Interspinous process devices for treatment of degenerative lumbar spine stenosis: A systematic review and meta-analysis

Effect of Different Interventions on Lumbar Spinal Stenosis: A Systematic Evaluation and Network Meta-Analysis

BACKGROUND

Surgery is the preferred option for lumbar spinal stenosis (LSS) when conservative methods cannot meet the needs. Recent advancements in surgical techniques have brought various new methods for treating LSS.

METHODS

Four databases, PubMed, Embase, the Cochrane Library, and Web of Science, were searched, covering the period from the establishment of the databases until May 2024. Randomized controlled trials were carried out to treat LSS using different surgical approaches. The outcome measures included the visual analog scale (VAS) score, Oswestry disability index score, surgical duration, intraoperative blood loss, and length of hospital stay of patients. Bayesian random-effects network meta-analysis was performed using R software (V4.4) and STATA17.0 software to analyze each surgical approach.

RESULTS

A total of 29 studies involving 4200 patients were included. Nine intervention methods, including laminotomy, decompression, decompression plus fusion, endoscopic decompression, interspinous process spacer device (IPSD), laminectomy, minimally invasive decompression, spinous process osteotomy, and lumbar interbody fusion, were analyzed. Network meta-analysis results indicated that endoscopic decompression (surface under the cumulative ranking curve [SUCRA = 88.70%) was the most effective in reducing short-term back VAS scores. IPSD (SUCRA = 98.00%) was the most effective in reducing long-term back VAS scores, surgical duration (SUCRA = 95.20%), and intraoperative blood loss (SUCRA = 100.00%). Endoscopic decompression (SUCRA = 83.60%) also showed the most significant effect in reducing hospital stays.

CONCLUSIONS

Endoscopic decompression can effectively improve short-term back VAS scores and reduce hospital stays, while IPSD is effective in reducing long-term back VAS scores with minimal surgical duration and blood loss.

Efficacy and safety of interspinous process device compared with alone decompression for lumbar spinal stenosis: A systematic review and meta-analysis

STUDY DESIGN

Systematic review and meta-analysis.

BACKGROUND

Interspinous process devices (IPD) were used as a treatment in selected patients with lumbar spinal stenosis (LSS). However, the use of IPD was still debated that it had significantly higher reoperation rates compared to traditional decompression. Therefore, the purpose of the meta-analysis was to evaluate the effectiveness and safety of IPD treatment in comparison to traditional treatment.

METHODS

The databases were searched of PubMed, Embase and the Cochrane, Chinese National Knowledge Infrastructure, Chongqing VIP Database and Wan Fang Database up to January 2024. Relevant studies were identified by using specific eligibility criteria and data was extracted and analyzed based on primary and secondary endpoints.

RESULTS

A total of 13 studies were included (5 RCTs and 8 retrospective studies). There was no significant difference of Oswestey Disability Index (ODI) score in the last follow-up (MD = -3.81, 95% CI: -8.91-1.28, P = .14). There was significant difference of Visual Analog Scale (VAS) back pain scoring in the last follow-up (MD = -1.59, 95% CI: -3.09--0.09, P = .04), but there existed no significant difference of leg pain in the last follow-up (MD = -2.35, 95% CI: -6.15-1.45, P = .23). What's more, operation time, bleeding loss, total complications and reoperation rate had no significant difference. However, IPD had higher device problems (odds ratio [OR] = 9.00, 95% CI: 2.39-33.91, P = .001) and lesser dural tears (OR = 0.32, 95% CI: 0.15-0.67, P = .002) compared to traditional decompression.

CONCLUSION

Although IPD had lower back pain score and lower dural tears compared with traditional decompression, current evidence indicated no superiority for patient-reported outcomes for IPD compared with alone decompression treatment. However, these findings needed to be verified in further by multicenter, double-blind and large sample RCTs.

Feasibility, safety, and efficacy of a new percutaneous interspinous device: a retrospective multicenter study

PURPOSE

To evaluate safety and efficacy of the novel percutaneous interspinous device (PID) for the treatment of symptomatic degenerative lumbar spinal stenosis (DLSS) in 3 different centers.

