Current Status of Lumbar Interbody Fusion for Degenerative Spondylolisthesis

MRI changes of adjacent segments after transforaminal lumbar interbody fusion (TLIF) and foraminal endoscopy: A case-control study

BACKGROUND

Intervertebral foramen endoscopy has developed rapidly, but compared with transforaminal lumbar interbody fusion (TLIF), the progress of degeneration is unknown. We aim to compare the changes of intervertebral disc and intervertebral foramen in adjacent segments after TLIF and endoscopic discectomy for patients with lumbar disc herniation (LDH).

METHODS

From 2014 to 2017, 87 patients who were diagnosed with single-level LDH and received surgery of TLIF (group T, n = 43) or endoscopic discectomy (group F, n = 44) were retrospectively analyzed. X-ray, MRI, CT and clinical symptoms were recorded before operation and at the last follow-up (FU). The neurological function was originally evaluated by the Japanese Orthopaedic Association (JOA) scores. Radiological evaluation included the height of intervertebral space (HIS), intervertebral foramen height (FH), intervertebral foramen area (FA), lumbar lordosis (CA) and intervertebral disc degeneration Pfirrmann scores.

RESULTS

There was no significant difference in baseline characteristics, JOA improvement rate, reoperation rate and complications between the two groups. The age, average blood loss, average hospital stays and average operation time in group F were lower than those in group T. During the last FU, HIS, CA and FA decreased in both groups, and the changes in group T were more significant than those in group F (P < .05). There was no significant difference in FH changes between the two groups (P > .05).

CONCLUSION

Both TLIF and endoscopic surgery can achieve good results in the treatment of LDH, but the risk of lumbar disc height loss and intervertebral foramina reduction in the adjacent segment after endoscopic surgery is lower.

Instrumented Versus Noninstrumented Spinal Fusion for Degenerative Lumbar Spondylolisthesis: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVE

This systematic review compares radiographic and clinical outcomes between instrumented and noninstrumented posterolateral lumbar spine fusions for the treatment of degenerative lumbar spondylolisthesis.

SUMMARY OF BACKGROUND DATA

The optimal method of fusion for instability from degenerative lumbar spondylolisthesis remains to be an area of debate amongst spine surgeons. There are no prior comprehensive systematic review of comparative studies that compares outcomes between instrumented and noninstrumented posterolateral spine fusions for the treatment of degenerative lumbar spondylolisthesis.

MATERIALS AND METHODS

A systematic review was registered with PROSPERO and performed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using the PubMed, SCOPUS, and Ovid MEDLINE databases. All level I-III comparative studies published in the English language investigating the clinical outcomes between instrumented and noninstrumented posterolateral spine fusions for the treatment of degenerative lumbar spondylolisthesis were included.

RESULTS

Seven studies (672 patients, 274 noninstrumented, 398 instrumented) were analyzed. One randomized study was level I evidence, 2 randomized studies were level II, and 4 nonrandomized studies were level III. Mean follow-up ranged from 1.4 to 5.9 years. Instrumented patients had a higher rate of solid fusion (87.6% vs. 77.1%, P=0.023) and a lower rate of definitive pseudarthrosis (5.3% vs. 19.9%, P<0.001). However, there was no difference in overall functional improvement at final follow-up between the 2 treatment groups (75.0% vs. 81.7%, P=0.258). In addition, there was no difference in reoperation or complication rates.

CONCLUSIONS

For the treatment of degenerative lumbar spondylolisthesis, there are significantly higher rates of fusion among patients undergoing instrumented posterolateral fusion compared with noninstrumented posterolateral fusion. However, there is no difference in overall functional improvement, pain-related outcome scores, reoperation rates, or complication rates between the 2 treatment groups.

LEVEL OF EVIDENCE

Level III-systematic review of level I-III studies.

Prevalence and risk factors for cage subsidence after lumbar interbody fusion: A protocol for systematic review and meta-analysis

INTRODUCTION

Lumbar interbody fusion (LIF) is an effective treatment for lumbar degenerative diseases. Cage subsidence (CS) contitutes one of the most common postoperative complications. Many risk factors for CS after LIF have been reported in some studies. However, controversies still exist. The objective of this study will be to summarize data on the prevalence and risk factors of CS after LIF.

