Minimally Invasive Transforaminal Lumbar Interbody Fusion for Isthmic Spondylolisthesis: In Situ Versus Reduction

Risk factors for low back pain after oblique lumbar interbody fusion in patients with low-grade degenerative lumbar spondylolisthesis: a retrospective study

Objective

To investigate the risk factors of low back pain after oblique lumbar interbody fusion (OLIF) in patients with low grade degenerative lumbar spondylolisthesis (DLS).

Methods

This retrospective study included 116 patients with single-level low-grade lumbar spondylolisthesis with low back pain who underwent OLIF surgery in our hospital from December 2017 to October 2020. Demographic, clinical, surgical, and radiological characteristics of this population were analyzed to determine the relationship between these characteristics and the degree of low back pain relief after OLIF.

Results

A total of 116 patients (average age 58.61 ± 7.01 years) were included in this study. Among them, 33 patients had poor improvement of low back pain after surgery, and 83 patients had satisfactory effect after surgery with obvious relief of low back pain. Postoperative disc height increase ≤2.5 mm (P = 0.000) was most correlated with poor improvement of low back pain symptoms after OLIF. The factors positively correlated with poor improvement of low back pain symptoms after OLIF in patients with low-grade degenerative lumbar spondylolisthesis included the increase of spondylolisthesis grade (OR = 17.665; 95%CI: 3.262-95.678 P = 0.001), disc height increase ≤2.5 mm (OR = 34.377; 95%CI: 5.632-209.818 P = 0.000). The factors negatively correlated with poor improvement of low back pain symptoms after OLIF in patients with low-grade degenerative lumbar spondylolisthesis included no osteoporosis (OR = 0.067; 95%CI: 0.013-0.350 P = 0.001), no cage subsidence (OR = 0.208; 95%CI: 0.048-0.903 P = 0.036), duration of preoperative low back pain symptoms ≤36 months (OR = 0.045; 95%CI: 0.007-0.277 P = 0.001).

Conclusions

OLIF can significantly improve the low back pain symptoms in patients with low-grade degenerative lumbar spondylolisthesis. High grade of spondylolisthesis before operation, duration of low back pain symptoms more than 36 months, osteoporosis, postoperative cage subsidence, and postoperative segmental disc height improvement less than 2.5 mm are risk factors for low back pain after operation.

Does intraoperative reduction result in better outcomes in low-grade lumbar spondylolisthesis after transforaminal lumbar interbody fusion? A systematic review and meta-analysis

Objective

This study aimed to compare the clinical efficacy and safety of reduction vs. arthrodesis in situ with transforaminal lumbar interbody fusion (TLIF) for low-grade lumbar spondylolisthesis.

Study design

Systematic review and meta-analysis.

Methods

A comprehensive literature search was implemented in PubMed, Embase, and Cochrane Library databases. Randomized or non-randomized controlled trials that were published until July 2023 that compared reduction vs. arthrodesis in situ techniques with minimally invasive or open-TLIF for low-grade spondylolisthesis were selected. The quality of the included studies was evaluated by the Newcastle-Ottawa Scale (NOS). Data were extracted according to the predefined outcome measures, including operation time and intraoperative blood loss; short- and long-time follow-up of visual analog scale (VAS) back pain (VAS-BP) and Oswestry Disability Index (ODI); slippage and segmental lordosis; and the complication and fusion rate.

Results

Five studies (n = 495 patients) were finally included. All of them were retrospective cohort studies with Evidence Level II. The pooled data revealed that both techniques had similar patient-reported outcomes (VAS, ODI, and good and excellent rate) during short- and long-term follow-up. In addition, no significant differences were observed in the fusion and complication rates. However, although the reduction group did achieve better slippage correction, it was associated with increased operation time and intraoperative blood loss compared with the in situ arthrodesis group.

Conclusions

Based on the available evidence, intraoperative reduction does not result in better clinical outcomes in low-grade spondylolisthesis after minimally invasive or open-TLIF, and the in situ arthrodesis technique could be an alternative.

Clinical efficacy of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in the treatment of II° lumbar isthmic spondylolisthesis: A retrospective cohort study