METHODS

From November 2016 to March 2020, 255 patients (male 125, mean age 71.2 years old range 49-91 years old) with neurogenic claudication, confirmed by electromyography, related to mono or bi-segmental lumbar central canal and/or foraminal stenosis were enrolled in the study. Magnetic resonance (MR) and/or computer tomography (CT), physical exam, and Visual Analogue Scale (VAS) and Zurich Claudication Questionnaire (ZCQ) were performed before and 6 months after the procedure. All treatments were performed under fluoroscopic guidance with local anesthesia and mild sedation. Technical success was defined as correct placement of the Lobster® (Demetrios Medical, Firenze, Italy) PID as demonstrated by computer tomography (CT) performed immediately after treatment; spinoplasty was performed in selected patients.

RESULTS

PID placement was accomplished with a 99.6% success rate (257/258). The one device that was not implanted was due to a spinous process fracture. In 28 patients, more than 1 device was implanted in the same session (max 3 PIDs); 6 patients required a second implant in different session. A total of 172 prophylactic spinoplasties were performed (59.3%). No major complications occurred; 3 device misplacements were successfully treated with percutaneous retrieval and new device deployment. 99.6% of patients experienced clinical improvement.

CONCLUSION

Lobster PID is an effective and safe minimally invasive decompression method for central canal and neural foraminal stenosis when patients are correctly selected.

Image-Guided Minimally Invasive Treatment Options for Degenerative Lumbar Spine Disease: A Practical Overview of Current Possibilities

Lumbar back pain is one of the main causes of disability around the world. Most patients will complain of back pain at least once in their lifetime. The degenerative spine is considered the main cause and is extremely common in the elderly population. Consequently, treatment-related costs are a major burden to the healthcare system in developed and undeveloped countries. After the failure of conservative treatments or to avoid daily chronic drug intake, invasive treatments should be suggested. In a world where many patients reject surgery and prefer minimally invasive procedures, interventional radiology is pivotal in pain management and could represent a bridge between medical therapy and surgical treatment. We herein report the different image-guided procedures that can be used to manage degenerative spine-related low back pain. Particularly, we will focus on indications, different techniques, and treatment outcomes reported in the literature. This literature review focuses on the different minimally invasive percutaneous treatments currently available, underlining the central role of radiologists having the capability to use high-end imaging technology for diagnosis and subsequent treatment, allowing a global approach, reducing unnecessary surgeries and prolonged pain-reliever drug intake with their consequent related complications, improving patients' quality of life, and reducing the economic burden.

Characterizing utilization patterns and reoperation risk factors of interspinous process devices: analysis of a national claims database

INTRODUCTION

Interspinous process devices (IPDs) were developed as minimally invasive alternatives to open decompression surgery for spinal stenosis. However, given high treatment failure and reoperation rates, there has been minimal adoption by spine surgeons. This study leveraged a national claims database to characterize national IPD usage patterns and postoperative outcomes after IPD implantation.

METHOD

Using the PearlDiver database, we identified all patients who underwent 1- or 2-level IPD implantation between 2010 and 2018. Univariate and multivariable logistic regression was performed to identify predictors of the number of IPD levels implanted and reoperation up to 3 years after the index surgery. Right-censored Kaplan-Meier curves were plotted for duration of reoperation-free survival and compared with log-rank tests.

RESULTS

Patients (n = 4865) received 1-level (n = 3246) or 2-level (n = 1619) IPDs. Patients who were older (adjusted odds ratio [aOR] 1.02, 95% confidence interval [CI] 1.01-1.03, P < .001), male (aOR 1.31, 95% CI 116-1.50, P < .001), and obese (aOR 1.19, 95% CI 1.05-1.36, P < .01) were significantly more likely to receive a 2-level IPD than to receive a 1-level IPD. The 3-year reoperation rate was 9.3% of patients when mortality was accounted for during the follow-up period. Older age decreased (aOR 0.97, 95% CI 0.97-0.99, P = .0039) likelihood of reoperation, whereas 1-level IPD (aOR 1.37, 95% CI 1.01-1.89, P = .048), Charlson Comorbidity Index (aOR 1.07, 95% CI 1.01-1.14, P = .018), and performing concomitant open decompression increased the likelihood of reoperation (aOR 1.68, 95% CI 1.35-2.09, P = .0014).

CONCLUSION

Compared with 1-level IPDs, 2-level IPDs were implanted more frequently in older, male, and obese patients. The 3-year reoperation rate was 9.3%. Concomitant open decompression with IPD placement was identified as a significant risk factor for subsequent reoperation and warrants future investigation.