METHODS AND ANALYSIS

Our study present a protocol that conducted a systematic review and meta-analysis of prevalence and risk factors for CS after LIF. Two reviewers retrieved the relevant articles using the 5 databases (PubMed, Scopus, EMBASE, Cochrane Library, and Web of Science) from inception to May 31st, 2021. Primary outcome will be the prevalence of CS after LIF. Second outcomes include the risk factors associated with postoperative CS and clinical outcomes associated with postoperative CS. Three reviewers will screen citation titles and abstracts and evaluated full-text of each potentially relevant citation, and then extracted the data using a data extraction form. Any discrepancies in decisions between reviewers will be resolved through discussion. We assessed the methodological quality and risk of bias of the included studies based on the Newcastle-Ottawa Quality Assessment Scale (NOS). The aim of the extra analysis is to explore the explanations of the heterogeneity (age, gender, race, year of publication, type of study and surgical procedure). Publication bias will be assessed by Begg test, Egger test and funnel plots.

ETHICS AND DISSEMINATION

No primary data will be collected and individual patient information and endangering participant rights, thus ethics approval is not required. Findings will be reported through publication and media.

PROTOCOL REGISTRATION NUMBER

PROSPERO CRD42021257981 (https://www.crd.york.ac.uk/PROSPERO/#joinuppage).

Caudad Insertion of Pedicle Screws Facilitates Interbody Distraction During Spondylolisthetic Vertebrae Restoration: A Retrospective Study

INTRODUCTION

Based on the results of long-term clinical and radiological follow-up studies of decompression and fusion with internal fixation for degenerative lumbar spondylolisthesis (DLS), we recognized that the direction of the pedicle screw affects the stability of the fixation. However, few studies have analyzed the role of pedicle screw insertion trajectory in disc height recovery after fusion. We therefore analyzed patients' general information, clinical efficacy and sagittal, coronal and implant parameters to determine whether there is a correlation between the insertion trajectory of screws and the recovery of intervertebral space height, with the ultimate aim to provide a basis for improving the clinical efficacy and radiological outcomes of patients with DLS and to identify an optimal technique for spine surgeons that would benefit patients with spondylolisthesis.

METHODS

From May 2015 to October 2019, patients who underwent single-segment decompression and fusion with internal fixation for DLS at our department were screened for enrollment in the study. The clinical history, pre- and post-operative lumbar sagittal parameters, intervertebral height, rate of recovery from spondylolisthesis and pedicle screw angle of inpatients were recorded and followed up for at least 6 months. Clinical assessments included the Oswestry Disability Index (ODI) and the Visual Analogue Scale (VAS) for lower back and leg pain. Data on screw angle, fusion segment intervertebral space height and clinical outcome were the primary outputs. Pearson correlation and multivariate regression analyses were performed to investigate the relationship between the pedicle screw angle, the sagittal parameters of the fusion segment and clinical efficacy.

RESULTS

A total of 50 patients were initially enrolled, two patients were lost to follow-up after 6 months, 48 patients (17 men, 31 women) were eventually enrolled, and the follow-up rate was 96%. At least 6 months after the operation, vertebral spondylolisthesis improved to varying degrees [> 80% in 17 cases (35.4%) and > 20% in 43 cases (87.5%), respectively]. Changes in disc height (DH) were significantly associated with lower pedicle screw angle, while lumbar lordosis and segment lordosis remained the same. Multivariate regression analysis showed a significant negative correlation between the upper and lower pedicle screw angles and the change in DH (P < 0.05). At 2 weeks post-operation, the VAS score for low back pain and the ODI had improved significantly compared to pre-operation (P < 0.05).

CONCLUSIONS

These results suggest that the Caudad insertion trajectory technique of pedicle screws may be an ideal alternative for the treatment of DLS.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry (ChiCTR): ChiCTR1800020368.

CURRENT RESULTS OF CONVENTIONAL LUMBAR ARTHRODESIS

ABSTRACT Objective: To evaluate the peri- and postoperative results and clinical repercussions in patients undergoing decompression surgery and single-level lumbar arthrodesis using the traditional technique (OTLIF) and to compare with the results of minimally invasive techniques (MITLIF) described in the literature. Methods: Our sample consisted of 22 patients who underwent TLIF surgery using the open technique (OTLIF) in the period October 2019 to January 2021, in our hospital. We compared the patients’ functional clinical results using the Oswestry scale in the preoperative period and 15 days after surgery, analyzed variables related to the perioperative period: surgery time, length of hospital stay, blood loss, use of a suction drain, and admission to the ICU, and compared these with the results reported in the literature for patients treated by the MITLIF technique. Results: The average age was 48.95 years and the most operated level was L4-L5 (55%). The average surgery time was 112.63 min. We did not use a suction drain in the postoperative period, there was no need for a blood transfusion in any patient, and no patient was admitted to the ICU. The average hospital stay was 1 day. Regarding the Oswestry Disability Index, the mean preoperative score was 44.73 and after 15 days, it was 24.05. Conclusions: surgical treatment using the OTLIF technique for single-level lumbar degenerative disease showed largely positive results, with improvement in disability scores, short hospital stay and low incidence of complications. When properly indicated, OTLIF is an excellent and safe option for the treatment of degenerative lumbar disease. Level of evidence IV; Case series study.

