Efficacy and Safety of the Use of Interspinous Spacers in the Treatment of Lumbar Spinal Stenosis: Mapping Gap and Scoping Review.

The evidence gap in low back pain management strategies – Authors' reply

To investigate the clinical effect of unilateral interlaminar approach 270° circular spinal canal decompression under the Interlaminar Endoscopic Surgical System(iLESSYS) Delta for the treatment of lumbar spinal stenosis (LSS) in the elderly. Total of 29 patients with LSS treated with the iLESSYS Delta from December 2018 to January 2021 were retrospectively analyzed, including 12 males and 17 females with an average age of (71.52±10.82) years old ranging from 63 to 83 years old. All patients had definite intermittent claudication, mainly neurogenic symptoms of both lower limbs. All patients had single-level spinal stenosis, including L3,4 5 cases, L4,5 21 cases, and L5S1 3 cases. Visual analogue scale (VAS), Oswestry Disability Index (ODI) and modified Macnab assessment criteria were used to evaluate pain, low back pain dysfunction index and clinical efficacy, respectively. All 29 cases were successfully completed. The operation time was (73.45±5.89) min, the intraoperative blood loss was (9.93±0.83) ml, the hospital stay was (4.03±0.41) days, and the follow-up was more than 12 months. The VAS scores of low back pain before surgery and 1 day, 1 month, 3 months, 1 year after surgery were 2.31±0.88, 1.45±0.62, 1.21±0.61, 1.10±0.55, 1.03±0.49;VAS of leg pain were 6.48±0.49 0.56, 1.97±0.61, 1.31±0.59, 1.17±0.59, 1.10±0.55;ODI scores were 38.41±2.74, 18.14±1.17, 5.17±0.53, 5.07±0.45, 4.90±0.48;low back and leg pain VAS score and ODI score have statistically significant differences between preoperative and postoperative follow-up time points (P<0.05). The MacNab efficacy evaluation at 1-year follow-up:excellent in 22 cases, good in 5 cases and fair in 2 cases. The clinical effect of unilateral interlaminar approach 270° circular spinal canal decompression under the iLESSYS Delta for the treatment of lumbar spinal stenosis in the elderly is satisfactory, with the advantages of less trauma and less bleeding, large microscopic operation space, sufficient decompression, and ideal post-operative recovery, and at the same time, it can minimize the damage to the stable structure of the lumbar spine, which is an ideal surgical method for the treatment of elderly lumbar spinal stenosis.

Background: Lumbar spinal stenosis with neurogenic claudication can be a debilitating condition, affecting quality of life. Interspinous spacer implantation is a minimally invasive procedure for treatment of lumbar spinal stenosis with neurogenic claudication and associated symptoms by minimizing spinal extension and therefore neural compression. Case Presentation: This case series presents 4 cases of patients with multilevel stenosis, most radiographically severe in the lumbar region, all who received interspinous spacers at L3-4 and L4-5 after minimal improvement in symptoms with conservative management including epidural injections. In all 4 cases, patients reported improved standing and gait but limited improvement in pain and overall function after interspinous spacer implantation. Each patient underwent repeat epidural injections at or below the level of the interspinous spacer with significant improvement in pain for up to 6 months. Conclusion: Our conclusion is that either postspacer epidural injections helped reduce inflammation associated with the implantation procedure, or the spacer maintained an open space to allow the injectate to permeate areas with the most stenosis and help reduce inflammation and therefore pain. Key words: Epidural injection, interspinous process decompression, interspinous spacer, interspinous spacer implant, low back pain, lumbar spinal stenosis, neurogenic claudication, spinal stenosis