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of lumbar spinal stenosis, 2021 - Secondary publication

BACKGROUND

The Japanese Orthopaedic Association (JOA) guideline for the management of lumbar spinal stenosis (LSS) was first published in 2011. Since then, the medical care system for LSS has changed and many new articles regarding the epidemiology and diagnostics of LSS, conservative treatments such as new pharmacotherapy and physical therapy, and surgical treatments including minimally invasive surgery have been published. In addition, various issues need to be examined, such as verification of patient-reported outcome measures, and the economic effect of revised medical management of patients with lumbar spinal disorders. Accordingly, in 2019 the JOA clinical guidelines committee decided to update the guideline and consequently established a formulation committee. The purpose of this study was to describe the formulation we implemented for the revision of the guideline, incorporating the recent advances of evidence-based medicine.

METHODS

The JOA LSS guideline formulation committee revised the previous guideline based on the method for preparing clinical guidelines in Japan proposed by the Medical Information Network Distribution Service in 2017. Background and clinical questions were determined followed by a literature search related to each question. Appropriate articles based on keywords were selected from all the searched literature. Using prepared structured abstracts, systematic reviews and meta-analyses were performed. The strength of evidence and recommendations for each clinical question was decided by the committee members.

RESULTS

Eight background and 15 clinical questions were determined. Answers and explanations were described for the background questions. For each clinical question, the strength of evidence and the recommendation were both decided, and an explanation was provided.

CONCLUSIONS

The 2021 clinical practice guideline for the management of LSS was completed according to the latest evidence-based medicine. We expect that this guideline will be useful for all medical providers as an index in daily medical care, as well as for patients with LSS.

Biomechanical Evaluation of Transforaminal Lumbar Interbody Fusion with Coflex-F and Pedicle Screw Fixation: Finite Element Analysis of Static and Vibration Conditions

OBJECTIVE

To investigate the biomechanics of transforaminal lumbar interbody fusion (TLIF) with interspinous process device (IPD) or pedicle screw fixation under both static and vibration conditions by the finite element (FE) method.

METHOD

A validated FE model of the L1-5 lumbar spine was used in this study. This FE model derived from computed tomography images of a healthy female adult volunteer of appropriate age. Then the model was modified to simulate L3-4 TLIF. Four conditions were compared: (i) intact; (ii) TLIF combined with bilateral pedicle screw fixation (BPSF); (iii) TLIF combined with U-shaped IPD Coflex-F (CF); and (iv) TLIF combined with unilateral pedicle screw fixation (UPSF). The intact and surgical FE models were analyzed under static and vibration loading conditions respectively. For static loading conditions, four motion modes (flexion, extension, lateral bending, and axial rotation) were simulated. For vibration loading conditions, the dynamic responses of lumbar spine under sinusoidal vertical load were simulated.

RESULT

Under static loading conditions, compared with intact case, BPSF decreased range of motion (ROM) by 92%, 95%, 89% and 92% in flexion, extension, lateral bending and axial rotation, respectively. While CF decreased ROM by 87%, 90%, 69% and 80%, and UPSF decreased ROM by 84%, 89%, 66% and 82%, respectively. Compared with CF, UPSF increased the endplate stress by 5%-8% in flexion, 7%-10% in extension, 2%-4% in lateral bending, and decreased the endplate stress by 16%-19% in axial rotation. Compared with CF, UPSF increased the cage stress by 9% in flexion, 10% in extension, and decreased the cage stress by 3% in lateral bending, and 13% in axial rotation. BPSF decreased the stress responses of endplates and cage compared with CF and UPSF. Compared BPSF, CF decreased the facet joint force (FJF) by 6%-13%, and UPSF decreased the FJF by 4%-12%. During vibration loading conditions, compared with BPSF, CF reduced maximum values of the FJF by 16%-32%, and vibration amplitudes by 22%-35%, while UPSF reduced maximum values by 20%-40%, and vibration amplitudes by 31%-45%.

CONCLUSION

Compared with other surgical models, BPSF increased the stability of lumbar spine, and also showed advantages in cage stress and endplate stress. CF showed advantages in IDP and FJF especially during vertical vibration, which may lead to lower risk of adjacent segment degeneration. CF may be an effective alternative to pedicle screw fixation in TLIF procedures.

