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

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

Implementing P-15/ABM Bone Graft as a Standardized Technique for Lumbar Fusion Approaches

Introduction: Lumbar fusion as low back pain treatment continues to be a challenge because of the multiple techniques and materials available, most popular techniques include Transforaminal lumbar interbody fusion (TLIF), Lateral lumbar interbody fusion (LLIF) and Anterior lumbar interbody fusion (ALIF). Successful lumbar fusion is associated with better clinical outcomes, and it is enhanced and targeted through the use of bone graft materials as an osteogenic cell binding peptide P-15, bound to an anorganic bone mineral (ABM). This peptide improves bone formation when used in fixation devices in a targeted and limited way to the implant surface by activating osteoblast precursor cells;by the osteogenic, osteoinductive and osteoconductive stimuli. The main objective of this study is to standardize the lumbar fusion process in the 3 techniques and achieve a more efficient and predictable lumbar fusion, evaluating results with radiological and clinical scales. Material and Methods: Patients underwent lumbar fusion with the use of P-15 Osteogenic Cell Binding Peptide, bound to an anorganic bone mineral (P-15/ABM) bone graft (5 cc) in three different techniques (TLIF, LLIF, ALIF), achieving a total of 100 lumbar levels. Radiological outcomes included fusion rates per Hounsfield Units at computed tomography (CT) scan and Lenke scale. Clinical outcomes were evaluated via the Oswestry Disability Index (ODI), Short Form Performance (SPF-36) and Visual Analog Scale (VAS and VASs) for pain and satisfaction. Results: 67 patients completed the 12 months follow-up, showing no differences in fusion rates between techniques. (Computed Tomography Hounsfield Units) CTHU reaches more than 200 UH at 3 months follow-up and continues fusion process till 12-month follow-up. Clinical scales showed no disability at ODI, improvement at VAS and VASs scales, absence of health restrictions at SPF-36 score since 6 months follow up. Conclusion: Bone graft volume of 5 cc is adequate for achieving successful lumbar fusion, regardless of the surgical technique employed.

Is Dynesys dynamic stabilization system superior to posterior lumbar fusion in the treatment of lumbar degenerative diseases?

Dynesys,a pedicle-based dynamic stabilization system,was introduced to overcome some undesirable complications of fusion procedures.Nevertheless,the theoretical advantages of Dynesys over fusion have not been clearly confirmed.The purpose of this editorial was to compare clinical and radiological outcomes of patients who underwent Dynesys system with those who underwent posterior lumbar fusion according to the existing literature and to see if the application of the Dynesys system is superior to the traditional lumbar fusion surgery.According to published clinical reports,the short-term effects of the Dynesys dynamic stabilization system are similar to that of traditional lumbar fusion surgery.Three comparative studies of Dynesys dynamic stabilization and fusion surgery with medium-term follow-up are encouraging.However,the results from four single-treatment-arm and small-sample studies of case series with long-term follow-up were not encouraging.In the present circumstances,it is not possible to conclude that the Dynesys dynamic stabilization system is superior to fusion surgery for lumbar degenerative diseases.

Two-Year Outcomes of Midline lumbar Fusion Versus Minimally Invasive Transforaminal Lumbar Interbody Fusion in the Treatment of L4-L5 Degenerative Disease

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.

Effect of low-intensity pulsed ultrasound on posterolateral lumbar fusion of rabbit

