Interspinous Process Distraction Research Articles

Biomechanical characteristics of a novel interspinous distraction fusion device in the treatment of lumbar degenerative diseases: a finite element analysis

BackgroundA novel interspinous distraction fusion (ISDF) device has been used to treat lumbar degenerative diseases. As a minimally invasive technique, ISDF differs from the traditional interspinous process distraction devices. Currently, biomechanical studies on ISDF are rare.ObjectiveTo investigate the biomechanical properties of the ISDF device (BacFuse) which is used to treat lumbar degenerative diseases.MethodsThree-dimensional L3-L5 models were created. The models were divided into four groups: intact (M1), local decompression alone (M2), internal fixation alone (M3) and local decompression combined with internal fixation (M4), based on different surgical procedures. Local laminectomy was performed to resect the lower part of the L4 lamina and the upper part of the L5 lamina at the right lamina of L4/5 in the M2 and M4 groups. After meshing the models elements, Abaqus were used to perform the finite element (FE) analysis. The intervertebral range of motion (ROM) was measured during flexion, extension, left lateral bending, right lateral bending, left rotation and right rotation under a follower load of 400 N with a 7.5Nm moment. The distributions of disc and facet joint stresses were observed and recorded. Spinal vertebral stress was compared, and internal fixation device stress was observed.ResultsThe ROM of L4/5 in M2 increased in flexion, extension, left lateral bending, right lateral bending, left rotation and right rotation compared with that in M1. In all motion directions, the ROM at L4/5 decreased, and the ROM at L3/4 increased after implantation of the ISDF device in M3 and M4 groups. The disc stress and facet joint stresses in the instrumented segment decreased after implantation of the ISDF device. The spinous process loaded a certain amount of stress in M3 and M4 groups. The spikes of the internal fixation device were loaded with the maximum stress.ConclusionBacFuse exhibited a reduction in intervertebral ROM, as well as decreased stress on the intervertebral disc and facet joint, while also demonstrating a discernible impact on the upper adjacent segment.

Transforaminal Endoscopic Discectomy Combined With an Interspinous Process Distraction System for Spinal Stenosis.

The combination of the percutaneous transforaminal endoscopic decompression (PTED) with an interspinous process distraction system (IPS) may offer additional benefit in the treatment of spinal stenosis in patients who have failed nonsurgical treatment. We retrospectively reviewed the medical records of 33 patients diagnosed with lumbar stenosis and radiculopathy and treated them with transforaminal endoscopic lumbar decompression between 2013 and 2017. Primary outcome measures were modified Macnab as well as preoperative and postoperative visual analog scale (VAS) criteria and the Oswestry Disability Index (ODI). Only patients with a minimum follow-up of 2 years were included. A total of 28 patients were treated with a combination of PTED and percutaneous IPS (group A), and 5 patients were treated with PTED and mini-open IPS (group B). In group A patients, there was a 4.48 reduction in the VAS score. The ODI changed from 50.25 preoperatively to 18.2 postoperatively, and excellent and good Macnab outcomes were obtained in 78% of patients. In group B patients, the mean VAS reduction was 5.2 points. The ODI changed from 44.34 preoperatively to 14.62 postoperatively, and 80% of group B patients achieved excellent and good Macnab outcomes. No complications related to PTED or IPS were observed throughout the 2-year follow-up. The addition of IPS to the PTED procedure in select patients may offer additional benefits to patients being treated for lumbar lateral stenosis and foraminal stenosis with low-grade spondylolisthesis. 3. Feasibility study.

A new interspinous process distraction device BacFuse in the treatment of lumbar spinal stenosis with 5 years follow-up study.