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is not suitable for high-grade isthmic spondylolisthesis, whether MIS-TLIF can treat II° lumbar isthmic spondylolisthesis (IS) is still controversial. This retrospective cohort study compared the clinical efficacy of MIS-TLIF and open transforaminal lumbar interbody fusion (OPEN-TLIF) in the treatment of II° lumbar IS. From January 2017 to January 2023, 101 patients with II° lumbar IS were diagnosed in our hospital and underwent surgical treatment, of which 53 received MIS-TLIF surgery and 48 received OPEN-TLIF surgery. The operation time, blood loss and surgical complications were compared between the 2 groups. The pain, function, reduction rate and fusion rate of the patients were evaluated during follow-up. The amount of intraoperative blood loss, postoperative drainage, and postoperative hospital stay in the MIS-TLIF group were significantly lower than those in the OPEN-TLIF group were (P < .01). In the MIS-TLIF group, there were 1 case of dural sac injury and 3 cases of lower limb paralysis. The complication rate of MIS-TLIF was lower than the OPEN-TLIF group (P = .032). In the visual analog scale score of low back pain, the MIS-TLIF group was lower than the OPEN-TLIF group after operation and at the last follow-up. There were no significant differences in postoperative leg pain score, slippage rate, and fusion rate between the 2 groups. Compared with OPEN-TLIF, MIS-TLIF has the advantages of better low back pain relief, less trauma, less bleeding and faster recovery, and is worthy of clinical promotion.

Research topics and hotspot trends of lumbar spondylolisthesis: A text-mining study with machine learning

Objectives

The study aimed to conduct a bibliometric analysis of publications concerning lumbar spondylolisthesis, as well as summarize its research topics and hotspot trends with machine-learning based text mining.

Methods

The data were extracted from the Web of Science Core Collection (WoSCC) database and then analyzed in Rstudio1.3.1 and CiteSpace5.8. Annual publication production and the top-20 productive authors over time were obtained. Additionally, top-20 productive journals and top-20 influential journals were compared by spine-subspecialty or not. Similarly, top-20 productive countries/regions and top-20 influential countries/regions were compared by they were developed countries/regions or not. The collaborative relationship among countries and institutions were presented. The main topics of lumbar spondylolisthesis were classified by Latent Dirichlet allocation (LDA) analysis, and the hotspot trends were indicated by keywords with strongest citation bursts.

Results

Up to 2021, a total number of 4,245 articles concerning lumbar spondylolisthesis were finally included for bibliometric analysis. Spine-subspecialty journals were found to be dominant in the productivity and the impact of the field, and SPINE, EUROPEAN SPINE JOURNAL and JOURNAL OF NEUROSURGERY-SPINE were the top-3 productive and the top-3 influential journals in this field. USA, Japan and China have contributed to over half of the publication productivity, but European countries seemed to publish more influential articles. It seemed that developed countries/regions tended to produce more articles and more influential articles, and international collaborations mainly occurred among USA, Europe and eastern Asia. Publications concerning surgical management was the major topic, followed by radiographic assessment and epidemiology for this field. Surgical management especially minimally invasive technique for lumbar spondylolisthesis were the recent hotspots over the past 5 years.

Conclusions

The study successfully summarized the productivity and impact of different entities, which should benefit the journal selection and pursuit of international collaboration for researcher who were interested in the field of lumbar spondylolisthesis. Additionally, the current study may encourage more researchers joining in the field and somewhat inform their research direction in the future.

Single-level Minimally Invasive Transforaminal Lumbar Interbody Fusion Versus Anterior Lumbar Interbody Fusion for the Surgical Treatment of Isthmic Spondylolisthesis

INTRODUCTION

Limited studies have compared minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) with anterior lumbar interbody fusion (ALIF) for the treatment of isthmic spondylolisthesis. This study aims to compare perioperative variables, patient-reported outcome measures (PROMs), and minimal clinically important difference (MCID) achievement rates between these surgical approaches.

METHODS

Patients with isthmic spondylolisthesis undergoing primary, single-level MIS TLIF or ALIF were identified in a surgical database. Patients were divided into MIS TLIF and ALIF cohorts. Demographics and perioperative characteristics were collected and compared between groups using the chi square test or Student t-test. PROMs including the Patient-Reported Outcomes Measurement Information System Physical Function, 12-Item Short Form Physical Composite Score, visual analog scale (VAS) back, VAS leg, and Oswestry Disability Index were collected at preoperative, 6-, 12-week, 6-month, 1-, and 2-year time points. Mean PROMs were compared using the Student t-test for independent samples. MCID attainment was determined using established values in the literature; achievement rates by grouping were compared using chi square analysis.

RESULTS

One hundred seventy-one patients were included, 121 MIS TLIF and 50 ALIF. No demographic differences were observed. Mean surgical times were 139.7 minutes (MIS TLIF) and 165.5 minutes (ALIF) (P < 0.001). No other perioperative differences were observed. Mean estimated blood loss values were 63.8 mL (MIS TLIF) and 73.7 mL (ALIF). Mean postoperative lengths of stay were 43.9 hours (MIS TLIF) and 42.5 hours (ALIF). Mean PROMs did not markedly differ among groups at any time point. MCID attainment was markedly higher among MIS TLIF patients for the Oswestry Disability Index at 6 weeks (P = 0.046) and 12 weeks (P = 0.007), Patient-Reported Outcomes Measurement Information System Physical Function at 12 weeks (P = 0.015), and VAS leg at 6 weeks (P = 0.031) and 12 weeks (P = 0.045). No other notable differences were observed among MCID achievement by grouping.

