Table 2

List of interspinous process spacer studies included into the meta-analysis with brief summary of study highlights.

#AuthorsYearTitleReferenceStudy Highlights
1.Abdel Ghany W, Amer A, et al128 2016Evaluation of interspinous spacer outcomes in degenerative lumbar canal stenosis: clinical study World Neurosurg. 2016;95:556–564 e553.Prospective 12 mo study comparing 28 decompression. In the second group, 25 patients underwent decompressive laminectomy.
2.Errico TJ, Kamerlink JR, et al70 2009Survivorship of coflex interlaminar-interspinous implant SAS J. 2009;3:59–67.Retrospective study of 127 patients underwent placement of a coflex implant for various stenosis-related indications with a mean follow-up of 6.3 y.
3.Gu H, Chang Y, et al131 2018Wallis interspinous spacer for treatment of primary lumbar disc herniation: three-year results of a randomized controlled trial World Neurosurg. 2018;120:e1331–e1336.Prospective, single-center, randomized, controlled clinical trial comparing the postoperative results of lumbar discectomy with and without the Wallis implant. A total of 77 patients were included in the randomized study group, with 40 undergoing lumbar discectomy with Wallis implant insertion (Wallis group) and 37 undergoing lumbar discectomy alone (control group).
4.Haley TR, Miller LE, et al129 2013Midterm outcomes of a prospective randomized controlled trial of interspinous spacer treatment for moderate lumbar spinal stenosis PM&R. 2013:S289.Prospective, randomized, controlled, IDE trial. Setting: 23 hospitals in the United States. Participants: 145 patients with intermittent neurogenic claudication secondary to moderate LSS and unresponsive to conservative care. Interventions: Patients were randomly treated with ISP implant (Superion 75; X-Stop 70) and followed for 18 mo.
5.Korovessis P, Syrimpeis V, et al130 2018PEEK vs silicon interspinous spacer for reduction of supradjacent segment degeneration following decompression and short-segment instrumentation for degenerative lumbar spinal stenosis Adv Orthop. 2018;2018:1623647.A consecutive retrospective study of 55 patients on incidence of ASD and spinopelvic balance in short lumbosacral instrumentation for degenerative LSS with IPS placement in the supradjacent segment and its interaction with spinopelvic balance: 17 patients received polyetheretherketone (PEEK) IPS; 18 received Silicon IPS and were compared with 20 controls without any ISP.
6.Lønne G, Johnsen LG, et al132 2015Comparing cost-effectiveness of X-Stop with minimally invasive decompression in lumbar spinal stenosis: a randomized controlled trial Spine (Phila Pa 1976). 2015;40:514–520.Randomized clinical trial of 96 patients with 1-level or 2-level LSS, and 2-y follow-up to compare the cost-effectiveness of X-Stop to minimally invasive decompression in patients with symptomatic LSS.
7.Masala S, Fiori R, et al133 2012Percutaneous decompression of lumbar spinal stenosis with a new interspinous device Cardiovasc Intervent Radiol. 2012;35:368–374.Retrospective 6-mo follow-up study with the Falena ISP implanted at a single level in 26 patients (17 men; mean age, 69 (range, 54–82 y)) suffering degenerative LSS.
8.Masala S, Marcia S, et al42 2016Degenerative lumbar spinal stenosis treatment with Aperius PerCLID system and Falena(R) interspinous spacers: 1-year follow-up of clinical outcome and quality of life. Interv Neuroradiol. 2016;22:217–226.Retrospectively 12-mo follow-up study of 24 patients (20 men and 4 women; 61 ± 9 y old), treated with an implantation of the Aperius, PerCLID system, and from 35 patients (29 men and 6 women; 65 ± 9 y old) treated with the Falena interspinous device.
9.Miller LE and Block JE46 2012Interspinous spacer implant in patients with lumbar spinal stenosis: preliminary results of a multicenter, randomized, controlled trial Pain Res Treat. 2012;2012:823509.A prospective, randomized, controlled trial 6-mo follow-up IDE trial of ISP (Superion) vs those treated with an FDA-approved spacer (X-Stop). A total of 166 patients with moderate LSS unresponsive to conservative care were treated randomly with the Superion (n = 80) or X-Stop (n = 86) ISP.
