Interspinous Process Decompression Device Research Articles

A Review of Emerging Evidence for Utilization of a Percutaneous Interspinous Process Decompression Device to Treat Symptomatic Lumbar Adjacent-Segment Degeneration.

ObjectivePostlaminectomy syndrome diagnoses secondary to adjacent segment degeneration are a substantial and rising cause of morbidity in the United States. Emerging spinal cord neuromodulation technologies have produced successful outcomes for postlaminectomy neuropathic pain but are less effective in treating neurogenic claudication secondary to recurrent lumbar stenosis. Percutaneous interspinous process decompression systems can be used as a salvage treatment modality for persistent structural neurogenic claudication in postlaminectomy syndrome or after spinal cord stimulator implantation.MethodsThis paper is a review of emerging evidence for efficacious utilization of percutaneous interspinous process decompression.ResultsA recent pragmatic trial of subjects who underwent percutaneous interspinous process decompression for lumbar stenosis with intermittent neurogenic claudication reported that 63% (26/41) maintained minimal clinically important improvement in visual analog scale (VAS) leg pain, 61% (25/41) in VAS back pain, 78% (32/41) in function objective values, and 88% (36/41) reported satisfaction with treatment at 12 months postop. All subjects in a small case series of seven individuals with postlaminectomy adjacent-segment disease reported postoperative satisfaction scores of 3 or 4 on a 0–4 scale and were also able to decrease or wean completely off controlled pain medications. In another study, there was a significant decrease in average leg pain (60% improvement, P < 0.0001, N = 25) and axial low back pain (58% improvement, P < 0.0001, N = 25) in patients who underwent one- or two-level percutaneous interspinous process decompression as a rescue treatment for reemerging neurogenic claudication after spinal cord stimulator implantation.ConclusionsThe spine often is a focus of progressive disease. Furthermore, mechanical changes associated with spinal instrumentation can lead to additional disease at adjacent levels. Many individuals will present with symptomatic neurogenic claudication recalcitrant to multimodal management strategies, including even the most sophisticated neuromodulation technologies. Implementation of salvage percutaneous interspinus process decompression implantation in cases of adjacent segment degeneration or incomplete spinal cord stimulation can decompress structural causes of neurogenic claudication while sparing the patient from more invasive surgical reoperation techniques.

Long-term results with percutaneous interspinous process devices in the treatment of neurogenic intermittent claudication.

Neurogenic intermittent claudication (NIC) is the main symptom of degenerative lumbar spinal stenosis. Percutaneous interspinous process decompression devices (IPDs) have been designed as an alternative therapy to conservative treatment and to open decompressive surgery for patients suffering from NIC. Initial short-term results were encouraging. We present the long-term results of a group of patients that we followed to provide insight on long-term outcomes and effectiveness of this technique compared to other decompression methods. Fifteen patients operated for NIC by implantation of percutaneous IPDs have been prospectively monitored for reoperations or complications. Follow-up (FU) was interrupted if the patient was reoperated. Results were considered poor if the patient had to be reoperated at any stage of the FU or if the treatment failed to alleviate the pain after 6 months. Results were considered average if the patient still suffered some pain but did not require reoperation. The patients were followed up to 7 years after the initial surgery. The mean length of the FU was 3.53 years and all patients could be followed. At the end of the FU, the results were good in only 20.0% (3/15), average in 13.3% (2/15) and poor in 66.7% (10/15). Despite initial satisfactory results, long-term FU is disappointing, with 80% poor or average results. The long-term reoperation rate is high (66.6%), increases over time and is higher than after implantation of IPDs for decompression augmentation. Although this technique is simple and safe, its effectiveness seems short-lived. We recommend cautious use and informing patients about the risk of relatively early failure and recurrence.

Baastrup Disease/Interspinous Bursitis

Baastrup disease (BD), an uncommon back pain syndrome, is characterized by pathologic approximation of adjacent spinous processes on a sagittal plane image. BD occurs most commonly at the lumbar L4-L5 level and tends to be more common in the elderly. The etiology is not precisely known, but BD may develop secondary to chronic active inflammatory facet arthropathy, leading to interspinous osteophytes and approximation of the adjacent spinous processes. Clinically, BD should be considered in the differential diagnosis of back pain if there is (1) midline back pain reproduced with palpation of the spinous process and exacerbated by extension of the lumbar spine and (2) direct contact of adjacent spinous processes on the lateral view of a plain x-ray image. Magnetic resonance imaging is more sensitive in detecting interspinous inflammation and the formation of bursa and new bone. Major differential diagnoses of BD include proliferative hyperostosis of the lumbar spinous processes, degenerative disease of the spine, sclerotic bone metastases to the spine, and ankylosing spondylosis. BD can be managed initially with nonsteroidal antiinflammatory drugs, a short-term steroid dose pack, and physical therapy. Injection of a local anesthetic to the inflamed spinous process and associated interspinous ligaments may be diagnostic, and injection of a local anesthetic/corticosteroid combination may be therapeutic. Surgery is reserved for patients with refractory BD. Surgical options include interspinous process decompression devices and excision of the affected spinous processes.