To explore a suitable indication of interspinous process distraction device for lumbar spinal stenosis with BacFuse.Patients of lumbar spinal stenosis (LSS) who experienced interspinous process distraction device surgery with BacFuse from June 2014 to January 2015 in our institute were included. We classified LSS into central and lateral types, and then divided these into severe and moderate according to the degree of stenosis. Each type was divided into 2 groups. Patients in group A underwent distraction without bone decompression (stand-alone), while patients in group B underwent bone decompression combined with distraction. Follow-up was performed at 1 month, 3 months, 6 months, 2 years, and 5 years after surgery. Zurich Claudication Questionnaire (ZCQ) was recorded to assess the patient's postoperative condition at each follow-up.A total of 142 patients were available for follow up at each time interval. There was a significant difference between the preoperative and final follow-up ZCQ scores for every LSS type. In addition, there was no difference between group A and group B in the postoperative ZCQ scores with the exception of the lateral severe type. In the study, 22 of the 23 patients (95.65%) in the lateral moderate type were considered to have a satisfactory result in group B, with a similar result of 93.33% (14/15) in group A (P = .75). In the lateral severe type, the patient satisfaction rate was 65.22% (15/23) and 90.63% (29/32) in group A and group B (P = .02), respectively. In the central moderate type, the patient satisfaction rate was 81.82% (15/23) and 76.92% (10/13) in group A and group B (P = .77), respectively. Satisfaction rate for the follow-up results in the central severe type reached 57.14% (4/7) in group A, and 54.55% (6/11) in group B (P = .91). Moreover, no relationship was found between satisfaction and neurogenic intermittent claudication.The most suitable indication for BacFuse treatment was the lateral moderate type. For lateral severe patients, distraction combined with decompression is suggested for a higher satisfaction rate. Severe central spinal stenosis was shown to be a relative contraindication for BacFuse.

250. Interspinous process distraction compared to nonoperative care for moderate lumbar degenerative disc disease: results of the FDA IDE clinical trial

BACKGROUND CONTEXT Interspinous process distraction (IPD) devices aim to alleviate back and leg pain by limiting extension and unloading the 3-joint complex at the affected lumbar level. IPDs may offer a treatment option for painful degenerative disc disease (DDD) that is not yet indicated for fusion or disc replacement. PURPOSE To compare the safety and effectiveness of IPD and nonoperative treatment after 2 years for the treatment of moderate lumbar DDD. STUDY DESIGN/SETTING A prospective, randomized, controlled FDA IDE clinical trial at 23 US centers (ClinicalTrials.gov: NCT00456378). PATIENT SAMPLE A total of 278 patients with moderate low back pain for less than 1 year and radiographic evidence of single-level DDD between L2 and L5 who failed at least 6 weeks but less than 6 months of conservative management were randomized and treated with investigational IPD (n=181) or control nonoperative treatment (n=97). OUTCOME MEASURES The primary endpoint was Overall Success, a composite variable that included: 1) Oswestry Disability Index (ODI) score improvement of ≥ 15 points; and 2) no serious adverse event (AE) caused by the implant or by both the implant and surgical procedure (IPD) or caused by the nonoperative treatment (control); and 3) no secondary surgery (IPD) or treatment surgery (control) at the involved level. Additional safety and effectiveness endpoints included back and leg pain numerical (0-20) rating scales, SF-36 PCS/MCS, AEs and secondary surgeries. METHODS Investigational treatment consisted of the IPD implantation (without decompression) and nonoperative treatments, as necessary. Control treatment consisted of information/ education on low back pain, medication, physical therapy, and epidural and/or facet joint steroidal injections. Clinical and radiographic assessments were performed preoperatively, intra-operatively, and postoperatively up to 2 years. Statistical analyses used Bayesian methods with non-informative priors. Last observation was carried forward (LOCF) for patients lost to follow-up including patients receiving surgery (control crossovers) or additional surgery (IPD investigational) at the involved level. RESULTS Baseline demographic characteristics and outcomes scores were not statistically different between the two groups, except back pain (16.8 for investigational vs 16.1 for control, p=0.033). The IPD rate of Overall Success at 24-months was statistically superior to control (observed rate of 63.0% vs 13.4%, respectively; posterior probability of superiority (pps) > 99.9%). The improvement in outcomes for IPD was statistically superior to control (pps > 99.9%) for: ODI (26.4 vs 1.1), back pain (8.4 vs 1.2), leg pain (4.9 vs -1.1, PCS (12.6 vs.1.4), and MCS (4.4 vs -0.8). Spinous process bony erosion increased slowly to 33.7% (61/181) of patients but was not related to clinical outcomes. Treatment-related serious AEs in the control group were associated with increasing low back pain. Fifteen (8.3%) IPD and 34 (35.1%) control patients experienced a treatment-related serious AE. Twenty (11.0%) IPD patients had secondary surgery and 10 (10.3%) control patients had treatment surgery at the index level. After 6 months of nonoperative treatment, control patients had the option to crossover to IPD: 57 (58.8%) control patients had crossed over by 24 months. CONCLUSIONS These analyses support the superiority of this IPD over conservative care for moderate back pain in appropriately selected patients. FDA DEVICE/DRUG STATUS DIAM™ Spinal Stabilization System (Investigational/Not approved)