Lumbar spinal stenosis is a progressive degenerative condition that manifests as low back pain with neurogenic claudication as a cardinal clinical feature. Although mild radicular symptoms can often be successfully treated with conservative care, management of lumbar spinal stenosis grows increasingly difficult as symptoms worsen. No satisfactory nonsurgical treatments exist to manage moderate radicular symptoms and, therefore, these patients are faced with the decision of continuing ineffective conservative options or opting to undergo invasive decompressive spine surgery. The Superion® Interspinous Spacer (Vertiflex, Inc., CA, USA) was developed specifically to fill the therapeutic void between conservative care and surgical decompression. The Superion device is a titanium implant that is delivered percutaneously and deployed between the spinous processes at the symptomatic vertebral levels. The Superion device improves radicular symptoms by limiting spinal extension and, consequently, minimizing impingement of neural and vascular elements. This article describes the rationale for and the design of the Superion device and summarizes initial clinical results with this novel, minimally invasive interspinous spacer.

9:26 Treatment of lumbar spinal stenosis with an interspinous spacer

To investigate the effectiveness of one-hole split endoscope (OSE) technique in the treatment of single segment lumbar spinal stenosis (LSS). The clinical data of 32 single segment LSS patients treated with OSE technique for simple spinal canal decompression between January 2022 and December 2022, who met the selection criteria, were retrospectively analysed. There were 18 males and 14 females, the age ranged from 45 to 82 years, with an average of 65.1 years. The disease duration was 9-72 months, with an average of 34.9 months. The surgical segments included L 3, 4 in 3 cases, L 4, 5 in 19 cases, and L 5, S 1 in 10 cases. The incision length, operation time, intraoperative blood loss, intraoperative radiation exposure frequency, postoperative mobilization time, and the area of the patient's lesion segment dural sac before operation and at 1 month after operation were recorded. Low back pain and leg pain were assessed by visual analogue scale (VAS) score before operation and at 3 days, 3 months, and 12 months after operation; functional recovery was assessed by Oswestry disability index (ODI) before operation and at 3 months and 12 months after operation; the effectiveness was assessed by modified MacNab criteria at last follow-up. All 32 patients successfully completed the operation, with an average incision length of 2.05 cm, an average operation time of 88.59 minutes, an average intraoperative blood loss of 46.72 mL, an average intraoperative radiation exposure frequency of 3.84 times, and an average postoperative mobilization time of 11.66 hours. All patients were followed up 12-16 months, with an average of 13.5 months. One patient experienced lower limb numbness, pain, and decreased muscle strength after operation, while the remaining patients did not experience complications such as dural tear or important nerve damage. The VAS scores of low back pain and leg pain and ODI in patients at various time points after operation were significantly better than preoperative ones, and each indicator further improved with time. The differences between time points were significant ( P<0.05). At 1 month after operation, the area of the patient's lesion segment dural sac was (123.13±19.66) mm 2, which significantly increased compared to preoperative (51.25±9.50) mm 2 ( t=-18.616, P<0.001). At last follow-up, the improved MacNab criteria were used to evaluate the effectiveness, with 18 cases achieving excellent results, 11 cases being good, and 3 cases being fair, with an excellent and good rate of 90.6%. The effectiveness of using OSE technique for simple spinal canal decompression treatment of single segment LSS is satisfactory, with the advantages of minimal surgical trauma and fast recovery.

In the treatment of lumbar spinal stenosis, interspinous spacers can be used in atissue and time sparing technique. Relief of low back pain might be achieved by stress reduction of facet joints and limitation of segmental mobility. Presentation of dynamic stabilization by means of an interspinous spacer with and without decompression and to compare it with the outcome of decompression and fusion. As part of aPubMed search, randomized controlled trials (RCTs) and non-RCTs from high-quality controlled clinical trials were selected and contrasted with our own experience. The current literature was evaluated, which assesses interspinous spacers with and without decompression in comparison with the "gold standard", the microsurgical interlaminar decompression. Published data indicate that the use of interspinous spacers with or without decompression for the treatment of lumbar spinal stenosis is not less effective than stand-alone decompression. The reoperation rate can only be proven for implants without decompression on the basis of Level Istudies. However, as alink between decompression alone and fusion, it cannot yet provide ascientifically clear solution.