164 Failure Rates and Complications of Interspinous Process Decompression Devices

INTRODUCTION: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 symptom

Indications and contraindications: interspinous process decompression devices in lumbar spine surgery.

Interspinous process decompression devices (IPD) allow a minimally invasive treatment of lumbar spinal stenosis (LSS), but their use is discussed highly controversial. Several level I studies suggest that IPD implantation is a viable alternative for both conservative treatment and decompression, but clear indications and contraindications are still missing. This study was designed to explore the perspectives and limitations of IPDs and to evaluate the role of these devices in general. The study is based on a questionnaire sent to all hospitals registered in the German Hospital Address Register 2010 with an orthopedic, neurosurgerical, or spine surgery department (n = 1,321). The questionnaire was reviewed by experienced spine surgeons and statisticians, and included both single-response, close-ended, and multiple-response open-ended questions. We received 329 (24.9%) entirely analyzable questionnaires. A total of 164 respondents (49.8%) stated that IPDs are a treatment option for LSS, and 135 of the 164 respondents (82.3%) use them. Poor clinical experience (60%) and lack of evidence (53.9%) are the main reasons cited for not using IPDs. We detected a high negative correlation between the size of the hospital, the number of outpatients and inpatients treated for LSS and other spine pathologies, and the use of IPDs (p = 0.001). Most respondents prefer the combination of open decompression and IPD (64.4%; n = 87). A total of 9.6% (n = 13) of the users favor IPD implantation as a stand-alone procedure. Overall, 25.9% n = 35 use both options. Most surgeons aim to relieve the facet joints (87.7%) and to stabilize a preexisting instability (75.4%). They recommend IPDs in the segments L2-L3 (77%), L3-L4 (98.5%), and L4-l5 (99.3%) and consider that IPD implanation also could be done at the L5-S1 segment (40.1%). Overall, 64.4% (n = 87) of the users recommend limiting IPD implantation to two segments. Infection (96.3%), fracture (94.8%), isthmic spondylolisthesis (77%), degenerative spondylolisthesis (higher than Meyerding I [57%]), lumbar spine scoliosis (48.1%), and osteoporosis (50.4%) are seen as contraindications for IPD. No clear consensus exists among spine surgeons concerning the use of IPD for LSS treatment. The study showed that hospital-related parameters also influence decision making for or against the use of IPDs. However, despite the lack of evidence, the indications and contraindications which had been identified in the present study might contribute to improved outcomes after IPD implantation or at least prevent harm to patients.

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.

One-year follow-up of a series of 100 patients treated for lumbar spinal canal stenosis by means of HeliFix interspinous process decompression device.

Purpose. New interspinous process decompression devices (IPDs) provide an alternative to conservative treatment and decompressive surgery for patients with neurogenic intermittent claudication (NIC) due to degenerative lumbar spinal stenosis (DLSS). HeliFix is a minimally invasive IPD that can be implanted percutaneously. This is a preliminary evaluation of safety and effectiveness of this IPD up to 12 months after implantation. Methods. After percutaneous implantation in 100 patients with NIC due to DLSS, data on symptoms, quality of life, pain, and use of pain medication were obtained for up to 12 months. Results. Early symptoms and physical function improvements were maintained for up to 12 months. Leg, buttock/groin, and back pain were eased throughout, and the use and strength of related pain medication were reduced. Devices were removed from 2% of patients due to lack of effectiveness. Conclusions. Overall, in a period of up to 12-month follow-up, the safety and effectiveness of the HeliFix offered a minimally invasive option for the relief of NIC complaints in a high proportion of patients. Further studies are undertaken in order to provide insight on outcomes and effectiveness compared to other decompression methods and to develop guidance on optimal patient selection.

