Interspinous dynamic stabilization adjacent to fusion versus double-segment fusion for treatment of lumbar degenerative disease with a minimum follow-up of three years

Effectiveness of Interspinous Process Devices in Managing Adjacent Segment Degeneration Following Lumbar Spinal Fusion: A Systematic Review and Meta-Analysis

Background: Adjacent segment degeneration (ASD) is a significant complication following lumbar spinal fusion, often necessitating further surgical interventions and impairing patient outcomes. Interspinous process devices were introduced as an alternative treatment for spinal stenosis and degenerative spondylolisthesis and can potentially reduce the incidence of ASDd. This systematic review and meta-analysis aims to evaluate the effectiveness of interspinous process devices or IPDs in managing ASD following a previous spinal fusion compared to traditional fusion techniques. Methods: Electronic databases, including PubMed, Embase, and the Cochrane Library, were queried for studies assessing IPDs against traditional lumbar fusion methods for managing ASD after previous lumbar fusion, which had been published between January 2014 and the present. Statistical analysis was conducted using Review Manager 5.4. Results: Seven retrospective cohort studies involving 546 patients met the inclusion criteria. The analysis revealed that IPDs were associated with a statistically significant reduction in the incidence of ASD (OR = 0.28, 95% CI: 0.16 to 0.51, p < 0.0001, and I2 = 0% after excluding outliers). The ODI demonstrated a non-significant trend towards improved outcomes with IPDs at the 2-year follow-up (SMD = -3.94; 95% CI: -11.72 to 3.85). Range of motion (ROM) was better preserved with IPDs compared to fusion (SMD = 0.00, 95% CI: -0.41 to 0.41, p = 1.00, I2 = 60%). The visual analogue scale or VAS lower back pain scores were significantly reduced at the 2-year follow-up (SMD = -0.69, 95% CI: -1.18 to -0.19, p = 0.006, and I2 = 74%). VAS leg pain showed consistent improvements (SMD = -0.29; 95% CI: -0.63 to 0.04). Intraoperative blood loss was significantly lower with IPDs (SMD = -2.07; 95% CI: -3.27 to -0.87, p = 0.0007, and I2 = 95%), and operation times were shorter (SMD = -2.22, 95% CI: -3.31 to -1.12, p < 0.0001, and I2 = 94%). Conclusions: The judicious use of IPDs might benefit a subset of patients, particularly those who are not suitable candidates for major corrective surgery.

A Biomechanical Comparison of 2 Different Topping-off Devices and Their Influence on the Sacroiliac Joint Following Lumbosacral Fusion Surgery

OBJECTIVE

Interspinous spacer (ISS)-based and pedicle screw-rod dynamic fixator (PDF)-based topping-off devices have been applied in lumbar/lumbosacral fusion surgeries for preventing the development of proximal adjacent segment degeneration. However, little attention has been paid to sacroiliac joint (SIJ), which belongs to the adjacent joints. Accordingly, the objective of this study was to compare how these 2 topping-off devices affect the SIJ biomechanics.

METHODS

A validated, normal finite-element lumbopelvic model (L3-pelvis) was initially adjusted to simulate interbody fusion with rigid fixation at the L5-S1 level, and then the DIAM or BioFlex system was instrumented at the L4-5 level to establish the ISS-based or PDF-based topping-off model, respectively. All the developed models were loaded with moments of 4 physiological motions using hybrid loading protocol.

RESULTS

Compared with the rigid fusion model (without topping-off devices), range of motion and von-Mises stress at the SIJs were increased by 23.1%-64.1% and 23.6%-62.8%, respectively, for the ISS-based model and by 51.2%-126.7% and 50.4%-108.7%, respectively, for the PDF-based model.

CONCLUSION

The obtained results suggest that the PDF-based topping-off device leads to higher increments in SIJ motion and stress than ISS-based topping-off device following lumbosacral fusion, implying topping-off technique could be linked to an increased risk of SIJ degeneration, especially when using PDF-based device.

The effect of interlaminar Coflex stabilization in the topping-off procedure on local and global spinal sagittal alignment

PURPOSE

To investigate the effect of interlaminar Coflex stabilization (ICS) at various segments in the topping-off procedure on local and global spinal sagittal alignment.