Resident Involvement in Posterior Lumbar Interbody Fusion is Associated With Increased Readmissions and Operative Time, But No Increased Short-term Risks

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

The aim was to compare rates of adverse events and additional posterior lumbar interbody fusion (PLIF) cases assisted by residents versus cases performed solely by an orthopedic attending.

SUMMARY OF BACKGROUND DATA

PLIF is a widely accepted surgical technique for the management of a variety of spinal conditions requiring spinal stabilization and fusion. However, no published studies have assessed the effects of resident involvement on intraoperative and postoperative outcomes in PLIF.

METHODS

This retrospective study utilized the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) registry from 2007 to 2012 to identify patients who underwent PLIF procedures. A propensity score matching model was utilized to reduce patient cohort variances. The perioperative data and outcomes in the matched population were analyzed using paired t test and the McNemar test in order to assess, based on resident presence, the rates of postoperative adverse events, readmission, reoperation within 30 days, and operative time.

RESULTS

In total, 1633 patients undergoing PLIF were included in the study, with 24.62% involving resident participation. The propensity score matching algorithm yielded 396 well-matched resident and nonresident pairs. Patients undergoing PLIF involving a resident were associated with a higher rate of readmission (1.77% vs. 0.00%; P=0.008), and longer operative time (245.7 vs. 197.7 min; P<0.001). However, these procedures were not associated with any significant difference in minor or severe adverse events.

CONCLUSIONS

Resident involvement in PLIF was associated with an increased rate of readmissions, and operative time; however, was not associated with an increase in minor or severe adverse events. Further investigation is needed to characterize the role of resident involvement based on level of training experience, as well as methods to improve the learning curve to independence while reducing postoperative hospital length of stay.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Lumbar facet distraction and fixation in patients with lumbar spinal stenosis: Long-term clinical outcome and reoperation rates

Objective:

Symptomatic lumbar spinal stenosis (LSS) unresponsive to conservative therapy is commonly treated by surgical decompression. In this study, we compared clinical outcomes after decompressive surgery for LSS in patients implanted with interarticular spacers along with microdecompression (MD) with those receiving only MD.

Methods:

A retrospective study was analyzed 40 patients (Group A) affected by LSS treated by MD and implant of interarticular spacers comparing the outcome with a homogeneous group of 40 patients with LSS treated with MD alone (Group B). Clinical outcome was evaluated using the Oswestry Disability Index (ODI) and visual analog scale (VAS) scores, as well as Macnab's criteria.

Results:

At 1-year follow-up, ODI improved in both groups with statistically significant differences as compared to baseline and both Groups (P < 0.05). Statistically significant differences were observed at 3-year follow-up (P < 0.05), without further variation at 5-year follow-up. At 1-year follow-up, VAS for back and leg pain scores was significantly better than that of Group B (P < 0.05). At 3-year follow-up, back and leg pain scores were no longer significantly improved (P > 0.01), resulting almost the same at 5-year follow-up. A comparison of functional outcomes between the groups showed significant improvements in Group A as compared to Group B (P < 0.05). The reoperation rate was 10% in Group A and 30% in Group B. In implanted patients, successful fusion was obtained in 90% of the cases.

Conclusions:

Interarticular spacers showed significant and clinically meaningful improvements in pain and disability, even in a long follow-up.

Top 100 Cited Articles on Spinal Disc Arthroplasty Research

STUDY DESIGN

A bibliometric review of current literature.

OBJECTIVE

The purpose of this study was to identify and analyze the 100 most cited articles in spinal disc arthroplasty (SDA) research.

SUMMARY OF BACKGROUND DATA

In the last several decades, SDA has been widely performed all over the world, with increasing popularity of cervical disc arthroplasty (CDA). While there is a large number of articles on this topic, to our knowledge, there is no bibliometric analysis yet.

METHODS

All databases from the Web of Science were searched in a three-step approach. The information of the 100 most cited studies was collected, including title, first and last author, year of publication, journal, total citations, geographic origin, subspecialty, and types of artificial intervertebral disc for further analysis.

