Patient-reported and radiographic outcomes of minimally invasive transforaminal lumbar interbody fusion for degenerative spondylolisthesis with or without reduction: A comparative study

Clinical effectiveness of reduction and fusion versus in situ fusion in the management of degenerative lumbar spondylolisthesis: a systematic review and meta-analysis

PURPOSE

To compare the clinical effectiveness of reduction and fusion with in situ fusion in the management of patients with degenerative lumbar spondylolisthesis (DLS).

METHODS

The systematic review was conducted following the PRISMA guidelines. Relevant studies were identified from PubMed, Embase, Scopus, Cochrane Library, ClinicalTrials.gov, and Google Scholar. The inclusion criteria were: (1) comparative studies of reduction and fusion versus in situ fusion for DLS patients, (2) outcomes reported as VAS/NRS, ODI, JOA score, operating time, blood loss, complication rate, fusion rate, or reoperation rate, (3) randomized controlled trials and observational studies published in English from the inception of the databases to January 2023. The exclusion criteria included: (1) reviews, case series, case reports, letters, and conference reports, (2) in vitro biomechanical studies and computational modeling studies, (3) no report on study outcomes. The risk of bias 2 (RoB2) tool and the Newcastle-Ottawa scale was conducted to assess the risk of bias of RCTs and observational studies, respectively.

RESULTS

Five studies with a total of 704 patients were included (375 reduction and fusion, 329 in situ fusion). Operating time was significantly longer in the reduction and fusion group compared to in situ fusion group (weighted mean difference 7.20; 95% confidence interval 0.19, 14.21; P = 0.04). No additional significant intergroup differences were noted in terms of other outcomes analyzed.

CONCLUSION

While the reduction and fusion group demonstrated a statistically longer operating time compared to the in situ fusion group, the clinical significance of this difference was minimal. The findings suggest no substantial superiority of lumbar fusion with reduction over without reduction for the management of DLS.

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.

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.

Posterior Oblique Square Decompression with a Three-Step Wanding Technique in Tubular Minimally Invasive Transforaminal Lumbar Interbody Fusion: Technical Report and Mid-Long-Term Clinical Outcomes

Although minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is the most common procedure in minimally invasive spine stabilization (MISt), details of the technique remain unclear. This technical report shows the mid-long-term clinical outcomes in patients who underwent posterior oblique square decompression (POSDe) with the three-step wanding technique of tubular MIS-TLIF for degenerative lumbar disease. Tubular MIS-TLIF (POSDe) was performed on 50 patients (males, 19; age, 69.2 ± 9.6 years), and traditional open surgery was performed (OS) on 27 (males, 4; age, 67.9 ± 6.6 years). We evaluated the clinical outcomes using the Visual Analog Scale for back pain, Japanese Orthopedic Association (JOA) scores, and JOA Back Pain Evaluation Questionnaire. We also assessed the fusion rate using the Bridwell grading system with computed tomography or plain radiography for at least 2 years postoperatively. Although there was no significant difference in the improvement rate of JOA scores between the two groups, the mean operation time and blood loss were significantly lower with MIS-TLIF than with OS. In the tubular MIS-TLIF group, there were no cases of deep wound infection; four cases had a pseudarthrosis, two had dural injury, and three had cage retropulsion. We revealed good clinical outcomes in patients who underwent POSDe.

