Interspinous Stabilization/Decompression with Viking and In-space Devices in Patients with Degenerative Disk Disease and Spinal Stenosis at a Lumbosacral Level

Abstract

Introduction In the last few years, several interspinous prostheses have been used for the treatment of several degenerative disk diseases involving the lumbosacral region; among them stenosis of the spinal canal or degenerative discopathy. Such devices share the same characteristics such as they require minimally invasive procedures and are implanted in the stenosis of lumbosacral joint or in the degenerative discopathy with the aim to increase canal diameters or upload the task of the intervertebral disk. In this paper, we present our experience in the implant of some interspinous devices (Viking and In-Space) in lumbosacral degenerative disk disease and lumbar spinal stenosis on a single to double level. AIMS The aim of this study is to verify the clinical results on pain and quality of life measured by the application of VAS scale and ODI index with a follow-up of 12 and 36 months. Also, to evaluate the tolerability of the prosthesis material. Materials and Methods From 2007 to 2010, 150 patients have undergone surgery concerning the interspinous dynamic decompression with Viking and In-Space on a single to double level. Viking is a interspinous prosthesis device made by Peek showing the following features: interspinous dynamic spacer able to absorb axial, flexional and torsional stresses applied on the movement segment involved by its implantation as well as, in the meanwhile, to preserve the degrees of freedom of the segment itself. In-Space is an interspinous prosthesis device made by Peek, intended to stop the segmental extension and to distract the interspinous space at a symptomatic level between L1 to L5. In-Space acts as a space-holder and protects mainly the posterior elements by maintaining the foraminal height, opening up the area of the spinal canal reducing stress on the facet joints and relieving pressure on the posterior annulus. Treatment with Viking and In-Space was indicated in case of LDDD and LLS (assessed by clinical and radiological examinations) linked or not to osteochondrosis, measured by X-ray or NMR. Flexion/extension Xray views are strongly recommended. The clinical situation was characterized by chronic lumbar back pain with episodic and irregular pain irradiation to inferior limb measured by using VAS scale and ODI index. Among 150 patients, 62 were men and 88 women, ranging from 32 to 77 years old (mean age 53.81). The site of the surgery has been distributed as shown: single level 130 patients ( L4-L5 67, L5-S1 49, L3-L4 10, L2-L3 3, D12-L1 1); double level 20 patients ( L3-L4 and L4-L5 7, L4-L5 and L5-S1 12, L1-L2 and L2-L3 1 ). Results Follow-up period ranged from 12 to 36 months. One patient did not show any clinical benefit and had, subsequently, a new surgery to stabilize L5-S1 area with peduncular screws in another hospital. After stabilization surgery in L5-S1 area, three patients had a radicular leg pain due to disk hernia; the interspinous device has been removed and a microdiscectomy has been performed. The patients achieved the complete pain resolution. In the other 146 patients, both scores of the VAS scale (preop. 7.2 +/-2; postop. 1.8 +/-1.5) and ODI index (preop. 64%; postop. 14%) revealed sensible pain reduction and improvements in the quality of life after surgery valued with Zurich Claudication Questionnaire. No postoperative complications have been reported in all patients. The interspinous devices resulted well tolerated, except for single cases of postoperative fever treated with antibiotics. The devices haven't been removed in any patient due to infections or reactions due to foreign bodies. Conclusion Our study shows the following points: The interspinous device Viking and In-Space represent a minimally invasive surgery; they are well tolerated by patients and do not show postoperative complications linked to infections or reactions to foreign bodies; The LDDD and LSS on single and, most rarely, double level, diagnosed by X-ray and NMR, represents a specific indication for the treatment of interspinous stabilization; the evidence of "black disks" and somatic osteochondrosis ( MODIC I-II ) at NMR examination is a favorable prognostic element for the good outcome of surgery. The surgical technique of interspinous decompression with Viking is based on the realization of a section of the interspinous and supraspinous ligament, the segment distraction and, later on, on the grafting of the prosthesis device. Implant of the In-Space is not necessary in the section of supraspinous ligament.These techniques allow to obtain a better distraction of the space, a greater increase of the canal diameters, and the utilization of the interspinous stabilization in some cases of discopathies in which the discal space is anatomically more "sacrificed"; the improvement of postoperatorive pain as well as of the quality of life need to be verified through a long-term follow-up.