Efficacy of an interspinous decompression device versus nonoperative treatment for lumbar spinal stenosis: an example for a randomized, controlled trial

Background: Lumbar spinal stenosis (LSS) with neurogenic intermittent claudication (NIC) is one of the most common degenerative spinal diseases in the elderly. One treatment option for LSS/neurogenic intermittent claudication is conservative management with oral analgesics, injections and physical therapy. Another relatively new operative alternative is interspinous process decompression. To date, there is no convincing evidence that these devices provide any patient benefits.Methods: This study is intended as a prospective, randomized, pilot-study to compare the safety and effectiveness of a minimally invasive, percutaneously implanted interspinous process decompression device with nonoperative treatment of LSS. Patients are randomized for surgical or nonsurgical treatment. The surgical group will undergo percutaneous implantation of an interspinous device (Aperius™ PercLID, Medtronic). The control group will receive nonoperative treatment with oral nonsteroidal anti-inflammatories, injections such as ep...

Clinical evaluation of the preliminary safety and effectiveness of a minimally invasive interspinous process device APERIUS® in degenerative lumbar spinal stenosis with symptomatic neurogenic intermittent claudication

New interspinous process decompression devices (IPDs) provide an alternative to conservative treatment and decompressive surgery for patients with neurogenic intermittent claudication (NIC) due to degenerative lumbar spinal stenosis (DLSS). APERIUS(®) is a minimally invasive IPD that can be implanted percutaneously. This multicentre prospective study was designed to make a preliminary evaluation of safety and effectiveness of this IPD up to 12 months post-implantation. After percutaneous implantation in 156 patients with NIC due to DLSS, data on symptoms, quality of life, pain, and use of pain medication were obtained for up to 12 months. Early symptom and physical function improvements were maintained for up to 12 months, when 60 and 58 % of patients maintained an improvement higher than the Minimum Clinically Important Difference for Zurich Claudication Questionnaire (ZCQ) symptom severity and physical function, respectively. Leg, buttock/groin, and back pain were eased throughout, and the use and strength of related pain medication were reduced. Devices were removed from 9 % of patients due to complications or lack of effectiveness. Overall, in a period of up to 12 months follow-up, the safety and effectiveness of the APERIUS(®) offered a minimally invasive option for the relief of NIC complaints in a high proportion of patients. Further studies are underway to provide insight on outcomes and effectiveness compared to other decompression methods, and to develop guidance on optimal patient selection.

The Interspinous Spacer: A Clinicoanatomical Investigation Using Plastination

Purpose. The relatively new and less-invasive therapeutic alternative “interspinous process decompression device (IPD)” is expected to result in improved symptoms of neurogenic intermittent claudication (NIC) caused by lumbar spinal stenosis. The aim of the study was to analyze IPD position particularly regarding damage originating from surgical implantation. Methods. Anatomic assessments were performed on a fresh human cadaver. For the anatomic examination, the lumbar spine was plastinated after implantation of the IPDs. After radiographic control, serial 4 mm thick sections of the block plastinate were cut in the sagittal (L1–L3) and horizontal (L3–L5) planes. The macroanatomical positioning of the implants was then analyzed. The insertion procedure caused only little injury to osteoligamentous or muscular structures. The supraspinous ligament was completely intact, and the interspinous ligaments were not torn as was initially presupposed. No osseous changes at the spinal processes were apparent. Contact of the IPD with the spinous processes was visible, so that sufficient biomechanical limitation of the spinal extension seems likely. Conclusions. Minimally invasive IPD implantation with accurate positioning in the anterior portion of the interspinous place is possible without severe surgical trauma.

Safety and efficacy of a new percutaneously implantable interspinous process device

BackgroundLumbar spinal stenosis is a degenerative disease of the elderly population. Although microsurgical decompression has shown good long-term results, percutaneous techniques could provide an alternative in the presence of significant comorbidities.MethodEighty-seven interspinous process decompression devices (In-space; Synthes, Umkirch, Germany) were implanted percutaneously in up to three segments of 50 patients. Outcome was assessed directly after surgery, at 6–8 weeks, and at average follow-up of 1 year (11.8 ± 6 months). Assessment included complications, pain and spinal claudication, neurodeficit, time to recurrence of symptoms, and time to second surgery. Subgroups with additional low back pain at presentation and mild spondylolisthesis were analyzed separately.FindingsIntraoperative complications were rare (one misplacement and two cases of failed implantation); average operation time was 16.4 ± 12.2 min per segment. Initial response was very good with 72% good or excellent relief of symptoms. After a 1-year follow-up, 42% reported of lasting relief from spinal claudication. Thirteen percent of these complained about lasting or new-onset low back pain. A second surgery had been performed in 22%. Subgroup analysis was performed for patients presenting with additional low back pain and spondylolisthesis patients. No significant differences could be noted between subgroups.ConclusionsThe In-space is a percutaneous treatment option of claudication in patients with lumbar spinal stenosis. Compared with microsurgical decompression surgery, recurrence rate within 1 year is, however, high and the device seems not suitable for the treatment of low back pain. Therefore, the authors suggest that the device should presently be used primarily in controlled clinical trials in order to get more information concerning the optimal indication.