Analysis of Long-Term Results of Lumbar Discectomy With and Without an Interspinous Device

BACKGROUND

Discectomy is the surgical treatment of choice for disc herniation. However, discectomy can lead to disc degeneration and vertebral instability over time. Interspinous devices (ISDs), added to conventional surgery, constitute a low-invasive alternative that attempts to prevent these complications. The aim of this study is to compare the long-term clinical and functional outcomes of patients undergoing conventional discectomy with those who had an ISD added during surgery.

METHODS

This analytical-descriptive, retrospective, and transversal studyinvestigated outcomes of 114 patients who underwent surgery for a lumbar disc herniation between 2008 and 2011. The results were evaluated with a minimum follow-up of 8 years (mean, 10 years) by means of different questionnaires: visual analog scale (VAS), Oswestry Disability Index (ODI), consumption of analgesic medication, work status, degree of satisfaction, and complications and reinterventions during the follow-up period.

RESULTS

At the end of the follow-up, an overall improvement of VAS of 5 points (71%) and ODI of 36 points (77%) was observed, with a degree of satisfaction of 76% with disc surgery. The analysis between both groups showed a better behavior in VAS and ODI in the implant group, with a pre- and postsurgery difference of 73% and 79% compared to 66% and 77% in the control group, respectively, though this finding was not statistically significant. The current analgesic consumption and the degree of satisfaction were also better in the group with an implant. Compared with the non-implant group, the number of reinterventions at the end of the follow-up was lower (7% vs 15.5%) and the time until the second intervention was higher (81.5 vs 41 months) in the group with an implant, but the differences were not statistically significant.

CONCLUSIONS

Lumbar discectomy proved to be a safe technique for the treatment of disc herniation, and results are maintained over time. The additional gesture of adding an ISD to conventional discectomy improves clinical outcomes overall, but not in a statistically significant way. The lower number of reinterventions and the longer period without surgery being required may mean a certain protective effect of the ISD on the intervertebral disc being operated on.

Interspinous Process Devices Do Not Reduce Intervertebral Foramina and Discs Heights on Adjacent Segments

Aim

Interspinous process device (IPD) placement is an attractive treatment option for lumbar spinal and foraminal stenosis. The goal of the treatment is to release the stress on facets joints as well as decompress the nerve roots by enlarging the intervertebral foramina and narrowed canal recesses.

Purpose

To evaluate possible structural changes in the lumbar spine after implantation of an IPD on operated and adjacent segments.

Patients and Methods

Twenty-two patients were enrolled in the study. Preoperative MRI scans of the lumbar spine evaluated recess and foraminal stenosis prior to the application of an IPD. CT exams were performed and morphometric measurements were made to assess the size of intervertebral foramina after implantation on the operated and adjacent segments.

Results

Statistically significant enlargements in diameter and surface area of the intervertebral foramen were seen at the operating level. On the right and left sides, foraminal enlargement after the procedure was 1 mm in diameter. The average enlargement of the foramina surface area at the level of implantation was 10 mm². The median interspinous distance was significantly enlarged by 3.5 mm. No significant changes in adjacent segments were observed. Clinical improvement was confirmed by the Oswestry Disability Index (ODI) and visual analog scale (VAS). Preoperative disability was reduced (mean ODI from 70.5 (12.25) to 49.5 (23.75)), as well as back pain (mean VAS from 8.0 (1.7) to 4.4 (2.6)) and pain in lower limbs (mean VAS from 7.4 (1.9) to 3.8 (2.9)).

Conclusion

Decompression surgery using an IPD is effective in the treatment of lumbar foraminal and canal stenosis. It provides relief of symptoms in short-term observation through enlargement of intervertebral foramina and decompression of neural roots. It reduces overload of facet joints of the operated segment and does not decrease the size of the intervertebral foramina and disc heights of adjacent segments.

Minimally Invasive Spine Surgery: An Overview

Spinal surgery is undergoing a major transformation toward a minimally invasive paradigm. This shift is being driven by multiple factors, including the need to address spinal problems in an older and sicker population, as well as changes in patient preferences and reimbursement patterns. Increasingly, minimally invasive surgical techniques are being used in place of traditional open approaches due to significant advancements and implementation of intraoperative imaging and navigation technologies. However, in some patients, due to specific anatomic or pathologic factors, minimally invasive techniques are not always possible. Numerous algorithms have been described, and additional efforts are underway to better optimize patient selection for minimally invasive spinal surgery (MISS) procedures in order to achieve optimal outcomes. Numerous unique MISS approaches and techniques have been described, and several have become fundamental. Investigators are evaluating combinations of MISS techniques to further enhance the surgical workflow, patient safety, and efficiency.