DISCUSSION

While single-level ALIF demonstrated markedly higher surgical times, other perioperative characteristics and PROMs were comparable among ALIF and MIS TLIF patients. Although MCID achievement rates were generally lower for disability and leg pain among ALIF patients, significance was not reached at 6 months, 1 year, or during the overall postoperative period after fusion.

Isthmic spondylolisthesis in adults… A review of the current literature

Isthmic spondylolisthesis can be defined as the anterior translation of a vertebral body relative to the one subjacent to it and secondary to an abnormality of the pars interarticularis. Isthmic spondylolisthesis is usually asymptomatic and discovered as an incidental radiographic finding. However, it can be symptomatic due to its biomechanical effects on the adjacent neural structures and patients may present with low back and/or radicular leg pain. Standing plain radiographs can be obtained to confirm the presence or assess the degree of isthmic spondylolisthesis. Computed tomography (CT) clearly shows the pars defect and provides a better assessment of the pathology. Magnetic resonance imaging (MRI) is indicated in patients with neurologic manifestations and can be used to assess the degree of foraminal or central stenosis. Conservative management including oral anti-inflammatory medication, physical therapy, and/or transforaminal epidural corticosteroid injections can be utilized initially. Surgery can be considered in the setting of persistent symptoms unrelieved with conservative management or significant neurologic compromise. Several surgical methods and techniques are available in the management of isthmic spondylolisthesis. There has been a significant national increase in the use of interbody fusion posteriorly for the management of isthmic spondylolisthesis. Reports have suggested that interbody fusion can be a cost-effective technique in selected patients with isthmic spondylolisthesis. Future studies are encouraged to further characterize the specific indications of various surgical modalities in patients with isthmic spondylolisthesis.

Minimally invasive tubular laminectomies in multilevel spine surgery-an illustrative case-based review of techniques and combined approaches

Minimally invasive techniques have become part of the spine surgeons' armamentarium and are currently utilized to treat many conditions involving the cervical, thoracic, lumbar and sacral spine. Surgical treatment of severe degenerative conditions such as multilevel spinal stenosis, tandem stenosis, combination of stenosis or disk herniation and spondylolisthesis at adjacent spinal levels, as well as extensive infections or hematomas, may require a multilevel tailored approach with all the challenges that such surgical planning entails. Although the use of minimally invasive tubular decompressive procedures has gained widespread popularity in the recent years, the adoption of such techniques during multilevel spine surgery can be at times challenging. A careful tailored selection of the surgical approach that better fits needs and expectations of the patient is therefore consequential to achieve good clinical and radiological outcome without compromising efficiency and results. Many surgical techniques have been described in literature but very few reports on the use of combined tubular approached are currently present. We therefore present an illustrative review of techniques for tubular laminectomies and combined approaches that can be utilized in the surgical treatment of multilevel spinal conditions. Illustrative cases documenting common and less common indications for the use of minimally invasive laminectomies are also presented.

Clinical outcomes of minimally invasive transforaminal lumbar interbody fusion via a novel tubular retractor

Objective

To assess the feasibility and clinical results of microscopic minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) using a novel tapered tubular retractor that preserves the multifidus.

Method

A total of 122 patients underwent MIS-TLIF using a tapered tubular retractor system from March 2016 to August 2017. Perioperative parameters and follow-up outcomes were reviewed.

Results

The follow-up period was 23.95 ± 1.43 months. The operative time averaged 130.48 ± 34.44 minutes. The estimated blood loss was 114.10 ± 96.70 mL. The mean time until ambulation was 16.33 ± 6.29 hours. The average visual analogue scale (leg/waist) and Oswestry Disability Index scores (preoperative to last follow-up) improved from 4.93 ± 2.68/3.74 ± 2.28 to 0.34 ± 0.77/0.64 ± 0.74 and from 59.09% ± 22.34 to 17.04% ± 8.49, respectively. At the last follow-up, 98.36% of the patients achieved solid fusion. Cerebrospinal fluid leakage occurred in two cases. The asymptote of the surgeon’s learning curve occurred at the 25th case. There were no significant differences between the preoperative qualitative and quantitative analyses of multifidus muscle fatty infiltration and those at the final follow-up.

Conclusion

MIS-TLIF can be performed safely and effectively using this tapered tubular retractor system, which helps preserve the multifidus.

Direct Pars Defect Tubular Decompression and TLIF for the Treatment of Low-Grade Adult Isthmic Spondylolisthesis: Surgical Challenges and Nuances of a Muscle-Sparing Minimally Invasive Approach

We present an illustrative report on the use of a minimally invasive, muscle-sparing, direct pars defect decompression with transforaminal lumbar interbody fusion (TLIF) and instrumentation for the treatment of low-grade adult isthmic spondylolysis with spondylolisthesis and discuss the surgical challenges and nuances associated with the technique.