Clinical outcomes, complications and fusion rates in endoscopic assisted intraforaminal lumbar interbody fusion (iLIF) versus minimally invasive transforaminal lumbar interbody fusion (MI-TLIF): systematic review and meta-analysis

This meta-analysis aims to determine the clinical outcomes, complications, and fusion rates in endoscopic assisted intra-foraminal lumbar interbody fusion (iLIF) and minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) for lumbar degenerative diseases. The MEDLINE, Embase, and Cochrane Library databases were searched. The inclusion criteria were: five or more consecutive patients who underwent iLIF or MI-TLIF for lumbar degenerative diseases; description of the surgical technique; clinical outcome measures, complications and imaging assessment; minimum follow-up of 12 months. Surgical time, blood loss, and length of hospital stay were extracted. Mean outcome improvements were pooled and compared with minimal clinically important differences (MCID). Pooled and direct meta-analysis were evaluated. We identified 42 eligible studies. The iLIF group had significantly lower mean intra-operative blood loss, unstandardized mean difference (UMD) 110.61 mL (95%CI 70.43; 150.80; p value < 0.0001), and significantly decreased length of hospital stay (UMD 2.36; 95%CI 1.77; 2.94; p value < 0.0001). Visual analogue scale (VAS) back, VAS leg and Oswestry disability index (ODI) baseline to last follow-up mean improvements were statistically significant (p value < 0.0001), and clinically important for both groups (MCID VAS back > 1.16; MCID VAS leg > 1.36; MCID > 12.40). There was no significant difference in complication nor fusion rates between both cohorts. Interbody fusion using either iLIF or MI-TLIF leads to significant and clinically important improvements in clinical outcomes for lumbar degenerative diseases. Both procedures provide high rates of fusion at 12 months or later, without significant difference in complication rates. iLIF is associated with significantly less intraoperative blood loss and length of hospital stay.

Study registration: PROSPERO international prospective register of systematic reviews: Registration No. CRD42020180980, accessible at https://www.crd.york.ac.uk/prospero/ April 2020.

Posterior fixation can further improve the segmental alignment of lumbar degenerative spondylolisthesis with oblique lumbar interbody fusion

Background

For patients with degenerative spondylolisthesis, whether additional posterior fixation can further improve segmental alignment is unknown, compared with stand-alone cage insertion in oblique lumbar interbody fusion (OLIF) procedure. The aim of this study was to compare changes of the radiographical segmental alignment following stand-alone cage insertion and additional posterior fixation in the same procedure setting of OLIF for patients with degenerative spondylolisthesis.

Methods

A retrospective observational study. Selected consecutive patients with degenerative spondylolisthesis underwent OLIF procedure from July 2017 to August 2019. Five radiographic parameters of disc height (DH), DH-Anterior, DH-Posterior, slip ratio and segmental lordosis (SL) were measured on preoperative CT scans and intraoperative fluoroscopic images. Comparisons of those radiographic parameters prior to cage insertion, following cage insertion and following posterior fixation were performed.

Results

A total of thirty-three patients including six males and twenty-seven females, with an average age of 66.9 ± 8.7 years, were reviewed. Totally thirty-six slipped levels were assessed with thirty levels at L4/5, four at L3/4 and two at L2/3. Intraoperatively, with only anterior cage support, DH was increased from 8.2 ± 1.6 mm to 11.8 ± 1.7 mm (p < 0.001), DH-Anterior was increased from 9.6 ± 2.3 mm to 13.4 ± 2.1 mm (p < 0.001), DH-Posterior was increased from 6.1 ± 1.9 mm to 9.1 ± 2.1 mm (p < 0.001), the slip ratio was reduced from 11.1 ± 4.6% to 8.3 ± 4.4% (p = 0.020) with the slip reduction ratio 25.6 ± 32.3%, and SL was slightly changed from 8.7 ± 3.7° to 8.3 ± 3.0°(p = 1.000). Following posterior fixation, the DH was unchanged (from 11.8 ± 1.7 mm to 11.8 ± 2.3 mm, p = 1.000), DH-Anterior and DH-Posterior were slightly changed from 13.4 ± 2.1 mm and 9.1 ± 2.1 mm to 13.7 ± 2.3 mm and 8.4 ± 1.8 mm respectively (P = 0.861, P = 0.254), the slip ratio was reduced from 8.3 ± 4.4% to 2.1 ± 3.6% (p < 0.001) with the slip reduction ratio 57.9 ± 43.9%, and the SL was increased from 8.3 ± 3.0° to 10.7 ± 3.6° (p = 0.008).