RESULTS

The 100 most-cited articles were published from 1966 to 2015 in 9 different journals and were cited from 66 to 346 times. A total of 11 countries contributed to the 100 articles and the United States topped the list, with 54 articles, followed by Germany and France, with 10 and nine articles, respectively. There were more studies in CDA (n = 53) than lumbar disc arthroplasty (n = 35). Most of the studies reported clinical and radiographic outcomes (n = 33). The most productive periods were from 2006 to 2010. The majority of publications were in Spine, which published 43 articles. In total, 12 authors published more than two articles on the list.

CONCLUSION

Of the top 100 most cited articles on SDA, cervical papers outnumbered lumbar articles and the United States had 55 articles, with no other countries having more than 10. Our paper can help readers determine which of the thousands of articles on this topic are the most impactful and important ones to be familiar with.

LEVEL OF EVIDENCE

3.

The limited area decompression, intervertebral fusion, and pedicle screw fixation for treating degenerative lumbar spinal stenosis with instability: Follow-up at least 12 months an observational study

The aim of the study was to evaluate the clinical effect of the limited area decompression, intervertebral fusion, and pedicle screw fixation for treating degenerative lumbar spinal stenosis (DLSS) with instability. Hemilaminectomy decompression, intervertebral fusion, and pedicle screw fixation for treating DLSS with instability as the control group.Follow-up of 54 patients (26 males and 28 females; average age, 59.74 ± 10.38 years) with DLSS with instability treated by limited area decompression, intervertebral fusion, and pedicle screw fixation (LIFP group), and 52 patients as control group with hemilaminectomy decompression, intervertebral fusion, and pedicle screw fixation (HIFP group). We assessed clinical effect according to the patients' functional outcome grading (good to excellent, fair, or poor), Oswestry Disability Index (ODI) and visual analogue scale (VAS) for low back pain and lower limb pain, which was administered preoperatively and at 3, 6, and 12 months postoperatively. Fusion status was assessed by radiologists at the last follow-up. Treatment satisfaction was assessed according to the subjective evaluations of the patients.At the 12-month follow-up, 96.2% (52/54) and 90.3% (47/52) of group LIFP and HIFP belonged to good to excellent outcome categories, respectively, while 3.7% (2/54) and 9.6% (5/52) of group LIFP and HIFP belonged to fair respectively, neither group belonged to poor. Satisfaction rates of patients in group LIFP and group HIFP were 98.1% (53/54) and 92.3% (48/52), respectively. The patients' functional outcome grading and satisfaction rate in group LIFP were better than that in group HIFP. The VAS for low back and lower limb pain and the ODI improved significantly during the 12 months after surgery (all P < .001) in 2 groups. The VAS for low back and lower limb pain were no difference between two groups, however, the ODI of group LIFP was lower than that of group HIFP (P < .001). All patients achieved radiological fusion.The limited area decompression, intervertebral fusion, and pedicle screw fixation had a satisfactory effect on patients with DLSS with instability.

Transforaminal Lumbar Interbody Fusion For Lumbar Degenerative Disease: Patient Selection And Perspectives

Most adults will experience low back pain during their lifetime, with most of these instances resolving or improving without sequelae in a few weeks. For the small number of patients with severe, recalcitrant pain, lumbar fusion may be required, particularly when concomitant leg pain or deformity is present. Lumbar interbody fusion surgery is the usual treatment for degenerative lumbar disease, but it requires a long recovery period. Many surgical techniques have been described in the literature for spondylolisthesis. The main objective is to create interbody fusion, decompression of normal structures and a stable vertebrae. TLIF surgical techniques has a long learning curve. Comorbidities of the patient may make surgery more difficult. Methods such as transforaminal lumbar interbody fusion (TLIF), posterior lumbar interbody fusion, anterior lumbar interbody fusion and lateral lumbar interbody fusion are also available for interbody fusion in the literatüre. The aim of this review is to show which patients are more suitable for TLIF surgery and to discuss the advantages and disadvantages of TLIF surgery over other techniques.

Conventional Versus Stereotactic Image-guided Pedicle Screw Placement During Posterior Lumbar Fusions: A Retrospective Propensity Score-matched Study of a National Longitudinal Database

STUDY DESIGN

Retrospective 1:1 propensity score-matched analysis on a national longitudinal database between 2007 and 2016.

OBJECTIVE

The aim of this study was to compare complication rates, revision rates, and payment differences between navigated and conventional posterior lumbar fusion (PLF) procedures with instrumentation.

SUMMARY OF BACKGROUND DATA

Stereotactic navigation techniques for spinal instrumentation have been widely demonstrated to improve screw placement accuracies and decrease perforation rates when compared to conventional fluoroscopic and free-hand techniques. However, the clinical utility of navigation for instrumented PLF remains controversial.