High-Grade Spondylolisthesis in Adults: Current Concepts in Evaluation and Management

Background

Information regarding the treatment of high-grade spondylolisthesis (HGS) in adults has been previously described; however, previous descriptions of the evaluation and surgical management of HGS do not represent more recent and now established approaches. The purpose of the current review is to discuss current concepts in the evaluation and management of patients with HGS.

Methods

Literature review.

Results

HGS is diagnosed in up to 11.3% of adults with spondylolisthesis and typically presents as nonspecific lower back pain. Regarding evaluation, a thorough history and physical examination should be performed, which may help predict the presence of HGS. Diagnostic imaging, and specifically the use of spino-pelvic parameters, are now commonly implicated in guiding treatment course and prognosis. When surgical intervention is indicated, surgical approaches include in situ fusion variations, reduction and partial reduction with fusion, and vertebrectomy. Although the majority of studies suggest improvements with these approaches, the literature is limited by a low level of evidence with regards to the superiority of one technique when compared with others.

Conclusions

HGS is a unique cause of low back pain in adults that carries considerable morbidity, but rarely presents with neurologic symptoms. Although the definitions, classifications, and methods of diagnosis of this spinal deformity have been established and accepted, the ideal surgical management of this deformity remains highly debated. Fusion in situ techniques are often technically easier to perform and provide lower risk of neurologic complications, whereas reduction and fusion techniques offer greater restoration of global spino-pelvic balance. Preoperative spino-pelvic parameters may have utility in assisting in procedural selection; however, future, higher-quality and longer-term studies are warranted to determine the optimal surgical intervention among the widely available techniques currently used, and to better define the indications for these interventions.

Fusion in situ versus reduction for spondylolisthesis treatment: grading the evidence through a meta-analysis

PURPOSE

During surgical procedure on lumbar spondylolisthesis, the role of reducing slip remains controversial. The purpose of the present study was to compare fusion in situ with reduction in clinical and radiographic outcomes.

METHODS

A literature research was performed at PubMed, Embase, Web of Science, and Cochrane Library. After screening by two authors, ten articles were brought into this meta-analysis finally, and the quality was evaluated by the modified Newcastle-Ottawa Scale (NOS). Isthmic, moderate, and serious spondylolisthesis were all analyzed separately. Sensitivity analyses were performed for high-quality studies, and the publication bias was evaluated by the funnel plot.

RESULTS

Most criteria did not have statistical differences between reduction and fusion in situ groups. However, in reduction group, the union rate was significantly higher (P=0.008), the slippage was much improved (P<0.001) and the hospital stay was much shorter comparing to no-reduction group (P<0.001). Subgroup analysis (containing moderate and serious slip, or isthmic spondylolisthesis) and sensitivity analysis were all consistent with original ones, and the funnel plot indicated no obvious publication bias in this meta-analysis.

CONCLUSIONS

Both reduction and fusion in situ for lumbar spondylolisthesis were related with good clinical results. Reduction led to higher rate of fusion, better radiographic slippage, and shorter hospital stay. After sufficient decompression, reduction did not incur additional risk of neurologic impairment compared with fusion in situ.

Defining the MIS-TLIF: A Systematic Review of Techniques and Technologies Used by Surgeons Worldwide

STUDY DESIGN

Systematic review.

OBJECTIVE

To date there is no consensus among surgeons as to what defines an MIS-TLIF (transforaminal lumbar interbody fusion using minimally invasive spine surgery) compared to an open or mini-open TLIF. This systematic review aimed to examine the MIS-TLIF techniques reported in the recent body of literature to help provide a definition of what constitutes the MIS-TLIF, based on the consensus of the majority of surgeons.

METHODS

We created a database of articles published about MIS-TLIF between 2010 and 2018. We evaluated the technical components of the MIS-TLIF including instruments and incisions used as well the order in which key steps are performed.

RESULTS

We could identify several patterns for MIS-TLIF performance that seemed agreed upon by the majority of MIS surgeons: use of paramedian incisions; use of a tubular retractor to perform a total facetectomy, decompression, and interbody cage implantation; and percutaneous insertion of the pedicle-screw rod constructs with intraoperative imaging.

CONCLUSION

Based on this review of the literature, the key features used by surgeons performing MIS TLIF include the use of nonexpandable or expandable tubular retractors, a paramedian or lateral incision, and the use of a microscope or endoscope for visualization. Approaches using expandable nontubular retractors, those that require extensive subperiosteal dissection from the midline laterally, or specular-based retractors with wide pedicle to pedicle exposure are far less likely to be promoted as an MIS-based approach. A definition is necessary to improve the communication among spine surgeons in research as well as patient education.

