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.

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.

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.

Delayed arterial symptomatic epidural hematoma on the 14th day after posterior lumbar interbody fusion:A case report

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.

Unilateral pedicle screw fixation combined with lumbar interbody fusion for the treatment of lumbar degenerative diseases

Objective To explore the feasibility and efficiency of the treatment of lumbar degenerative diseases after transforaminal lumbar interbody fusion (TLIF) and posterolateral fusion (PLF) procedures in which unilateral pedicle screw fixation was used.

Comparison between Minimally Invasive Transforaminal Lumbar Interbody Fusion and Conventional Open Transforaminal Lumbar Interbody Fusion： An Updated Meta-analysis

Background： The previous studies agree that minimally invasive transforaminal lumbar interbody fusion （MIS-TLIF） has better function outcomes, less blood loss, and shorter hospital stay, when compared to open-TLIF. However, there are no significance differences on operative time, complication, and reoperation rate between the two procedures. This could be from less relative literatures and lower grade evidence. The further meta-analysis is needed with more and higher grade evidences to compare the above two TLIF procedures. Methods： Prospective and retrospective studies that compared open-TLIF and MIS-TLIF were identified by searching the Medline, Embase, Web of Science, China National Knowledge Infrastructure, Wanfang, and VIP database （the literature search comprised Medical Subject Heading terms and key words or Emtree term）. The retrieval time ranged from the date when the database was founded to January 2015. Pooled risk ratios （RRs） and weighted mean differences （WMDs） with 95% confidence intervals were calculated for the clinical outcomes and perioperative data. Results： Twenty-four studies （n =1967 patients） were included in this review （n =951, open-TLIF, n 1016, MIS-TLIF）. MIS-TLIF was associated with a significant decrease in the visual analog score （VAS）-back pain score （WMD 0.44; P= 0.001）, Oswestry Disabilities Index （WMD 1.57; P =0.005）, early ambulation （WMD = -1.77; P = 0.0001）, less blood loss （WMD = -265.59; P 〈 0.00001）, and a shorter hospital stay （WMD =-1.89; P 〈 0.0001）. However, there were no significant differences in the fusion rate （RR =0.99; P = 0.34）, VAS-leg pain （WMD = -0.10; P = 0.26）, complication rate （RR = 0.84; P = 0.35）, operation time （WMD = 5.23; P = 0.82）, or reoperation rate （RR = 0.73; P = 0.32）. Conclusions： MIS-TLIF resulted in a similar fusion rate with better functional outcome, less blood loss, shorter ambulation, and hospital stay; furthermore, it did not increase the complication or reoperation rate based on the existing evidence.

Comparison of simple discectomy and instrumented posterior lumbar interbody fusion for treatment of lumbar disc herniation combined with Modic endplate changes

Background The purpose of this retrospective study was to compare the surgical outcomes of simple discectomy and instrumented posterior lumbar interbody fusion （iPLIF） in patients with lumbar disc herniation and Modic endplate changes.Our hypothesis was that iPLIF could provide better outcome for patients with refractory lumbar disc herniation and Modic changes （LDH-MC）.Methods Ninety-one patients with single-segment LDH-MC were recruited.All patients experienced low back pain as well as radicular leg pain,and low back pain was more severe than leg pain.Forty-seven patients were treated with discectomy and 44 were treated with iPLIE The outcomes of both low back pain and radicular leg pain using visual analogue scale （VAS） as well as the clinical outcome related to low back pain using Japanese Orthopaedic Association （JOA） score were assessed before and 18 months after surgery,respectively.Results Both low back and leg pain were significantly improved 18 months after simple discectomy and iPLIE Compared to patients undergoing simple discectomy,low back pain was significantly reduced in patients undergoing iPLIE but there was no significant difference in leg pain between two groups.Solid fusion was achieved in all patients who underwent iPLIF.Conclusions In patients with LDH-MC,iPLIF can yield significantly superior outcome on the relief of low back pain compared to simple discectomy.Simple discectomy can relieve radicular leg pain as efficient as iPLIE Accordingly,iPLIF seems to be a reliable treatment for patients with LDH-MC and predominant low back pain.

