effectiveness and safety of the facet fixation (ffx®) implant in the treatment of degenerative lumbar spinal stenosis

Conditions: Degenerative Lumbar Spinal Stenosis

Summary: this is a prospective, multicentric, comparative, randomised-controlled study to evaluate the safety and efficacy of the facet fixation implant. the main objective is to evaluate the effectiveness of spinal decompression associated with ffx® implants compared to spinal decompression alone in treating lumbar spinal stenosis after 2 years of treatment.


Eligibility criteria:
inclusion criteria: * age ≥ 50 years. * radiographic confirmation of clinical symptoms of at least moderate degenerative spinal stenosis, of 1 to 3 adjacent segments in the l1-s1 region with the need for surgical decompression. * radiographic confirmation of no translational instability in main segment as well as in adjacent segments (dynamic translational instability ≤3 mm); * visual analogue scale (vas) back pain score ≥ 50 mm (on a 100-mm scale). * minimum of 3 months of conservative therapy without improvement of symptoms. * mental \& physical ability of the subject to follow the protocol (i.e., compliance with time schedule \& treatment plan, able to fill in questionnaire \& to undergo further study procedures). * personally signed and dated informed consent document prior to any study-related procedures indicating that the subject has been informed of all pertinent aspects of the clinical investigation. exclusion criteria: * prior lumbar spine surgery. * radiographically confirmed damage of a vertebral body (e.g., osteoporotic compression fracture or because of tumours), at any lumbar level. * isthmic or degenerative spondylolisthesis (anterolisthesis; retrolisthesis ≥ grade ii) or spondylolysis (pars fracture). * degenerative lumbar scoliosis (cobb angle \> 25°). * adipositas (obesity); defined as a body mass index (bmi) \>40. * pregnancy, or wish to get pregnant during the course of the study, or breastfeeding. * known allergy or sensitivity to titanium, titanium alloys, or mri contrast agents. * active or chronic infection-systemic or local. * history of significant peripheral neuropathy. * significant peripheral vascular disease (e.g., with diminished dorsalis pedis or posterior tibial pulses). * paget disease, osteomalacia or other metabolic bone disorders. * cauda equina syndrome. * known or documented history of transmissible disease, including aids, hiv and active hepatitis. * more than 3 vertebral levels requiring surgery. * disc herniation at any lumbar level requiring surgical intervention. * known osteoporosis (bone mineral density, bmd \< 120 mg/cm3). * chronically taking medications or any drug known to potentially interfere with bone/soft tissue healing (e.g., steroids), not including a medrol (methylprednisolone) dose pack. * fixed and complete motor, sensory, or reflex deficit. * rheumatoid arthritis or other autoimmune diseases. * active malignancy: a subject with a history of any invasive malignancy (except non-melanoma skin cancer) unless he/she has been treated with curative intent and there has been no clinical signs or symptoms of the malignancy for at least 5 years. subjects with a primary bony tumour are excluded as well. * subject with a history of substance abuse (e.g., recreational drugs, narcotics, or alcohol). * bone destruction, demineralisation or any affection potentially affecting fixation of an implant. * spondylodiscitis or spine tumour. * currently seeking or receiving workman's compensation. * in active spinal litigation. * subjects who participate(d) in another clinical trial (within the last 4 weeks) that might influence the safety \& effectiveness assessment of this trial. * subjects who are lawfully kept in an institution. * subject who, in the opinion of the investigator, will be inappropriate for inclusion in this clinical trial or who will not comply with requirements of the study. * subject under supervision or legal guardianship, or judicial protection. * subject deprived of liberty by judicial or administrative decision. * subject not covered by a social security scheme.