Ignite Creation Date:
2024-05-11 @ 8:30 AM
Last Modification Date:
2024-10-26 @ 3:29 PM
Study NCT ID:
NCT06407063
Status:
ACTIVE_NOT_RECRUITING
Last Update Posted:
2024-05-09
First Post:
2024-05-06
Brief Title:
Long-term Reoperations After Lumbar Spinal Stenosis Surgery
Sponsor:
University Hospital of North Norway
Organization:
University Hospital of North Norway
Study Overview
Official Title:
Long-term Frequency of Reoperations After Micro-decompression Alone Versus Decompression and Instrumented Fusion in Patients With Lumbar Spinal Stenosis and Degenereative Spondylolisthesis
Status:
ACTIVE_NOT_RECRUITING
Status Verified Date:
2024-04
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
Severe and persisting pain and disability due to a degenerative narrowing of the spinal canal lumbar spinal stenosis can be operated with a simple surgical decompression Sometimes there is also a slippage of vertebra degenerative spondylolisthesis In such cases instrumental stabilization eg screws and rods has been recommended Even though additional fusion is more complex and riskier and evidence in high-quality Scandinavian studies shows that it is unnecessary decompression plus fusion is still the treatment of choice in the USA and most European countries This reluctance to change clinical practice is mainly due to concerns about long-term results especially higher reoperation rates among patients operated with decompression only This register-based non-inferiority study aims to assess long-term reoperations among those treated with and without additional fusion surgery
Detailed Description:
The use of fusion surgery in addition to decompression in the treatment of degenerative lumbar spondylolisthesis DS with spinal stenosis LSS is a long-standing controversy in spine surgery The main goal of LSS surgery is to decompress the nerve roots In the 1990s two observational studies recommended that decompression with additional fusion should be the treatment of choice 1 2 Consequently the practice shifted towards more complex fusion procedures In 2016 two randomized controlled trials RCTs reported conflicting data about reoperations The American study showed a higher frequency of reoperations in the decompression arm compared to the decompression and fusion arm 3 while the Swedish study showed no difference 4 In 2020 Austevoll et al published an observational relative effectiveness study from the Norwegian registry for spine surgery NORspine comparing micro-decompression alone vs decompression and instrumented fusion 5 The study had a non-inferiority design similar to the RCT published by the same author in 2021 6 Both studies concluded that micro-decompression alone was non-inferior to decompression and instrumented fusion regarding clinical outcomes and reoperation rates Despite an increasing number of studies showing no extra benefits from the more risky and complex additional fusion procedures the surgical practice has changed little outside Scandinavia This is probably due to the concerns about subsequent instability and higher long-term reoperation rates among those operated with decompression only
This study is a long-term follow-up of the previously mentioned NORspine study 5NCT03469791 comprising 794 patients having an index operation for LSS and DS between September 19th 2007 and December 21st 2015 The present study aims to assess long-term reoperations resulting from everyday clinical practice We hypothesise that micro-decompression alone is non-inferior to decompression plus instrumented fusion The non-inferior margin is specified to correspond to a number needed to treat 8 to avoid reoperation on one patient in the first 10 postoperative years corresponding to a between-group difference of 125 percentage points 1008 125
Our dataset contains NORspine data at baseline 3 months one year and long-term follow-up performed at 7 to 15 years NCT03469791 NORspine also provides dates of death for all deceased patients The Norwegian Patient Registry NPR will serve as an external data source providing data about all reoperations until August 31st 2023 and the baseline Charlson Comorbidity Index CCI NPR data will ensure follow-up of 8 to 16 years concerning reoperations For these cases we will review the electronic health records to validate NPR data regarding classification of reoperation level indication surgical technique total number of reoperations spinal cord stimulation reoperations within 90 days after the index operation participation in other studies