Objective:To observe the effect of low-intensity pulsed ultrasound in the posterolateral Lumbar fusion of rabbit.Methods:A total of 48 New Zealand white rabbits were randomly divided into the observation group and control group,including the autogenous iliac observation group.artificial bone observation group,artificial bone control group and autogenous iliac control group according to the different bone grafting.The posterolateral lumbar fusion of rabbits in each group was analyzed and compared.Results:After 4 weeks of treatment using the low-intensity pulsed ultrasound,the fusion in the bone grafting area of observation group was good.There was the relatively dense fusion area between the right transverse process and artificial bone.The left transverse process had been completely fused,with the clear bone trabecula through the fusion area.There was no significant fusion sign in the control group.According to the fusion comparison between two groups,the fusion rale of the observation group was 83.3%and it was significantly higher than the one of the control group(37.5%).Results of the comparison were statistically significant(P<0.05).The number of chondrocytes and the increase in the relative gray-scale in the fusion area of the iliac observation group were significantly higher than ones of the iliac control group(P<0.05).The number of chondrocytes and the increase in the relative gray-scale in the fusion area of the artificial bone observation group were significantly higher than ones of the artificial bone control group(P<0.05).The expression of IL-1.IL-6 and IL-17 4 weeks after the treatment of the observation group was significantly lower than the one of the control group,with the statistical significance(P<0.05).It indicated that the treatment of low-intensity pulsed ultrasound could reduce the expression level of inflammatory factors.Conclusions:The low-intensity pulsed ultrasound can significantly increase the bone grafting fusion rate of the rabbit's posterolateral lumbar fusion.The possible mechanism is that it promotes the lumbar posterolateral endochondral ossification and reduces the inflammatory reaction.

Meta-Analysis of Clinical Outcomes of Lumbar Fusion Surgical Interventions for Degenerative Spondylolisthesis

Introduction: Surgical interventions for degenerative spondylolisthesis are varied with comparable claims of success. Fusion based technique is one of the most commonly used surgical interventions in treating this condition. The aim of this meta-analysis is to compare the effectiveness of the Lumbar Interbody Fusion techniques (specifically Posterolateral Interbody approach—PLIF) versus Posterolateral Instrumented Fusion (PLF). The clinical outcomes investigated were: back pain, leg pain, function, Oswestery Disability Index (ODI), Disability Rating Index (DRI), fusion and revision rates if reported. Methods: Combinations of keywords and MeSH terms, where appropriate, were used to search for studies in Medline via Ovid, Embase, Cochrane Library, and Google scholar. The initial search was conducted on 10 August 2016 and updated on 13 June 2017. Eligibility criteria for the studies to be selected for this meta-analysis were: Randomised Controlled Trials (RCTs), cohort and consecutive cases studies that compared at PLIF versus PLF surgical interventions at the lumbar region. Heterogeneity indicators and Forest plot were computed using RevMan 5. Results: Out of the initial hits of 3021, 5 articles were selected as relevant and assessed for risk of bias and then data was extracted and tabulated. These 5 studies reported data from (900 patients’ records, follow up ranges from 6 months to 5 years) undergone one of 2 interventions (PLIF or PLF). The overall effect for ODI and leg pain showed no advantage of any intervention over the other while there was a greater odd ratio of fusion if the operation applied PLIF techniques (Overall Z = 2.86, p = 0.004). Conclusions: There is a need for more high quality clinical trials to compare these two interventions. However, available data indicate that there are comparable results in the main clinical outcomes between PLIF and PLF. PLIF has superior fusion rate which does not seem to affect post-operative pain ratings.

Current strategies for the restoration of adequate lordosis during lumbar fusion

Not restoring the adequate lumbar lordosis during lumbar fusion surgery may result in mechanical low back pain, sagittal unbalance and adjacent segment degeneration. The objective of this work is to describe the current strategies and concepts for restoration of adequate lordosis during fusion surgery. Theoretical lordosis can be evaluated from the measurement of the pelvic incidence and from the analysis of spatial organization of the lumbar spine with 2/3 of the lordosis given by the L4-S1 segment and 85% by the L3-S1 segment. Technical aspects involve patient positioningon the operating table, release maneuvers, type of instrumentation used(rod, screw-rod connection, interbody cages), surgical sequence and the overall surgical strategy. Spinal osteotomies may be required in case of fixed kyphotic spine. AP combined surgery is particularly efficient in restoring lordosis at L5-S1 level and should be recommended. Finally, not one but several strategies may be used to achieve the need for restoration of adequate lordosis during fusion surgery.