METHODS

Eighty-nine consecutive patients with degenerative lumbar spinal stenosis (DLSS) who underwent ICS and transforaminal lumbar interbody fusion (TLIF) were retrospectively reviewed. They were divided into Group A (L4-L5 ICS + L5-S1 TLIF), Group B (L3-L4 ICS + L4-S1 TLIF), and Group C (L2-L3 ICS + L3-S1 TLIF) according to their fusion levels. The measured local sagittal parameters included the implanted segmental angle (ISA), intervertebral disc angle (IDA), intervertebral foreman height (IFH), and disc height. The assessed global sagittal parameters included thoracic kyphosis, lumbar lordosis (LL), the fused segment angle (FSA), the sacral slope, the pelvic tilt, pelvic incidence, and the sagittal vertical axis. The Oswestry Disability Index (ODI) and visual analog scales (VAS) were recorded to evaluate the clinical outcomes.

RESULTS

Regarding the local alignment parameters, the ISA and IDA decreased immediately after surgery in Groups A and B, followed by an increase at the last follow-up (all, P < 0.05). Conversely, the IFH of Groups A and B first increased after surgery and then decreased to approximately the original value (all, P < 0.05). No significant differences were evident between the local sagittal parameters at different time points in Group C. Regarding the global sagittal profiles, the LL and FSA exhibited a significant postoperative increase (both at P < 0.05) in all the groups. All three groups displayed significant improvements in the ODI, VAS-back pain, and VAS-leg pain. Furthermore, 4.5% (4/89) of the patients exhibited radiographic adjacent segment degeneration (ASD) at the last follow-up.

CONCLUSION

ICS during topping-off surgery led to a temporary loss of local lordosis, especially in the lower lumbar segment, while the intervertebral space realigned after middle-term follow-up. The topping-off procedure with ICS is a feasible and promising surgical option of DLSS since it reduces fusion levels and prevents ASD development.

Efficacy and Safety of Lumbar Dynamic Stabilization Device Coflex for Lumbar Spinal Stenosis: A Systematic Review and Meta-analysis

BACKGROUND

This systematic review and meta-analysis were performed to investigate evidence for the comparison of lumbar dynamic stabilization device Coflex (Surgalign, Deerfield, IL) with posterior lumbar fusion for lumbar spinal stenosis).

METHODS

Relational databases were searched to October 2022. The main outcome measures included operation time, Japanese Orthopedic Association score (JOA), visual analog scale (VAS), Oswestry disability index (ODI), total complications, and adjacent segment degeneration (ASD). Statistical analysis was performed with Review Manager 5.3 (Cochrane Collaboration).

RESULTS

A total of 26 studies were included. The main results of this meta-analysis showed lumbar dynamic stabilization device Coflex had shorter operation time (mean difference [MD] -50.77 min, 95% CI -57.24 to -44.30, P < 0.00001), less intraoperative blood loss (MD -122.21 mL, 95% CI -129.68 to -94.74, P < 0.00001), and shorter hospital stays (MD -3.21 days, 95% CI -4.04 to -2.37, P < 0.00001). What's more, the JOA score and ODI score were higher in the Coflex group during early follow-up. Yet, there was no significant difference between the 2 groups with the extension of follow-up time. Moreover, the Coflex group had a lower VAS score than fusion treatment (P < 0.00001). Finally, the Coflex group had lower total complications rate (P = 0.03), lower ASD rate (P = 0.001), and higher range of motion (P < 0.00001), but there was no significant difference in reoperation rate and internal fixation problems rate.

CONCLUSIONS

Current evidence suggests that lumbar dynamic stabilization device Coflex is superior to posterior lumbar fusion in early follow-up. However, considering that the dynamic stabilization device group also has its limitations, these findings need to be further verified by multicenter, double-blind, and large-sample randomized controlled trials.

Comparison of long-term outcomes of spinal fusion surgeries supplemented with "topping-off" implants in lumbar degenerative diseases: A systematic review and network meta-analysis

Background Context

Spinal fusion surgery is a common treatment for lumbar degenerative diseases and has been associated with the long-term complication of adjacent segment disease (ASD). In recent years, the "topping-off" technique has emerged as a new surgical method, combining spinal fusion with a hybrid stabilization device (HSD) or interspinous process device (IPD) proximal to the fused vertebrae.

Methods

A literature search using the PubMed, Cochrane Central Register of Controlled Trials, EMBASE, and Web of Science databases identified eligible studies comparing topping-off implant(s) with spinal fusion surgery for lumbar degenerative diseases. Risk of bias was assessed using the Cochrane RoB 2.0 tool for randomized controlled trials and the Newcastle-Ottawa scale for retrospective studies. Each outcome was analyzed using the statistical Confidence in NMA (CINeMA) 1.9.0 software.