Biomechanical comparison of different interspinous process devices in the treatment of lumbar spinal stenosis: a finite element analysis

Background

Lumbar spinal stenosis (LSS) is a common disease among elderly individuals, and surgery is an effective treatment. The development of minimally invasive surgical techniques, such as the lumbar interspinous process device (IPD), has provided patients with more surgical options.

Objective

To investigate the biomechanical properties of different IPDs, including BacFuse, X-Stop and Coflex, in the treatment of LSS.

Methods

Based on the computed tomography images of a patient with LSS, four finite element (FE) models of L3-S5 were created in this study. The FE models included a surgical model of the intact lumbar spine and surgical models of the lumbar IPDs BacFuse, X-Stop, and Coflex. After validating the models, they were simulated for four physiological motions: flexion, extension, lateral bending and axial rotation, and range of motion (ROM). Stress distribution of discs and facet joints in each segment, stress distribution of the spinous process in the operated section, and stress distribution of the internal fixation were compared and analysed.

Results

Compared to the model of the intact lumbar spine, the other three models showed a decrease in ROM and disc and facet joint stresses in the surgical segment during movement and an increase in ROM and disc and facet joint stresses in the adjacent segments. These effects were greater for the proximal adjacent segment with BacFuse and more pronounced for the distal adjacent segment with Coflex, while X-Stop had the greatest stress effect on the spinous process in the surgical segment.

Conclusion

BacFuse, Coflex and X-Stop could all be implemented to effectively reduce extension and disc and facet joint stresses, but they also increase the ROM and disc and facet joint stresses in adjacent segments, which may cause degeneration.

Clinical Evaluation of Surgery for Single-Segment Lumbar Spinal Stenosis: A Systematic Review and Bayesian Network Meta-Analysis

To compare the efficacy and safety of different surgical procedures for patients with single‐segment lumbar spinal stenosis (LSS), Bayesian network meta‐analysis (NMA) was conducted in this study. Randomized controlled trials (RCTs) which reported 2 years' results after surgery were searched from PubMed, Embase, and Cochrane Register of Controlled Trials up to February 2021. Eligible RCTs that contained at least two of the following surgical procedures, bilateral decompression via the unilateral approach (BDUL), decompression with conventional laminectomy (CL), decompression with fusion (DF), endoscopic decompression (ED), interspinous process devices only (IPDs), decompression with interlaminar stabilization (DILS), decompression with lumbar spinal process‐splitting laminectomy (LSPSL), and minimally invasive tubular decompression (MTD), would be included after screening based on the inclusion and exclusion criteria. The primary outcome was Oswestry Disability Index (ODI). Twenty eligible RCTs were included, with a total of 2201 patients enrolled. The NMA showed that the following surgical procedures ranked first (surface under the cumulative ranking) when compared with CL and DF: DILS for ODI (SUCRA 87.8%); LSPSL for back pain (95%); and MTD for leg pain (95.6%). MTD ranked among the top three surgical procedures for most outcomes. The quality of the synthesized evidence was low according to the Grading of Recommendations Assessment, Development, and Evaluation criteria. DILS, LSPSL, MTD, IPDs, and ED are the most effective procedures for patients with single‐segment LSS. Because of combining efficacy and safety, MTD may be the most promising routine surgical option for treating single‐segment LSS.

Less Invasive Decompressive Laminectomy and One-Level Lumbar Fusion in the Setting of Interspinous Fixation: A Retrospective Analysis of 15 Patients

Lumbar decompressive laminectomy for spinal stenosis can be performed using a less-invasive, unilateral approach with subperiosteal dissection and decompression by undermining the lamina from the ipsilateral to the contralateral side. A unilateral approach to bilateral decompression can be supplemented with interspinous instrumentation and facet fusion, a combined procedure that has not been studied before. The less-invasive technique appears to be as effective for lumbar stenosis as the traditional lumbar laminectomy. It also causes less blood loss and reduced operating time, and so may benefit patients who are elderly, medically frail, or with multiple comorbidities. 

