Innovative technologies in thoracolumbar and lumbar spine surgery failing to reach standard of care: state-of-art review.

PURPOSE: To evaluate previously popular technologies in the field of spine surgery, and to better understand their advantages and limitations to the current standards of care. Spine surgery is an ever-evolving field that serves to resolve various spinal pathologies in patients of all ages. While there are established treatments for various conditions, such as lumbar spinal stenosis, idiopathic scoliosis, and degenerative lumbar disease, there is always further research and development in these areas to produce innovative technologies that can lead to better outcomes. As this process progresses, we must remind ourselves of previously tried and tested inventions and their outcomes that have fallen short of becoming a standard to ensure we are able to learn lessons from the past. METHODS: A thorough literature review was conducted with the aim of compiling literature of previously utilized technologies in spine surgery. Biomedical databases were utilized to gather relevant articles including PubMed, MEDLINE, and EMBASE. Emphasis was placed on gathering articles with technologies or therapeutics aimed at treating common spinal pathologies including lumbar spinal stenosis (LSS), adolescent idiopathic scoliosis (AIS), and other degenerative lumbar spine diseases. The keywords used were: "failed technologies", "historical technologies", "spine surgery", "spinal stenosis", "adolescent idiopathic scoliosis", and "degenerative lumbar spine disease". A total of 47 articles were gathered after initial review. RESULTS: Different technologies pertaining to spine surgery were identified and critically evaluated. Some of these technologies included X-STOP, Vertiflex, Vertebral Body Stapling, and Dynesys. These technologies were evaluated for their strengths and limitations across their spinal pathology applications. While each type of technology had their benefits, the data tended to be mixed with various limitations across studies. CONCLUSION: These technologies have been trialed in the field of spine surgery across various spinal pathologies, but still prove of limited efficacy and shortcomings to the current standards of care.

Perspective: Efficacy and outcomes for different lumbar interspinous devices (ISD) vs. open surgery to treat lumbar spinal stenosis (LSS).

Background: Interspinous devices (ISD) constitute a minimally invasive (MI) alternative to open surgery (i.e., laminectomy/decompression with/without fusion (i.e., posterior lumbar interbody fusion (PLIF)/posterolateral instrumented fusion (PLF)) for treating lumbar spinal stenosis (LSS). Biomechanically, static and/or dynamic ISD "offload" pressure on the disc space, increase intervertebral foraminal/disc space heights, reverse/preserve lordosis, limit range of motion (ROM)/stabilize the surgical level, and reduce adjacent segment disease (ASD). Other benefits reported in the literature included; reduced operative time (OR Time), length of hospital stay (LOS), estimated blood loss (EBL), and improved outcomes (i.e., ODI (Oswestry Disability Index), VAS (Visual Analog Scale), and/or SF-36 (Short-Form 36)). Methods: Various studies documented the relative efficacy and outcomes of original (i.e., Wallis), current (i.e., X-STOP, Wallis, DIAM, Aperius PercLID), and new generation (i.e., Coflex, Superion Helifix, In-Space) ISD used to treat LSS vs. open surgery. Results: Although ISD overall resulted in comparable or improved outcomes vs. open surgery, the newer generation ISD provided the greatest reductions in critical cost-saving parameters (i.e., OR time, LOS, and lower reoperation rates of 3.7% for Coflex vs. 11.1% for original/current ISD) vs. original/current ISD and open surgery. Further, the 5-year postoperative study showed the average cost of new generation Coflex ISD/decompressions was $15,182, or $11,681 lower than the average $26,863 amount for PLF. Conclusion: Patients undergoing new generation ISD for LSS exhibited comparable or better outcomes, but greater reductions in OR times, EBL, LOS, ROM, and ASD vs. those receiving original/current ISD or undergoing open surgery.

Effectiveness of X-stop Interspinous Distractor Device Versus Laminectomy for Treatment of Lumbar Stenosis: A Systematic Review and Meta-Analysis.

Lumbar spinal stenosis refers to the narrowing of the spinal canal in the lumbar region. There is an increasing need to determine the treatment modality for lumbar spinal stenosis by comparing the outcomes of X-stop interspinous distractors and laminectomy. The objective of this study is to determine the effectiveness of the X-stop interspinous distractor compared to laminectomy. This systematic review fundamentally abides by the procedures delineated in the Cochrane methodology while the reporting is done according to the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. Three databases searched generated a total of 943 studies, with PubMed being the source for the bulk of the articles. Six studies were selected for inclusion in this study. The effectiveness of the interspinous distractor devices and laminectomy can be determined through their impact on the quality of life, rates of complications, and the amount of money utilized. This meta-analysis fundamentally emphasizes that laminectomy is a more effective intervention for the treatment of lumbar spinal stenosis as it is more cost-effective and results in fewer complications in the long term.