Combining Posterolateral Lumbar Fusion and Posterior Lumber Interbody Fusion Surgery for Treating Three-Level Lumber Spondylolysis and Single-Level Spondylolisthesis: Case Report

Lumbar spondylolysis is a relatively common condition that can cause a variety of clinical manifestations related to the lumbar spine. However, multi-level lumbar spondylolysis is rare and accounts for less than 6% of lumbar spondylolysis. We report a case of three-level lumbar spondylolysis with single-level spondylolisthesis. A 47-year-old woman presented to us with low back pain for 9 years that progressively worsened and the pain was exacerbated with standing and walking. She was diagnosed with three-level lumbar spondylolysis at L3-5 and spondylolisthesis at L4. We performed posterolateral lumber fusion (PLF) and posterior lumbar interbody fusion (PLIF) surgery for her. During the same period, pain recovery and fusion rate of the patient were evaluated after surgery. The results were favorable and proved the efficacy of combining PLF and PLIF technique for treatment for three-level lumbar spondylolysis and single-level spondylolisthesis.

Risk factors and care of early surgical site infection after primary posterior lumbar interbody fusion

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.

Correlation study between the changes of motor evoked potential and the improvement of spinal canal volume in minimally invasive transforaminal lumbar interbody fusion

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.

Retrospective Case Series of Porous Titanium Cages in Oblique Lumbar Interbody Fusion Surgery Assessing Subsidence, Fusion and Functional Outcomes

Purpose: Implant subsidence is a possible complication of spinal interbody fusion. We aim to evaluate porous titanium cages subsidence, fusion and functional outcomes in patients subjected to oblique lumbar interbody fusion (OLIF) with these novel devices. Methods: Our institutional review board approved a single-center experience which included 60 patients who underwent OLIF from June 2018 to June 2020 utilizing the porous titanium implants. Data was collected in accordance with the Declaration of Helsinki, and written informed consent was obtained. Imaging studies including radiographs 1, 3, 6 and 12 months and computed tomography (CT) scan at 6 months obtained during routine postoperative follow-up visits, were studied for signs of implant subsidence, fusion and clinical parameters to determine the effectiveness of surgery such as Oswestry disability index (ODI). Results: Radiographic subsidence occurred in 1 out of 89 porous titanium interbody cages (1.1%). No subsidence was observed in the posterior screws and rods fixation group (N = 57). However, one case of subsidence occurred in the lateral plate fixation group (N = 3). The subsidence occurred in an osteoporotic elderly patient operated for adjacent segment disease, and she was later revised with posterior instrumentation using cemented screws and rods. She had an uneventful recovery. Fusion rates were evaluated under CT scan at 6 months with a rate of 88%. In terms of clinical outcomes, ODI decreased significantly from 20.3 preop to 10.7 postop with a P-value Conclusions: In our study, the subsidence rate was lower than previously reported in the literature. Also, we had good fusion rates at 6 months likely due to the porous titanium cages use. We had no subsidence in the posterior instrumented group and one case in the lateral fixation group with improved clinical outcomes.

Treatment of Single Level Lumbar Spondylolisthesis with Lumbar Interbody Fusion via Oblique Lateral Approach (OLIF)

