Interspinous Distraction Device Research Articles

Preliminary Results of a Prospective Clinical and Radiological Study with Roentgen Stereophotogrammetric Analysis (RSA) after Implantation of a Posterior Dynamic Stabilization Device in the Lumbar Spine

Introduction: Posterior dynamic stabilization (PDS) can be based on interspinous distraction devices (IDD). The goals of these implants are maintaining or restoring intervertebral range of motion (ROM) in a controlled fashion and avoiding a complete restriction of mobility. Clinical and radiological data with the Wallis® spacer as one type of IDD have been rarely reported. The goal of this study was to present clinical and radiological data including roentgen stereophotogrammetric analysis (RSA) after a short- to mid-term follow-up period.
 Patients and Methods: 10 patients were included in this prospective monocentric study and had PDS of the lumbar spine with an IDD (Wallis® spacer). Before and soon after operation and 3, 6, and 12 months later clinical and radiological evaluations were performed. Pain and disability were analyzed by use of visual analog scale for back and leg pain, Oswestry Disability Index, Roland-Morris Disability Questionnaire and Short-Form-36 Health Survey. The ROM of the operated levels and the total lumbar spine was determined by use of lateral functional x-ray images with calculation of the differences of the segmental and total lumbar spine angles in flexion and extension. Furthermore, RSA was used to measure the segmental ROM.
 Results: After a follow-up of 12 months, the results of the pain intensity and the disability and health related quality of life scores showed statistical significant improvement. The segmental angles of the operated levels demonstrated statistical significant reduction in ROM during the different follow-up examinations. The discrepancy of the conventionally determined segmental angles and the data measured by RSA were low with a mean of 1.77°. The mean total lumbar spine angles did not change statistically significantly during the postoperative controls.
 Conclusions: According to the radiological results of this study, the used implant leads to a posterior dynamic stabilization. The clinical findings are promising, but they are to be interpreted with caution because of the small number of patients and the lack of a control group.

The use of minimally invasive interspinous process devices for the treatment of lumbar canal stenosis: a narrative literature review.

Minimally invasive interspinous process devices (IPD), including interspinous distraction devices (IDD) and interspinous stabilizers (ISS), are increasingly utilized for treating symptomatic lumbar canal stenosis (LCS). There is ongoing debate around their efficacy and safety over traditional decompression techniques with and without interbody fusion (IF). This study presents a comprehensive review of IPD and investigates if: (I) minimally invasive IDD can effectively substitute direct neural decompression and (II) ISS are appropriate substitutes for fusion after decompression. Articles published up to 22nd January 2020 were obtained from PubMed search. Relevant articles published in the English language were selected and critically reviewed. Observational studies across different IPD brands consistently show significant improvements in clinical outcomes and patient satisfaction at short-term follow-up. Compared to non-operative treatment, mini-open IDD was had significantly greater quality of life and clinical outcome improvements at 2-year follow-up. Compared to open decompression, mini-open IDD had similar clinical outcomes, but associated with higher complications, reoperation risks and costs. Compared to open decompression with concurrent IF, ISS had comparable clinical outcomes with reduced operative time, blood loss, length of stay and adjacent segment mobility. Mini-open IDD had better outcomes over non-operative treatment in mild-moderate LCS at 2-year follow-up, but had similar outcomes with higher risk of re-operations than open decompression. ISS with open decompression may be a suitable alternative to decompression and IF for stable grade 1 spondylolisthesis and central stenosis. To further characterize this procedure, future studies should focus on examining enhanced new generation IPD devices, longer-term follow-up and careful patient selection.

Effects of modified U-shaped interspinous distraction device on cadaveric intervertebral disc pressure

Effects of modified U-shaped interspinous distraction device on cadaveric intervertebral disc pressure

Interspinous Distraction Devices, has this Lost its Place in Treatment Algorithm?

Interspinous Distraction Devices, has this Lost its Place in Treatment Algorithm?

Interspinous Distraction Device U May Avoid Posterior Artrothesis in the Future?