Results

17 RCTs and retrospective studies that included 1255 participants and five interventions were identified. The topping-off implants device for intervertebral assisted motion (DIAM; OR = 0.235, p < 0.001), Dynesys (OR = 0.413, p < 0.001), and Coflex (OR = 0.417, p < 0.01) significantly lowered the incidence of radiographic adjacent segment degeneration (RASDeg) compared with spinal fusion surgery alone. Spinal fusion supplemented with DIAM significantly reduced the incidence of clinical adjacent segment disease (CASD) (OR = 0.358, p = 0.032).

Conclusions

Spinal fusion supplemented with DIAM substantially reduced the incidence of radiographic and clinical adjacent segment disease. No significant difference was observed between the treatment comparators for reoperation due to ASD and back pain relief score.

Biomechanical Investigation of Lumbar Interbody Fusion Supplemented with Topping-off Instrumentation Using Different Dynamic Stabilization Devices

STUDY DESIGN

A biomechanical comparison study using finite element method.

OBJECTIVE

The aim of this study was to investigate effects of different dynamic stabilization devices, including pedicle-based dynamic stabilization system (PBDSS) and interspinous process spacer (ISP), used for topping-off implants on biomechanical responses of human spine after lumbar interbody fusion.

SUMMARY OF BACKGROUND DATA

Topping-off stabilization technique has been proposed to prevent adjacent segment degeneration following lumbar spine fusion. PBDSS and ISP are the most used dynamic stabilizers for topping-off instrumentation. However, biomechanical differences between them still remain unclear.

METHODS

A validated, normal FE model of human lumbosacral spine was employed. Based on this model, rigid fusion at L4-L5 and moderately disc degeneration at L3-L4 were simulated and used as a comparison baseline. Subsequently, Bioflex and DIAM systems were instrumented at L3-L4 segment to construct PBDSS-based and ISP-based topping-off models. Biomechanical responses of the models to bending moments and vertical vibrational excitation were computed using FE static and random response analyses, respectively.

RESULTS

Results from static analysis showed that at L3-L4, the response parameters including annulus stress and range of motion were decreased by 41.6% to 85.2% for PBDSS-based model and by 6.3% to 67% for ISP-based model compared with rigid fusion model. At L2-L3, these parameters were lower in ISP-based model than in PBDSS-based model. Results from random response analysis showed that topping-off instrumentation increased resonant frequency of spine system but decreased dynamic response of annulus stress at L3-L4. PBDSS-based model generated lower dynamic stress than ISP-based model at L3-L4, but the dynamic stress was higher at L2-L3 for PBDSSbased model.

CONCLUSION

Under static and vibration loadings, the PBDSSbased topping-off device (Bioflex) provided a better protection for transition segment, and likelihood of degeneration of supraadjacent segment might be relatively lower when using the ISPbased topping-off device (DIAM).Level of Evidence: 5.

Current concepts of spondylosis and posterior spinal motion preservation for radiologists

Spinal fusion is performed to eliminate motion at a degenerated or unstable segment. However, this is associated with loss of motion at the fused levels and increased stress on adjacent levels. Motion-preserving implants have been designed in effort to mitigate the limitations of fusion. This review will focus on posterior spinal motion-preserving technologies. In the cervical spine, laminoplasty is a posterior motion-preserving procedure used in the management of myelopathy/cord compression. In the lumbar spine, motion-sparing systems include interspinous process devices (also referred to as interspinous process spacers or distraction devices), posterior dynamic stabilization devices (also referred to as pedicle screw/rod fixation-based systems), and posterior element replacement systems (also referred to as total facet replacement devices). Knowledge of the intended physiologic purpose, hardware utilized, and complications is important in the assessment of imaging in those who have undergone posterior motion preservation procedures.

The Efficacy of Lumbar Hybrid Fusion for the Prevention of Adjacent Segment Disease: Fact or Artifact? A Meta-analysis

STUDY DESIGN

A systematic literature review and meta-analysis.

OBJECTIVE

The aim of this study is to compare hybrid constructs with traditional fusion-only constructs for the incidence of adjacent segment degeneration (ASDeg) and clinical outcomes in patients with degenerative lumbar diseases.

