Interspinous Process Devices Research Articles

Interspinous Process Devices for Motion Preservation and Fusion

Dr. Hoskins is Research Assistant, Department of Orthopedic Surgery, Rush University Medical Center; Mr. Zaglama is Second-Year Medical Student, Rush University Medical Center School of Medicine; Mr. Smith is Second-Year Medical Student, Rush University Medical Center School of Medicine; and Dr. Singh is Assistant Professor, Department of Orthopedic Surgery, Rush University Medical Center, 1725 W Harrison Street, PO Box 1063, Chicago, IL 60612; E-mail: [email protected]. Unless otherwise disclosed, each faculty and staff and their spouse/life partner (if any) has no financial relationships with, or financial interests in, any commercial organizations related to this CME activity. Dr. Singh has disclosed that he is/was a consultant/advisor to Pioneer, DePuy, and Stryker. Lippincott CME Institute has identified and resolved all conflicts of interest concerning this educational activity. Lippincott Continuing Medical Education Institute is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. Lippincott Continuing Medical Education Institute designates this enduring material for a maximum of 1.5 AMA PRA Category 1 Credits™. Physicians should only claim credit commensurate with the extent of their participation in the activity. To earn CME credit, you must read the CME article and complete the quiz and evaluation assessment survey on the enclosed form, answering at least 70% of the quiz questions correctly. This activity expires on January 31, 2012.

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.

Using Lumbar Interspinous Anchor with Transforaminal Lumbar Interbody Fixation

As minimally invasive surgery has become increasingly popular, interspinous process devices (IPDs) have evolved beyond cases of simple focal spinal stenosis. Despite design differences, all IPDs aim to achieve indirect decompression of the nerve roots by enlarging the caliber of the neural foramina via distraction of the adjacent spinous processes. Whether IPDs reduce the risk of adjacent level stenosis compared to decompression and fusion for degenerative spondylolisthesis remains unclear. Ultimately, the paucity of high-quality, long-term, comparative, clinical studies precludes any strong recommendation for the use of IPDs for the treatment of degenerative spondylolisthesis.

Langzeitergebnisse des interspinösen Distraktionssystems X-STOP

A growing number of interspinous process devices are currently under investigation. No long-term results are currently available for the X-STOP spacer, but short-term and midterm results are promising.The X-STOP spacer is a good alternative to decompression surgery in elderly patients with moderate spinal stenosis without spondylolisthesis or severe osteoporosis. Further prospective controlled randomized studies comparing the X-STOP with decompression surgery must be done to clearly define the indications and to allow prediction of long-term results.

The use of Interspinous Process Spacers in elderly people: preliminary experience

Background The spinous processes are located in the very back of the spinal column near the skin surface. In fact, by passing the hand down the center of the low back one is usually able to feel several small prominences. These are the spinous processes. The near proximity of the spinous processes to the skin allows for the implantation of interspinous process spacers with minimal operative intervention and spinal morbidity.The interspinous process devices are designed to distract (open) the foramen, where the nerve endings pass away from the center of the spinal region and into the legs. It is thought that these devices may also unload the intervertebral disc. They may limit spinal extension (the position the spine takes on when bending backward). This backward bending position may be painful for patients with spinal stenosis because it reduces the space available for the nerve roots in the exiting foraminal openings.The interspinous devices may be implanted with the patient under a mild sedative and local anesthesia as a day surgery procedure (patient goes home the same day) or under light anesthesia. This may be particularly beneficial for elderly patients for whom more extensive open surgery may present too great of a surgical risk due to less favorable general health and fitness level.

Does an interspinous device (Coflex™) improve the outcome of decompressive surgery in lumbar spinal stenosis? One-year follow up of a prospective case control study of 60 patients

A number of interspinous process devices have recently been introduced to the lumbar spinal market as an alternative to conventional surgical procedures in the treatment of symptomatic lumbar stenosis. One of those "dynamic" devices is the Coflex device which has been already implanted worldwide more than 14,000 times. The aim of implanting this interspinous device is to unload the facet joints, restore foraminal height and provide stability in order to improve the clinical outcome of surgery. Published information is limited, and there are so far no data of comparison between the implant and traditional surgical approaches such as laminotomy. The purpose of our prospective study is to evaluate the surgical outcome of decompressive surgery in comparison to decompressive surgery and additional implantation of the Coflex interspinous Device. 60 patients who were all treated in the Spine Center of Klinikum Neustadt, Germany for a one or two level symptomatic LSS with decompressive surgery were included. Two groups were built. In Group one (UD) we treated 30 patients with decompression surgery alone and group two (CO) in 30 patients a Coflex device was additional implanted. Pre- and postoperatively disability and pain scores were measured using the Oswestry disability index (ODI), the Roland-Morris score (RMS), the visual analogue scale (VAS) and the pain-free walking distance (WD). Patients underwent postoperative assessments 3, 6 and 12 month including the above-mentioned scores as well as patient satisfaction. In both groups we could see a significant improve (p < 0.001) in the clinical outcome assessed in the ODI, in the RMS for evaluation of back pain, in the VAS and in the pain-free WD at all times of reinvestigation compared to base line. At 1-year follow up there were no statistically differences between both groups in all ascertained parameters including patient satisfaction and subjective operation decision. Because there is no current evidence of the efficacy of the Coflex device we need further data from randomized controlled studies for defining the indications for theses procedures. To the best of our knowledge this is the first prospective controlled study which compares surgical decompression of lumbar spinal stenosis with additional implanting of an interspinous Coflex device in the treatment of symptomatic LSS.