Early Outcome of Discectomy with Interspinous Process Distraction Device a Retrospective Cross-Sectional Study

Orthopedic Research Online Journal Early Outcome of Discectomy with Interspinous Process Distraction Device a Retrospective Cross-Sectional Study Gunaseelan Ponnusamy* Nasional Universty of Malaysia, Malaysia *Corresponding author: Gunaseelan Ponnusamy, Nasional Universty of Malaysia, 1938 Jalan G-1, Taman Melawati 53100 Kuala Lumpur, Malaysia Submission: February 25, 2017; Published: March 21, 2018 DOI: 10.31031/OPROJ.2018.02.000536 ISSN : 2576-8875Volume2 Issue3

Biomechanical effect of interspinous process distraction height after lumbar fixation surgery: An in vitro model.

Pedicle screw fixation may induce abnormal activity at adjacent segment and accelerate the degeneration of lumbar vertebrae. Dynamic stabilizers could provide an intermediate solution between conservative treatment and fusion surgery. Lumbar vertebral segment cephalad to instrumented fixation was the most common localization of adjacent segment degeneration. The aim of this study is to explore the use of interspinous process devices in the lumbar vertebral segment cephalad to fixation segment in changing the mechanical distribution and limiting abnormal activity of the spine. Eight specimens were tested in the following groups: intact group, instability group (bilateral facetectomy at L3-L4), fixation group (bilateral facetectomy and pedicle screw fixation at L3-L4), and hybrid fixation group (fixation at L3-L4 and simulating interspinous device implantation of 6, 8, 10, 12, 14, 16, and 18 mm at L2-L3). Range of motion, motion of vertebral body, and strain distribution change were recorded. The range of motion in extension with 16- and 18-mm hybrid constructs was significantly lower than intact, instability, and fixation groups. In flexion and lateral bending, the strain values of L4 inferior articular process with 18-mm hybrid construct have a significant difference compared with other groups. In axial rotation, under the condition of a contralateral state, the strain values of L2 superior articular process with 18-mm hybrid construct have a significant difference compared with intact and fixation groups. The strain value of the L4 inferior articular process had negative correlation with height distraction in three dimensions, except extension. A negative correlation between the strain value of the L2 superior articular process and distraction height was found in contralateral bending and contralateral axial rotation. Interspinous process devices above the fixation segment can change the mechanical distribution of the spine and limit activity in some of the segments of the spine, which may delay the degeneration of the adjacent segment.

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.

IPD Coupled Decompression of Degenerative Spinal Stenosis: Comparative Results with Traditional Methods

Introduction The goal of this study was to obtain the success rate of decompression with concomitant interspinous process distraction device (IPD) implantation for degenerative lumbar spinal stenosis (DLSS) and to compare the results to historical series treated with traditional decompression with or without posterolateral (PL) instrumented fusion. Material and Methods This study prospectively analyzed the success rates of 18 DLSS patients treated with decompressive surgery and implantation of soft IPD (DIAM) at one or two levels. We compared the results with a historic group of 20 patients which were treated with traditional surgical decompression with or without PL fusion at one or two levels. In the DIAM group, outcomes were measured with the Zurich Claudication Questionnaire (ZCQ) and the short form health survey 36 (SF-36), completed preoperatively and at 6, 12, 24, and 48 months postoperatively. In the historic group, outcomes were measured with the ZCQ preoperatively and at 20.5 ± 10.5 months. The groups were compared in ZCQ results at 24 months. In the DIAM group, postoperative X-rays taken at 4 years were examined for erosions or fractures of the spinous processes Results The operating time was 89 (± 29) minutes in the DIAM and 139 (± 40) minutes in historic group. The blood loss was 265 (± 308) mL in the DIAM and 913 (± 630) mL in the historic group. The hospital stay was 6.3 (±2.4) days in the DIAM and 9.6 (± 5.4) days in the historic group. The narcotic use was 2.3 (± 1.5) days in the DIAM and 4.6 (± 2.6) days in the historic group. Overall, 61.1% (11/18) in the DIAM and 70% (14/20) of the patients in the historic group were considered to be clinically successful. In the DIAM group, SF-36 results significantly improved on follow-up at 6 months and continued to improve to 4 years. No erosions or fractions of the spinous processes were found on the X-rays in the DIAM group at the latest follow-up at 48 months. Conclusion The adjunct of a soft IPD to the decompression has provided patients with comparative results to traditional surgical methods. The main advantages of decompression coupled with soft IPD implantation for DLSS are shorter operating time, less blood loss, less hospital stay, and less narcotic use. The main disadvantage is increased cost of surgery.