SUMMARY OF BACKGROUND DATA

Spinal fusion is a standard surgery for various pathologies of the lumbar spine, which results in changes to the biomechanics of the spine, potentially leading to ASDeg. Although ASDeg can occur slowly as a natural course, early-onset ASDeg is regarded to be related to fusion surgery.

MATERIALS AND METHODS

A systematic search was conducted to identify studies that match the purpose. Included studies were compared using the incidence of ASDeg, Oswestry Disability Index, Visual Analog Score, and perioperative outcomes. We calculated the Peto odds ratio and mean difference (MD) for the continuous variables, respectively. In the hybrid group, subgroup analysis was also performed among devices.

RESULTS

Among 10 papers involving 767 patients, 372 patients underwent hybrid fusion and 395 patients underwent fusion-only. ASDeg occurred in 10.2% in the hybrid and 21.5% in the fusion-only group [Peto odds ratio, 0.39; 95% confidence interval (CI), 0.23-0.64]. The MD for Visual Analog Score were 0.45 (95% CI, 0.05-0.85) between 2 groups, which was statistically significant but was too small to have clinical significance. The MD for Oswestry Disability Index was 0.93 (95% CI, -1.016 to 2.872), which was not statistically different between 2 groups. The hybrid is superior for 18 minutes (95% CI, 5.78-30.72) shorter than typical surgery.

CONCLUSIONS

Hybrid lumbar surgery decreased the incidence of early-onset ASDeg for about 2 years of follow-up. Among the hybrid constructs, the interspinous devices group accomplished favorable results with a lower risk. Adjacent segment disease was not as statistically significant as ASDeg, but adjacent segment disease may show a substantial difference for >2-year follow-up.

Dynamic Fixation Techniques for the Prevention of Adjacent Segment Disease: A Retrospective Controlled Study

Study Design

Retrospective, controlled study.

Purpose

Dynamic fixation (topping-off technique) adjacent to a transforaminal lumbar interbody fusion (TLIF) level was developed to reduce the risk of adjacent segment disease (ASDi). This study was designed to compare the clinical and radiological outcomes between patients who underwent circumferential lumbar fusion (CLF) without the topping-off technique, CLF with dynamic rod constructs (DRC), and CLF with interspinous device (ISD).

Overview of Literature

Lumbar fusion can result in the re-distribution of stress, increased mobility, and increased intradiscal pressure at adjacent levels, ultimately leading to adjacent segment degeneration (ASDe) and ASDi. Dynamic fixation techniques (topping-off techniques) adjacent to vertebral fusion have been developed to reduce the risk of ASDe and ASDi because they provide a transitional zone between a caudal rigid fused segment and cephalad-mobile unfused levels.

Methods

A single-center, retrospective, controlled study was designed, including all patients who underwent CLF due to degenerative lumbar spinal disease in Hospital Clinic of Barcelona between 2012 and 2018. Three groups of patients were evaluated as per the type of topping-off technique used: CLF alone group, DRC group, and ISD group. Clinical and radiological outcomes were evaluated.

Results

A total of 117 patients were enrolled in the study. Sixty patients (51.3%) underwent CLF without dynamic stabilization, 24 (20.5%) were treated with DRC as topping-off technique, and 33 (28.5%) were treated with an ISD. A total of 12 patients (20.0%) in the CLF alone group showed ASDi at the final follow-up, compared to 1 (4.2%) in the DRC group (p=0.097) and 2 (6.1%) in the ISD group (p=0.127). The Cox regression model identified a significantly decreased risk of ASDi when a topping-off technique (DRC or ISD) was used (hazard ratio, 0.154; 95% confidence interval, 0.31–0.77).

Conclusions

Dynamic fixation adjacent to CLF was a safe and efficient procedure associated with improved clinical outcomes in patients with lumbar spine degenerative disease.

