab scale was used to assess clinical results.RESULTS After indirect decompression employing anterior reconstruction using OLIF,the statistically significant increase in the disc space height,vertebral canal square,right and left lateral canal depth were detected(Р<0.0001).The median(M)relative vertebral canal square increase came toМ=24.5%with 25%-75%quartile border(16.3%;33.3%)if indirect decompression was achieved by restoration of the segment height.In patients with the reduction of the upper vertebrae slip,the median of the relative increase in vertebral canal square accounted for 49.5%with 25%-75%quartile border(2.35;99.75).Six out of 80 patients(7.5%)presented with unsatisfactory results because of residual nerve root compression.The critical values for lateral recess depth and vertebral canal square that were associated with indirect decompression failure were 3 mm and 80 mm2 respectively.CONCLUSION Indirect decompression employing anterior reconstruction is achieved by the increase in disc height along the posterior boarder and reduction of the slipped vertebrae in patients with degenerative spondylolisthesis.Vertebral canal square below 80 mm2 and lateral recess depth less than 3 mm are associated with indirect decompression failures that require direct microsurgical decompression.
基金the Returned Overseas Chinese Scholars Startup Fund[No.LXHG2018001]。
文摘Objective We aimed to compare the clinical and radiological outcomes of midline lumbar fusion(MIDLF)versus minimally invasive transforaminal lumbar interbody fusion(MI-TLIF)in patients with degenerative spondylolisthesis and/or stenosis in L4-L5 two years after surgery.Methods Consecutively treated patients with lumbar pathology who underwent MIDLF(n=16)and a historical control group who underwent MI-TLIF(n=34)were included.Clinical symptoms were evaluated using Oswestry Disability Index(ODI),the 36-Item Short-Form Health Survey,and visual analog scale(VAS)scores before surgery and 3,6,12,and 24 months after surgery.Results The mean operative time and hematocrit(HCT,Day 1)were significantly shorter and lower in MIDLF cases(174 min vs.229 min,P<0.001;0.34 vs.0.36,P=0.037).The MI-TLIF group showed better improvement than the MIDLF group in ODI and VAS back and leg pain at 3 months postoperatively.VAS leg pain was higher in MIDLF than in MI-TLIF cases at 6 months.At 24 months follow-up,VAS back pain was higher in MI-TLIF than in MIDLF cases(P=0.018).Conclusion MIDLF is comparable to MI-TLIF at L4-5 in clinical outcomes and fusion rates,and the results verified the meaningful advantage of using MIDLF for the elderly with osteoporosis.
文摘To evaluate the clinical outcome,effectiveness and safety of the surgical management of traumatic lumbar spondylolisthesis with transforaminal lumbar interbody fusion (TLIF) with short segmental instrumentation fixation.A retrospective review of a consecutive series of 24 patients with traumatic lumbar spondylolisthesis treated with TLIF procedure was carried out.Intraoperative spinal cord monitoring was used to confirm the peripheral neural function intact during the reduction of the spondylolisthesis.Preoperative clinical and radiographic evaluation of all cases were originally collected prospectively.Data regarding blood loss,operative time,duration of hospital stay,radiographic fusion,instrumentation failure and clinical result were collected and observed at regular follow-up periods.All patients were engaged in high-energy accidents in the lower back and 16 patients had concomitant injuries.The mean operative time was 124 min,mean blood loss was 350 mL,and mean hospital stay was 6.5 days.There were no complications such as incision infection,cerebrospinal fluide (CSF) leakage and nerve root injury and so on.All patients demonstrated a solid lumbar interbody fusion within 4 months,and no evidence of spondylolisthesis correction loss,instrumentation failure and loosing.They all were completely asymptomatic,with normal neurologic findings,and had resumed their previous level of physical activities on the final follow-up.Meticulous clinical examination and careful imaging assessment could assist an early diagonosis in cases of traumatic lumbar spondylolisthesis.Performing open reduction and the TLIF procedure as soon as possible could restore segmental stability and painless function.The TLIF procedure was a safe,effective technique to treat traumatic lumbar spondylolisthesis.