Biomechanical effect of Coflex and X-STOP spacers on the lumbar spine: a finite element analysis.

OBJECTIVE: To explore the biomechanical differences between Coflex and X-STOP devices by finite element analysis. METHODS: Based on the normal lumbar CT images from a healthy adult volunteer, four finite element models including the healthy lumbar segment model, the mild degenerated lumbar segment model, a Coflex fixed lumbar segment model and X-STOP fixed lumbar segment model were constructed. A simulation analysis under the conditions of flexion, extension, lateral bending, and rotation was performed to compare range of motion (ROM), intradiscal pressure, the facet joint force, the maximum Von Mises stress and the peak facet contact forces, between Coflex and X-STOP devices. RESULTS: Compared to the mild degenerated lumbar segment model at surgical level L4-L5, Coflex and X-STOP could reduce ROM in extension by 98.34% and 95.86%, respectively, decrease peak stress of intervertebral discs in extension by 59.4% and 66.17%, respectively, and release peak force of facet joint in extension by 97.09% and 95.42%, respectively. Both devices had no significant impact on adjacent levels. The maximum Von Mises stress in Coflex device was 637.56 Mpa in flexion, 528.86 Mpa in extension, while the maximum Von Mises stress in X-STOP device was 476.65 Mpa at extension position. The peak facet contact forces of Coflex and X-STOP devices appeared in extension and were 19.76 Mpa and 49.28 Mpa, respectively. CONCLUSIONS: Coflex and X-STOP devices can effectively decrease the ROM and intradiscal pressure in extension, without affecting the adjacent levels.

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.

Biomechanics and Mechanism of Action of Indirect Lumbar Decompression and the Evolution of a Stand-alone Spinous Process Spacer.

OBJECTIVE: Objective Interspinous process spacers are used in the treatment of lumbar spinal stenosis by preventing extension at the implanted level and reducing claudication, which is a common symptom of lumbar spinal stenosis. This review assessed the current safety and performance of lumbar spinal stenosis treatments and the biomechanical effects of spinal position, range of motion, and the use of interspinous process spacers. METHOD: Method EMBASE and PubMed were searched to find studies reporting on the safety and performance of nonsurgical treatment, including physical therapy and pharmacological treatment, and surgical treatment, including direct and indirect lumbar decompression treatment. Results were supplemented with manual searches to include studies reporting on the use of interspinous process spacers and the review of biomechanical testing performed on the Superion device. RESULTS: Results The effects of spinal position in extension and flexion have been shown to have an impact in the variation in dimensions of the spinal canal and foramina areas. Overall studies have shown that spinal positions from flexion to extension reduce the spinal canal and foramina dimensions and increase ligamentum flavum thickness. Biomechanical test data have shown that the Superion device resists extension and reduces angular movement at the implantation level and provides significant segmental stability. CONCLUSIONS: Conclusions Superion interspinous lumbar decompression is a minimally invasive, low-risk procedure for the treatment of lumbar spinal stenosis, which has been shown to have a low safety profile by maintaining sagittal alignment, limiting the potential for device dislodgment or migration, and to preserve mobility and structural elements.

Comparative effectiveness and safety of posterior lumbar interbody fusion, Coflex, Wallis, and X-stop for lumbar degenerative diseases: A systematic review and network meta-analysis.

Posterior lumbar interbody fusion and lumbar interspinous non-fusion technique are common surgical procedures for lumbar degenerative diseases, but the effectiveness and safety of these two techniques are still unclear. We performed this network meta-analysis to evaluate the comparative effectiveness and safety of posterior lumbar interbody fusion and the three commonly used interspinous devices including Coflex, Wallis, and X-stop for lumbar degenerative diseases. Randomized controlled trials and cohort studies comparing among posterior lumbar interbody fusion, Coflex, Wallis, and X-stop for lumbar degenerative diseases were identified using the databases including PubMed, the Cochrane Library, Web of Science, the China National Knowledge Infrastructure, Chinese Science and Technology Periodical Database, and Wanfang data. A network meta-analysis was performed using R 3.4.3 software. 27 studies with 2241 patients were included. The results of network meta-analysis revealed that no significant differences in Oswestry Disability Index, Visual Analogue Scale, Japanese Orthopedic Association Scores, and posterior disc height were found among posterior lumbar interbody fusion group, Coflex, Wallis, or X-stop. However, compared with posterior lumbar interbody fusion, the three interspinous process devices presented with significantly more range of motion in surgical segment, but no significant difference was found among these three interspinous process devices. Node-splitting analysis showed no significant inconsistency in our network meta-analysis. We concluded that compared with posterior lumbar interbody fusion, Coflex, Wallis and X-stop had the same effectiveness in relieving pain, improving quality of life, recovering disc space height and lumbar function, but may lower incidence of adjacent segment degeneration.