A minimum 8-year follow-up comparative study of decompression and coflex stabilization with decompression and fusion

The current study aimed to compare the outcomes of decompression and interlaminar stabilisation with those of decompression and fusion for the treatment of lumbar degenerative disease (LDD) at a minimum 8-year follow-up. The current study also aimed to analyse the risk factors of radiographic adjacent segment degeneration (ASD). A total of 82 consecutive patients with LDD who underwent surgery between June 2007 and February 2011 were retrospectively reviewed. Of these patients, 39 underwent decompression and Coflex interspinous stabilisation (Coflex group) and 43 underwent decompression and posterior lumbar interbody fusion (PLIF) (PLIF group). All patients had a minimum of 8-years of follow-up data. Radiographic and clinical outcomes were compared between the groups, and the risk factors of developing radiographic ASD were also evaluated. The Oswestry disability index and visual analogue scale leg and back pain scores of both groups significantly improved compared with the baseline (all P<0.05), and no difference were indicated between the two groups at each follow-up time point (P>0.05). The Coflex group exhibited preserved mobility (P<0.001), which was associated with a decreased amount of blood loss (P<0.001), shorter duration of surgery (P=0.001), shorter duration of hospital stay and a lower incidence of ASD (12.8 vs. 32.56%; P=0.040) compared with the fusion group. The current study indicated that coflex and fusion technologies are safe and effective for the treatment of LDD, based on long-term follow-up data. However, Coflex interspinous stabilisation was revealed to reduce ASD incidence. Under strict indications, Coflex interspinous stabilisation is an effective and safe treatment method.

Coflex interspinous process dynamic stabilization for lumbar spinal stenosis: Long-term follow-up

OBJECTIVE

To evaluate the long-term efficacy of Coflex dynamic stabilization device in the treatment of lumbar spinal stenosis.

METHODS

The clinical and imaging data of 73 patients undergoing Coflex dynamic stabilization surgery from July 2008 to June 2012 were retrospectively analyzed. All patients had a minimum of 8 years of follow-up. Clinical data were used to assess the clinical efficacy, and radiographic parameters were measured for evaluation of ASD.

RESULTS

56 Patients were followed up for 107.6 ± 13.3 months. The visual analogue scale of pain (VAS), Owestry disability index (ODI) and Japanese Orthopedic Association Scores (JOA) improved significantly after surgery. At 6 months after surgery and the last follow-up, lumbar range of motion (ROM) was significantly lower than that before surgery (P < 0.001). ROM was slightly increased at the last follow-up compared with that 6 months after operation (P > 0.05). ROM of adjacent segments increased at 6 months and at the last follow-up compared with that before surgery (P > 0.05). At 6 months after surgery, intervertebral space height (ISH) and intervertebral foramen height (IFH) of implanted segment was significantly higher than that before surgery (P < 0.05). At the last follow-up, there was a decrease in ISH and IFH (P > 0.05). During the follow-up period, a total of 11 patients (19.6%) experienced complications and 6 patients (10.7%) underwent secondary surgery.

CONCLUSION

Coflex interspinous process dynamic stabilization is effective in the long-term treatment of lumbar spinal stenosis, the ISH and IFH of implanted segment could be increased in a short period of time.

Current incidence of adjacent segment pathology following lumbar fusion versus motion-preserving procedures: a systematic review and meta-analysis of recent projections

BACKGROUND CONTEXT

Lumbar fusion has shown to be an effective surgical management option when indicated, improving patient outcomes and functional status. However, concerns of adjacent segment pathology (ASP) due to reduced mobility at the operated segment have fostered the emergence of motion-preserving procedures (MPP).

PURPOSE

To assess rates of radiographic adjacent segment degeneration (ASDeg) and symptomatic adjacent segment disease (ASDis) as well as reoperation rates due to ASP in patients who have undergone lumbar fusion compared to motion-preservation for degenerative disorders.

STUDY DESIGN

Systematic Review and Meta-Analysis.

METHODS

Following PRISMA guidelines, a systematic review and meta-analysis was conducted to find current (1/2012-12/2019) retrospective cohort studies and randomized controlled trials evaluating rates of ASDeg, ASDis, and reoperations due to lumbar ASP.

RESULTS

A total of 1,751 patients (791 underwent fusion surgery and 960 motion-preserving procedures) in 19 publications were included in the final analysis. Overall incidence rates of ASDeg, ASDis, and reoperation rates were 27.8%, 7.6%, and 4.6%, respectively. Results showed no significant difference between the lumbar fusion versus MPP cohorts in incidence of ASDeg (36.4% vs. 19.2%, p: 0.06), ASDis (10.7% vs. 4.42%, p: 0.25), or reoperation due to ASP (7.40% vs. 1.80%, p: 0.19). Fixed-effects analysis revealed patients who underwent MPP had significantly lower odds of ASDeg (OR: 2.57, CI: 1.95, 3.35, p<.05) and reoperations (OR: 3.18, CI: 1.63, 6.21, p<.05) compared to lumbar fusion patients.