基金Supported by the Health Science and Technology of Tianjin Municipality,No.RC20204Tianjin Institute of Orthopedics,No.2019TJGYSKY03the National Natural Science Foundation of China,No.818717771177226。
文摘BACKGROUND Whether it’s better to adopt unilateral pedicle screw(UPS)fixation or to use bilateral pedicle screw(BPS)one for lumbar degenerative diseases is still controversially undetermined.AIM To make a comparison between UPS and BPS fixation as to how they work efficaciously and safely in patients suffering from lumbar degenerative diseases.METHODS We have searched a lot in the databases through 2020 with index terms such as“unilateral pedicle screw fixation”and“bilateral pedicle screw fixation.”Only randomized controlled trials and some prospective cohort studies could be found,yielding 15 studies.The intervention was unilateral pedicle screw fixation;Primarily We’ve got outcomes of complications and fusion rates.Secondarily,we’ve achieved outcomes regarding total blood loss,operative time,as well as length of stay.Softwares were installed and utilized for subgroup analysis,analyzing forest plots,sensitivity,heterogeneity,forest plots,publication bias,and risk of bias.RESULTS Fifteen previous cases of study including 992 participants have been involved in our meta-analysis.UPS had slightly lower effects on fusion rate[relative risk(RR)=0.949,95%CI:0.910 to 0.990,P=0.015],which contributed mostly to this metaanalysis,and similar complication rates(RR=1.140,95%CI:0.792 to 1.640,P=0.481),Δvisual analog scale[standard mean difference(SMD)=0.178,95%CI:-0.021 to 0.378,P=0.080],andΔOswestry disability index(SMD=-0.254,95%CI:-0.820 to 0.329,P=0.402).In contrast,an obvious difference has been observed inΔJapanese Orthopedic Association(JOA)score(SMD=0.305,95%CI:0.046 to 0.563,P=0.021),total blood loss(SMD=-1.586,95%CI:-2.182 to-0.990,P=0.000),operation time(SMD=-2.831,95%CI:-3.753 to-1.909,P=0.000),and length of hospital stay(SMD=-0.614,95%CI:-1.050 to-0.179,P=0.006).CONCLUSION Bilateral fixation is more effective than unilateral fixation regarding fusion rate after lumbar interbody fusion.However,JOA,operation time,total blood loss,as well as length of stay were improved for unilateral fixation.
文摘Objectives:To explore the risk factors and nursing measures of early surgical site infection(SSI)after posterior lumbar interbody fusion(PLIF).Methods:A total of 468 patients who received PLIF in our hospital from January 2017 to June 2020 were enrolled into this study.According to the occurrence of early SSI,the patients were divided into two groups,and the general data were analyzed by univariate analysis.Multivariate logistic regression analysis was conducted with the dichotomous variable of whether early SSI occurred and other factors as independent variables to identify the risk factors of early SSI and put forward targeted prevention and nursing measures.Results:Among 468 patients with PLIF,18 patients developed early SSI(3.85%).The proportion of female,age,diabetes mellitus and urinary tract infection(UTI),operation segment,operation time,post-operative drainage volume,and drainage time were significantly higher than those in the uninfected group,with statistical significance(P<0.05),whereas the preoperative albumin and hemoglobin in the infected group were significantly lower than those in the uninfected group,with statistical significance(P<0.05).There was no significant difference between the two groups in the American Society of Anesthesiologists(ASA)grading,body mass index(BMI),complications including cardiovascular and cerebrovascular diseases or hypertension(P>0.05).Logistic regression analysis showed that preoperative diabetes mellitus(OR=2.109,P=0.012)/UTI(OR=1.526,P=0.035),prolonged drainage time(OR=1.639,P=0.029)were risk factors for early SSI.Men(OR=0.736,P=0.027)and albumin level(OR=0.526,P=0.004)were protective factors in reducing early SSI.Conclusions:Women,preoperative diabetes/UTI,hypoproteinemia,and prolonged drainage time are risk factors for early SSI after PLIF.Clinical effective preventive measures should be taken in combination with targeted nursing intervention to reduce the risk of early SSI.