Risk factors of postoperative low back pain for low-grade isthmic spondylolisthesis: a retrospective study

Objective

To investigate the risk factors of postoperative low back pain (LBP) following posterior lumbar interbody fusion (PLIF) surgery for low-grade isthmic spondylolisthesis (IS).

Methods

This retrospective study enrolled patients with IS that underwent PLIF between January 2011 and January 2016. Demographic, clinical, surgical and radiological characteristics were analysed to determine associations between these characteristics and LBP as measured using a visual analogue scale (VAS) pain score.

Results

A total of 192 patients were enrolled in the study. The mean VAS pain score of LBP decreased significantly after surgery. The mean preoperative VAS pain score was significantly greater in patients with symptoms of ≤3 years duration compared with those with symptoms lasting >3 years. The postoperative VAS pain score was significantly lower in patients with grade 1 slippage compared with those with grade 2 slippage. There was a significant correlation between preoperative to postoperative change of VAS pain score and postoperative disc height (r = 0.99).

Conclusion

PLIF significantly improved LBP in patients with low-grade IS, although patients still reported some postoperative LBP. The grade of slippage was a risk factor for postoperative LBP. Restoring the disc height appeared to improve LBP.

Assessment of radiographic and clinical outcomes of an articulating expandable interbody cage in minimally invasive transforaminal lumbar interbody fusion for spondylolisthesis

OBJECTIVE The inability to significantly improve sagittal parameters has been a limitation of minimally invasive surgery for transforaminal lumbar interbody fusion (MIS TLIF). Traditional cages have a limited capacity to restore lordosis. This study evaluates the use of a crescent-shaped articulating expandable cage (Altera) for MIS TLIF. METHODS This is a retrospective review of 1- and 2-level MIS TLIF. Radiographic outcomes included differences in segmental and lumbar lordosis, disc height, evidence of fusion, and any endplate violations. Clinical outcomes included the numeric rating scale for leg and back pain and the Oswestry Disability Index (ODI) for low-back pain. RESULTS Thirty-nine patients underwent single-level MIS TLIF, and 5 underwent 2-level MIS TLIF. The mean age was 63.1 years, with 64% women. On average, spondylolisthesis was corrected by 4.3 mm (preoperative = 6.69 mm, postoperative = 2.39 mm, p < 0.001), the segmental angle was improved by 4.94° (preoperative = 5.63°, postoperative = 10.58°, p < 0.001), and segmental height increased by 3.1 mm (preoperative = 5.09 mm, postoperative = 8.19 mm, p < 0.001). At 90 days after surgery the authors observed the following: a smaller postoperative sagittal vertical axis was associated with larger changes in back pain at 90 days (r = -0.558, p = 0.013); a larger decrease in spondylolisthesis was associated with greater improvements in ODI and back pain scores (r = -0.425, p = 0.043, and r = -0.43, p = 0.031, respectively); and a larger decrease in pelvic tilt (PT) was associated with greater improvements in back pain (r = -0.548, p = 0.043). For the 1-year PROs, the relationship between the change in PT and changes in ODI and numeric rating scale back pain were significant (r = 0.612, p = 0.009, and r = -0.803, p = 0.001, respectively) with larger decreases in PT associated with larger improvements in ODI and back pain. Overall for this study there was a 96% fusion rate. Fourteen patients were noted to have endplate violation on intraoperative fluoroscopy during placement of the cage. Only 3 of these had progression of their subsidence, with an overall subsidence rate of 6% (3 of 49) visible on postoperative CT. CONCLUSIONS The use of this expandable, articulating, lordotic, or hyperlordotic interbody cage for MIS TLIF provides a significant restoration of segmental height and segmental lordosis, with associated improvements in sagittal balance parameters. Patients treated with this technique had acceptable levels of fusion and significant reductions in pain and disability.

Expectations for Postoperative Improvement in Health-Related Quality of Life in Young Patients With Lumbosacral Spondylolisthesis: A Prospective Cohort Study

STUDY DESIGN

Prospective multicenter study of the changes in Scoliosis Research Society Outcome Questionaire 22 (SRS-22) scores for 78 patients younger than 25 years old surgically treated for lumbosacral spondylolisthesis OBJECTIVE.: Report the change of health-related quality of life (HRQOL) in patients younger than 25 years after surgical treatment of lumbosacral spondylolisthesis.

SUMMARY OF BACKGROUND DATA

There is a paucity of data with regard to the influence of surgical treatment on the HRQOL of patients with lumbosacral spondylolisthesis. Large prospective studies are needed to clearly define the benefits of surgery in the young patient population.