CONCLUSIONS

This meta-analysis revealed no statistically significant difference in incidence of ASDeg, ASDis, or reoperations due to ASP for patients after lumbar fusion versus MPP. Weighted analysis, however, showed that MPP patients had significantly lower odds of ASDeg and reoperations due to ASP. While previous studies have established the biomechanical efficacy of MPP on cadaveric models, further high-quality studies are required to evaluate the long-term consequences of these procedures on patient-reported outcomes, postoperative complications, and associated inpatient/outpatient costs.

Dynamic Stabilization Adjacent to Fusion versus Posterior Lumbar Interbody Fusion for the Treatment of Lumbar Degenerative Disease: A Meta-Analysis

This study evaluated differences in outcome variables between dynamic stabilization adjacent to fusion (DATF) and posterior lumbar interbody fusion (PLIF) for the treatment of lumbar degenerative disease. A systematic review of PubMed, EMBASE, and Cochrane was performed. The variables of interest included clinical adjacent segment pathologies (CASPs), radiological adjacent segment pathologies (RASPs), lumbar lordosis (LL), visual analogue scale (VAS) of back (VAS-B) and leg (VAS-L), Oswestry disability index (ODI), Japanese Orthopaedic Association (JOA) score, duration of surgery (DS), estimated blood loss (EBL), complications, and reoperation rate. Nine articles identified as meeting all of the inclusion criteria. DATF was better than PLIF in proximal RASP, CASP, and ODI during 3 months follow-up, VAS-L. However, no significant difference between DATF and PLIF was found in distal RASP, LL, JOA score, VAS-B, ODI after 3 months follow-up, complication rates, and reoperation rate. These further confirmed that DATF could decrease the proximal ASP both symptomatically and radiographically as compared to fusion group; however, the influence of DATF on functional outcome was similar with PLIF. The differences between hybrid surgery and topping-off technique were located in DS and EBL in comparison with PLIF. Our study confirmed that DATF could decrease the proximal ASP both symptomatically and radiographically as compared to the fusion group; however, the influence of DATF on functional outcome was similar with PLIF. The difference between hybrid surgery and topping-off technique was not significant in treatment outcomes.

Biomechanical changes of degenerated adjacent segment and intact lumbar spine after lumbosacral topping-off surgery: a three-dimensional finite element analysis

Background

Previous studies have revealed positive effect of Topping-off technique on upper adjacent segment after fusion surgery, while for the cases with fusion surgery on L5-S1 segment, owning maximal range of motion, and preexisting degenerated upper adjacent disc, it is necessary to clarify the superiority of Topping-ff technique and the effect exerted on the lumbar spine.

Methods

A young healthy male volunteer was selected for thin-slice CT scanning. Then the image information was imported into the computer to establish the whole lumbar spine model as the health model. The medium degeneration model of intervertebral disc was established by changing the material properties of L4-S1 disc on the basis of the health model, and the fusion model and Topping-off model were respectively established on the basis of the degenerated model. The variation trend of ROM of L2-L5 and the stress changes of L4-L5 intervertebral disc, nucleus pulposus and facet joints were calculated respectively.

Results

The L4-L5 ROM of fusion model increased significantly but the ROM of L2-L3 and L3-L4 segments did not change significantly. Compared with the degenerated model, L4-L5 activity of the Topping-off model decreased, and ROM of the L2-L3 and L3-L4 increased to some extent in the flexion and extension positions. The stress on the disc, nucleus pulposus and facet joint of the fusion model L4-L5 increased in four positions of flexion, extension, rotation and bending compared with the degenerated model, while the fiber stress on the Topping-off model decreased significantly in all four positions.

Conclusion

Topping-off technology can decrease the stress and ROM of the adjacent upper degenerated segment, and increase the ROM of other upper segments, thereby protecting the degenerated upper adjacent segments and compensating the lumbar spine mobility.