文摘Posterior lumbar interbody fusion (PLIF) is a common surgical procedure and widely used in the treatment of lumbar degenerative disc disorders. Traditionally, posterior lumbar interbody fusion is done by using the traditional pedicle screw (PS) which offers great advantages, but at the same time it has some disadvantages which include the risk of superior facet joint violation and muscle damage. Recently, an alternative method of screw insertion via cortical bone trajectory (CBT) has been invented which has less invasive process and can be placed without the drawbacks associated with the traditional pedicle screw. However, it has to remain an interest whether CBT will provide similar or greater clinical outcomes compared to PS in PLIF. So the main aim of this review is to compare the clinical outcomes of cortical bone trajectory and traditional pedicle screw fixation in posterior lumbar interbody fusion based on the articles published on this topic. Compared to the traditional pedicle screw fixation, PLIF with CBT has similar clinical outcome based on pain intensity, ODI status and JOA score, as well as similar fusion rate and radiological evaluated complication such as loosening of screw. In addition PLIF with CBT has advantages of less facet joint violation, less blood loss, less intraoperative muscle damage and perioperative pain. On the basis of this study, we can suggest that PLIF with CBT can be considered as a reasonable alternative to PS in PLIF.
文摘BACKGROUND Oblique lumbar interbody fusion is a mini-open retroperitoneal approach that uses a wide corridor between the left psoas muscle and the aorta above L5.This approach avoids the limitations of lateral lumbar interbody fusion,is considered less invasive than anterior lumbar interbody fusion,and is similarly effective for indirect decompression and improving lordosis while maintaining a low complication profile.Including L5-S1,when required,adds to these advantages,as this allows single-position surgery.However,variations in vascular anatomy can affect the ease of access to the L5-S1 disc.The nuances of three different oblique anterolateral techniques to access L5-S1 for interbody fusion,namely,left-sided intra-bifurcation,left-sided pre-psoas,and right-sided pre-psoas approaches,are illustrated using three representative case studies.CASE SUMMARY Cases of three patients who underwent multilevel oblique lumbar interbody fusion including L5-S1,using one of the three different techniques,are described.All patients presented with symptomatic degenerative lumbar pathology and failed conservative management prior to surgery.The anatomical considerations that affected the decisions to utilize each approach are discussed.The pros and cons of each approach are also discussed.A parasagittal facet line objectively assesses the relationship between the left common iliac vein and the L5-S1 disc and assists in choosing the approach to L5-S1.CONCLUSION Oblique retroperitoneal access to L5-S1 in the lateral decubitus position is possible through three different approaches.The choice of approach to L5-S1 may be individualized based on a patient’s vascular anatomy using preoperative imaging.While most surgeons will rely on their experience and comfort level in choosing the approach,this article elucidates the nuances of each technique.
文摘Few biomechanical data exist regarding whether the polyetheretherketone (PEEK) spacer or titanium spacer is better for posterior lumbar interbody fusion (PLIF). This study evaluated the biomechanical influence that these types of spacers with different levels of hardness exert on the vertebra by using finite element analysis including bone strength distribution. To evaluate the risk of spacer subsidence for PLIF, we built a finite element model of the lumbar spine using computed tomography data of osteoporosis patients. Then, we simulated PLIF in L3/4 and built models with the hardness of the interbody spacer set as PEEK and titanium. Bones around the spacer were subjected to different load conditions. Then, fracture elements and some stress states of the two modalities were compared. In both models of PLIF simulation, fracture elements and stress were concentrated in the bones around the spacer. Fracture elements and stress values of the model simulating the PEEK spacer were significantly smaller compared to those of the titanium simulation model. For PLIF of osteoporotic vertebrae, this suggested that the PEEK spacer is in a mechanical environment less susceptible to subsidence caused by microfractures of bone tissue and bone remodeling-related fusion aspects. Therefore, PEEK spacers are bio-mechanically more useful.
