This trial, conducted in adult patients with degenerative spondylolisthesis needing surgical treatment at one level, aimed at comparing two approaches of spinal fusion.
Degenerative spondylolisthesis is defined as the slip of one vertebra onto the other due to degenerative lesions; the L4-L5 intervertebral space is mainly involved. Mean age of symptomatic disease is about 60. Surgery is indicated in the presence of radiculalgia and/or neurological claudication and/or invalidating lombalgia, worsening neurological deficit, presence of sphincterian incontinence. Surgical treatment of degenerative spondylolisthesis usually consists in neural decompression followed by posterolateral fusion with instrumentation. In the literature, fusion rate is estimated to be 80% with GPLI and seems to be increased by interbody fusion, especially transforaminal lumbar interbody fusion which has the advantage of unilateral disc interspace route, and fusion rate over 90%. It seems that hypolordosis in the instrumented segments caused increased loading of the posterior column in the adjacent segments. These biomechanical effects may explain the degenerative changes at the junction level that have been observed as long-term consequences of lumbar fusion. In addition to fusion, segmental lordosis gain seems to be an important long-term prognostic factor. Segmental lordosis recovery (upper than 3° in order to take into account measurement variability), was never assessed after TLIF procedure nor compared to that after posterolateral fusion in controlled randomized clinical trials. The main objective of the study is the comparison of efficacy between circumferential fusion (TLIF plus GPLI) and GPLI alone as surgical treatment of degenerative spondylolisthesis in term of "Success" rate, defined as fusion and at least 3-degree increase of segmental lordosis angle, 24 months after surgery. In this trial, included patients will be randomly assigned to undergo either posterolateral fusion with instrumentation (GPLI) or circumferential fusion with transforaminal lumbar interbody fusion (TLIF) combined to GPLI. In both arms, bone autograft will be performed using loose fragments obtained during neurological decompression. Six visits are planned during the study: pre-inclusion visit within 3 months before surgery, inclusion/randomisation on the day before surgery, 3 follow-up visits (2, 6, and 12 months after surgery) and an end of study visit 24 months after surgery (or at time of withdrawal if relevant). Hospital stay (about one week, on average) is planned after surgery.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
60
Patients are carefully positioned in the proned position and submitted to a posterior surgical approach under general anaesthesia. Surgical levels are viewed laterally by mean of intraoperative radiographs which can be performed at surgeon's demand during the whole surgery time. The preceding procedure is performed. In case of foraminal stenosis, decompression is performed at the same time as discal approach via the narrowest foramen. In addition to this, before preparation of bed for bone grafting, nerve roots are retracted and the disc nucleus is removed entirely, then endplate decortication is performed. The disc space is distracted. The most anterior part of the disc space is packed with cancellous bone. A cage packed with bone is inserted into the anterior portion of the interspace. According to cage location, bone graft could be inserted in the posterior portion of the interspace. Cage placement is radiologically checked. The end of the procedure is the same as for GPLI.
Patients are carefully positioned in pronation and submitted to a posterior surgical approach under general anaesthesia. Surgical levels are viewed laterally by mean of intraoperative radiographs performed at surgeon's demand during the whole surgery time. Pedicle screw instrumentation is performed, followed by posterior neural decompression depending on the type of stenosis: * Central stenosis: decompression is performed including medial facectomy, laminectomy; * Foraminal stenosis: foraminotomy is performed, while preserving a graft bed as large as possible; * Pure foraminal stenosis: spinal duct is not opened. Local bone is harvested from the lamina and the spinous process and carefully fragmented for autologous graft. Subperiosteal dissection is performed between the transverse processes and lateral aspects of the facet joints. Two rods are placed and locked on screws in maximum compression to optimize segmental lordosis. Bone autograft is placed into this bed.
Service de chirurgie orthopédique, Hôpital Pellegrin Tripode
Bordeaux, France
Success rate defined as fusion associated to at least a 3-degree increase of segmental lordosis angle and the absence of a reintervention due to a failure of the initial intervention
Time frame: 24 months after surgery
Major complication (ie, life threatening haemorrhage, severe and persisting neurological worsening, deep infection) rate, and minor complication rate
Time frame: within 24 months after surgery
Success rate defined as both fusion and at least 3-degree increase of segmental lordosis angle
Time frame: 6 and 12 months after surgery
Lumbar and radicular pain outcome
Time frame: 2, 6, 12 and 24 months after surgery
Functional outcome: Oswestry Disability Index and modified Prolo Economic and Functional scores
Time frame: 2, 6, 12 and 24 months after surgery
Change of pelvic and radiological parameters (ie, lumbar lordosis angle, medial intervertebral space height
Time frame: 2, 6, 12 and 24 months after surgery
Quality of life outcome: SF-36
Time frame: 2, 6, 12 and 24 months after surgery
Per and post operative surgery parameters (ie, operative time, blood loss, hospitalization stay duration)
Time frame: within hospital stay due to surgery
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