SPONGIT: Comparison of Two Surgical Approaches in the Treatment of Degenerative Spondylolysthesis

Study Overview
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Brief Summary
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This trial, conducted in adult patients with degenerative spondylolisthesis needing surgical treatment at one level, aimed at comparing two approaches of spinal fusion.

Detailed Description
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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.

Official Title
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Comparison of 2 Surgical Approaches in the Treatment of Degenerative Spondylolysthesis: Posterolateral Fusion With Instrumentation (GPLI) Plus or Minus Transforaminal Lumbar Interbody Fusion (TLIF)

Conditions
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Degenerative Spondylolisthesis

Intervention / Treatment
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* Procedure: Circumferential arthrodesis
* Procedure: Posterolateral fusion with instrumentation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adults aged less than 75, Having been informed about clinical trial objectives and risk, Covered by health insurance system, Suffering from degenerative spondylolisthesis (whatever the grade and intervertebral disc height) needing one-level surgical fusion due to either invalidating lombalgia/radiculalgia despite 6-month optimal medical treatment and/or motor neurological symptoms. Exclusion Criteria: Previous lumbar fusion, Previous spine traumatism, Presence of at least one major contraindication to surgery and/or general anaesthesia (ie, non controlled coagulopathy, active infection, or serious underlying disease, auto-immune affection). Presence of at least one contraindication to either TLIF or GPLI, Severe radiological osteoporosis. Active cancer at time of inclusion into the study. Unlikely to comply with the requirements of the study and/or to complete the study for psychological, social, familial or geographical reasons. Under any administrative or legal supervision.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 74 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1<br>Posterolateral fusion with instrumentation combined to transforaminal lumbar interbody fusion | Procedure: Circumferential arthrodesis<br>* 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.<br>* Other names: TLIF+GPLI;|
| Active Comparator: 2<br>Posterolateral fusion with instrumentation | Procedure: Posterolateral fusion with instrumentation<br>* 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.<br>* Other names: GPLI;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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 |  | 24 months after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Major complication (ie, life threatening haemorrhage, severe and persisting neurological worsening, deep infection) rate, and minor complication rate |  | within 24 months after surgery | 
| Success rate defined as both fusion and at least 3-degree increase of segmental lordosis angle |  | 6 and 12 months after surgery | 
| Lumbar and radicular pain outcome |  | 2, 6, 12 and 24 months after surgery | 
| Functional outcome: Oswestry Disability Index and modified Prolo Economic and Functional scores |  | 2, 6, 12 and 24 months after surgery | 
| Change of pelvic and radiological parameters (ie, lumbar lordosis angle, medial intervertebral space height |  | 2, 6, 12 and 24 months after surgery | 
| Quality of life outcome: SF-36 |  | 2, 6, 12 and 24 months after surgery | 
| Per and post operative surgery parameters (ie, operative time, blood loss, hospitalization stay duration) |  | within hospital stay due to surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Spondylolisthesis, degeneration, spinal fusion