基金The study was funded by Zhejiang Provincial Nature Science Foundation of China(LY17H060006)Zhejiang Provincial Medical and Health Science Project(2017198461).
文摘Objective:Many factors affect intraoperative blood loss(BL)in mini-invasive posterior lumbar interbody fusion(PLIF)procedures,but only few has examined.Specifically,the impact of bone mineral density(BMD)levels on intraoperative BL.This study aims to examine the correlation between these two factors.Methods:Retrospective review of 120 patients with low back disorders who were scheduled to undergo mini-invasive PLIF from October 2018 to October 2019 was performed.Patients were divided into two groups based on BMD of the lumbar spine:normal group and abnormal group(osteoporosis and osteopenia).Comparison of age,gender,BMD,BL,BMI,prothrombin time,activated partial thromboplastin time,haemoglobin concentration,intraoperative mean arterial pressure,platelet count,and operative time(OT)between the two groups,and correlation analysis of BMD and BL were conducted.Results:The mean BL of patients in the abnormal group was remarkably higher than that in the normal group:357.22±152.55 ml and 259.37±125.90 ml respectively(p<0.001).The partial correlation coefficient between BL and BMD was0.45(p<0.001).The results of univariate regression analysis demonstrated that only BMD,gender,and OT were related to BL(BMD,r=0.427,p<0.001;gender,r=0.211,p=0.024;OT,r=0.318,p=0.001).While multivariate linear regression analysis demonstrated that patients with lower BMD and longer OT had a higher amount of intraoperative BL(p<0.001).Conclusions:BMD is an important factor influencing intraoperative BL in mini-invasive PLIF.It should be assessed routinely as a part of the preoperative examination to improve preoperative assessment and ensure patient safety.
文摘This work focuses on the influence of elastic modulus on biomechanical properties of lumbar interbody fusion cages by selecting two titanium alloys with different elastic modulus. They were made by a new β type alloy with chemical composition of Ti-24Nb-4Zr-7.6Sn having low Young＇s modulus -50 GPa and by a conventional biomedical alloy Ti-6Al-4V having Young＇s modulus -110 GPa. The results showed that the designed cages with low modulus （LMC） and high modulus （HMC） can keep identical compression load -9.8 kN and endure fatigue cycles higher than 5× 10^6 without functional or mechanical failure under 2.0 kN axial compression. The anti-subsidence ability of both group cages were examined by axial compression of thoracic spine specimens （T9-T10） dissected freshly from the calf with averaged age of 6 months. The results showed that the LMC has better anti-subsidence ability than the HMC （p〈0.05）. The above results suggest that the cage with low elastic modulus has great potential for clinical applications.
文摘BACKGROUND Allograft interbody spacers are utilized during transforaminal lumbar interbody fusion(TLIF) to reestablish anterior column support and disc height. While the TLIF technique offers many improvements over previous surgical methods,instrumentation and bone graft-related complications such as spacer misplacement or migration, screw fracture or misplacement, or rod breakage continue to be reported. The objective of this manuscript is to report on a fractured allograft interbody spacer that displaced into the neural foramen and resulted in impingement on the exiting nerve root that required revision.CASE SUMMARY A 50-year-old male had two-level TLIF with immediate post-operative right L5 radiculopathy. Computed tomography scan demonstrated a fractured allograft interbody spacer that displaced into the right neural foramen and impinged on the exiting L5 nerve root. Revision surgery was performed to remove the broken allograft fragments from the right L5 foramen and the intact portion of the spacer was left in place. The right leg L5 radicular pain resolved. At the last follow up 12 mo after the index procedure, computed tomography scan confirmed sound interbody and posterolateral fusion.CONCLUSION Displacement of broken allograft interbody spacer following TLIF procedures can result in neurological sequelae that require revision. To avoid such an occurrence,the authors recommend allowing sufficient time for the reconstitution of the graft in saline prior to use to decrease brittleness, to use an impactor size that is as close as possible to the spacer size and meticulous inspection of the cortical allograft spacer for any visible imperfection prior to insertion.