METHODS

A prospective multicenter cohort of 78 patients younger than 25 years (14.8 ± 2.9, range: 7.9-23.6 yr) undergoing posterior fusion for lumbosacral spondylolisthesis were enrolled. There were 17 patients with low-grade (<50%) and 61 with high-grade (≥50%) slips. SRS-22 scores calculated before surgery and after 2 years of follow-up were compared for all patients using two-tailed paired t tests. Subanalyses for low- and high-grade patients were done using two-tailed Wilcoxon signed ranked and paired t tests, respectively. The level of significance was set at 0.05.

RESULTS

HRQOL was significantly improved 2 years after surgery for all domains and for the total score of the SRS-22 questionnaire. The individual total score was improved in 66 patients (85%), and 52 patients (67%) improved by at least 0.5 point. All domains and the total score of the SRS-22 questionnaire were significantly improved for high-grade patients, whereas only pain, function, and total score were improved for low-grade patients.

CONCLUSION

This is the largest study comparing the HRQOL before and after surgery in young patients with low- and high-grade lumbosacral spondylolisthesis. HRQOL significantly improves after surgery for the majority of patients, especially for high-grade patients. This study helps clinicians to better counsel patients with regard to the benefits of surgery for lumbosacral spondylolisthesis.

LEVEL OF EVIDENCE

2.

A systematic review of clinical outcomes in surgical treatment of adult isthmic spondylolisthesis

BACKGROUND CONTEXT

A variety of surgical methods are available for the treatment of adult isthmic spondylolisthesis, but there is no consensus regarding their relative effects on clinical outcomes.

PURPOSE

To compare the effects of different surgical techniques on clinical outcomes in adult isthmic spondylolisthesis.

DESIGN

A systematic review was carried out.

PATIENT SAMPLE

A total of 1,538 patients from six randomized clinical trials (RCTs) and nine observational studies comparing different surgical treatments in adult isthmic spondylolisthesis.

OUTCOME MEASURES

Primary outcome measures of interest included differences in pre- versus postsurgical assessments of pain, functional disability, and overall health as assessed by validated pain rating scales and questionnaires. Secondary outcome measures of interest included intraoperative blood loss, length of hospital stay, surgery duration, reoperation rates, and complication rates.

METHODS

A search of the literature was performed in September 2017 for relevant comparative studies published in the prior 10-year period in the following databases: PubMed, Embase, Web of Science, and ClinicalTrials.gov. Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed and studies were included or excluded based on strict predetermined criteria. Quality appraisal was conducted using the Newcastle-Ottawa scale (NOS) for observational studies and the Cochrane Collaboration risk of bias assessment tool for RCTs. The authors received no funding support to conduct this review.

RESULTS

A total of 15 studies (six RCTs and nine observational studies) were included for full-text review, a majority of which only included cases of low-grade isthmic spondylolisthesis. One study examined the effects of adding pedicle screw fixation (PS) to posterolateral fusion (PLF) and two studies examined the effects of adding reduction to interbody fusion (IF)+PS on clinical outcomes. Five studies compared PLF, four with PS and one without PS, with IF+PS. Additionally, three studies compared circumferential fusion (IF+PS+PLF) with IF+PS and one study compared circumferential fusion with PLF+PS. Three studies compared clinical outcomes among different IF+PS techniques (anterior lumbar IF [ALIF]+PS vs. posterior lumbar IF [PLIF]+PS vs. transforaminal lumbar IF [TLIF]+PS) without PLF. As per the Cochrane Collaboration risk of bias assessment tool, four RCTs had an overall low risk of bias, one RCT had an unclear risk of bias, and one RCT had a high risk of bias. As per the NOS, three observational studies were of overall good quality, four observational studies were of fair quality, and two observational studies were of poor quality.

CONCLUSIONS

Available studies provide strong evidence that the addition of reduction to fusion does not result in better clinical outcomes of pain and function in low-grade isthmic spondylolisthesis. Evidence also suggests that there is no significant difference between interbody fusion (IF+PS) and posterior fusion (PLF±PS) in outcomes of pain, function, and complication rates at follow-up points up to approximately 3 years in cases of low-grade slips. However, studies with longer follow-up points suggest that interbody fusion (IF+PS) may perform better in these same measures at later follow-up points. Available evidence also suggests no difference between circumferential fusion (IF+PS+PLF) and interbody fusion (IF+PS) in outcomes of pain and function in low-grade slips, but circumferential fusion has been associated with greater intraoperative blood loss, longer surgery duration, and longer hospital stays. In terms of clinical outcomes, insufficient evidence is available to assess the utility of adding PS to PLF, the relative efficacy of different interbody fusion (IF+PS) techniques (ALIF+PS vs. TLIF+PS vs. PLIF+PS), and the relative efficacy of circumferential fusion and posterior fusion (PLF+PS).