Conclusions

Compared with stand-alone cage insertion, additional posterior fixation provides better segmental alignment improvement in terms of slip reduction and segmental lordosis in OLIF procedures in the treatment of lumbar degenerative spondylolisthesis.

Minimally invasive versus traditional open transforaminal lumbar interbody fusion for the treatment of low-grade degenerative spondylolisthesis: a retrospective study

This was a retrospective study. We aimed to compare the clinical efficacy and safety between minimally invasive and traditional open transforaminal lumbar interbody fusion in the treatment of low-grade lumbar degenerative spondylolisthesis (LDS). 81 patients with LDS grades 1 and 2 treated in our spinal department from January 2014 to July 2016 were retrospectively analyzed. The MIS-TLIF group included 23 males and 11 females, while the TO-TLIF group included 29 males and 18 females. Follow-up points were set at 7 days, 3 months, 6 months, 12 months postoperatively and the last follow-up. Various clinical and radiological indicators were used to evaluate and compare the efficacy and safety between the two procedures. 8 cases (3 in the MIS-TLIF group and 5 in the TO-TLIF group) were loss of follow-up after discharge. And the remaining 73 patients were followed up for at least 2 years. No statistically significant difference was observed in the terms of age, sex, BMI, slippage grade, and surgical segments. The MIS-TLIF group had a longer operation and fluoroscopy time compared with the TO-TLIF group. But the MIS-TLIF group was associated with less blood loss, ambulation time, hospital stay, and time of return to work. In each group, significant improvement were observed in BP-VAS, ODI and vertebral slip ratio at any time-point of follow-up when compared with the preoperative condition. When the time-point of follow-up was less than 1 year, the MIS-TLIF group had significant advantages in the BP-VAS and ODI compared with TO-TLIF group. But no significant difference was observed in the BP-VAS and ODI at either 12 month follow-up or the last follow-up. Besides, no statistical difference was detected in vertebral slip ratio at any time-point of follow-up between the two groups. Successful intervertebral bone fusion was found in all patients and no significant difference was found in the incidence of total complications. Thus, we considered that MIS-TLIF and TO-TLIF both achieve satisfactory clinical efficacy in the treatment of low-grade single-segment LDS. But MIS-TLIF appears to be a more efficacious and safe technique with reduced tissue damage, less blood loss and quicker recovery.

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.

Biomechanical evaluation of traditional posterior versus anterior spondylolisthesis reduction in a cadaveric grade I slip model

OBJECTIVE

Posterior reduction with pedicle screws is often used for stabilization of unstable spondylolisthesis to directly reduce misalignment or protect against micromotion while fusion of the affected level occurs. Optimal treatment of spondylolisthesis combines consistent reduction with a reduced risk of construct failure. The authors compared the reduction achieved with a novel anterior integrated spacer with a built-in reduction mechanism (ISR) to the reduction achieved with pedicle screws alone, or in combination with an anterior lumbar interbody fusion (ALIF) spacer, in a cadaveric grade I spondylolisthesis model.

METHODS

Grade I slip was modeled in 6 cadaveric L5-S1 segments by creation of a partial nucleotomy and facetectomy and application of dynamic cyclic loading. Following the creation of spondylolisthesis, reduction was performed under increasing axial loads, simulating muscle trunk forces between 50 and 157.5 lbs, in the following order: bilateral pedicle screws (BPS), BPS with an anterior spacer (BPS+S), and ISR. Percent reduction and reduction failure load-the axial load at which successful reduction (≥ 50% correction) was not achieved-were recorded along with the failure mechanism. Corrections were evaluated using lateral fluoroscopic images.