Establishment of minimally acute spinal cord injury in mice model by the self-made device

Objective Try to construct the self-made spinal impactor and the simple interspinous process distraction stabilizing device.Discussion on the feasibility,stability and reliability of method establishing the acute spinal cord injury in mice model retaining the lamina.Methods Using a electric push fool,a pressure sensor and so on,to manufacture the spinal inpactor and the interspinous process distraction stabilizing device.32 adult female rats were randomly divided into four groups,using the self-made spinal impactor device to make varying degrees on the spinal cord of the mice model retaining the lamina,non-combat (0 g),mild (5 g),medium (10 g),and severe (20 g).Taking two mice from every group randomly and making pathological section of damage zone spinal cord after 12 h,testing the behavior BBB grade post operation 1,3 d,7,14 w,in order to evaluate its correlation with the strike force.Results The spinal impactor device and the interspinous process distraction stabilizing device was producted successfully,and the minimally invasive spinal cord injury model retaining the lamina was built.Pathological examination and behavioral score was related with the strike force closely and the grade differences was obvious (P ＜ 0.05).Conclusion A a stable and reliable spinal cord injury model retaining the lamina can be made by the self-made device,and this conducive to the further research on spinal cord injury. Key words: Self-made device; Minimally invasive; Spinal cord injury; Mice model

Device-Related Complications of the Coflex Interspinous Process Implant for the Lumbar Spine