Topping-Off Technology versus Posterior Lumbar Interbody Fusion in the Treatment of Lumbar Disc Herniation: A Meta-Analysis

The treatment effects of topping-off technique were still controversial. This study compared all available data on postoperative clinical and radiographic outcomes of topping-off technique and posterior lumbar interbody fusion (PLIF). PubMed, EMBASE, and Cochrane were systematically reviewed. Variations included radiographical adjacent segment disease (RASD), clinical adjacent segment disease (CASD), global lumbar lordosis (GLL), visual analogue scale (VAS) of back (VAS-B) and leg (VAS-L), Oswestry disability index (ODI), Japanese Orthopaedic Association (JOA) score, duration of surgery, estimated blood loss (EBL), reoperation rates, and complication rates. Sixteen studies, including 1372 cases, were selected for the analysis. Rates of proximal RASD (P=0.0004), distal RASD (P=0.03), postoperative VAS-B (P=0.0001), postoperative VAS-L (P=0.02), EBL (P=0.007), and duration of surgery (P=0.02) were significantly lower in topping-off group than those in PLIF group. Postoperative ODI after 3 years (P=0.04) in the topping-off group was significantly less than that in the PLIF group. There was no significant difference in the rates of CASD (P=0.06), postoperative GLL (P=0.14), postoperative ODI within 3 years (P=0.24), and postoperative JOA (P=0.70) and in reoperation rates (P=0.32) and complication rates (P=0.27) between topping-off group and PLIF. The results confirmed that topping-off technique could effectively prevent ASDs after lumbar internal fixation. However, this effect is effective in preventing RASD. Topping-off technique is more effective in improving the subjective feelings of patients rather than objective motor functions compared with PLIF. With the development of surgical techniques, both topping-off technique and PLIF are safe.

Comparison between topping-off technology and posterior lumbar interbody fusion in the treatment of chronic low back pain: A meta-analysis

BACKGROUND

The difference between topping-off technique and posterior lumbar interbody fusion (PLIF) in postoperative outcomes is still controversial. The aim of this study is to compare all available data on outcomes of topping-off technique and PLIF in the treatment of chronic low back pain.

METHODS

Articles in PubMed, EMBASE and Cochrane were reviewed. Parameters included radiographical adjacent segment disease (RASD), clinical adjacent segment disease, range of motion (ROM), global lumbar lordosis (GLL), visual analog scale (VAS), visual analog scale of back, (VAS-B) and visual analog scale leg (VAS-L), Oswestry disability index, Japanese Orthopaedic Association (JOA) score, duration of surgery, estimated blood loss (EBL), reoperation rates, complication rates.

RESULTS

Rates of proximal RASD (P = .001) and CASD (P = .03), postoperative VAS-B (P = .0001) were significantly lower in topping-off group than that in PLIF group. There was no significant difference in distal RASD (P = .07), postoperative GLL (P = .71), postoperative upper intervertebral ROM (P = .19), postoperative VAS-L (P = .08), DOI (P = .30), postoperative JOA (P = .18), EBL (P = .21) and duration of surgery (P = .49), reoperation rate (P = .16), complication rates (P = .31) between topping-off group and PLIF.

CONCLUSIONS

Topping-off can effectively prevent the adjacent segment disease from progressing after lumbar internal fixation, which is be more effective in proximal segments. Topping-off technique was more effective in improving subjective feelings of patents rather than objective motor functions. However, no significant difference between topping-off technique and PLIF can be found in the rates of complications.

Formation, function, and exhaustion of notochordal cytoplasmic vacuoles within intervertebral disc: current understanding and speculation

Notochord nucleus pulposus cells are characteristic of containing abundant and giant cytoplasmic vacuoles. This review explores the embryonic formation, biological function, and postnatal exhaustion of notochord vacuoles, aiming to characterize the signal network transforming the vacuolated nucleus pulposus cells into the vacuole-less chondrocytic cells. Embryonically, the cytoplasmic vacuoles within vertebrate notochord originate from an evolutionarily conserved vacuolation process during neurulation, which may continue to provide mechanical and signal support in constructing a mammalian intervertebral disc. For full vacuolation, a vacuolating specification from dorsal organizer cells, synchronized convergent extension, well-structured notochord sheath, and sufficient post-Golgi trafficking in notochord cells are required. Postnatally, age-related and species-specific exhaustion of vacuolated nucleus pulposus cells could be potentiated by Fas- and Fas ligand-induced apoptosis, intolerance to mechanical stress and nutrient deficiency, vacuole-mediated proliferation check, and gradual de-vacuolation within the avascular and compression-loaded intervertebral disc. These results suggest that the notochord vacuoles are active and versatile organelles for both embryonic notochord and postnatal nucleus pulposus, and may provide novel information on intervertebral disc degeneration to guide cell-based regeneration.