RESULTS

The average loads at which BPS and BPS+S failed were 92.5 ± 6.1 and 94.2 ± 13.9 lbs, respectively. The ISR construct failed at a statistically higher load of 140.0 ± 27.1 lbs. Reduction at the largest axial load (157.5 lbs) by the ISR device was tested in 67% (4 of 6) of the specimens, was successful in 33% (2 of 6), and achieved 68.3 ± 37.4% of the available reduction. For the BPS and BPS+S constructs, the largest axial load was 105.0 lbs, with average reductions of 21.3 ± 0.0% (1 of 6) and 32.4 ± 5.7% (3 of 6) respectively.

CONCLUSIONS

While both posterior and anterior reduction devices maintained reduction under gravimetric loading, the reduction capacity of the novel anterior ISR device was more effective at greater loads than traditional pedicle screw techniques. Full correction was achieved with pedicle screws, with or without ALIF, but under significantly lower axial loads. The anterior ISR may prove useful when higher reduction forces are required; however, additional clinical studies will be needed to evaluate the effectiveness of anterior devices with built-in reduction mechanisms.

Sagittal Balance Correction Following Lumbar Interbody Fusion: A Comparison of the Three Approaches

STUDY DESIGN

Retrospective cohort study.

PURPOSE

The objective of this study was to compare three widely used interbody fusion approaches in regard to their ability to correct sagittal balance, including pelvic parameters.

OVERVIEW OF LITERATURE

Restoration of sagittal balance in lumbar spine surgery is associated with better postoperative outcomes. Various interbody fusion techniques can help to correct sagittal balance, with no clear consensus on which technique offers the best correction.

METHODS

The charts and imaging of patients who have undergone surgery through either open transforaminal lumbar interbody fusion (TLIF), minimally invasive TLIF (MIS TLIF), or oblique lumbar interbody fusion (OLIF) were retrospectively reviewed. The following sagittal balance parameters were measured pre- and postoperatively: segmental lordosis, lumbar lordosis, disk height, pelvic tilt, and pelvic incidence. Data on postoperative complications were gathered.

RESULTS

Only OLIF managed to significantly improve segmental lordosis (4.4°, p <0.001) and lumbar lordosis (4.8°, p =0.049). All approaches significantly augmented disk height, with OLIF having the greatest effect (3.7°, p <0.001). No approaches were shown to significantly correct pelvic tilt. Pelvic incidence remained unchanged in all approaches. Open TLIF was the only approach with a higher rate of postoperative complications (33%, p =0.009).

CONCLUSIONS

The OLIF approach might offer greater correction of sagittal balance over open and MIS TLIF, mainly in regard to segmental lordosis, lumbar lordosis, and disk height. MIS TLIF, although offering more limited access than open TLIF, was not inferior to open TLIF in regard to sagittal balance correction. A higher rate of complications was shown for open TLIF than the other approaches, possibly due to its more invasive nature.

Microendoscope-assisted posterior lumbar interbody fusion: a technical note

Background

Various surgical options for lumbar interbody fusion have been reported. Minimally invasive techniques are widely used to reduce soft tissue damage. Here, we report our novel technique of microendoscope-assisted posterior lumbar interbody fusion (ME-PLIF) using an 18-mm tubular retractor system (METRx, Medtronic Sofamor Danek, Memphis, TN, USA) for lumbar spine degeneration treatment.

Methods

Between January 2011 and December 2011, 48 patients underwent one level ME-PLIF by a surgeon in our hospital. We followed up 46 patients (95.8%). A 20-mm skin incision was made in the craniocaudal direction at the level of the intervertebral disc, 15 mm outside the midline (symptomatic side). The surgeon placed the tubular retractor and performed decompression, thoroughly discarded the intervertebral disc, and then inserted the autologous crushed bone on the opposite side. Subsequently, a cage was inserted using fluoroscopic guidance. Following the end of the microendoscopic operation, pedicle screws (PS) were inserted percutaneously using fluoroscopic guidance. Clinical outcomes were evaluated using the Oswestry Disability Index (ODI) and the Japanese Orthopedic Association (JOA) scores. For radiological outcomes, fusion rates based on the Bridwell fusion grading system were evaluated using plain radiography or a computed tomography scan at the most recent follow-up timepoint.