Complications associated with posterior lumbar interbody fusion using Bagby and Kuslich method for treatment of spondylolisthesis

Objective To analyze complications associated with posterior lumbar interbody fusion (PLIF) in which two Bagby and Kuslich (BAK) interbody fusion cages were implanted.Methods A total of 118 patients with spondylolytic spondylolisthesis underwent single-level PLIF using two BAK cages filled with morselized autogenous bone. The major clinical and radiographic complications were analyzed after a follow-up with an average time of 2 years and 9 months.Results Complications were divided into intraoperative and postoperative complications. Intraoperative complications mainly included dural tear (4 patients, 3.4%), nerve root injury (3 patients, 2.5%) and suboptimal cage position (9 patients, 7.5%). No death was caused by the operation. Postoperative complications chiefly consisted of cage retropulsion (3 patients, 2.5%), cage subsidence (4 patients, 3.4%), and postlaminectomy arachnoiditis (2 patients, 1.7%). Pseudarthrosis was noted radiographically with evidence of motion between adjacent vertebra on lateral flexion-extension films and luciencies around the cages (2 patient, 1.7%), continuous posterior cage migration (2 patients, 1.7%) or continuous cage subsidence (2 patients, 1.7%). Two patients died, one from a traffic accident and the other from metastatic cancer 1 year postoperatively.Conclusions The results of this study indicate that PLIF with BAK cages is an effective but also technically difficult procedure. The relatively high incidence of complications reminds us of the importance of surgical indications and proper manipulations.

Comparing minimally invasive and open transforaminal lumbar interbody fusion for treatment of degenerative lumbar disease： a meta-analysis

Background Transforaminal lumbar interbody fusion （TLIF） through a minimally invasive approach （mTLIF） was introduced to reduce soft tissue injury and speed recovery. Studies with small numbers of patients have been carried out, comparing mTLIF with traditional open TLIF （oTLIF）, but inconsistent outcomes were reported.

Transforaminal Lumbar Interbody Fusion for Traumatic Lumbar Spondylolisthesis

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.

Biomechanical evaluation of two fusion techniques based on finite element analysis:Percutaneous endoscopic and minimally invasive transforaminal lumbar interbody fusion

As a novel minimally invasive technique,percutaneous endoscopic transforaminal lumbar interbody fusion(PETLIF)has been widely used in the treatment of lumbar degenerative diseases.The purpose of this study was to analyze these two operation types’biomechanical performances of PE-TLIF and traditional minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF)using the finite element(FE)method.The intact FE models of L4-L5 were established and validated based on the CT images.On this basis,the FE models of MIS-TLIF and PETLIF were established and analyzed.It is demonstrated that for lumbar interbody fusion with the oblique asymmetrically implanted cage under bilateral pedicle screws and rods fixation,such as MIS-TLIF and PE-TLIF,different degrees of articular process resection have no significant effect on the cage subsidence,and the surgical segment can achieve similar stability.In addition,the maximum stress of the L4 inferior endplate of MIS-TLIF and PE-TLIF is greater than that of the L5 superior endplate,which indicates that MIS-TLIF and PE-TLIF can cause cage subsidence in the L4 inferior endplate.

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.

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.

Standardizing MI-TLIF, a Proposal for a Reproducible Technique

Background: Minimally invasive transforaminal lumbar interbody fusion (MI TLIF) is a widely known and performed technique, however its versatility among different physicians continues to hinder its replication and results. Therefore, this study aimed to provide a step-by-step surgical guide to perform a safe MI-TLIF, based on the results obtained in patients operated on by a single surgeon over a period of 12 years. Patients and methods: A retrospective, single center, longitudinal, and observational cohort study was conducted with 931 patients who underwent MI TLIF by a single surgeon between 2010 and 2022 using the technique described on this paper, each with a minimum follow-up of 12 months. Criteria included Schizas classification, listhesis according to Meyerding classification, number of levels treated, cage size, and complications (screw repositioning or cerebrospinal fluid leak). Patient clinical outcomes were assessed using the Oswestry Disability Index (ODI), Visual Analog Scale (VAS) for pre- and postoperative radicular pain. Thin slice CT scans were used to assess the progression of the fusion using the Bridwell classification. In the statistical analysis, percentages, median, and interquartile range (IQR) were calculated. Results: Nine hundred and thirty one patients underwent MI TLIF using the technique described, eight hundred and eighty (94.5%) had a single level treated and fifty one (5.5%) had a 2 level procedure (982 levels), an 8mm cage was placed on five hundred and seventeenlevels (52.7%), six hundred and sixty three levels(67.6%) achieved grade I fusion, two hundred and sixty six levels (27.1%) achieved grade II fusion, 52 levels (5.3) achieved grade III fusion and one level (0.1) achieved a grade IV fusion or non-union. Revision surgery was performed on 3 patients (0.3%) for screw repositioning, cerebrospinal fluid leak was present on 2 patients during surgery and treated before closure. VAS scores and ODI were improved at 12 months postop (VAS from 8.70 to 2.30 and ODI from 34.2 to 14.1, (p = 0.001). Conclusions: The MI TLIF technique described could be a safe and easy to replicate way to achieved lumbar interbody fusion, providingclinical and radiological benefits.