Fifteen patients (eight females, seven males) underwent outpatient surgery by the author (HA) using this technique. These patients complained of progressive lower back pain associated with radicular pain exacerbated by prolonged standing or walking with improvement in flexed position of the lumbar spine with decreased walking distance ability. A one-level less-invasive lumbar laminectomy and foraminotomy with facet fusion and interspinous fixation were performed for spinal stenosis in conjunction with a Grade I degenerative spondylolisthesis. These patients all had a single-level facet fusion with bone graft material and local autograft. The approximate surgical time for each patient was between 50 and 80 minutes. The visual analog scale for pain (VAS) score decreased significantly after surgery; patients presented with preoperative VAS scores of 5-10/10 (mean 8.33/10). Postoperative VAS scores were 0-6/10 (mean 2/10), yielding a mean VAS improvement of 76% following surgery. Future analysis should be performed for evaluation of sustained VAS score, Oswestry Disability Index (ODI), Form 36 Health Survey Questionnaire (SF 36), and the Zurich Claudication Questionnaire (ZCQ).

Which is the most effective treatment for lumbar spinal stenosis: Decompression, fusion, or interspinous process device? A Bayesian network meta-analysis

Objective

To compare the clinical efficacy, complications, and reoperation rates among three major treatments for lumbar spinal stenosis (LSS): decompression, fusion, and interspinous process device (IPD), using a Bayesian network meta-analysis.

Materials and methods

Databases including Pubmed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science were used for the literature search. Randomized Controlled Trials (RCTs) with three treatment methods were reviewed and included in the study. R software (version 3.6.0), Stata (version 14.0), and Review Manager (version 5.3) were used to perform data analysis.

Results

A total of 10 RCTs involving 1254 patients were enrolled in the present study and each study met an acceptable quality according to our quality assessment described later. In direct comparison, IPD exhibited a higher incidence of reoperation than fusion (OR ​= ​2.93, CI: 1.07–8.02). In indirect comparison, the rank of VAS leg (from best to worst) was as follows: IPD (64%) ​> ​decompression (25%) ​> ​fusion (11%), and the rank of ODI (from best to worst) was: IPD (84%) ​> ​fusion (13%) ​> ​decompression (4%). IPD had the lowest incidence of complications; the rank of complications (from best to worst) was: IPD (60%) ​> ​decompression (27%) ​> ​fusion (14%). However, for the rank of reoperation, fusion showed the best results (from best to worst): fusion (79%) ​> ​decompression (20%) ​> ​IPD (1%). Consistency tests at global and local level showed satisfactory results and heterogeneity tests using loop text indicated a favorable stability.

Conclusion

The present study preliminarily indicates that non-fusion methods including decompression and IPD are optimal choices for treating LSS, which achieves favorable clinical outcomes. IPD exhibits a low incidence of complications, but its high rate of reoperation should be treated with caution.

The translational potential of this article

For the treatment of LSS, several procedures including decompression, fusion, and IPD have been reported. However, each method has its own advantages and disadvantages. To date, the golden standard treatment for LSS is still controversial. In this network meta-analysis, our results demonstrate that both decompression and IPD obtain satisfactory clinical effects for LSS. IPD is accompanied with a low incidence of complications, however, its high rate of reoperation should be acknowledged with discretion.

Spine Fixation Hardware: An Update

OBJECTIVE. The purpose of this article is to provide a review of the imaging of spine fixation hardware. CONCLUSION. As the prevalence of neck and back pain continues to increase, so does the number of surgical procedures used to treat such pain. Accordingly, new techniques and hardware designs are used, and the hardware will be seen on postoperative imaging. It is critical that radiologists understand the appropriate imaging modalities for the assessment of spine fixation hardware, recognize the normal imaging appearance of such hardware, and be able to detect hardware-related complications.

Interlaminar stabilization offers greater biomechanical advantage compared to interspinous stabilization after lumbar decompression: a finite element analysis

BACKGROUND

Interlaminar stabilization and interspinous stabilization are two newer minimally invasive methods for lumbar spine stabilization, used frequently in conjunction with lumbar decompression to treat lumbar stenosis. The two methods share certain similarities, therefore, frequently being categorized together. However, the two methods offer distinct biomechanical properties, which affect their respective effectiveness and surgical success.

OBJECTIVE

To compare the biomechanical characteristics of interlaminar stabilization after lumbar decompression (ILS) and interspinous stabilization after lumbar decompression (ISS). For comparison, lumbar decompression alone (DA) and decompression with instrumented fusion (DF) were also included in the biomechanical analysis.