文摘Objective: To quantify the strength of the grafts from different body sites and determine the optimalselection of corticocancellous allografts for anterior interbody fusion. Methods: Complete sets of paired freshfrozen femurs, humeri, tibias and iliac crests were obtained from 6 individual donors. One centimeter thick slicesstarting from the proximal and distal bone ends were cut from the non--diaphysial portions of the long bones usinga razor saw with a customized miter box. 2. 5 cm× 3. 0 cm × 1. 0 cm unicortical bone blocks were shaped similarlyfor clinical use as a lumbar interbody graft. Multiple 1 cm thick grafts with 1. 5 cm depth were obtained from theiliac crests, to simulate a cervical interbody graft. The left and right sides of each pair were randomized intoperpendicular and parallel cut groups in the long bones or tricortical and bicortical preparations of the iliac graft.The samples were tested on an MTS by applying a compressive load to failure. Results: The failure loads of distaltibia and femoral head grafts were significantly higher than distal femur, proximal tibia and burneral head grafts(PR0. 05). The strength of the grafts prepared by parallel cutting decreased significantly as compared with theperpendicular cutting (P <0. 05). No significant changes were seen in femoral and burneral head grafts for the 2sectioning orientations. The grafts closer to the anterior superior iliac spine had significant higher failure loads andfailure strengths than those closer to the posterior superior iliac spine. After trimming off the lateral cortex, themean strength of the bicortical grafts decreased significantly as compared with the tricortical grafts (P <0. 05).Conclusion: The grafts from femoral head and distal tibia by perpendicular cutting have higher failure load than theload bearing in lumbar spine. The grafts cut close to the anterior superior iliac spine are recommended for cervicalinterbody fusion.
文摘BACKGROUND Delayed arterial symptomatic epidural hematoma(SEH)on the 14th day after posterior lumbar interbody fusion(PLIF)is rare but it may lead to severe complications if not identified and treated in a timely manner.After diagnosis of the current case,early surgical removal of the hematoma and strict hemostasis treatment was accomplished.This case report highlights the importance of swift diagnosis and treatment in SEH patients.CASE SUMMARY A 41-year-old male patient with a single-segment lumbar disc herniation underwent left-side PLIF.On the 14th post-operative day,the patient complained of lumbar incision pain with sudden onset accompanied by left limb radiation pain and aggravated cauda equina symptoms.Magnetic resonance imaging examination and a puncture blood draw at the incision site confirmed a delayed arterial SEH.Emergency surgical removal of the hematoma and hemostasis was performed.About 70 mL of hematoma was found in the left incision.Continuous bleeding was found in the anterior branch of the transverse process of the 4th lumbar artery in the muscle area about 2 cm below the transverse process of the 4th lumbar vertebra.A blood jet of about 10 cm in height was observed and bipolar electrocoagulation was used to stop the bleeding.Post-operative lumbar incision pain and left lower limb pain were relieved immediately and gradually disappeared.There was no recurrence during the 12-mo follow-up.CONCLUSION For delayed arterial SEH on the 14th day after PLIF,preventive measures including pre-,intra-and post-operative prevention should be implemented.