Biomechanical change of lumbar unilateral graded facetectomy and strategies of its microsurgical reconstruction:report of 23 cases

Objective： To evaluate the lumbar stability and the primary clinical results of unilateral facetectomy, transforaminal lumbar interbody fusion （TLIF） and unilateral pedicle screw fixation by X-Tube system. Methods： Five human lumbar cadaveric functional spine units（FSU） were obtained and graded facetectomy by 0, 1/4, 1/2, 3/4 and 4/4 were performed respectively on the left articular process of them. The stability of these 5 models was evaluated at flexion, extension, lateral bending and axial rotation. After a serial of biomechanical researches, 23 patients from June 2004 to March 2006 in our department underwent unilateral facetectomy, transforaminal lumbar interbody fusion （posterior lumbar interbody fusion） and unilateral pedicle screw instrumentation by X-Tube system. After general anaesthesia, with the guide of fluoroscopy and using X-Tube system, procedures of unilateral endoscopic facetectomy, spinal nerve root decompression, autologus spongy bone transplantation, one cage oblique insertion and unilateral pedicle screw instrumentation were performed. Results： There was no significant difference in flexion, extension, lateral bending and axial rotation of lumbar motion range after unilateral graded facetectomy. The stability of left/right axial direction was greatly affected when the range of graded facetectomy exceed 1/2. According to the Nakai criteria, for the 23 patients, the clinical result was excellent in 15 （65.2%）, good in 6 （26.1%） and fair in 2 （8.7%）. The fusion rate was 95.6% in excellent and good cases. Although partial absorption of bone grafts was observed in 1 case which might indicate a unsuccessful fusion, there was no loosing and replacement of instrument and no clinical symptoms occurred. Conclusion： The lumbar stability will be affected significantly when the range of graded facetectomy exceeds 1/2. Procedures of unilateral facetectomy, transforaminal lumbar interbody fusion and unilateral pedicle screw fixation is an optional strategy for microsurgical reconstruction, though the indications of the procedure should be carefully restricted.

Is the transsacral axial interbody fusion a candidate surgical approach for fusing both L5/S1 and L4/5？

Background Previous clinical and basic research of axial lumbar interbody fusion （AxiaLIF） all focused on the L5/S1.However,there is no data on the feasibility of this approach for the fusion of both L4/5 and L5/S1.This study aimed to explore whether transsacral axial interbody fusion is a candidate for the fusion of both L4/5 and L5/S1.Methods The subjects （n=40） underwent lumbosacral magnetic resonance imaging （MRI）.The median sagittal MRI images were analyzed and five measurement markers were defined as follows：the center of the L4/5 disc （A）,the center of the L5/S1 disc （B）,the anterior margin of the S1/2 space （C）,the sacrococcygeal junction （D）,and the coccygeal tip （E）.The measurement markers were connected each other to produce nine lines （AB,AC,AD,AE,BC,BD,BE,CD and CE） as the reference lines for surgical approaches.The distance between each reference line and the anterior and posterior margins of the L4,L5 and S1 vertebral bodies were measured to determine the safety of the respective approaches.Results Twenty subjects were capable of finding one reference line to fuse both L4/5 and L5/S1 via transsacral axial interbody fusion approach.The surgical approach reference line was AE or CE line.In the other 20 subjects,it was failed to find a reference line which met the safety criteria for fusing both L4/5 and L5/S1.Conclusions About half of subjects were capable of finding a suitable AxiaLIF reference line to fuse both L4/5 and L5/S1.In some subjects,it was difficult to find a suitable AxiaLIF reference line to fuse both L4/5 and L5/S1.