The increase in dural sac area is maintained at 2 years after X-stop implantation for the treatment of spinal stenosis with no significant alteration in lumbar spine range of movement

Background context The X-stop interspinous process decompression (IPD) device has been used effectively in the management of symptomatic spinal stenosis. This study examines the radiological outcomes at 2 years postoperatively after X-stop implantation. Purpose To measure the effect of X-stop IPD device on the dural sac and foraminal areas at 24 months postoperatively at instrumented level in symptomatic lumbar canal stenosis. We also aimed to assess its effect on change in lumbar spine movement. Study design Prospective observational study. Patient sample Forty-eight patients treated with X-stop had preoperative positional magnetic resonance imaging (MRI) scans, 40 of whom had 2 years postoperative positional MRI scans. Complete scans were available for 39 of these patients. Outcome measures Positional MRI scans were performed pre- and postoperatively. Measurements were done on these scans and are presented as the outcome measures. Methods All patients had a multipositional MRI scan preoperatively and at 6 and 24 months postoperatively. Foraminal area was measured in flexion and extension. Dural cross-sectional area was measured in standing erect and in sitting neutral, flexion, and extension (sitting) positions. The total range of movement (ROM) of the lumbar spine and individual segments was also measured. Results Complete scan data for 39 patients' scans were available. An increase in mean dural sac area was found in all positions. At 24 months after surgery, the mean dural sac area increased significantly in all four postures mentioned above. A small increase in mean foraminal area was noted, but this was not statistically significant. Mean anterior disc height reduced from 5.9 to 4.1 mm (p=.006) at 24 months at the instrumented level in single-level cases, from 7.7 to 6.1 mm (p=.032) in double-level cases caudally, and from 8.54 to 7.91 (p=.106) mm cranially. We hypothesize that the reduction in anterior disc heights could be a result of the natural progression of spinal stenosis with aging. There was no significant change in posterior disc heights at instrumented level or adjacent levels. The mean lumbar spine motion was 21.7° preoperatively and 23° at 24 months (p=.584) in single-level cases. This was 32.1° to 31.1° (p=.637) in double-level cases. There was no significant change in the individual segmental range of motion at instrumented and adjacent levels. Conclusion X-stop interspinous device remains effective in decompressing the stenosed spinal segment by increasing the anatomic dural cross-sectional area and foraminal area of spinal canal. It does not significantly alter the ROM of lumbar spine at instrumented and adjacent levels at 24 months postoperatively.

P118. Epidemiology and In-Hospital Complications Following Interspinous Process Decompression Device Procedures in the U.S.

P118. Epidemiology and In-Hospital Complications Following Interspinous Process Decompression Device Procedures in the U.S.

The X STOP Device

Object. Interspinous process decompression (IPD) theoretically relieves narrowing of the spinal canal and neural foramen in extension and thus reduces the symptoms of neurogenic intermittent claudication (NIC). The purpose of this study was to compare the efficacy of IPD with nonoperative treatment in patients with NIC secondary to degenerative spondylolisthesis. Methods. The authors conducted a randomized controlled study in patients with NIC; they compared the results obtained in patients treated with the X STOP IPD device with those acquired in patients treated nonoperatively. The X STOP implant is a titanium alloy device that is placed between the spinous processes to reduce the canal and foraminal narrowing that occurs in extension. In a cohort of 75 patients with degenerative spondylolisthesis, 42 underwent surgical treatment in which the X STOP IPD device was placed and 33 control individuals were treated nonoperatively. Patients underwent serial follow-up evaluations. The Zurich Claudication Questionnaire (ZCQ), 36-Item Short Form Health Survey (SF-36), and radiographic assessment were used to determine outcomes. Two-year follow-up data were obtained in 70 of 75 patients. Statistically significant improvement in ZCQ and SF-36 scores was seen in X STOP device-treated patients but not in the nonoperative control patients at all postoperative intervals. Overall clinical success occurred in 63.4% of X STOP device-treated patients and only 12.9% of controls. Spondylolisthesis and kyphosis were unaltered. Conclusions. The X STOP device was more effective than nonoperative treatment in the management of NIC secondary to degenerative lumbar spondylolisthesis.