Comparison of two FDA-approved interspinous spacers for treatment of lumbar spinal stenosis: Superion versus X-STOP-a meta-analysis from five randomized controlled trial studies.

BACKGROUND: Decompressive laminectomy (DI) is a standard operation for lumbar spinal stenosis (LSS) patient with severe claudication symptoms for many years. However, patients whose symptom severity does not meet undergoing invasive surgery make therapeutic options into dilemma. Interspinous spacers (ISP) bridge the gap between surgical interventions and CC in management of LSS. In our study, we aim to systematically assess the two FDA-approved interspinous spacers for treatment of lumbar spinal stenosis: Superion versus X-STOP. METHODS: Electronic databases, including PubMed, Embase, MEDLINE, Cochrane Library were searched to retrieve clinical trials concerning the comparison between Superion and X-STOP in treatment for lumbar spinal stenosis before April 2017. The following outcome measures were extracted: (1) Zurich Claudication Questionnaire (ZCQ) patient satisfaction score, (2) axial pain severity, (3) extremity pain severity, (4) back-specific functional impairment, (5) reoperation, and (6) complication. The data analysis was conducted with Review Manager 5.3. RESULTS: Five randomized controlled trials (RCTs) with 1118 patients were included in this meta-analysis. The pooled analysis indicated that the Superion group is superior to X-STOP in axial pain severity (SMD: 0.03; 95% CI 0.15, 0.45; p < 0.0001, I2 = 41%, p = 0.16), ZCQ patient satisfaction score (SMD: 0.23; 95% CI 0.08, 0.38; p = 0.002, I2 = 0%, p = 0.61). However, Superion group showed similarity outcome in extremity pain severity (SMD: 0.18; 95% CI - 0.06, 0.43; p = 0.14, I2 = 62%, p = 0.05), back-specific functional impairment (SMD: 0.04; 95% CI - 0.10, 0.19; p = 0.56, I2 = 0%, p = 0.77), reoperation rate (RR: 1.10; 95% CI 0.82, 1.48; p = 0.51, I2 = 19%, p = 0.30), and complication (RR: 0.98; 95% CI 0.63, 1.53; p = 0.92, I2 = 0%, p = 0.83). CONCLUSION: Both the Superion and X-STOP interspinous spacers can relieve symptoms of LSS. In addition, the Superion spacer may represent a promising spacer for patient with LSS. As we know, the effectiveness and safety of ISP is still considered investigational and unfavor clinical results in the medical literature may continue to limit the appeal of IPS to many surgeons in the future. However, because of the advantage of IPS technique, it will win a wide place in the future degenerative lumbar microsurgery.

Interspinous implants: are the new implants better than the last generation? A review.

PURPOSE OF REVIEW: Interspinous process devices (IPDs) are used in the surgical treatment of lumbar spinal stenosis. The purpose of this review is to compare the first generation with the next-generation devices in terms of complications, device failure, reoperation rates, symptom relief, and outcome. RECENT FINDINGS: Thirty-seven studies were included from 2011 to 2016. Device failure occurred at a mean of 3.7%, with a lower tendency to happen with next-generation IPDs. Reoperations occurred at a lower rate with the next-generation devices, with a mean follow up of 24 months (3.7% vs. 11.1%). The clinical outcome is not influenced by the type of IPD. The long-term functionality of these devices is questionable, with radiologic changes and recurrence of symptoms often seen by 2 years following implantation. Next-generation devices do not appear to be subject to the same "bounce back" effect of symptom re-emergence after several years.

Lumbar lateral shift in a patient with interspinous device implantation: a case report.