Introduction Coflex, a type of interspinous process implant, can provide intervertebral dynamic stability for surgical segments and relieve lumbocrural pain effectively. However, few studies have described the avoidance and therapeutic strategies of Coflex implant complications. Materials and Methods Coflex implant complications included intraoperative or postoperative spinous process fracture, aggravated postoperative lumbocrural pain, dislodgment, and malposition in this study. The complications were analyzed, and therapeutic strategies were applied according to the specific complication. The Visual Analogue Scale and Oswestry Disability Index scores were evaluated by using the paired-samples test of SPSS 12.0 Results Conservative treatment was provided to seven patients who experienced aggravated lumbocrural pain even though their devices remained in the correct position, and pedicle screw treatment was used as an alternative in four cases. The Visual Analogue Scale and Oswestry Disability Index scores showed evident improvement in these patients. The Visual Analogue Scale and Oswestry Disability Index scores of two patients who underwent revision also improved. Conclusion Coflex implants should be avoided in patients with osteoporosis, a narrow interspinous space and intervertebral coronal spondylolysis, or sagittal instability; furthermore, the device choice, depth of implantation, and clamping intensity should be appropriate. Conservative treatment can be provided to patients with symptoms if the device remains in the correct position; however, revisions and salvages should be undertaken with internal fixation of pedicle screws for patients with device malposition, intraoperative implantation failure, or device intolerance. Disclosure of Interest None declared References Richards JC, Majumdar S, Lindsey DP, Beaupré GS, Yerby SA. The treatment mechanism of an interspinous process implant for lumbar neurogenic intermittent claudication. Spine 2005;30(7):744–749 Siddiqui M, Nicol M, Karadimas E, Smith F, Wardlaw D. The positional magnetic resonance imaging changes in the lumbar spine following insertion of a novel interspinous process distraction device. Spine 2005;30(23):2677–2682 Lee J, Hida K, Seki T, Iwasaki Y, Minoru A. An interspinous process distractor (X STOP) for lumbar spinal stenosis in elderly patients: preliminary experiences in 10 consecutive cases. J Spinal Disord Tech 2004;17(1):72-77, discussion 78 Kong DS, Kim ES, Eoh W. One-year outcome evaluation after interspinous implantation for degenerative spinal stenosis with segmental instability. J Korean Med Sci 2007;22(2):330–335 Errico TJ, Kamerlink JR, Quimo M, et al. Survivorship of coflex interlaminar-interspinous implant. SAS J 2009;3(2):59–67 Park SC, Yoon SH, Hong YP, Kim KJ, Chung SK, Kim HJ. Minimum 2-year follow-up result of degenerative spinal stenosis treated with interspinous u (coflex). J Korean Neurosurg Soc 2009;46(4):292–299 Bono CM, Vaccaro AR. Interspinous process devices in the lumbar spine. J Spinal Disord Tech 2007;20(3):255–261 Trautwein FT, Lowery GL, Wharton ND, Hipp JA, Chomiak RJ. Determination of the in vivo posterior loading environment of the Coflex interlaminar-interspinous implant. Spine J 2010;10(3):244–251 Tsai KJ, Murakami H, Lowery GL, Hutton WC. A biomechanical evaluation of an interspinous device (Coflex) used to stabilize the lumbar spine. J Surg Orthop Adv 2006;15(3):167–172 Christie SD, Song JK, Fessler RG. Dynamic interspinous process technology. Spine 2005; 30 (16, Suppl)S73-S78 Lindsey DP, Swanson KE, Fuchs P, Hsu KY, Zucherman JF, Yerby SA. The effects of an interspinous implant on the kinematics of the instrumented and adjacent levels in the lumbar spine. Spine 2003;28(19):2192–2197 Swanson KE, Lindsey DP, Hsu KY, Zucherman JF, Yerby SA. The effects of an interspinous implant on intervertebral disc pressures. Spine 2003;28(1):26–32 Bowers C, Amini A, Dailey AT, Schmidt MH. Dynamic interspinous process stabilization: review of complications associated with the X-Stop device. Neurosurg Focus 2010;28(6):E8 Chao S, Malloy JP, Bono CM. Complications specific to motion-sparing devices in the lumbar spine. Semin Spine Surg 2011;23(2):123–134 Kim DH, Tantorski M, Shaw J, et al. Occult spinous process fractures associated with interspinous process spacers. Spine 2011;36(16):E1080-E1085 Barbagallo GM, Olindo G, Corbino L, Albanese V. Analysis of complications in patients treated with the X-Stop Interspinous Process Decompression System: proposal for a novel anatomic scoring system for patient selection and review of the literature. Neurosurgery 2009;65(1):111-119, discussion 119–120 Barbagallo GM, Corbino LA, Olindo G, Foti P, Albanese V, Signorelli F. The “sandwich phenomenon”: a rare complication in adjacent, double-level X-stop surgery: report of three cases and review of the literature. Spine 2010;35(3):E96-E100 Anderson PA, Tribus CB, Kitchel SH. Treatment of neurogenic claudication by interspinous decompression: application of the X STOP device in patients with lumbar degenerative spondylolisthesis. J Neurosurg Spine 2006;4(6):463–471 Zucherman JF, Hsu KY, Hartjen CA, et al. A multicenter, prospective, randomized trial evaluating the X STOP interspinous process decompression system for the treatment of neurogenic intermittent claudication: two-year follow-up results. Spine 2005;30(12):1351–1358 Siddiqui M, Smith FW, Wardlaw D. One-year results of X Stop interspinous implant for the treatment of lumbar spinal stenosis. Spine 2007;32(12):1345–1348

Change in Sagittal Balance With Placement of an Interspinous Spacer

A prospective case series. To determine the effect of X-STOP implantation on sagittal spinal balance using 36-inch films. Interspinous process spacers have been shown as an effective treatment of neurogenic claudication. The devices block the last few degrees of extension at the stenotic level, thus preventing compression of the nerve roots. These devices have been criticized because they may push the patient's spine into a kyphotic position. However, opening the stenotic level may allow a patient to stand more upright, thereby improving sagittal balance. Institutional review board's approval was obtained. A prospective study of 20 patients who were undergoing an X-STOP insertion was utilized. Their spines were x-rayed preoperatively and postoperatively with 36-inch films. Preoperative and postoperative sagittal balance was measured with a C7 body plum line on both films and the difference was measured. Lumbar lordosis was also compared using Cobb angles. Measurements taken from lateral full-length spine radio-graphs showed an average improvement in sagittal balance of 2.0 cm (range -3.7 to 6.1 cm). The average change in lordosis was -1.1°. Although previous studies of interspinous process distraction have examined segmental lordosis, disc angles, and other parameters, this study is the first to examine overall spinal balance on full-length films. Interspinous distraction does not seem to be detrimental to sagittal balance, and may improve it.