METHODS

Patients who underwent elective laminectomy and instrumented PLF were stratified into "single level" and "3- to 6-level" cohorts. Navigation and conventional groups within each cohort were balanced using 1:1 propensity score matching, resulting in 1786 navigated and conventional patients in the single-level cohort and 2060 in the 3 to 6 level cohort. Outcomes were compared using bivariate analysis.

RESULTS

For the single-level cohort, there were no significant differences in rates of complications, readmissions, revisions, and length of stay between the navigation and conventional groups. For the 3- to 6-level cohort, length of stay was significantly longer in the navigation group (P < 0.0001). Rates of readmissions were, however, greater for the conventional group (30-day: P = 0.0239; 90-day: P = 0.0449). Overall complications were also greater for the conventional group (P = 0.0338), whereas revision rate was not significantly different between the 2 groups. Total payments were significantly greater for the navigation group in both the single level and 3- to 6-level cohorts (P < 0.0001).

CONCLUSION

Although use of navigation for 3- to 6-level instrumented PLF was associated with increased length of stay and payments, the concurrent decreased overall complication and readmission rates alluded to its potential clinical utility. However, for single-level instrumented PLF, no differences in outcomes were found between groups, suggesting that the value in navigation may lie in more complex procedures.

LEVEL OF EVIDENCE

3.

The Influence of Conflicts of Interest on Outcomes in the Lumbar Disc Arthroplasty Literature: A Systematic Review

STUDY DESIGN

A systematic review.

OBJECTIVE

The aim of this study was to determine the association between study outcomes and the presence of a conflict of interest (COI) in the lumbar disc arthroplasty (LDA) literature.

SUMMARY OF BACKGROUND DATA

Previous studies have evaluated the efficacy of LDA as a surgical alternative to arthrodesis. As investigators may have financial relationships with LDA device companies, it is important to consider the role of COI on study outcomes.

METHODS

A systematic review was performed to identify articles reporting clinical outcomes of LDA. Any financial COIs disclosed were recorded and confirmed through Open Payments and ProPublica databases. Study outcomes were graded as favorable, unfavorable, or equivocal. Pearson Chi-squared analysis was used to determine an association between COI and study outcomes. Favorable outcomes were tested for an association with study characteristics using Poisson regression with robust error variance.

RESULTS

Fifty-seven articles were included, 30 had a financial COI, while 27 did not. Ninety percent of the conflicted studies disclosed their COI in the article. Studies with United States authors were more likely to be conflicted (P = 0.019). A majority of studies reported favorable outcomes for LDA (n = 39). Conflicted studies were more likely to report favorable outcomes than nonconflicted studies (P = 0.020). Articles with COIs related to consultant fees (P = 0.003), research funding (P = 0.002), and stock ownership (P < 0.001) were more likely to report favorable outcomes.

CONCLUSION

This study highlights the importance for authors to accurately report conflicting relationships with industry. As such, orthopedic surgeons should critically evaluate study outcomes with regard to potential conflicts before recommending LDA as a surgical option to their patients.

LEVEL OF EVIDENCE

3.

A UK-based pilot study of current surgical practice and implant preferences in lumbar fusion surgery

Lumbar fusion surgery is an established procedure for the treatment of low back pain. Despite the wide set of alternative fusion techniques and existing devices, uniform guidelines are not available yet and common surgical trends are scarcely investigated.The purpose of this UK-based study was to provide a descriptive portrait of current surgeons' practice and implant preferences in lumbar fusion surgery.A UK-based in-person survey was designed for this study and submitted to a group of consultant spinal surgeons (n = 32). Fifteeen queries were addressed based on different aspects of surgeons' practice: lumbar fusion techniques, implant preferences, and bone grafting procedures. Answers were analyzed by means of descriptive statistics.Thirty-two consultant spinal surgeons completed the survey. There was clear consistency on the relevance of a patient-centered management (82.3%), along with a considerable variability of practice on the preferred fusion approach. Fixation surgery was found to be largely adopted (96.0%) and favored over stand-alone cages. With regards to the materials, titanium cages were the most used (54.3%). The geometry of the implants influenced the choice of lumbar cages (81.3%). Specifically, parallel-shape cages were mostly avoided (89.2%) and hyperlordotic cages were preferred at the lower lumbar levels. However, there was no design for lumbar cages which was consistently favored. Autograft bone graft surgeries were the most common (60.0%). Amongst the synthetic options, hydroxyapatite-based bone graft substitutes (76.7%) in injectable paste form (80.8%) were preferred.Current lumbar fusion practice is variable and patient-oriented. Findings from this study highlight the need for large-scale investigative surveys and clinical studies aimed to set specific guidelines for certain pathologies or patient categories.