Spinal Biologics in Minimally Invasive Lumbar Surgery

As the use of minimally invasive spine (MIS) fusion approaches continues to grow, increased scrutiny is being placed on its outcomes and efficacies against traditional open fusion surgeries. While there are many factors that contribute to the success of achieving spinal arthrodesis, selecting the optimal fusion biologic remains a top priority. With an ever-expanding market of bone graft substitutes, it is important to evaluate each of their use as it pertains to MIS techniques. This review will summarize the important characteristics and properties of various spinal biologics used in minimally invasive lumbar surgeries and compare their fusion rates via a systematic review of published literature.

Risk Factors Associated With Failure to Reach Minimal Clinically Important Difference in Patient-reported Outcomes Following Minimally Invasive Transforaminal Lumbar Interbody Fusion for Spondylolisthesis

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To determine risk factors associated with failure to reach the minimal clinically important difference (MCID) in patient-reported outcomes (PROs) for patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) for spondylolisthesis.

SUMMARY OF BACKGROUND DATA

The MCID of PROs are often utilized to determine the benefit of spinal procedures. However, negative predictive factors for reaching MCID in patients surgically treated for lumbar spondylolisthesis have been difficult to elucidate.

MATERIALS AND METHODS

A prospectively maintained surgical database of patients who were diagnosed with lumbar spondylolisthesis and surgically treated with a single level MIS TLIF from 2010 to 2016 was reviewed. Patients with incomplete PRO survey data or <6-month follow-up were excluded from the analysis. MCID for visual analogue scale (VAS) back, VAS leg, and Oswestry Disability Index (ODI) was obtained from established values in the literature. All risk factors were then assessed for association with failure to reach MCID using bivariate and multivariate regression adjusting for preoperative characteristics.

RESULTS

A total of 165, 76, and 73 patients treated with MIS TLIF for spondylolisthesis had complete PRO data for VAS back, VAS leg, and ODI, respectively, and were thus included in the analysis for the respective PRO. Overall, 75.76%, 71.05%, and 61.64% of patients treated with a single level MIS TLIF for spondylolisthesis reached MCID for VAS back, VAS leg, and ODI, respectively. On multivariate analysis, patients were less likely to achieve MCID for VAS back following surgical treatment if they received workers' compensation (P<0.001). No other measured factors were noted to independently correlate with MCID achievement.

CONCLUSIONS

The results of this study suggest that a majority of patients with spondylolisthesis achieve MCID for commonly measured PROs following MIS TLIF for spondylolisthesis. However, worker's compensation insurance status may serve as a negative predictive factor for reaching MCID.

Which is the optimum surgical strategy for spondylolisthesis: Reduction or fusion in situ? A meta-analysis from 12 comparative studies

PURPOSE

To compare the clinical outcomes and complications and radiographic outcomes of the two different surgical strategies (arthrodesis in situ and arthrodesis following reduction) for the surgical management of spondylolisthesis.

METHODS

After systematic search the PubMed, Ovid MEDLINE, Cochrane, and Embase databases, comparative studies were selected according to eligibility criteria. Checklists by Furlan and by The Newcastle-Ottawa quality assessment scale (NOS scale) were used to evaluate the risk of bias of the included randomized clinical trials (RCTs) and nonrandomized controlled studies, respectively. The final strength of evidence was expressed as different levels recommended by the GRADE Working Group.

RESULTS

Three RCTs. and nine comparative observational studies were identified. Low-quality evidence indicated that reduction group (RG) was not more effective than fusion in situ group for clinical satisfaction (OR 0.77, 95% CI 0.39-1.54, P = 0.46). and neurologic complication rate (OR 0.89, 95 CI 0.38-2.03, P = 0.78). In secondary outcomes, Low-quality evidence indicated that RG improved fusion rate (OR 2.66, 95% CI 1.15-6.14, P = 0.02). There was no significant difference in the other complication rate (OR 0.89, 95% CI 0.44-1.79, P = 0.63) and blood loss (WMD 14.22, 95% CI -9.53-37.79, P = 0.24) between two groups. Statistical difference was found between the two groups with regard to slipping angle (WMD -6.33, 95% CI -12.60 to -0.06, P = 0.05).

CONCLUSIONS

There was no definite benefit of reduction over fusion in situ in clinical satisfaction rate and neurologic complication rate. The fusion rate significantly improved while the slipping angle considerably decreased postoperation in reduction group.