Effectiveness of interspinous implant surgery in patients with intermittent neurogenic claudication: a systematic review and meta-analysis.

IntroductionDespite an increasing implantation rate of interspinous process distraction (IPD) devices in the treatment of intermittent neurogenic claudication (INC), definitive evidence on the clinical effectiveness of implants is lacking. The main objective of this review was to perform a meta-analysis of all systematic reviews, randomized clinical trials and prospective cohort series to quantify the effectiveness of IPDs and to evaluate the potential side-effects.MethodsData from all studies prospectively describing clinical results based on validated outcome scales and reporting complications of treatment of patients with INC with IPD placement. We searched MEDLINE, EMBASE, Web of Science, Cochrane (CENTRAL), CINAHL, Academic Search Premier, Science Direct up to July 2010. Studies describing patients with INC caused by lumbar stenosis, reporting complication rate and reporting based on validated outcome scores, were eligible. Studies with only instrumented IPD results were excluded.ResultsEleven studies eligible studies were identified. Two independently RCTs and eight prospective cohorts were available. In total 563 patients were treated with IPDs. All studies showed improvement in validated outcome scores after 6 weeks and 1 year. Pooled data based on the Zurich Claudication Questionnaire of the RCTs were more in favor of IPD treatment compared with conservative treatment (pooled estimate 23.2, SD 18.5–27.8). Statistical heterogeneity after pooled data was low (I-squared 0.0, p = 0.930). Overall complication rate was 7%.ConclusionAs the evidence is relatively low and the costs are high, more thorough (cost-) effectiveness studies should be performed before worldwide implementation is introduced.

Die Behandlung der dynamischen Spinalkanalstenose mit einem interspinösen Spacer

Indirect decompression of the spinal canal and the neuroforamina by means of interspinous process distraction and limitation of extension movements. Reduction of forces acting on the posterior joint structures of a functional spinal unit (posterior anulus, facet joints, intervertebral discs). Primary indication: Spinal claudication with improvement of the clinical symptomatology upon taking an inclined position. Secondary indication: Low back pain in the presence of accompanying retrolisthesis. Hyperlordosis Facet joint complaints Annulus lesions with high intensity zones (HIZ) M. Baastrup ("kissing spine"). Adjacent segment preservation (e.g. prophylaxis of recurrent disc herniation after discectomy or topping-off following previous fusion). Spinal instabilities which prohibit a solid fixation of the implant (e.g. spondylolysis, isthmus fractures, condition following previous (hemi-) laminectomy) Degenerative spondylolisthesis ffl 1st degree. Severe structural narrowing of the spinal canal. Absent dynamic aspect without improvement upon inclination, segmental ankylosis. Positioning of the patient in an inclined position. Approximately 4 cm median skin incision, bilateral access with preservation of the supraspinous ligament. Perforation of the interspinous ligament. Following interspinous distraction the adequate size implant is established. Insertion of the interspinous process distraction device (IPD) unit and fixation of the mobile wing unit from the contralateral side. Medial positioning and solid fixation of the implant by connecting the two implant units. Lumbar orthosis (optional), otherwise no further support required. Daily living activities immediately after the operation. Physiotherapeutic exercises (optional). Low impact sporting activities from 2nd week after operation, intense/ high impact sporting activities from 6 months postoperatively. Previous studies have reported satisfactory results for interspinous distraction devices for the treatment of dynamic spinal canal stenosis. However, the majority of these previously published studies are based on data with only shortterm follow-up or small patient numbers. In particular, the results of interspinous spacers for the treatment of different indications have not been evaluated separately. Complications and long-term results still need to be established.