Interspinous process devices for the treatment of lumbar degenerative disease

A growing number of interspinous process devices are currently under evaluation for use in the management of lumbar degenerative disease. Although some clinical and biomechanical evidence exists for several of these devices, their individual indications of use and effectiveness are still in the early stages of investigation. The only FDA-approved device available at present is the X-Stop (Kyphon, Inc., Sunnyvale, CA; Medtronic, Memphis, TN), which has indications for use in the management of neurogenic claudication resulting from lumbar stenosis. In this review, we highlight the role of these devices in the management of lumbar spine disease, their proposed mechanisms of action, and areas for future development.

Stress Fracture of Bilateral Posterior Facet After Insertion of Interspinous Implant

A case report of stress fracture of bilateral lumbar posterior facet after implantation of interspinous process device is reported and the literature reviewed. OBJECTIVE.: To report the rare case of stress fracture of bilateral lumbar posterior facet after implantation of interspinous process device. A 64-year-old woman presented with severe back pain and radiating pain in both legs. In her history, she had undergone implantation of L4-L5 interspinous process device (Coflex, Paradigm Spine, Wurmlingen, Germany) for her neurogenic claudication at 6 years ago. Magnetic resonance image demonstrated signal change suggesting bilateral L4 inferior process. To the best of the authors' knowledge, there has been no report stress fracture of posterior facet after implantation of interspinous process device. This study reviewed the patient's medical record, her imaging studies, and related literatures. In the reported case, stress fracture of bilateral posterior facet was documented with MRI and confirmed with surgical treatment for the surgical treatment of spinal stenosis. The involved facet joint was at the site affected by previously implanted interspinous process device. Posterior facet fracture can occur as a complication of interspinous process device.

P108. Five Year Outcomes in Patients Treated with the X-STOP Interspinous Process Device for Neurogenic Intermittent Claudication Due to Lumbar Spinal Stenosis

BACKGROUND CONTEXT: Patients with neurogenic intermittent claudication (NIC) secondary to lumbar spinal stenosis experience pain, decrements in physical function and quality of life. The X-STOP interspinous process device (IPD) is a minimally invasive treatment option. Results of a multicenter randomized trial demonstrated that 2-year treatment success with the X-STOP IPD was significantly better compared with non-surgical care.

A Novel Technique of Intra-Spinous Process Injection of PMMA to Augment the Strength of an Inter-Spinous Process Device Such as the X STOP

Biomechanical. To determine if cement injection into the spinous process will improve compression strength. The X STOP (St. Francis Medical Technologies) has been shown to be a safe and effective means for decompressing 1- or 2-level lumbar spinal stenosis (LSS). The X STOP is indicated for LSS patients with osteoporosis, but contraindicated for patients with severe osteoporosis. In an attempt to address these LSS patients with demonstrably weaker bone, a technique to strengthen the spinous process with polymethylmethacrylate (PMMA) injection is presented. Nine pairs of adjacent fresh frozen cadaveric lumbar vertebrae were DEXA scanned before testing. They were randomly assigned to the PMMA group and a control group. Nine of the specimens were injected with PMMA. Each spinous process was then compressed between 2 X STOPs. The testing model was designed to simulate the loading of a 2-level X STOP placement. The mean load to failure and stiffness values of the treated and untreated groups were calculated. The specimens were inspected carefully for PMMA infiltration and extrusion. The mean bone mineral density (BMD) values of the control and PMMA treatment groups were 0.99 +/- 0.13 g/cm and 0.98 +/- 0.10 g/cm, respectively; P > 0.616. The mean volume of cement injected was 2.2 +/- 0.3 cc. The mean failure load values of the control and PMMA treatment groups were 1250 +/- 627 N and 2386 +/- 1034 N, respectively; P < 0.001. The mean stiffness values of the control and PMMA treatment groups were 296 +/- 139 N/mm and 381 +/- 131 N/mm, respectively; P > 0.059. Most specimens had flow of the cement into the laminae and some into the facet and pedicle. No PMMA was found within the spinal canal. This first reported technique of posterior element vertebroplasty may increase the indications and success for patients with decreased BMD who seek an interspinous implant such as the X STOP. A possible role may exist in increasing the effectiveness of such devices. However, clinical trials have yet been performed. These results demonstrate that PMMA injection in the spinous processes is effective in increasing resistance to compressive forces in an X STOP model.

Interspinous Process Devices in the Lumbar Spine

A growing number of interspinous process devices have been introduced to the lumbar spine implant market. Implant designs vary from static spacers to dynamized devices. Furthermore, they are composed of a range of different materials including bone allograft, titanium, polyetheretherketone, and elastomeric compounds. The common link between them is the mechanical goal of distracting the spinous processes to affect the intervertebral relationship. In contrast, the purported clinical goals are more variable, ranging from treatment of degenerative spinal stenosis, discogenic low back pain, facet syndrome, disk herniations, and instability. Though some clinical data exist for some of these devices, defining the indications for these minimally invasive procedures will be crucial. Indications should emerge from thoughtful consideration of data from randomized controlled studies.

Interspinous Process Devices in the Lumbar Spine

Contemporary Spine Surgery: September 2007 - Volume 8 - Issue 9 - p 8 doi: 10.1097/01.CSS.0000285190.82679.a3

Interspinous Process Devices in the Lumbar Spine

A growing number of interspinous process devices have been introduced to the lumbar spine implant market. Implant designs vary from static spacers to dynamized devices. Furthermore, they are composed of a range of different materials including bone allograft, titanium, polyetheretherketone, and elastomeric compounds. The common link between them is the mechanical goal of distracting the spinous processes to affect the intervertebral relationship. In contrast, the purported clinical goals are more variable, ranging from treatment of degenerative spinal stenosis, discogenic low back pain, facet syndrome, disk herniations, and instability. Though some clinical data exist for some of these devices, defining the indications for these minimally invasive procedures will be crucial. Indications should emerge from thoughtful consideration of data from randomized controlled studies.