文摘Aim: Intervertebral spacers for anterior spine fusion are made of different materials, which can affect the post-fusion MRI scans. Suscep- tibility artifacts specially for implants made of titanium alloys can decrease the image quality. This study focused on the influence of deter-mined implant parameters like shape and implant volume in MRI artifacting independent from se-lected MRI-sequences. Methods: In this study the post-implantation MRI scans of determined cuboids and cylinders were evaluated. All in-terbody test implants were made of titanium alloys. MRI scans were carried out by using T1 TSE sequences. The total artifact volume (TAV) of all examined implants were calculated for sta-tistical t-test correlation and implant volume (IV)/TAV-relation. Results: Considering all ex-amined test implants with an increasing implant size the TAV became significant larger (p<0,001) with simultaneous reduction of the respective IV/TAV-relation. According to an intergroup TAV- correlation for cylinders and cuboids with an equivalent implant volume the cylindric test im-plants demonstrated a significant smaller arti-fact range (p<0,05). Conclusions: Based on these results the MRI artifacts of larger test im-plants were more limited to the to the implant’s direct surroundings. In this connection for im- plants with identical material volumes a cylin- dric shape demonstrated more advantages con- sidering MRI artifacting than cubic forms.
文摘Interbody disc spacers for anterior spine fusion are made of different materials, such as titanium alloys or carbon fiber reinforced polymers (CFRP). Implant-related susceptibility artifacts can decrease the quality of MRI scans. This cadaveric study aimed to demonstrate the extent that implant-related MRI artifacting affects the post fusion differentiation of the spinal canal (SC) and intervertebral disc space (IDS). In 6 cadaveric porcine spines, we evaluated the post-im- plantation MRI scans of a titanium and CFRP spacer that differed in shape and surface qualities. A spacer made of human cortical bone was used as a control. A defined evaluation unit was divided into regions of interest (ROI) to characterize the SC and IDS. Considering 15 different MRI sequences read independently by an interobserver-validated team of specialists artifact-affected image quality of the median MRI slice was rated on a modified score of 0-1-2-3. A maximum score of 15 points for the SC and 9 points for the IDS (100%) was possible. Turbo spin echo sequences produced the best scores for both spacers and the control. Only the control achieved a score of 100%. For the IDS the titanium and CFRP spacer maximally scored 0% and 74%, for the SC 80% and 99%, respectively. By using favored T1 TSE sequences the CFRP-spacer represented clear advantages in post fusion spinal imaging. Independent of artifact dimensions the used scoring system allowed us to create an implant-related ranking of MRI scan quality in reference to the bone control.
文摘Preventing subsidence of intervertebral cages in posterior lumbar interbody fusion (PLIF) requires understanding its mechanism, which is yet to be done. We aimed to describe the mechanism of intervertebral cage subsidence by using finite element analysis through simulation of the osteoporotic vertebral bodies of an elderly woman. The data from computed tomography scans of L2-L5 vertebrae in a 72-year-old woman with osteoporosis were used to create 2 FE models: one not simulating implant placement (LS-INT) and one simulating L3/4 PLIF using polyetheretherketone (PEEK) cages (LS-PEEK). Loads and moments simulating the living body were applied to these models, and the following analyses were performed: 1) Drucker-Prager equivalent stress distribution at the cage contact surfaces;2) the distribution of damage elements in L2-L5 during incremental loading;and 3) the distribution of equivalent plastic strain at the cage contact surfaces. In analysis 1, the Drucker-Prager equivalent stress on the L3 and L4 vertebral endplates was greater for LS-PEEK than for LS-INT under all loading conditions and tended to be particularly concentrated at the contact surfaces. In analysis 2, compared with LS-INT, LS-PEEK showed more damage elements along the bone around the cages in the L3 vertebral body posterior to the cage contact surfaces, followed by the area of the L4 vertebral body posterior to the cage contact surfaces. In analysis 3, in the L3 inferior surface in LS-PEEK the distribution of equivalent plastic strain was visualized as gradually expanding along the cages from the area posterior to the cages to the area anterior to them with increased loading. These analyses suggested that in PLIF for osteoporotic vertebral bodies, the localized stress concentration generated by the use of PEEK cages may cause accumulation of microscopic damage in the fragile osteoporotic vertebral bodies around the cages, which may result in cage subsidence.