PurposeTo assess the safety and effectiveness of a novel, minimally invasive interspinous spacer in patients with moderate lumbar spinal stenosis (LSS).MethodsA total of 53 patients (mean age, 70 ± 11 years; 45% female) with intermittent neurogenic claudication secondary to moderate LSS, confirmed on imaging studies, were treated with the Superion® Interspinous Spacer (VertiFlex, Inc, San Clemente, CA) and returned for follow-up visits at 6 weeks, 1 year, and 2 years. Study endpoints included axial and extremity pain severity with an 11-point numeric scale, Zurich Claudication Questionnaire (ZCQ), back function with the Oswestry Disability Index (ODI), health-related quality of life with the Physical Component Summary (PCS) and Mental Component Summary (MCS) scores from the SF-12, and adverse events.ResultsAxial and extremity pain each decreased 54% (both P < 0.001) over the 2-year follow-up period. ZCQ symptom severity scores improved 43% (P < 0.001) and ZCQ physical function improved 44% (P < 0.001) from pre-treatment to 2 years post-treatment. A statistically significant 50% improvement (P < 0.001) also was noted in back function. PCS and MCS each improved 40% (both P < 0.001) from pre-treatment to 2 years. Clinical success rates at 2 years were 83%–89% for ZCQ subscores, 75% for ODI, 78% for PCS, and 80% for MCS. No device infection, implant breakage, migration, or pull-out was observed, although two (3.8%) patients underwent explant with subsequent laminectomy.ConclusionModerate LSS can be effectively treated with a minimally invasive interspinous spacer. This device is appropriate for select patients who have failed nonoperative treatment measures for LSS and meet strict anatomical criteria.

BackgroundDynamic interspinous spacers, such as X-stop, Coflex, DIAM, and Aperius, are widely used for the treatment of lumbar spinal stenosis. However, controversy remains as to whether dynamic interspinous spacer use is superior to traditional decompressive surgery.MethodsMedline, Embase, Cochrane Library, and the Cochrane Controlled Trials Register were searched during August 2013. A track search was performed on February 27, 2014. Study was included in this review if it was: (1) a randomized controlled trial (RCT) or non-randomized prospective comparison study, (2) comparing the clinical outcomes for interspinous spacer use versus traditional decompressive surgery, (3) in a minimum of 30 patients, (4) with a follow-up duration of at least 12 months.ResultsTwo RCTs and three non-randomized prospective studies were included, with 204 patients in the interspinous spacer (IS) group and 217 patients in the traditional decompressive surgery (TDS) group. Pooled analysis showed no significant difference between the IS and TDS groups for low back pain (WMD: 1.2; 95% CI: −10.12, 12.53; P = 0.03; I2 = 66%), leg pain (WMD: 7.12; 95% CI: −3.88, 18.12; P = 0.02; I2 = 70%), ODI (WMD: 6.88; 95% CI: −14.92, 28.68; P = 0.03; I2 = 79%), RDQ (WMD: −1.30, 95% CI: −3.07, 0.47; P = 0.00; I2 = 0%), or complications (RR: 1.39; 95% CI: 0.61, 3.14; P = 0.23; I2 = 28%). The TDS group had a significantly lower incidence of reoperation (RR: 3.34; 95% CI: 1.77, 6.31; P = 0.60; I2 = 0%).ConclusionAlthough patients may obtain some benefits from interspinous spacers implanted through a minimally invasive technique, interspinous spacer use is associated with a higher incidence of reoperation and higher cost. The indications, risks, and benefits of using an interspinous process device should be carefully considered before surgery.

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.