Results

The mean age was 61.4 (range, 36.0-86.0) years, the mean operation time was 102 (range, 59-162) min, and the mean blood loss was 86 (range, small amounts-315) mL. The average pre- and post-operative ODI scores were 22.1 and 9.7, respectively, with an improvement rate of 56.1%, and the pre- and post-operative JOA scores were 9.8 and 16.4, respectively, with an improvement rate of 50%. There were no cases of pseudarthrosis. One case (2.2%) had a deep wound infection that required total removal of the implants. Four (8.7%) cases had a dural tear and required dural sutures under microendoscopy, though they had good recovery.

Conclusions

This technique yielded good results. The advantages of using only the microendoscope were: (I) better visual field and (II) higher operability (it was possible to change the tubular retractor to various angles; this was difficult under direct viewing or under a microscope). These features are considered to lead to reduce soft tissue damage. Although long-term follow-up results are needed, this appears to be a safe and minimally invasive treatment option for lumbar spine degeneration.

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.

The design and application of a customized navigation board for lumbar disc ablation

PURPOSE

This paper aimed to explore the design and application of a customized navigation board for lumbar disc ablation.

METHODS

Eight cases of lumbar disc herniation (diagnosed by spiral computerized tomography, CT) to be treated via intervertebral ablation using a path from the skin to the herniated intervertebral disc were included. The lumbar vertebrae, sacrum, and skin (adhered to a standard base, Figure 1) were reconstructed based on continuous spiral CT slices. The path was designed by the surgeon (Figure 2) to be line between the base and the puncture point, and was guided by the navigation board. The board was prototyped and used in ablation localization as a guide canal. The intra- and post-operative complications were recorded during the operation and 48-hours post operation, respectively.

RESULTS

In all eight cases, target discs were punctured after a duration ranging from 6 to 13 minutes. No complications were observed either during the operation or at 48 hours post-operatively.

CONCLUSION

This customized navigation board could promote the accuracy and diminish the duration of intervertebral disc ablation. A stereolithography apparatus (SLA) and photosensitive resin could generate a customized reverse guide board with high fidelity for intervertebral disc ablation. Manually performed rigid registration can meet the accuracy requirements. The results presented in the present paper demonstrated that rapid prototyping via an SLA and photosensitive resin could maintain the accuracy and dynamic stability of a customized navigation board for lumbar disc ablation.

Treatment for Degenerative Lumbar Spondylolisthesis: Current Concepts and New Evidence

PURPOSE OF REVIEW

Current guidelines for the optimal treatment degenerative spondylolisthesis are weak and based on limited high-quality evidence.

RECENT FINDINGS

There is some moderate evidence that decompression alone may be a feasible treatment with lower surgical morbidity and similar outcomes to fusion when performed in a select population with a low-grade slip. Similarly, addition of interbody fusion may be best suited to a subset of patients with high-grade degenerative spondylolisthesis, although this remains controversial. Minimally invasive techniques are increasingly being utilized for both decompression and fusion surgeries with more and more studies showing similar outcomes and lower postoperative morbidity for patients. This will likely be an area of continued intense research. Finally, the role of spondylolisthesis reduction will likely be determined as further investigation into optimal sagittal balance and spinopelvic parameters is conducted. Future identification of ideal thresholds for sagittal vertical axis and slip angle that will prevent progression and reoperation will play an important role in surgical treatment planning. Current evidence supports surgical treatment of degenerative spondylolisthesis. While posterolateral spinal fusion remains the treatment of choice, the use of interbodies and decompressions without fusion may be efficacious in certain populations. However, additional high-quality evidence is needed, especially in newer areas of practice such as minimally invasive techniques and sagittal balance correction.