BACKGROUND: Lumbar lateral shift (LLS) is a common clinical observation but has rarely been described in a patient with a history of lumbar surgery. The purpose of the current case report was to describe the use of the McKenzie Method of Mechanical Diagnosis and Therapy (MDT) in the multi-modal treatment of a patient with an LLS and a history of multiple surgical procedures in the lumbar spine, including interspinous process device (IPD) implantation. CASE DESCRIPTION: A 72-year-old female with chronic low back pain (LBP) and a surgical history in the lumbar spine was referred to physical therapy for radiating leg pain and presented with a right LLS. Her chief complaints included sitting for long periods, vacuuming and ascending stairs into her home. OUTCOMES: The patient was treated during eight visits over 30 days. Treatment interventions included manual shift correction, self-correction and management, joint mobilisation below the level of IPD implantation ,neurophysiology education, and development of a home exercise programme. At discharge, her leg pain was resolved and all goals had been met. The patient reported maintenance of gains at 6-month follow-up. DISCUSSION: Utilisation of the MDT approach, including LLS correction, produced positive outcomes in a complex patient with previous IPD implantation. Future research should investigate treatment and outcomes after invasive spinal procedures in similar patient populations to better inform clinical management. LEVEL OF EVIDENCE: 4.

Failure rates and complications of interspinous process decompression devices: a European multicenter study.

OBJECT Spacers placed between the lumbar spinous processes represent a promising surgical treatment alternative for a variety of spinal pathologies. They provide an unloading distractive force to the stenotic motion segment, restoring foraminal height, and have the potential to relieve symptoms of degenerative disc disease. The authors performed a retrospective, multicenter nonrandomized study consisting of 1108 patients to evaluate implant survival and failure modes after the implantation of 8 different interspinous process devices (IPDs). METHODS The medical records of patients who had undergone placement of an IPD were retrospectively evaluated, and demographic information, diagnosis, and preoperative pain levels were recorded. Preoperative and postoperative clinical assessments in the patients were based on the visual analog scale. A minimum of 3 years after IPD placement, information on long-term outcomes was obtained from additional follow-up or from patient medical and radiological records. RESULTS One thousand one hundred eight patients affected by symptomatic 1- or 2-level segmental lumbar spine degenerative disease underwent placement of an IPD. The complication rate was 7.8%. There were 27 fractures of the spinous process and 23 dura mater tears with CSF leakage. The ultimate failure rate requiring additional surgery was 9.6%. The reasons for revision, which always involved removal of the original implant, were acute worsening of low-back pain or lack of improvement (45 cases), recurrence of symptoms after an initial good outcome (42 cases), and implant dislocation (20 cases). CONCLUSIONS The IPD is not a substitute for a more invasive 3-column fusion procedure in cases of major instability and spondylolisthesis. Overdistraction, poor bone density, and poor patient selection may all be factors in the development of complications. Preoperatively, careful attention should be paid to bone density, appropriate implant size, and optimal patient selection.

Grade 1 spondylolisthesis and interspinous device placement: removal in six patients and analysis of current data.

BACKGROUND: In the treatment of patients with Grade 1 spondylolisthesis, the use of interspinous devices has been controversial for nearly a decade. Several authors have suggested that Grade 1 spondylolisthesis be considered a contraindication for interspinous device placement. METHODS: We removed interspinous devices in six symptomatic Grade 1 spondylolisthesis patients and analyzed pertinent literature. RESULTS: All six patients reported an improvement in symptoms following device removal and subsequent instrumented fusion. One patient who had not been able to walk due to pain regained the ability to walk. Several articles were identified related to spondylolisthesis and interspinous devices. CONCLUSIONS: Regarding patients receiving interspinous devices for symptomatic lumbar spinal stenosis, several high-quality studies have failed to demonstrate a statistical difference in outcomes between patients with or without Grade 1 spondylolisthesis. Nevertheless, surgeons should have a high degree of suspicion when considering use of interspinous devices in this patient population.

Interspinous spacer decompression (X-STOP) for lumbar spinal stenosis and degenerative disk disease: a multicenter study with a minimum 3-year follow-up.