Objective To investigate the difference of short-term clinical efficacy between decompressive laminectomy into In-Space and simple decompressive laminectomy for treatment of lumbar spinal stenosis with vertebral instability.Methods Thirty-three patients with lumbar spinal stenosis with vertebral instability admired from May 2009 to July 2010,were divided into two groups by random number table.Group A of 16 cases was treated with laminectomy decompression and placement In-Space,group B of 17 cases was treated with laminectomy decompression.Lumbar anteroposterior,lateral and flexion-extension X-ray films,preoperatively,and the follow-up were used to measure anterior and posterior disc height,foraminal height,segmental lordotic angle at surgical level.Using Oswestry disability index (ODI) and the visual analogue scale (VAS) to evaluate the clinical efficacy.Results All patients were followed up for (13.20 ± 2.91 ) months (range 6 to 21 months).The anterior disc height after operation of group A was slightly decreased compared with the preoperative(P＞ 0.05 ),the posterior disc height at 1 day after operation and foraminal height after operation of group A were significantly increased compared with the preoperative (P＜ 0.05).The anterior and posterior disc height,foraminal height of group B at 1 day,1 month,3 months after operation were no significantly different compared with the preoperative (P ＞ 0.05 ),at 6 months after operation and the end of follow-up were significantly decreased compared with the preoperative or 1 day after operation (P ＜ 0.05 ).Activity of lumbar vertebra by preoperative 9.86° ± 1.90° decreased to the end of followup 5.60° ± 2.02°in group A,while activity of lumbar vertebra by preoperative 9.89° ± 2.00°increased to the end of follow-up 10.76° ± 3.14° in group B.At the end of follow-up,lumbar back pain VAS,ODI score [ (2.02 ± 1.98 ),( 20.18 ± 18.80) scores ] of group A were significantly lower than those of group B [ (4.15 ±2.36),(30.39 ± 16.62 ) scores ],the differences were statistically significant (P ＜ 0.05 ).No patient suffered In-Space loosening,fracture and emerge.Conclusion The operation of In-Space can maintain spinal mobility and stability as well as avoiding lumbar vertebral instability,and its short-term efficacy is satisfactory. Key words: Spinal stenosis; Decompression,surgical; Dynamic stabilization system

P63. Current incidence of adjacent segment pathology following lumbar fusion versus motion preserving procedures: a systematic review and meta-analysis of recent projections

Background: Coflex, a kind of dynamic interspinous spacer, has been widely used for the treatment of lumbar spinal stenosis in the past a few years. However, controversy remains as to whether dynamic interspinous spacer use is superior to traditional decompression and fusion surgery. High complication, reoperation rate, and costs with poor outcomes were also mentioned in the literature. The aim of the present study is to evaluate whether Coflex implantation following spinal decompression provided better clinical outcomes compared with traditional decompression and fusion for symptomatic lumbar spinal stenosis through midterm follow-up. Methods and findings: A total of 100 patients who were confirmed L4/5 lumbar spinal stenosis was surveyed from June 2007 to June 2010. They were randomly and equally divided into two groups: 50 cases underwent spinal decompression with Coflex implantation, and 50 cases were treated with spinal decompression with fixation and fusion. The operation time, intraoperative blood loss, ambulation time, and hospitalization days, Japanese Orthopedic Association scores, visual analogue scale scores, Oswestry disability index and SF-36 scores were compared between the two groups. The ranges of motion and the height loss at adjacent segments (L3/4 and L5/S1) were measured preoperative and postoperative, respectively. Adjacent segment degeneration at L3/4 and L5/Sl was assessed by Pfirrmann classification. Complications were also recorded. The average age was 57.6 ± 5.9 years old in Coflex implantation group and 59.0 ± 6.7 years old in fusion group, respectively. The average follow-up period was 7.12 ± 1.1 year in Coflex implantation group and 7.31 ± 1.6 year in fusion group, respectively. JOA, ODI, VAS and SF-36 scores were improved at the last follow-up in all the two groups with significant differences (P 0.05). The intervertebral heights of adjacent segments were decreased at the last follow-up and the ranges of intervertebral motions were increased in both groups. The height loss and the range of motion increase of adjacent segments were greater in fusion group than those in Coflex group with statistical significant difference (P<0.01). At the last follow-up, adjacent segment disc Pfirrmann grade progressed more obviously in fusion group compared with that in Coflex group, and there was significant difference (P<0.05) between the two groups. Conclusion: Based on the present study, it showed that Coflex implantation and fusion after spinal decompression had the same clinical outcomes and satisfaction in treatment of symptomatic lumbar spinal stenosis after 7 years follow-up. Nevertheless, Coflex implantation had the advantages of less bleeding loss, less trauma and quick recovery. Compared with fusion surgery, Coflex implantation had also advantages in maintaining intervertebral height and delaying intervertebral disc degeneration of adjacent segments.