The authors conducted a prospective study in patients with disc herniation. We compared the results obtained in patients treated with the U device with those acquired in patients treated without any device. The u implant is a titanium alloy device that is placed between the spinous processes. In a cohort of patients with degenerative Lumbar Disc underwent surgical treatment in which the U device was placed and control individuals were treated with discectomy alone. Patients underwent serial follow-up evaluations and radiographic assessment was used to determine outcome. Up to ten years follow-up data were obtained in all patients (2005-2006). Statistically significant improvement was seeing patients treated with the coflex device. In the management of lumbar disc degeneration, to avoid lumbar instability in the future 85% vs. 70% (p<0.01). Our study shows that the U device was more effective than the discectomy group in the management of lumbar instability.

RESEARCH PROGRESS OF INTERSPINOUS DISTRACTION DEVICES FOR TREATMENT OF DEGENERATIVE LUMBAR SPINAL STENOSIS

To review the research status in respect of interspinous distraction devices (IDD) in the treatment of degenerative lumbar spinal stenosis (DLSS). Recent original articles related to IDD in the treatment of DLSS were retrieved extensively, and the effectiveness was analyzed and summarized. Its short-term effectiveness was superior to that of conservative treatment, no significant difference was found when compared with decompression or fusion alone. Its complication rate was higher than that of decompression or fusion alone, although complication dose not significantly affect treatment results, it still will increase the medical care cost of patients. IDD is appropriate for patients who have failed to nonoperative treatment measures and can not tolerate open surgery, but the long-term effectiveness and durability of IDD need further research.

Posterior dynamic stabilization in the lumbar spine – 24 months results of a prospective clinical and radiological study with an interspinous distraction device

BackgroundInterspinous distraction devices (IDD) are due to maintain or restore intersegmental range of motion (iROM) in a controlled fashion with the aim of stabilization the affected level dynamically. The following study is the first to present clinical and radiological data with the Wallis® spacer during a follow-up of 24 months.MethodsTen patients underwent posterior dynamic stabilization (PDS) of the lumbar spine with an IDD (Wallis® spacer) and were controlled clinically and radiologically after 3, 6, 12, and 24 months in a prospective study design. Pain intensity, functional disability and life quality were assessed by use of subjective scores. Motion analyses were performed with the help of lateral functional x-rays to determine the iROM of the operated segments and total ROM (tROM) of the lumbar spine. In addition, roentgen stereophotogrammetric analysis (RSA) was used to measure the iROM of the treated levels.ResultsDuring the postoperative course pain and disability most clinical scores were significantly improved. After 24 months we observed statistically significant reduction in back pain intensity with a mean value of 6.0 on visual analog scale (VAS) before surgery and of 2.7 at the latest evaluation. The leg pain was also decreased without statistical significance from 4.7 preoperatively to 2.1 at final follow-up. The functional disability according to Oswestry Disability Index (ODI) and Roland-Morris Disability Questionnaire (RM) was decreased both with statistical significance at all examination dates with a mean value in ODI of 40.0 % before operation and of 17.3 % after 2 years and an initial mean value in RM of 55.2 and of 23.5 % after latest follow-up. After 24 months, the results of the health related quality of life score also showed much better values with only two exceptions. The iROM of the treated levels was reduced during each follow-up examination with preserved residual mobility. Directly postoperatively and after 3 and 12 months intersegmental mobility was statistically significantly decreased with an average iROM of 6.62° before operation and of 2.69° few days after surgery, of 3.79° and 3.16° 3 and 12 months later. At 6 (4.37°) and 24 (4.01°) months follow-up iROM was also but not statistically significantly reduced. The mean tROM did not change significantly during all postoperative controls.ConclusionsThe radiological findings support the thesis of posterior dynamic stabilization by the used implant. The positive clinical findings should be interpreted with caution because of the limited number of patients and the missing control group.

A Report on the early Results of the BacJac Interspinous Distraction Device: A Prospective Study in Patients with Lumbar Spinal Stenosis

A Report on the early Results of the BacJac Interspinous Distraction Device: A Prospective Study in Patients with Lumbar Spinal Stenosis

Aperius interspinous device for degenerative lumbar spinal stenosis: a review.