10.Nunley PD, Patel VV, et al134 2017Superion interspinous spacer treatment of moderate spinal stenosis: 4-year results World Neurosurg. 2017;104:279–283.Prospective 4-y clinical outcomes study in patients with intermittent neurogenic due to moderate LSS treated with minimally invasive standalone ISP decompression using the Superion device. The data were extracted from a randomized, controlled FDA IDE trial.
11.Patel VV, Whang PG, et al53 2014Two-year clinical outcomes of a multicenter randomized controlled trial comparing two interspinous spacers for treatment of moderate lumbar spinal stenosis BMC Musculoskelet Disord. 2014;15:221.Prospective, multicenter, randomized, 2-y controlled trial in patients with moderate LSS treated with the Superion (experimental) or the X-Stop, an FDA-approved ISP (control). A total of 250 patients with moderate LSS unresponsive to conservative care were randomly allocated to treatment with the experimental (n = 123) or control (n = 127) ISP.
12.Postacchini R, Ferrari E, et al135 2011Aperius interspinous implant vs open surgical decompression in lumbar spinal stenosis Spine J. 2011;11:933–939.Prospective comparative cohort 12 mo study of patients with moderate or severe LSS treated with the Aperius or by open decompression.
13.Puzzilli F, Gazzeri R, et al141 2014Interspinous spacer decompression (X-Stop) for lumbar spinal stenosis and degenerative disk disease: a multicenter study with a minimum 3-year follow-up Clin Neurol Neurosurg. 2014;124:166–174.Prospective 36 mo study comparing clinical outcomes of 422 ISP patients (X-Stop) to 120 control cases were managed conservatively.
14.Richter A, Schutz C, et al136 2010Does 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 Eur Spine J. 2010;19:283–289.Prospective 12 mo study of 60 patients comparing 1-level or 2-level symptomatic LSS decompressive surgery to LSS decompressive surgery (30 patients) and additional implantation of the Coflex ISP (30 patients).
15.Senegas J137 2002Mechanical supplementation by non-rigid fixation in degenerative intervertebral lumbar segments: the Wallis system Eur Spine J. 2002;11(suppl 2):S164–S169.A 3-y prospective cohort study comparing discectomy alone with discectomy and ISP implantation using Wallis.
16.Sobottke R, Schluter-Brust K, et al142 2009Interspinous implants (X-Stop, Wallis, Diam) for the treatment of LSS: is there a correlation between radiological parameters and clinical outcome? Eur Spine J. 2009;18:1494–1503.Retrospective comparative study of 129 consecutive patients with LSS treated with X-Stop, Wallis, or Diam.
17.Surace MF, Fagetti A, et al138 2012Lumbar spinal stenosis treatment with Aperius perclid interspinous system Eur Spine J. 2012;21(suppl 1): S69-S74.Prospective cohort 18 mo study of 37 patients (20 men and 17 women) with mean age of 64.3 y treated with Aperius and PercLID ISP) foraminal stenosis.
18.Stromqvist BH, Berg S, et al139 2013X-Stop vs decompressive surgery for lumbar neurogenic intermittent claudication: randomized controlled trial with 2-year follow-up. Spine (Phila Pa 1976). 2013;38:1436–1442.Prospective comparative 18 mo cohort study of 100 patients with symptomatic 1-level or 2-level LSS: 50 in the X-Stop group and 50 in the decompression group.
19.Tekmyster G, Sayed D, et al140 2019Interspinous process decompression with the Superion® spacer for lumbar spinal stenosis: real-world experience from a device registry Med Devices (Auckl). 2019;12:423–427.Retrospective study of clinical outcomes with Superion. Indirect decompression system in 1426 LSS patients with intermittent neurogenic claudication treated by 316 physicians at 86 clinical sites in the United States participated.

  • ASD, adjacent segment degeneration; FDA, Food and Drug Administration; IDE , investigational device exemption; ISP, interspinous spacer; LSS, lumbar spinal stenosis.