Objectives: To investigate the effect of lumbar interbody fusion via the oblique lateral approach (OLIF) in the treatment of single level lumbar spondylolisthesis. Methods: Retrospective analysis was made on 32 cases of single level lumbar spondylolisthesis treated by lumbar interbody fusion via the oblique lateral approach from July 2020 to July 2021. 14 males and 18 females;the age was (66.5 ± 11.5) years (55 - 82 years). 1) The operation time, intraoperative blood loss and complications were recorded;2) the scores of visual analog scale. VAS and Oswestry disability index (ODI) of low back pain and lower limb pain were collected before operation and at the last follow-up;by observing the imaging data, the height of the intervertebral space, the anterior convex angle of the intervertebral space, the anterior convex angle of the lumbar spine, the sagittal diameter of the dural sac and the spondylolisthesis were measured. Results: All patients successfully completed the operation, the average operation time was (103.9 ± 21.1) min, the average intraoperative bleeding volume was (72.3 ± 16.4) ml. There was no vascular injury during the operation, no infection occurred in all surgical incisions, and Class I/A healing was achieved. The VAS scores of low back pain and leg pain before operation and at the last follow-up were lower than those before operation, and the difference was statistically significant (P < 0.05);the ODI at the last follow-up was lower than that before operation, and the difference was statistically significant (P < 0.05). At the last follow-up, the height of intervertebral space, the height of intervertebral foramen and the sagittal diameter of dural sac were greater than those before operation, with statistically significant differences (P < 0.05);the spondylolisthesis rate at the last follow-up was lower than that before operation, with a statistically significant difference (P < 0.05). Left thigh surface numbness occurred in 2 cases (6.3%) and disappeared after 1 week;Hip flexion weakness occurred in 1 case (0.03%), which recovered after 12 days;there were no complications such as retroperitoneal hematoma, ureteral injury, retrograde ejaculation, intestinal and lumbar plexus injury. Conclusion: The early clinical effect of OLIF in the treatment of single level lumbar spondylolisthesis is significant. This surgical method is minimally invasive, safe and effective, which can significantly reduce the amount of intraoperative bleeding and reduce the risk of postoperative complications. Its main working principle is to make the annulus fibrosus, posterior longitudinal ligament and ligamentum flavum shrink and recover the height of the intervertebral space through decompression, loosening and stretching of the intervertebral space, so as to achieve the reduction of the slipped vertebral body, increase the height of the intervertebral foramen Enlarge the spinal canal volume and eliminate dynamic compression to play an indirect decompression role, improve the symptoms of low back and leg pain, and reconstruct the stability of the spine through interbody fusion.

Treatment of lumbar disc herniation with robot combined with unilateral biportal endoscopic technology:A case report

BACKGROUND This reported procedure combines the orthopedic surgical robot with the unilateral biportal endoscopy-lumbar interbody fusion(UBE-LIF),utilizing the UBE's wide viewing field and operating space to perform minimally invasive decompressive fusion of the lesioned segment,and the orthopedic surgical robot's intelligence and precision to perform percutaneous pedicle screw placement.The advancement of this procedure lies in the superposition of advantages and offsetting disadvantages of the two new technologies,and the maximum effect of treatment is achieved with maximum minimization of invasiveness and precision under the monitoring of imaging instruments to maximize the benefit of patients,and this review reports a case of multiple-segment lumbar decompression and fusion surgery for lumbar disc herniation via robot-assisted UBE for reference.CASE SUMMARY A 44-year-old patient presented to our hospital.Combining various clinical data,we diagnosed the patient with lumbar disc herniation with radiculopathy,lumbar spondylolisthesis,and lumbar spinal stenosis.We developed a surgical plan of"UBE decompression+UBE-LIF+orthopedic surgery robot-assisted percutaneous pedicle screw implantation for internal fixation".The results were satisfactory.CONCLUSION We present an extremely rare case of multiple-segment lumbar decompression and fusion surgery for lumbar disc herniation via robot-assisted UBE and achieved good results.Therefore,the technique is worthy of clinical promotion.

Effects of low-intensity pulsed ultrasound stimulation on porous hydroxyapatite blocks for posterolateral fusion of lumbar spine in rabbits

he effects of porous hydroxyapatite blocks（PHABs） and an adjunct low-intensity pulsed ultrasound stimulation（LIPUS） on the fusion rate in a rabbit spinal posterolateral fusion（PLF） model were evaluated.Twenty rabbits underwent PLF with autograft and PHABs were randomly assigned to two groups：treated group with 20 min LIPUS daily and untreated control group for 4 weeks until euthanasia.The fused motion segments were subjected to manual palpation,gross observation,and radiographic investigation before histomorphologic and scanning electron microscopic analyses.Statistical differences between the LIPUS group and the control group are found in the fusion rate,bone density gray scale,trabecular bone formation,osteoblast-like cells,chondrocytes and positive expression of BMP-2 and TGF-β1 in the junction zone（significance level p〈0.05）.The results suggest that LIPUS can increase fusion rates and accelerate bone in-growth into PHAB.Hence,PHAB and LIPUS may be used together to increase fusion rates in a rabbit spinal fusion model with a promising extension to human application.