Significant reduction of fluoroscopy repetition with lumbar localization system in minimally invasive spine surgery: A prospective study

The conventional location methods for minimally invasive spinal surgery (MISS) were mainly based on repeated fluoroscopy in a trial-and-error manner preoperatively and intraoperatively. Localization system mainly consisted of preoperative applied radiopaque frame and intraoperative guiding device, which has the potential to minimize fluoroscopy repetition in MISS. The study aimed to evaluate the efficacy of a novel lumbar localization system in reducing radiation exposure to patients.Included patients underwent minimally invasive transforaminal lumbar interbody fusion (MISTLIF) or percutaneous transforaminal endoscopic discectomy (PTED). Patients treated with novel localization system were regarded as Group A, and patients treated without novel localization system were regarded as Group B.For PTED, The estimated effective dose was 0.41 ± 0.13 mSv in Group A and 0.57 ± 0.14 mSv in Group B (P < .001); the fluoroscopy exposure time of PTED was 22.18 ± 7.30 seconds in Group A and 30.53 ± 7.56 seconds in Group B (P < .001); The estimated cancer risk of radiation exposure was 22.68 ± 7.38 (10) in Group A and 31.20 ± 7.96 (10) in Group B (P < .001). For MISTLIF, the estimated effective dose was 0.45 ± 0.09 mSv in Group A and 0.58 ± 0.09 mSv in Group B (P < .001); The fluoroscopy exposure time was 25.41 ± 5.52 seconds in Group A and 32.82 ± 5.03 seconds in Group B (P < .001); The estimated cancer risk was 24.90 ± 5.15 (10) in Group A and 31.96 ± 5.04 (10) in Group B (P < .001). There were also significant differences in localization time and operation time between the 2 groups either for MISTLIF or PTED.The lumbar localization system could be a potential protection strategy for minimizing radiation hazards.

Clinical outcomes after minimally invasive transforaminal lumbar interbody fusion and lateral lumbar interbody fusion for treatment of degenerative lumbar disease: a systematic review and meta-analysis

The surgical procedures used for arthrodesis in the lumbar spine for degenerative lumbar diseases remain controversial. This systematic review aims to assess and compare clinical outcomes along with the complications and fusion of each technique (minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) or minimally invasive lateral lumbar interbody fusion (MIS LLIF)) for treatment of degenerative lumbar diseases. Relevant studies were identified from Medline and Scopus from inception to July 19, 2016 that reported Oswestry Disability Index (ODI), back and leg pain visual analog score (VAS), postoperative complications, and fusion of either technique. Fifty-eight studies were included for the analysis of MIS-TLIF; 40 studies were included for analysis of LLIF, and 1 randomized controlled trial (RCT) study was included for comparison of MIS-TLIF to LLIF. Overall, there were 9506 patients (5728 in the MIS-TLIF group and 3778 in the LLIF group). Indirect meta-analysis, MIS-TLIF provided better postoperative back and leg pain (VAS), disabilities (ODI), and risk of having complications when compared to LLIF technique, but the fusion rate was not significantly different between the two techniques. However, direct meta-analysis between RCT study and pooled indirect meta-analysis of MIS-TLIF have better pain, disabilities, and complication but no statistically significant difference when compared to LLIF. In LLIF, the pooled mean ODI and VAS back pain were 2.91 (95% CI 2.49, 3.33) and 23.24 (95% CI 18.96, 27.51) in MIS approach whereas 3.14 (95% CI 2.29, 4.04) and 28.29 (95% CI 21.92, 34.67) in traditional approach. In terms of complications and fusion rate, there was no difference in both groups. In lumbar interbody fusion, MIS-TLIF had better ODI, VAS pain, and complication rate when compared to LLIF with direct and indirect meta-analysis methods. However, in terms of fusion rates, there were no differences between the two techniques.

Is reduction better than arthrodesis in situ in surgical management of low-grade spondylolisthesis? A system review and meta analysis

PURPOSE

To compare the clinical and radiographic outcomes of arthrodesis in situ with arthrodesis after reduction in low-grade spondylolisthesis.

METHODS

We performed a comprehensive search of both observational and randomized clinical trials published up to April 2016 in PubMed, MEDLINE, Cochrane Library, and Embase databases. The outcomes included age, sex, operative time, blood loss, and at least 2 years clinical results of Oswestry disability index (ODI), visual analogue scale (VAS), lumbar lordosis, slippage, fusion rate, the rate of good and excellent and the complication rate. Two authors independently extracted the articles and the predefined data.

RESULTS

Seven eligible studies, involving four RCTs and three cohort studies were included in this systematic review and meta-analysis. Patients who underwent reduction did achieved better slippage correction comparing with arthrodesis in situ (P < 0.00001). However, there was no significant difference in the case of operative time, blood loss, VAS (P = 0.36), ODI (P = 0.50), lumbar lordosis (P = 0.47), the rate of good and excellent (P = 0.84), fusion rate (P = 0.083) and complication rate (P = 0.33) between the arthrodesis in situ group and the reduction group.

CONCLUSIONS

On the basis on this review, arthrodesis after reduction of low-grade spondylolisthesis potentially reduced vertebral slippage. Reduction was neither associated with a longer operative time nor more blood loss. There was no significant difference in the outcomes between reduction and arthrodesis in situ group. Both procedures could be expected to achieve good clinical result.

LEVEL OF EVIDENCE

Therapeutic Level IIa.