With an aging population, degenerative lumbar spinal stenosis (DLSS) leading to neurogenic intermittent claudication (NIC) is a growing problem. For patients suffering from this condition, interspinous process distraction devices (IPDs) offer an effective and cheap alternative to conservative or decompressive surgery. Aperius is one such device that has been gaining popularity for its percutaneous insertion under local anesthetic, short operative time, and low risk of complications. The main objective of this review was to carry out a comprehensive search of the literature to evaluate the effectiveness and potential complications of Aperius. A database search, including PubMed, Clinical trials.gov, Cochrane (CENTRAL), MEDLINE, CINAHL, EMBASE, and Scopus, was carried out to identify relevant articles written in English reporting on complications with a minimum 12-month follow-up. The literature search resulted in six eligible studies; two nonrandomized comparative and four prospective case series were available. The analysis revealed that in total, 433 patients underwent treatment with Aperius, with all studies demonstrating an improvement in outcome measures. The average follow-up was 17 months with an overall complication rate of 10.62%. Overall, the quality of evidence is low, suggesting that currently, the evidence is not compelling and further prospective randomized trials including cost-effectiveness studies are required.

A report on the early results of the BacJac interspinous distraction device: a prospective study in patients with lumbar spinal stenosis

Aims: This is a report on the early clinical outcome of the BacJac interspinous distraction device in patients with lumbar spinal stenosis. Materials and methods: This is a prospective study on a group of patients who underwent surgery from February 2010 to December 2012. There were 21 consecutive patients who had insertion of a BacJac. Data prospectively recorded included Visual Analogue Scores for leg pain (VL), back pain (VB), the Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ), and walking distance (WD). Scores were recorded preand postoperatively and at final review. The follow-up period varied from 6 to 40 months. Results: We found all clinical outcome measures improved following surgery. Mean scores for VL improved from 76 to 27, for VB from 49 to 24, and for ODI from 42 to 26 at final follow-up. There were also improvements noted in ZCQ scores and patient-reported WD. We also noted a high rate of osteolysis (76%) around the implant at 1 year from insertion. Conclusion: This small prospective study suggests that there is a role for the use of the BacJac interspinous distraction devices in selected patients. Osteolysis around the implant remains an issue although this did not appear to compromise the early outcome in this study.

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.

A biomechanical cadaveric study of a modified U-shaped interspinous distraction device.

An experimental study. To analyze the effects of a modified U-shape interspinous distraction device (IDD) on the stability of a destabilized lumbar spine model. The use of IDD for treatment of lumbar spine pathology remains a subject of debate. A modified design of an IDD consisted of a titanium (Ti) U-shape dynamic stabilizer and a Ti tensioning wire loop was biomechanically tested. Six sets of cadaveric lumbar vertebrae levels 1-5 (L1-L5) were subjected to loads in flexion, extension, and lateral bending in the 4 following sequences: intact specimen, unilateral facetectomy and discectomy at L3-L4, insertion of the modified U-shape IDD at L3-L4, and pedicle screw fixation at L3-L4. The range of motion (ROM) of L3-L4 following modified U-shape IDD insertion was compared with that of the intact specimen. The ROM of the adjacent vertebrae (L2-L3 and L4-L5) following modified U-shape IDD insertion was compared with that after pedicle screw fixation. Statistical analysis was performed using the Wilcoxon signed-rank test. The modified U-shape IDD decreased the ROM of a destabilized L3-L4 in all testing load (P<0.05). The stability of L3-L4 following the modified U-shape IDD insertion was restored to that of the intact specimen (P>0.05). The ROM at adjacent vertebrae after the modified U-shape IDD placement was similar to the ROM obtained after pedicle screw fixation at L3-L4. The modified version of a U-shape IDD is effective in stabilizing an unstable segment of the lumbar spine. The device does not create deleterious effects on the adjacent vertebrae.

Biomechanical comparison of interspinous distraction device and facet screw fixation system on the motion of lumbar spine: a finite element analysis