基金National Natural Science Foundation of China(No.82160435)。
文摘Objective:To analyze the correlation between the amplitude changes of motor evoked potential(MEP),the 3D volume changes of spinal canal measuring by postoperative CT and the improvement rate of clinical symptoms after the spinal canal decompression in minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF),and to explore the predictive value of the changes of both MEP amplitude and spinal canal volume in the assessment of long-term clinical prognosis in MIS-TLIF.Methods:A retrospective study of 68 patients with L4/5 spinal stenosis treated with MIS-TLIF was performed.The changes of both intraoperative MEP amplitude and 3D spinal canal volume during the spinal canal decompression,as well as the visual analogue scale(VAS)and Oswestry dysfunction index(ODI)scores in the long-term follow-up were all recorded.Results:The values of intraoperative MEP amplitude was 159.04%higher in 68 patients with MIS-TLIF after spinal canal decompression(P<0.01).The 3 postoperative 3D spinal canal volume(4.89±1.27)cm increased by 31.22%in comparison 3 with preoperative date(3.78±1.08)cm(P<0.01).The VAS and ODI scores were improved to 78.55%and 80.60%,respectively at the last follow-up(P<0.01).The improvement rate of MEP amplitude on the decompression side was positively correlated with the improvement rate of postoperative spinal canal volume(r=0.272,P=0.025).The improvement rate of postoperative spinal canal volume was positively correlated with the improvement rate of VAS and ODI at the last follow-up(r=0.656,r=0.490,P<0.01).Moreover,the improvement rate of MEP amplitude on the decompression side was also positively correlated with the improvement rate of VAS and ODI at the last follow-up(r=0.322 and 0.235,respectively,P<0.05).Conclusion:The increase of MEP amplitude after spinal canal decompression in patients with lumbar spinal stenosis treated by MIS-TLIF was closely correlated with both of the increase of spinal canal volume and the improvement of clinical symptoms.Therefore,MEP amplitude monitoring was not only the one of the important monitoring methods for predicting the prognosis of MIS-TLIF but also the reliably predictive value in the long-term clinical prognosis in MIS-TLIF.
文摘Objective: To evaluate the surgical results of posterior lumber interbody fusion with transpedicular fixation with rod screw system in management of spondylolisthesis. Study Design: Retrospective study reviewed all patient treated by lumber interbody fusion with transpedicular fixation with rod screw system. Patients and Methods: They were 40 patients operated for lumber and lumbosacral spondylolisthesis from Feb 2014 to April 2017 in Al-Azhar university hospital. These patients followed postoperatively clinically for improved neural function and for fusion stability and hardware fixation by radiological investigation. Data about pain intensity (by Visual Analogue Scale) was collected pre- and postoperatively;and outcome was assessed by Oswetry disability index (ODI). Outcome was graded as excellent, good, fair, or poor. Pre- and Post-operative data were statistically compared. Results: The mean age was 45 years (range between 30 - 60 years) with female sex predominance (male:female = 1:3). They had lytic (n = 30) or degenerative (n = 10) spondylolisthesis;and all underwent PLIF (posterior lumbar interbody fusion). In lytic group, the level was L4/L5 in 19 patients and L5/S1 in 11 patients, while in degenerative group the level was L4/L5 in 4 patients, L5/S1 in 3 patients, L2/L3 in 2 and L3/L4 in one patient. The spondylolisthesis grade was grade I among 25 subjects, grade two among 11 subjects and retrolisthesis among 4 subjects. Sensory deficits reported in 22 subjects (19 had lytic and 3 had degenerative spondylolisthesis);while motor deficits reported among 10 subjects and reduced reflexes among 8 subjects. The outcome was excellent, good, and fair among 30, 7, and 3 subjects respectively. The return to previous levels of activity was reported among 32 patients. VAS was 3.5 ± 2.94 at the end of follow up, while ODI was 28% and 36.0% and 3 and 6 months respectively. Conclusion: PLIF associated with transpedicular rod screw fixation system for management of spondylolisthesis is considered a safe and effective surgical intervention in both lytic and degenerative types.