METHODS

Four finite element models were constructed, i.e., DA, DF, ISS, and ILS. To minimize device influence and focus on the biomechanical properties of different methods, Coflex device as a model system was placed at different position for the comparison of ISS and ILS. The range of motion (ROM) and disc stress peak at the surgical and adjacent levels were compared among the four surgical constructs. The stress peak of the spinous process, whole device, and device wing was compared between ISS and ILS.

RESULTS

Compared with DA, the ROM and disc stress at the surgical level in ILS or ISS were much lower in extension. The ROM and disc stress at the surgical level in ILS were 1.27° and 0.36 MPa, respectively, and in ISS 1.51°and 0.55 MPa, respectively in extension. This is compared with 4.71° and 1.44 MPa, respectively in DA. ILS (2.06-4.85° and 0.37-0.98 MPa, respectively) or ISS (2.07-4.78° and 0.37-0.98 MPa, respectively) also induced much lower ROM and disc stress at the adjacent levels compared with DF (2.50-7.20° and 0.37-1.20 MPa, respectively). ILS further reduced the ROM and disc stress at the surgical level by 8% and 25%, respectively, compared to ISS. The stress peak of the spinous process in ILS was significantly lower than that in ISS (13.93-101 MPa vs. 31.08-172.5 MPa). In rotation, ILS yielded a much lower stress peak in the instrumentation wing than ISS (128.7 MPa vs. 222.1 MPa).

CONCLUSION

ILS and ISS partly address the issues of segmental instability in DA and hypermobility and overload at the adjacent levels in DF. ILS achieves greater segmental stability and results in a lower disc stress, compared to ISS. In addition, ILS reduces the risk of spinous process fracture and device failure.

Degenerative Lumbar Spinal Stenosis

Degenerative lumbar spinal stenosis is the most frequent cause of low back pain and/or sciatica in the elderly patient. Epidemiology, pathophysiology, clinical manifestations and testing are reviewed in a wide current bibliographic investigation. The importance of the relationship between clinical presentation and imaging study, especially magnetic resonance imaging (MRI), is emphasized. Prior to treatment indication, it is necessary to identify the precise location of pain, as well as the differential diagnosis between neurological and vascular lameness. Conservative treatment combining medications with various physical therapy techniques solves the problem in most cases, while therapeutic testing with injections, whether epidural, foraminal or facetary, is performed when pain does not subside with conservative treatment and before surgery is indicated. Injections usually perform better results in relieving sciatica symptoms and less in neurological lameness. Equine tail and/or root decompression associated or not with fusion is the gold standard when surgical intervention is required. Fusion after decompression is necessary in cases with segmental instability, such as degenerative spondylolisthesis. When canal stenosis occurs at multiple levels and is accompanied by axis deviation, whether coronal and/or sagittal, correction of axis deviations should be performed in addition to decompression and fusion, especially of the sagittal axis, in which a lumbar lordosis correction is required with techniques that correct the rectified lordosis to values close to the pelvic incidence.

An Algorithmic Approach to Treating Lumbar Spinal Stenosis: An Evidenced-Based Approach

OBJECTIVE

Lumbar spinal stenosis (LSS) can lead to compression of the neural and vascular elements and is becoming more common due to degenerative changes that occur because of aging processes. Symptoms may manifest as pain and discomfort that radiates to the lower leg, thigh, and/or buttocks. The traditional treatment algorithm for LSS consists of conservative management (physical therapy, medication, education, exercise), often followed by epidural steroid injections (ESIs), and when nonsurgical treatment has failed, open decompression surgery with or without fusion is considered. In this review, the variables that should be considered during the management of patients with LSS are discussed, and the role of each treatment option to provide optimal care is evaluated.

RESULTS

This review leads to the creation of an evidence-based practical algorithm to aid clinicians in the management of patients with LSS. Special emphasis is directed at minimally invasive surgery, which should be taken into consideration when conservative management and ESI have failed.

Mobility-Preserving Surgery for Lumbar Spinal Stenosis: WFNS Spine Committee Recommendations

Background

Although decompression is the basis of surgical treatment for lumbar spinal stenosis (LSS), under various circumstances instrumented fusion is performed as well. The rationale for mobility-preserving operations for LSS is preventing adjacent segment disease (ASD). We review the rationale for mobility preservation in ASD and discuss related topics such as indications for fusion and the evolving role of minimally invasive approaches to lumbar spine decompression. Our focus is on systematic review and consensus discussion of mobility-preserving surgical methods as related to surgery for LSS.