Application of X STOP Device in the Treatment of Lumbar Spinal Stenosis

Low back pain is exceptionally ubiquitous, complex, and costly. Nevertheless, lumbar spinal stenosis (LSS) with neurogenic intermittent claudication (NIC) is a frequent cause of low back and lower extremity pain. Although the phenomena and pathophisiology of lumbar spinal stenosis has been described for decades, therapeutic treatment options remain considerably limited. Current care consists of conservative measures including physical therapy, rest, medications, and epidural steroid injection therapy or invasive surgical treatment including laminectomy with or without fusion. Despite standard of care intervention, many patients are often left inadequately treated and suffer from debilitating low back and lower extremity pain as a result of lumbar spinal stenosis. Interspinous process distraction (IPD) devices were originally described in the 1950s, but technological advances, which have contributed to improved safety and efficacy, have rekindled an interest in IPD implantation. By mimicking lumbar flexion at affected levels of stenosis, it is thought these devices decompress neural structures within the neural foramina and therefore provide pain relief. X-STOP is one such device that is currently approved in the United States for the treatment of mild to moderate NIC resulting from LSS. This manuscript presents a focused review of NIC and LSS and comprehensively presents literature related to the use of the X-STOP IPD device.

Interspinous implant in lumbar spinal stenosis: a prospective cohort

Prospective study on clinical outcome of interspinous process distraction with X-STOP in patients with lumbar spinal stenosis. To determine the safety and efficacy of X-STOP interspinous distractor. A total of 45 patients (24 males, 21 females) with lumbar spinal stenosis were treated with X-STOP system. They had preoperative and postoperative (3, 6 and 12 months) assessments using the Back and Sciatica Questionnaire, the Oswestry Disability Index (ODI) and the SF12 Questionnaire. Patient satisfaction was assessed at each visit. The average VAS of back and leg pain was 6.7 and 6.8 preoperatively and improved to 2.7 and 2.8 postoperatively. A total of 68% had improvement in their walking distance following the operation. The average preoperative ODI of 42% improved to 16.38% postoperatively (P < 0.0001). A total of 70% of patients had improvement in physical score and 80% in mental score. A total of 82% were very satisfied with the outcome of the operation. X-STOP implant is clinically effective with fewer complications and it is a simple procedure.

A NEW CERAMIC INTERSPINOUS PROCESS SPACER FOR LUMBAR SPINAL CANAL STENOSIS

Abstract Objective: Because surgery in elderly patients should be minimally invasive, interspinous process distraction has been widely used in this group to treat lumbar canal stenosis. We developed a new interspinous process distraction spacer composed of hydroxyapatite ceramic. In this work, we demonstrate the usefulness of this novel device. Methods: Since 2003, we operated on 19 elderly patients with lumbar canal stenosis, including 14 men and five women. Their mean age was 70.1 years. We compared the intervertebral angle, posterior disc height, and interspinous process distance on midsagittal magnetic resonance images obtained before and after the surgery. We also assessed clinical outcomes by using the Visual Analog Scale and the Zurich Claudication Questionnaire. Results: The average operation time per level was 44.7 minutes. Postoperatively, there were significant changes in the angle (from 12.5 to 8.6 degrees, P &amp;lt; 0.0001), the posterior disc height (from 10.6 to 13.1 mm, P &amp;lt; 0.0001), and the interspinous process distance (from 9.7 to 14.1 mm, P &amp;lt; 0.0001). The clinical outcomes, which we assessed by using the Visual Analog Scale and the Zurich Claudication Questionnaire, were considered satisfactory. (Visual Analog Scale, from 6.88 to 3.00; Zurich Claudication Questionnaire, symptom severity domain from 2.94 to 1.92, physical function from 2.51 to 1.73.) Conclusion: Our ceramic spacer is useful in the treatment of elderly patients with lumbar canal stenosis. Treatment comprises an easy surgical procedure and produces no metal artifact on radiological evaluations, such as magnetic resonance imaging and computed tomographic scans.

Self-rated evaluation of outcome of the implantation of interspinous process distraction (X-Stop) for neurogenic claudication

