Review
doi: 10.21037/jss-21-57.
Affiliations
Item in Clipboard
Review
J Spine Surg.
2021 Sep.
Abstract
Minimally invasive interspinous process devices (IPD), including interspinous distraction devices (IDD) and interspinous stabilizers (ISS), are increasingly utilized for treating symptomatic lumbar canal stenosis (LCS). There is ongoing debate around their efficacy and safety over traditional decompression techniques with and without interbody fusion (IF). This study presents a comprehensive review of IPD and investigates if: (I) minimally invasive IDD can effectively substitute direct neural decompression and (II) ISS are appropriate substitutes for fusion after decompression. Articles published up to 22nd January 2020 were obtained from PubMed search. Relevant articles published in the English language were selected and critically reviewed. Observational studies across different IPD brands consistently show significant improvements in clinical outcomes and patient satisfaction at short-term follow-up. Compared to non-operative treatment, mini-open IDD was had significantly greater quality of life and clinical outcome improvements at 2-year follow-up. Compared to open decompression, mini-open IDD had similar clinical outcomes, but associated with higher complications, reoperation risks and costs. Compared to open decompression with concurrent IF, ISS had comparable clinical outcomes with reduced operative time, blood loss, length of stay and adjacent segment mobility. Mini-open IDD had better outcomes over non-operative treatment in mild-moderate LCS at 2-year follow-up, but had similar outcomes with higher risk of re-operations than open decompression. ISS with open decompression may be a suitable alternative to decompression and IF for stable grade 1 spondylolisthesis and central stenosis. To further characterize this procedure, future studies should focus on examining enhanced new generation IPD devices, longer-term follow-up and careful patient selection.
Keywords:
Interspinous spacer; interspinous decompression device; interspinous stabilizers; lumbar canal stenosis; outcomes.
2021 Journal of Spine Surgery. All rights reserved.
Conflict of interest statement
Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://dx.doi.org/10.21037/jss-21-57). KP serves as the Co-Editor-in-Chief of Journal of Spine Surgery. LM is the Chairperson of Diagnostic and Interventional Spine – European Society of Neuroradiology. LM serves on the European Radiology Scientific Editorial Board, and is the Director of Minimal Invasive Spine Therapy department – Mediterranean Institute for Oncology I.O.M, Catania – Italy. JAH reports grant from the Neiman health Policy Institute, and he is a consultant for Medtronic and persic. The other authors have no conflicts of interest to declare.
Figures
Figure 1
Preoperative (top row) and postoperative (bottom row) CT sagittal images of a 64-year-old male, demonstrating increased interspinous space, and greater foraminal space after insertion of two interspinous distraction devices (Lobster, Techlamed, ITA). The patient’s symptoms of neurogenic Intermittent claudication due to lumbar canal stenosis was completely resolved after intervention.
Figure 2
(Clockwise from top left): Insertion of ISS Lobster (Techlamed, ITA) at L3/4 level. (A) Introducer inserted through percutaneous approach, (B) the probe is inserted through outer sheath and between L3/4 spinous processes, (C) ISS device deployed, (D) ISS device expanded to achieve distraction of spinous processes. The patient was a 77-year-old female with neurogenic intermittent claudication due to lumbar canal stenosis, which was completely resolved after intervention.
Figure 3
Pre- and post-operative CT images of insertion of ISS at the L4/5 level: top row demonstrating an increase in cross sectional area of the spinal canal from 3.4 to 4.2 cm2 after instrumentation, and an increase in the cross sectional area of the intervertebral foramen from 1.0 to 2.0 cm2 after instrumentation.
Figure 4
Meta-analysis of reoperation rate between IDD and Decompression groups, with results favouring decompression.
Figure 5
Meta-analysis of all complications between IDD and Decompression groups, with results favouring decompression.
Figure 6
Meta-analysis of mean blood loss (millimetres, mL) between ISS and Interbody fusion groups, with results favouring ISS.
Figure 7
Meta-analysis of mean operative time (minutes, mins) between ISS and Interbody fusion groups, with results favouring ISS.
Figure 8
Meta-analysis of reoperations between ISS and Interbody fusion groups, with results showing no significant difference.
Figure 9
Gauge needle positioning for spinoplasty.
Figure 10
L4/5 PMMA cement augmentation of the spinous processes via 13gauge needle followed by L4/5 insertion of ISS. The cement augmentation was performed to strengthen the spinous processes, and decrease the risk of fracture upon insertion of the ISS. The patient was a 74 years old female, with a T-score less than −1.5.