Interspinous distraction devices provide an effective treatment for patients suffering from lumbar spinal stenosis and/or degenerative disk disease. The aim of this multicenter study was the prospective evaluation of patients treated for symptomatic lumbar spinal stenosis with interspinous process decompression (IPD) implants compared with a population of patients managed with conservative treatment. 542 patients affected by symptomatic lumbar spine degenerative disease were enrolled in a controlled trial. 422 patients underwent surgical treatment consisting of X-STOP device implantation, whereas 120 control cases were managed conservatively. Both patient groups underwent follow-up evaluations at 6, 12, 24, and 36 months using the Zurich Claudication Questionnaire, the Visual Analog Scale score and spinal lumbar X-rays, CT scans and MR imaging. One-year follow-up evaluation revealed positive good results in the 83.5% of patients treated with IPD with respect to 50% of the nonoperative group cases. During the first three years, in 38 out of the 120 control cases, a posterior decompression and/or spinal fixation was performed because of unsatisfactory results of the conservative therapy. In 24 of 422 patients, the IPD device had to be removed, and a decompression and/or pedicle screw fixation was performed because of the worsening of neurological symptoms. Our results support the effectiveness of surgery in patients with stenosis. IPD may offer an effective and less invasive alternative to classical microsurgical posterior decompression in selected patients with spinal stenosis and lumbar degenerative disk diseases.

Analysis of Internet information on the controversial X-Stop device.

BACKGROUND CONTEXT: The Internet is frequently used by patients to aid in medical decision making. Multiple studies display the Internet's ineffectiveness in presenting high-quality information regarding surgical procedures and devices. With recent reports of unacceptably high complication rates and poor outcomes with the X-Stop device, it is important that online information is comprehensive and accurate. This study is the first to examine Internet information on the controversial X-Stop. PURPOSE: To determine how accurately public information over the Internet portrays the existing primary literature on the X-Stop, how extensively the X-Stop is characterized online, and how patient decision making could foreseeably be affected. STUDY DESIGN: This cross-sectional study analyzed publicly available Internet information, including videos on the web site YouTube regarding the X-Stop device. PATIENT SAMPLE: No patients were involved in this study. OUTCOME MEASURES: No specific outcome measures were used. METHODS: Search engines Google, Yahoo, and Bing were used to identify 105 web sites providing information on the X-Stop. Videos on the web site YouTube were included. Web sites were categorized based on the authorship. Each site was analyzed for the provision of appropriate patient inclusion and exclusion criteria, surgical and nonsurgical treatment alternatives, purported benefits, common complications, peer-reviewed literature citations, and descriptions/diagrams of the procedure. Data were evaluated for each authorship subgroup and the entire group of sites. RESULTS: Forty-three percent of sites were authored by a private medical group, 4% by an academic medical group, 16% by an insurance company, 9% by a biomedical industry, 10% by news sources, and 19% by other. Thirty-one percent of web sites and 11% of sites authored by private medical groups contained references to peer-reviewed literature. Fifty-six percent of web sites reported patient inclusion criteria, whereas 33% reported exclusion criteria. Benefits and complications were reported within 91% and 23% of sites, respectively. Surgical and nonsurgical treatment options were mentioned within 59% and 61% of web sites, respectively. CONCLUSIONS: Our study demonstrates the Internet's ineffectiveness in reporting quality information on the X-Stop. Information was often incomplete and potentially misleading. Significant controversy exists within primary literature regarding the safety and efficacy of the X-Stop. Yet, publicly available Internet information largely provided misinformation and did not reflect any such controversy. This raises the concern that such information lends itself more toward patient recruitment than patient education. Medical professionals need to know how this may affect their patients' decision making.

Evaluation of interspinous process distraction device (X-STOP) in a representative patient cohort.

OBJECTIVE: To test the hypothesis that the level of clinical efficacy reported in the investigational device exemption (IDE) study of the X-STOP device that led to its approval by the U.S. Food and Drug Administration could also be achieved in patients who are representative of the population approved for treatment, irrespective of whether they met all the stringent requirements of the IDE study. METHODS: A retrospective analysis was conducted of a consecutive series of 31 patients who received the X-STOP interspinous process distraction device as treatment for neurogenic intermittent claudication. Outcome was assessed at an average of 2 years after surgery by use of the Zurich Claudication Questionnaire (ZCQ), which used the definition of clinical success used in the IDE study. RESULTS: On the basis of the ZCQ, clinically significant improvement occurred in 38% of the evaluable patients (21 patients), compared with 48.4% in the IDE study; at the sites other than those of the device's inventors, the improvement level was 37%. Four patients needed additional surgery, which was a rate comparable with that reported in the IDE study. CONCLUSIONS: The success level in the controlled IDE study that established the safety and efficacy of the X-STOP device was achieved in a representative patient cohort that did not necessarily meet all the strict requirements of the IDE plan. Nevertheless, the overall results were not good, suggesting that the ZCQ definition of success might not have captured the true outcome of surgical treatment with the X-STOP device.