The treatment of lumbar spinal stenosis is either conservative or surgical decompression. Recently, an interspinous decompression device (X-Stop) has been developed as an alternative. Patients treated with an X-Stop between 2003 and 2006 are subject of this study. The SF-36 Health Survey and Zürich Questionnaires are used. The data of pre- and post-operative self-rated questionnaires are collected and analysed by independent investigators. The data were statistically analysed. A good outcome was defined when the mean score at the ZQ for satisfaction was at maximal 2.0, and the mean improvement of the severity score was at least 0.5, and also for vitality score. For relations between outcome and gender, smoking, BMI, orthopaedic co-morbidity, number of implanted X-Stops were sought. The change in SF-36 scales was related to the outcome. Sixty-five patients did undergo implantation of an X-Stop. The mean age was 64.4 +/- 10.0 years (range: 37.0-85.0 years). 31.1% Of the patients had a good outcome. A good outcome was not related to smoking, BMI, number of implanted X-Stops. However, a good outcome was related to the absence of orthopaedic co-morbidity or male gender. Patients with a good outcome had significantly a better improvement of the scales of the SF-36 concerning physical pain or impairment. The X-Stop does improve the clinical situation. However, a good outcome is achieved less often than previously reported. Probable explanations are discussed.

Interspinous Process Distraction Devices for Spinal Stenosis

Interspinous process distraction devices represent a relatively new option for minimally invasive surgical treatment of lumbar spinal stenosis. The X STOP device is the first such implant to receive FDA approval for this indication, and promising results from initial clinical studies have encouraged development of multiple alternative implant designs. These devices are designed for placement between adjacent spinous processes and function to create relative segmental flexion at the treated level, indirectly increasing the cross-sectional area of the spinal canal as well as the neuroforamina. This technology is an option for patients with neurogenic claudication aggravated by standing or walking and relieved by sitting. Short-term clinical results appear comparable to laminectomy and superior to nonoperative treatment. Long-term clinical follow-up data are not yet available.

One-Year Results of X STOP Interspinous Implant for the Treatment of Lumbar Spinal Stenosis

Prospective observational study. To prospectively assess the clinical outcome of patients with symptomatic lumbar spinal stenosis before and at periodic intervals after X Stop implantation and to compare the data with previous studies. The X Stop Interspinous Process Distraction Device is a relatively new interspinous implant designed for patients with symptomatic spinal stenosis particularly neurogenic claudication. Previously, a randomized study has shown a 75% improvement in symptoms and physical function at 1-year post-X Stop implantation for lumbar spinal stenosis. The only other study is a preliminary report of only 10 patients with variable intervals of clinical outcome assessment. Forty consecutive patients were enrolled and surgically treated with X Stop implantation. The X Stop device was implanted at the stenotic segment, which was either at 1 or 2 levels in each patient. They were clinically evaluated at the preoperative, 3-month, 6-month, and 1-year stage with clinical questionnaires (Zurich Claudication Questionnaire, Oswestry Disability Index, and SF-36). Sixteen patients failed to complete all the questionnaires at all time intervals and hence were excluded, leaving 24 patients who had completed all questionnaire at all time interval. By 12 months, 54% of these 24 patients reported clinically significant improvement in their symptoms, 33% reported clinically significant improvement in physical function, and 71% expressed satisfaction with the procedure. 29% of the patients required caudal epidural after 12 months after surgery for recurrence of their symptoms of neurogenic claudication. The results of this prospective observational study indicate that X Stop offers significant short-term improvement over a 1-year period. It is a safe, effective, and less invasive alternative for treatment of lumbar spinal stenosis. Our results, however, are less favorable than the previous multicenter, randomized study.

The Positional Magnetic Resonance Imaging Changes in the Lumbar Spine Following Insertion of a Novel Interspinous Process Distraction Device

Patients with symptomatic lumbar spinal stenosis underwent magnetic resonance imaging to study changes in the lumbar spine in various postures before and after implantation of the X STOP Interspinous Process Distraction Device (St. Francis Medical Technologies, Concord, CA). To visualize the effect of the device in vivo. Previous studies have shown vertebral canal and exit foraminal area to reduce from flexion to extension. Recently, reports on improved kinematics in vitro at the implantation level of the X STOP device have also been published. Using positional magnetic resonance imaging, patients were scanned before and 6 months after surgery. Images were taken with the patient in sitting flexed, extended, neutral, and standing positions. The total range of motion of the lumbar spine and individual segments were measured, along with changes in disc height, areas of the exit foramens, and dural sac. In 12 patients with 17 distracted levels, the area of the dural sac at these levels increased from 77.8 to 93.4 mm after surgery in the standing position (P = 0.006), with increase in the exit foramens, but no change in lumbar posture. This study shows that the X STOP device increases the cross-sectional area of the dural sac and exit foramens without causing changes in posture.