Background A large amount of biomechanical and clinical evidence from previous studies suggest the efficiency of the two different posterior lumber non-fusion methods, interspinous distraction device (ISDD) and facet screw fixation system (FSS), but the biomechanical comparison of ISDD and FSS has not been thoroughly clarified. Methods In the current study, finite element methods were used to investigate the biomechanical comparison of ISDD and FSS. The range of motion (ROM), intradiscal pressure (IDP) and the protective effects gained by maintaining disc heights were evaluated. Results The ROM was similar between the two non-fusion methods under static standing, flexion and lateral bending. The FSS appeared to be more effective in resisting extension. At the implanted level L3/4, FSS displayed better results for maintaining and increasing posterior disc heights. At the L4/5 level in extension and lateral bending, FSS was better than ISDD, with comparable results observed in other motions. Comparing the posterior and lateral disc heights, FSS appeared to be more effective than ISDD. FSS also had a minor effect on the inferior adjacent segment than ISDD. FSS was more effective in reducing IDP than ISDD in extension. Conclusion Through the finite element analysis study, it can be seen that FSS demonstrates more beneficial biomechanical outcomes than does ISDD, such as being more effective in resisting extension, maintaining and increasing lumbar disc heights and reducing the inferior adjacent IDP in extension.

Why Do Interspinous Motion Preservation Devices (ISDs) Show Unfocused Results? Clinical Anatomy of Lumbar Lamina and Spinous Process

IntroductionInterspinous motion preservation technique for various spondylotic conditions has been supposed to be useful as a time-sparing technique before rigid instrumentation with a potential se...

Percutaneous interspinous distraction device for the treatment of lumbar spinal canal stenosis: clinical and radiographic results at 2-year follow-up.

ObjectiveTo evaluate the effectiveness of the In- space (Synthes, Umkirch, Germany) and the correlation between radiographic parameters and clinical outcome in patients with lumbar spinal canal stenosis (LSS).MethodsBetween June 2009 and May 2013, 56 patients with LSS underwent In-space by one senior surgeon. All of the patients were evaluated both clinically and radiographic measurements before the procedure and each visit at the postoperative follow-up. Preoperative and postoperative X-ray imaging was performed before the procedure and at follow-up to assess the correlation with the clinical outcome. Radiological measurements and clinical outcomes were recorded to establish a relationship between the radiographic parameters and clinical outcome of this procedure. All patients had at least 2 years of follow-up.ResultsThe mean VAS score of back pain decreased significantly (p < 0.05).ConclusionsOur data suggest that percutaneous interspinous devices are a good alternative to treat LSS. The device offers significant decrease in back pain, leg pain and ODI score with 2-year lasting relief from symptoms. The increased intervertebral foramenal space explains the improvement of leg pain, but the mechanism of back pain relief remains unclear. A very weak correlation between the radiographic changes and improvement of pain was found.

Surgical Role of Interspinous Distraction Devices (Coflex, DIAM) for the Treatment of Neurologic Pain and Intermittent Claudication Due to Lumbar Spinal Stenosis

Neurogenic intermittent claudication and degenerative low back pain caused by lumbar spinal stenosis (LSS) often occur after the age of 50 years and represent one of the most common degenerative spinal diseases of the elderly. We reviewed medical records and radiographs for patients with LSS who received an interspinous process device (IPD) between October 2009 and December 2010. The aim of the study was to evaluate surgical outcomes for decompressive surgery involving IPD implantation. We reviewed data for 62 patients who were treated with decompressive surgery and IPD (Coflex or DIAM). Neurogenic signs after surgery are important indicators. The patients were examined the day before, 2 weeks after, and 3 months after surgery. Pain was measured according to a visual analog scale (VAS) and neurologic changes were recorded. Postoperative assessments at 2 weeks and 3 months after surgery included pain and neurologic scores and a patient satisfaction survey. For some groups we observed a significant improvement ( p < 0.05) in back pain according to the VAS. Symptom relief on forward flexion is a key indicator for prognosis. Interspinous implants offer significant, long-lasting symptom control and IPDs are safe and effective devices for LSS.