Successful outcomes of unilateral vs bilateral pedicle screw fixation for lumbar interbody fusion:A meta-analysis with evidence grading

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.

Nuances of oblique lumbar interbody fusion at L5-S1:Three case reports

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.

Surgical Outcome of Fusion in Recurrent Lumbar Disc Herniation

Background Data: Recurrent lumbar disc herniation means re-herniation of disc on the same site and at the same level where a previous discectomy had been performed: recurrent lumbar disc herniation occurs in 7% to 24% of patient underwent discectomy. Tow mean surgical options after reherniated lumbar disc are revision discectomy alone or revision discectomy with fusion discectomy alone in recurrent lumbar disc herniation may not be an efficient treatment without fusion. Objective: To evaluate the efficacy and safety of revision discectomy with fusion in management of recurrent lumbar disc. Study Design: Retrospective study reviewed all patient underwent revision discectomy with fusion, they were 40 patients operated for recurrent lumbar disc from September 2014 to April 2018 in Al-Azhar University Hospital Damietta. Pre- and post-operative data collection and analysis of the outcome were completed based on the “Japanese Orthopedic Association score” (JOAs), and radiographic follow-up. Patients and Methods: 40 patients (30 male and 10 female) underwent revision discectomy with fusion as surgical management for reherniated lumbar disc from September 2014 to April 2018. All patients presented with low back pain and radicular pain with mean duration of 18 months. The patients were investigated by standard plain X-ray CT SCAN and MRI of the lumbar spine. All patients had a discectomy and postero-lateral fusion in revision surgery. These patients followed post operatively clinically for improving pain and neural function, and radiologically for disc removal stability and fusion. Results: The age ranged from 30 to 60 years, mean age was 45 years, male to female ratio 3:1. Follow-up ranged from 18 - 30 months with a mean follow-up 24 months. 30 patients had an excellent outcome, 6 patients had a good outcome, 2 patients had a fair outcome, and 2 patients had a poor outcome. Conclusion: Recurrent lumbar disc herniation occurs in 7% to 24% of patient underwent discectomy. Revision surgery when indicated can be done by various techniques. Revision discectomy with fusion for reherniated lumbar disc is effective and safe with confident results.

Comparison of Clinical Outcomes of Cortical Bone Trajectory and Traditional Pedicle Screw Fixation in Posterior Lumbar Interbody Fusion

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.

Biomechanical Effects of Implant Materials on Posterior Lumbar Interbody Fusion: Comparison of Polyetheretherketone and Titanium Spacers Using Finite Element Analysis and Considering Bone Density

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.

Application of the cortical bone trajectory technique in posterior lumbar fixation

The cortical bone trajectory(CBT) is a novel technique in lumbar fixation and fusion.The unique caudocephalad and medial-lateral screw trajectories endow it with excellent screw purchase for vertebral fixation via a minimally invasive method.The combined use of CBT screws with transforaminal or posterior lumbar interbody fusion can treat a variety of lumbar diseases,including spondylolisthesis or stenosis,and can also be used as a remedy for revision surgery when the pedicle screw fails.CBT has obvious advantages in terms of surgical trauma,postoperative recovery,prevention and treatment of adjacent vertebral disease,and the surgical treatment of obese and osteoporosis patients.However,the concept of CBT internal fixation technology appeared relatively recently;consequently,there are few relevant clinical studies,and the long-term clinical efficacy and related complications have not been reported.Therefore,large sample and prospective studies are needed to further reveal the long-term complications and fusion rate.As a supplement to the traditional pedicle trajectory fixation technique,the CBT technique is a good choice for the treatment of lumbar diseases with accurate screw placement and strict indications and is thus deserving of clinical recommendation.