Methods

Groups of spinal surgeons (members of the World Federation of Neurosurgical Societies Spine Committee) performed systematic reviews of dynamic fixation systems, including hybrid constructs, and of interspinous process devices; consensus statements were generated based on the reviews at 2 voting sessions by the committee several months apart. Additional review of background data was performed, and the results summarized in this review.

Results

Decompression is the basis of surgical treatment of LSS. Fusion is an option, especially when spondylolisthesis or instability are present, but indications remain controversial. ASD incidence reports show high variability. ASD may represent the natural progression of degenerative disease in many cases. Older age, poor sagittal balance, and multilevel fusion may be associated with more ASD. Dynamic fixation constructs are treatment options that may help prevent ASD.

Successful use of percutaneous interspinous spacers and adjunctive spinoplasty in a 9 year cohort of patients

Purpose

Lumbar spinal canal stenosis and lumbar spinal foraminal stenosis are common, degenerative pathologies which can result in neurogenic claudication and have a negative impact on function and quality of life. Percutaneous interspinous devices (PIDs) are a recently-developed, minimally-invasive, alternative treatment option. This study details a 9 year single-centre experience with PIDs and examines the complementary use of spinous process augmentation (spinoplasty) to reduce failure rates.

Methods

A retrospective cohort assessment of 800 consecutive patients who presented to a specialized spine hospital was performed with 688 receiving treatment. Inclusion was based on high-grade stenosis, failure of conservative management and electromyography. 256 had a PID alone while 432 had concurrent polymethyl methacrylate (PMMA) augmentation of the adjacent spinous processes. The patients were followed up at 3 and 12 months using the Zurich Claudication Questionnaire (ZCQ) and Oswestry Disability Index (ODI).

Results

Both groups showed marked improvement in the patients’ ZCQ scores (3.2 to 1.3) and ODI scores (32 to 21), with strong satisfaction results (1.7). The symptom recurrence rate from complications for the group which received concurrent spinous process augmentation was reduced when compared with the PID alone cohort (<1% vs 11.3%).

Conclusion

This study demonstrates the efficacy of percutaneous interspinous devices in treating lumbar spinal stenosis. It also provides evidence that concurrent spinous process augmentation reduces the rate of symptom recurrence.

Percutaneous Interspinous Spacer in Spinal-Canal-Stenosis Treatment: Pros and Cons

A comprehensive description of the literature regarding interspinous process devices (IPD) mainly focused on comparison with conservative treatment and surgical decompression for the treatment of degenerative lumbar spinal stenosis. Recent meta-analysis and articles are listed in the present article in order to establish IPD pros and cons.

Percutaneous endoscopic ventral facetectomy: An innovative substitute of open decompression surgery for lateral recess stenosis surgical treatment?

Background:

Percutaneous transforaminal endoscopic surgery (PTES) constitutes an innovative method principally recruited for the treatment of lumbar disc herniation. Indication spectrum of PTES is constantly widened in current years. Hence, PTES has been proposed to represent a satisfactory alternative for the treatment of lateral recess stenosis (LRS), being defined as percutaneous endoscopic ventral facetectomy (PEVF) in these cases. The aim of this original study is to determine, for the first time in the literature, the outcomes of PEVF, especially in otherwise healthy nonelderly patients with LRS, alongside with special focus in health-related quality of life (HRQoL) assessment.

Materials and Methods:

Eighty-five otherwise healthy individuals from 58 to 64 years were diagnosed with LRS, being subjected to successful PEVF. Patients were prospectively evaluated in 6 weeks, in 3, 6, and 12 months, and in 2 years postoperatively. Visual analog scales (VASs) were separately utilized for leg and low back pain evaluation (VAS-LP and VAS-BP, respectively), whereas Short Form-36 (SF-36) questionnaire was sequentially implemented for HRQoL assessment.

Results:

All indexes of SF-36 as well as VAS-LP featured maximal amelioration in 6 weeks postoperatively, with subsequent further enhancement until 3 months and successor stabilization until 2 years. In contrast, VAS-BP presented minimal quantitative amelioration in 6 weeks, featuring no additional alterations. Values of all indexes in all follow-up intervals were demonstrated to be statistically significant in comparison with preoperative values (P < 0.05). No remarkable differentiation was observed between distinct parameters of SF-36.

Conclusions:

PEVF implementation in nonelderly patients with LRS was displayed to be safe and effective, providing alongside considerable improvement in HRQoL 2 years postoperatively.