Detection of Modern Spinal Implants by Airport Metal Detectors

Prospective cohort observational study. To determine the detection rates of modern spinal implants by post-9/11 airport metal detectors. There are few data on the detection rates of modern spinal implants and few that examine the effects of body mass, construct complexity, or implant density. Implants were tested ex vivo and in vivo using standard arch way metal detectors (AMDs) and handheld metal detectors (HHMDs) in use at the majority of European airports.A volunteer carried individual spinal implants both individually and in various combinations of increasing mass in clothing pockets into the AMD. The same instrumentation was bench tested using HHMD at a distance of 5 cm. Forty patients with modern spinal implants were tested: lumbar disc replacement (8), cervical disc replacement (1), posterior deformity instrumentation (17), anterior deformity instrumentation (2), anterior reconstruction (2), PLIF (6), interspinous distraction device (1), anterior cervical plate (2), and anterior lumbar interbody fusion with cage (1)-all implants were titanium unless indicated. Mean metal mass was 98 g (range, 6-222 g). Subject ages ranged from 13 to 65 years and the mean body mass index was 25 kg/m (range, 15-32). Ex vivo, the AMD did not detect any instrumentation individually or in combination up to a titanium mass of 215 g. The HHMD detected all instrumentation at a distance of 5 cm, with the minimum mass being 2 g. No implants were detected in patients by the AMD.The HHMD did not detect any anterior lumbar or thoracic surgical implants. It detected anterior cervical implants. The HHMD detected all posterior surgical implants. There was no significant relationship between detection rate, body mass index, total metal mass, and metal density/segment. AMDs do not detect modern spinal implants. HHMDs detect all modern posterior spinal implants; this has implications for patient documentation.

Interspinous Distraction Devices: Too Good to Be True? Yes

Interspinous Distraction Devices: Too Good to Be True? Yes

Role of lumbar interspinous distraction on the neural elements

The interspinous distraction devices are used to treat variable pathologies ranging from facet syndrome, diskogenic low back pain, degenerative spinal stenosis, diskopathy, spondylolisthesis, and instability. The insertion of a posterior element with an interspinous device (ISD) is commonly judged responsive to a relative kyphosis of a lumbar segment with a moderate but persistent increase of the spinal canal and of the foraminal width and area, and without influence on low-grade spondylolisthesis. The consequence is the need of shared specific biomechanical concepts to give for each degenerative problem the right indication through a critical analysis of all available experimental and clinical biomechanical data. We reviewed systematically the available clinical and experimental data about kyphosis, enlargement of the spinal canal, distraction of the interspinous distance, increase of the neural foramina, ligamentous structures, load of the posterior annulus, intradiskal pressure, strength of the spinous processes, degeneration of the adjacent segment, complications, and cost-effectiveness of the ISD. The existing literature does not provide actual scientific evidence over the superiority of the ISD strategy, but most of the experimental and clinical data show a challenging potential. These considerations are applicable with different types of ISD with only few differences between the different categories. Despite--or because of--the low invasiveness of the surgical implantation of the ISD, this technique promises to play a major role in the future degenerative lumbar microsurgery. The main indications for ISD remain lumbar spinal stenoses and painful facet arthroses. A clear documented contraindication is the presence of an anterolisthesis. Nevertheless, the existing literature does not provide evidence of superiority of outcome and cost-effectiveness of the ISD strategy over laminectomy or other surgical procedures. At this time, the devices should be used in clinical randomized independent trials in order to obtain more information concerning the most advantageous optimal indication or, in selected cases, to treat tailored indications.

Surgical treatment of lumbar spinal stenosis with microdecompression and interspinous distraction device insertion. A case series

BackgroundInterspinous distraction devices (IPDD) are indicated as stand-alone devices for the treatment of spinal stenosis. The purpose of this study is to evaluate the results of patients undergoing surgery for spinal stenosis with a combination of unilateral microdecompression and interspinous distraction device insertion.MethodsThis is a prospective clinical and radiological study of minimum 2 years follow-up. Twenty-two patients (average age 64.5 years) with low-back pain and unilateral sciatica underwent decompressive surgery for lumbar spinal stenosis. Visual Analogue Scale, Oswestry Disability Index and walking capacity plus radiologic measurements of posterior disc height of the involved level and lumbar lordosis Cobb angle were documented both preoperatively and postoperatively. One-sided posterior subarticular and foraminal decompression was conducted followed by dynamic stabilization of the diseased level with an IPDD (X-STOP).ResultsThe average follow-up time was 27.4 months. Visual Analogue Scale and Oswestry Disability Index improved statistically significantly (p < 0.001) in the last follow-up exam. Also, the walking distance increased in all patients but two. Posterior intervertebral disc height of the diseased level widened average 1.8 mm in the postoperative radiograph compared to the preoperative. No major complication, including implant failure or spinous process breakage, has been observed.ConclusionsThe described surgical technique using unilateral microdecompression and IPDD insertion is a clinically effective and radiologically viable treatment method for symptoms of spinal stenosis resistant to non-operative treatment.