Interspinous implants to treat spinal stenosis

PURPOSE OF REVIEW

Lumbar spinal stenosis has historically been treated with open decompressive surgery which is associated with significant morbidity and may give rise to various complications. Interspinous spacers (ISS) have been developed as a less invasive strategy which may serve to avoid many of these risks. The two current spacers that are FDA approved and commercially available are the Coflex and Superion devices. The goal is to review these two implants, their indications, and patient selection.

RECENT FINDINGS

The Coflex device has been shown to be analogous to decompression and fusion when treating moderate spinal stenosis. It provides dynamic stability after a decompression is performed, without the rigidity of pedicle-screw instrumentation. Recent results show improved outcomes in Coflex patients at 3 years of follow-up, as compared to decompression and fusion. The Superion implant is placed percutaneously in the interspinous space with minimal disruption of spinal anatomy. When compared to the X-Stop device (which is no longer available), the Superion implant shows improved outcomes at 3 years of follow-up. ISS are lesser invasive options as compared to formal decompression and fusion for the treatment of lumbar spinal stenosis.

The Likelihood of Reaching Substantial Clinical Benefit After an Interlaminar Dynamic Spacer for Chronic Low Back Pain: A Clinical and Radiologic Analysis of a Prospective Cohort

OBJECTIVE

Chronic low back pain (CLBP) often causes disabling pain that impairs a patient's quality of life. Surgical treatment is recommended for patients who do not respond to conservative treatments lasting more than 6 months. The purpose of this study is to present results after the use of an interlaminar dynamic spacer for CLBP.

METHODS

We enrolled consecutive patients with CLBP irresponsive to more than 6 months of conservative treatment into the present study. Included patients underwent an interlaminar dynamic spacer insertion without direct decompression. We assessed radiographic parameters and health-related quality of life (HRQoL) data included visual analog scale back/leg pain and Oswestry Disability Index scores. Substantial clinical benefit achievement was assessed.

RESULTS

Thirty-five patients (average age, 47.8 years; 21 female) were included. The mean preoperative symptom duration was 29.6 months. Surgeries involved 1-level (n = 18) and 2-levels (n = 17) procedures. Operative levels included L4-5 (n = 8), L5-S1 (n = 10), L3-4-5 (n-2), and L4-5-S1 (n = 15). The average follow-up period was 16.6 months. After the procedure, all radiographic parameters (including disc height, segmental extension angle, and foraminal area) improved significantly. All preoperative HRQoL parameters improved significantly at the final follow-up. Substantial clinical benefit achievement was observed in 75.8% of the cases on the Oswestry Disability Index, and in 72.7% and 84.8% of the cases on the visual analog scale back and leg pain, respectively.

CONCLUSIONS

An interlaminar dynamic spacer significantly improves HRQoL scores in patients with CLBP who do not respond to conservative treatment. Although encouraging, these results should be confirmed with studies assessing a larger cohort and a longer follow-up.

Decompression and coflex interlaminar stabilisation compared with conventional surgical procedures for lumbar spinal stenosis: A systematic review and meta-analysis

BACKGROUND

Decompression plus spinal fusion is one of the most common surgeries for the treatment of degenerative spine disease in older adults. However, complications caused by fusion surgery have been reported in some studies. Recently published studies have reported that coflex is a safe and viable option in the selection of instrumentation for spinal stabilisation. Our meta-analysis was conducted to investigate whether decompression and coflex results in better performance for lumbar spinal stenosis (LSS) patients when compared with decompression and fusion surgery.

METHOD

Web of Science, PubMed, Embase, and the Cochrane Library were comprehensively searched. Ten studies that compared coflex with fusion surgery were included in our meta-analysis. The PRISMA guidelines and Cochrane Handbook were applied to assess the quality of the results published in all included studies to ensure that the results of our meta-analysis were reliable and veritable.

RESULTS

The results of our meta-analysis showed that decompression and coflex was more effective than the control procedure in terms of the Oswestry Disability Index (ODI), length of hospital stay (LOS) and blood loss. However, no significant difference was found in visual analogue scale (VAS) and major device-related complications.

CONCLUSIONS

Compared with conventional decompression plus fusion surgery, coflex was not inferior in terms of functional clinical outcomes, including ODI and VAS pain score. Moreover, coflex showed less blood loss, shorter LOS and similar device-related complications compared to decompression plus fusion surgery. Therefore, the coflex interlaminar stabilisation device was found to be safe and effective compared to decompression plus fusion for the treatment of LSS.