Page 13 -
P. 13
Nevertheless, long-term clinical results after surgery are quite poor: only 64% of the patients are satisfied after surgical treatment.13 Numerous patients still complain about back pain after surgery. In order to solve this ‘problem’, a French group introduced a new, non-rigid fixation for patients with LSS and associated back pain in 1984: the Wallis system.14-16 It was a new idea to implant non-rigid implants to indirectly decompress the lumbar canal and to ‘unload’ the facet joints. The idea was based on their experience of implanting non-rigid implants in other joints. The Wallis system was first implanted in 1986.14, 15 Nowadays, (other) interspinous process devices (IPDs) are used in the treatment for LSS and also others for back pain.17-19 The X-stop and Coflex implants were first used in the USA in an FDA trial.17 In contrast, in the European countries surgeons started to implant these devices right away (not in any prospective study design).14, 15 As a result, these implants are widely used for almost 30 years to treat patients with INC caused by LSS.
Objective and outline of this thesis
The main objective of this thesis is to compare bony decompression with implantation of interspinous process devices (IPDs) in patients with intermittent neurogenic claudication (INC) caused by lumbar spinal stenosis (LSS). At the start of this research project, no double blind randomized study on this subject was published. However, implantation of IPDs was already part of the daily practice in some Dutch neurosurgical and orthopedic clinics. In chapter 2 a national survey among Dutch spine surgeons is presented about the usual care of patients with intermittent neurogenic claudication caused by lumbar spinal stenosis. Surgeons’ expectations of different treatment options are presented. The existing evidence on interspinous implant surgery will be systematically reviewed in chapter 3. Results of treatment with IPDs are compared with other (conservative) treatment options. In chapter 4 the design of the Foraminal Enlargement Lumbar Interspinosus distraXion (FELIX) trial is described. This double-blind, multicenter, randomized (cost)effectiveness study was designed to answer the question whether treatment with IPDs would be more (cost) effective compared with conventional bony decompression. Short-term results (eight weeks), long-term results (one year) and results in different subgroups are described in chapter 5. The two-year results are presented in chapter 6. The analysis based on total direct and indirect costs of both procedures (treatment with IPD and bony decompression) are presented in chapter 7.
General Introduction
11
1