Interspinous spacers are used in selected patients for the treatment of lumbar spinal stenosis. The uses of interspinous devices are still debated, with reports of significantly higher reoperation rates and unfavourable cost-effectiveness compared to traditional decompression techniques. Six electronic databases were searched from their date of inception to December 2015. Relevant studies were identified using specific eligibility criteria and data was extracted and analyzed based on predefined primary and secondary endpoints. Eleven comparative studies were obtained for qualitative and quantitative assessment, data extraction and analysis. There was no significant difference in VAS back pain, leg pain or ODI scores for standalone interspinous process device (IPD) vs. bony decompression. However, standalone IPD was associated with lower surgical complications (4% vs. 8.7%, P=0.03) but higher long-term reoperation rates (23.7% vs. 8.5%, P<0.00001). IPD as an adjunct to decompression had comparable patient-reported scores, complications and reoperation rates to decompression alone. Current evidence indicates no superiority for mid- to long-term patient-reported outcomes for IPD compared with traditional bony decompression, with lesser surgical complications but at the risk of significantly higher reoperation rates and costs.

BackgroundDecompressive laminectomy (DI) is a standard operation for lumbar spinal stenosis (LSS) patient with severe claudication symptoms for many years. However, patients whose symptom severity does not meet undergoing invasive surgery make therapeutic options into dilemma. Interspinous spacers (ISP) bridge the gap between surgical interventions and CC in management of LSS. In our study, we aim to systematically assess the two FDA-approved interspinous spacers for treatment of lumbar spinal stenosis: Superion versus X-STOP.MethodsElectronic databases, including PubMed, Embase, MEDLINE, Cochrane Library were searched to retrieve clinical trials concerning the comparison between Superion and X-STOP in treatment for lumbar spinal stenosis before April 2017. The following outcome measures were extracted: (1) Zurich Claudication Questionnaire (ZCQ) patient satisfaction score, (2) axial pain severity, (3) extremity pain severity, (4) back-specific functional impairment, (5) reoperation, and (6) complication. The data analysis was conducted with Review Manager 5.3.ResultsFive randomized controlled trials (RCTs) with 1118 patients were included in this meta-analysis. The pooled analysis indicated that the Superion group is superior to X-STOP in axial pain severity (SMD: 0.03; 95% CI 0.15, 0.45; p < 0.0001, I2 = 41%, p = 0.16), ZCQ patient satisfaction score (SMD: 0.23; 95% CI 0.08, 0.38; p = 0.002, I2 = 0%, p = 0.61). However, Superion group showed similarity outcome in extremity pain severity (SMD: 0.18; 95% CI − 0.06, 0.43; p = 0.14, I2 = 62%, p = 0.05), back-specific functional impairment (SMD: 0.04; 95% CI − 0.10, 0.19; p = 0.56, I2 = 0%, p = 0.77), reoperation rate (RR: 1.10; 95% CI 0.82, 1.48; p = 0.51, I2 = 19%, p = 0.30), and complication (RR: 0.98; 95% CI 0.63, 1.53; p = 0.92, I2 = 0%, p = 0.83).ConclusionBoth the Superion and X-STOP interspinous spacers can relieve symptoms of LSS. In addition, the Superion spacer may represent a promising spacer for patient with LSS. As we know, the effectiveness and safety of ISP is still considered investigational and unfavor clinical results in the medical literature may continue to limit the appeal of IPS to many surgeons in the future. However, because of the advantage of IPS technique, it will win a wide place in the future degenerative lumbar microsurgery.