High failure rate of the interspinous distraction device (X-Stop) for the treatment of lumbar spinal stenosis caused by degenerative spondylolisthesis

The X-Stop interspinous distraction device has shown to be an attractive alternative to conventional surgical procedures in the treatment of symptomatic degenerative lumbar spinal stenosis. However, the effectiveness of the X-Stop in symptomatic degenerative lumbar spinal stenosis caused by degenerative spondylolisthesis is not known. A cohort of 12 consecutive patients with symptomatic lumbar spinal stenosis caused by degenerative spondylolisthesis were treated with the X-Stop interspinous distraction device. All patients had low back pain, neurogenic claudication and radiculopathy. Pre-operative radiographs revealed an average slip of 19.6%. MRI of the lumbosacral spine showed a severe stenosis. In ten patients, the X-Stop was placed at the L4–5 level, whereas two patients were treated at both, L3–4 and L4–5 level. The mean follow-up was 30.3 months. In eight patients a complete relief of symptoms was observed post-operatively, whereas the remaining 4 patients experienced no relief of symptoms. Recurrence of pain, neurogenic claudication, and worsening of neurological symptoms was observed in three patients within 24 months. Post-operative radiographs and MRI did not show any changes in the percentage of slip or spinal dimensions. Finally, secondary surgical treatment by decompression with posterolateral fusion was performed in seven patients (58%) within 24 months. In conclusion, the X-Stop interspinous distraction device showed an extremely high failure rate, defined as surgical re-intervention, after short term follow-up in patients with spinal stenosis caused by degenerative spondylolisthesis. We do not recommend the X-Stop for the treatment of spinal stenosis complicating degenerative spondylolisthesis

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

Item does not contain fulltextINTRODUCTION: Despite 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. METHODS: Data 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. RESULTS: Eleven 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%. CONCLUSION: As the evidence is relatively low and the costs are high, more thorough (cost-) effectiveness studies should be performed before worldwide implementation is introduced

The Felix-trial. Double-blind randomization of interspinous implant or bony decompression for treatment of spinal stenosis related intermittent neurogenic claudication

Abstract. Background. Decompressive laminotomy is the standard surgical procedure in the treatment of patients with canal stenosis related intermittent neurogenic claudication. New techniques, such as interspinous process implants, claim a shorter hospital stay, less post-operative pain and equal long-term functional outcome. A comparative (cost-) effectiveness study has not been performed yet. This protocol describes the design of a randomized controlled trial (RCT) on (cost-) effectiveness of the use of interspinous process implants versus conventi

Two-year results of interspinous spacer (X-Stop) implantation in 175 patients with neurologic intermittent claudication due to lumbar spinal stenosis

The clinical outcome of patients with symptomatic lumbar spinal stenosis (LSS) was assessed during a follow-up period of 2 years after X-Stop implantation. The X-Stop is the most commonly used interspinous distraction device in patients with neurogenic intermittent claudication due to LSS. Between 2003 and 2007, more than 1,000 patients were examined in our centre with symptoms of intermittent claudication due to spinal stenosis. Between February 2003 and June 2007, in 175 of these patients an X-Stop device was implanted in one or two levels. Patients were clinically evaluated regularly during a follow-up period of up to 4 years using the VAS (leg pain) score and the Oswestry disability index. The mean VAS (leg pain) score in these 175 patients was reduced from 61.2% preoperatively to 39.0% at the first clincal follow-up examination at 6 weeks postoperatively. The mean VAS score at 24 months postoperatively was 39.0%. Oswestry score was 32.6% preoperatively, 22.7% at 6 weeks, and 20.3% at 24 months postoperatively on average. In eight out of the implanted 175 patients, the X-Stop had to be removed and a microsurgical decompression had to be performed because of unsatisfactory effect of the interspinous distraction device. Our single-centre results indicate not only a satisfactory short-term, but also a good long-term effect during a follow-up period of 2 years. Functional MRI examinations provide helpful, positional-dependent preoperative information. More than any radiological feature, the typical clinical picture of positional-dependent claudication with a relief of symptoms during flexion is the most important factor for appropriate patient selection. The interspinous device does not replace microsurgical decompression in patients with massive stenosis and continuous claudication, but offers a save, effective and less invasive alternative in selected patients with spinal stenosis. Concerning the operative technique, a minimally invasive implantation with preservation of the interspinous ligament is appropriate. Functional (upright-) MRI examinations were able to demonstrate the positional-dependent stenosis. If available, fMRI represents the most helpful radiologic examination in assessing the outcome of interspinous spacer implantation

Critical analysis of lumbar interspinous devices failures: a retrospective study

Interspinous devices (IDs) were introduced in the 90s. Since then, they have rapidly become very popular for the minimally invasive treatment of lumbar pain disorders. They feature different shapes and biomechanical characteristics, and are used in the spine degenerative pathologies or as motion segment stabilizers (dynamic stabilization) or to obtain the decompression of neurological structures. The indications seem to be rather narrow and still to be verified in terms of their clinical efficacy. However, IDs are being extensively utilized beyond their classical indications with the inevitable risk of a clinical failure. The aim of the present work was to carry out a critical analysis of the causes of failure in a series of 19 patients. From January 2007 to March 2009, 19 patients with residual painful syndrome after the implantation of IDs were observed. The series includes 11 males and 8 females with a mean age of 53.6 years (range 38–84 years) who were operated on elsewhere and who underwent revision surgery at our hospital. The inclusion criteria were low back pain and/or radiculopathy after the device implantation without improvement of the painful symptomatology, radiculopathy with signs of sensory and motor deficit, intermittent neurogenic claudication, and infection. All patients were thoroughly re-assessed with new standard imaging examinations such as MRI and CT scans, considering the following image features: the position of the device with respect to the spinous processes (X-ray), the intervertebral disc disease of the level operated upon or of the adjacent levels (MRI), the segmental instability (dynamic X-rays), the severity of the canal stenosis (CT). The accurate evaluation of the clinical and imaging parameters revealed three main causes of failure: errors of indication, technical errors and the structural failure of the ID. The most frequent cause of failure was a wrong indication. The results of the study are presented and the causes of failure are discussed in detail