In the short-term follow-up study 5NCT03469791 propensity score matching PSM was performed to reduce the risk of allocation bias We will reuse this matching PSM is used to make the distribution of observed baseline patient characteristics in the micro-decompression and instrumented fusion group as similar as possible The following parameters were included in the calculation of the propensity score Age Gender American Society of Anaesthesiologists ASA grade Body Mass Index BMI Smoking Oswestry Disability Index ODI Numeric Rating Scale for leg pain and back pain Euroqol 5D EQ-5D-3L foraminal stenosis degenerative disc disease predominating back pain number of levels operated on and neurological palsy The propensity scores were derived from a logistic regression model and reflected a patients theoretical baseline probability for being instrumentally fused Using the 11 matching without replacement method pairs of fused and non-fused patients with a difference in propensity scores less than 02 in the logit of the standard deviation were formed Statistical Package for the Social Sciences SPSS version 24 was used for propensity score matching For comparison complete case analyses will also be performed
In this non-inferiority designed study with one sided testing our primary outcome is the occurrence of a reoperation defined as new lumbar spine operation more than 90 days after the index operation during the observation period ie from 90 days after index operation until August 31st 2023 years range from 8 to 16 years We will use survival analysis to detect whether the probability for reoperation during the first 10 postoperative years is more than 125 higher non-inferiority margin in the micro-decompression group than in the decompression and instrumented fusion group This is to be tested by deriving a 90 confidence interval CI for the difference of the survival function St at 10 years between the groups St in decompression and instrumented fusion group - St in micro-decompression group where t 10 years and rejected if the lower limit of the CI is above -0125 If this is rejected the conclusion will be that in the setting of everyday clinical practice micro-decompression is non-inferior to decompression and instrumented fusion regarding the risk of reoperation We will further report the survival functions and observed reoperation rates at multiple timepoints 2 5 and 10 years hazard ratio HR for reoperation at 2 5 and 10 years if the proportional hazard assumption in violated as well as complications including reoperations within 90 days We will also investigate the indication for reoperation surgical techniques used and risk factors associated with reoperation
For the power analysis conducted with PASS 2019 we made two assumptions 1 Expected reoperation rate Based on NORspine data about 271 of lumbar surgical procedures are performed on patients previously operated on in the lumbar spine We use this as a proxy for the expected probability of the event reoperation in the total cohort 2 HR 16 decompression and instrumented fusion as baseline approximates the event ratio between the groups This non-inferiority margin choosing a type 1 error 005 and power 08 gives sample size 269 per group Our sample size is 285 per group and since our data source are national administrative registries and patients health records we do not expect substantial loss to follow-up
We will employ SAS Enterprise Guide 83 for analyses including descriptive statistics tests for data distribution cross-tabulations with χ2 test Student t-tests and Mann-Whitney U tests Reoperation survival hazard and rates will be assessed by stratified log-rank test cox regression modelling time-dependent if the proportional hazard assumption is violated Kaplan-Meier plots and multivariable regression analyses
1 Herkowitz HN Kurz LT Degenerative lumbar spondylolisthesis with spinal stenosis A prospective study comparing decompression with decompression and intertransverse process arthrodesis J Bone Joint Surg Am 1991736802-8
2 Bridwell KH Sedgewick TA OBrien MF Lenke LG Baldus C The role of fusion and instrumentation in the treatment of degenerative spondylolisthesis with spinal stenosis J Spinal Disord 199366461-72
3 Ghogawala Z Dziura J Butler WE Dai F Terrin N Magge SN et al Laminectomy plus Fusion versus Laminectomy Alone for Lumbar Spondylolisthesis N Engl J Med 2016374151424-34
4 Försth P Ólafsson G Carlsson T Frost A Borgström F Fritzell P et al A Randomized Controlled Trial of Fusion Surgery for Lumbar Spinal Stenosis N Engl J Med 2016374151413-23
5 Austevoll IM Gjestad R Solberg T Storheim K Brox JI Hermansen E et al Comparative Effectiveness of Microdecompression Alone vs Decompression Plus Instrumented Fusion in Lumbar Degenerative Spondylolisthesis JAMA Netw Open 202039e2015015
6 Austevoll IM Hermansen E Fagerland MW Storheim K Brox JI Solberg T et al Decompression with or without Fusion in Degenerative Lumbar Spondylolisthesis N Engl J Med 20213856526-38
This study is a long-term follow-up of the previously mentioned NORspine study 5NCT03469791 comprising 794 patients having an index operation for LSS and DS between September 19th 2007 and December 21st 2015 The present study aims to assess long-term reoperations resulting from everyday clinical practice We hypothesise that micro-decompression alone is non-inferior to decompression plus instrumented fusion The non-inferior margin is specified to correspond to a number needed to treat 8 to avoid reoperation on one patient in the first 10 postoperative years corresponding to a between-group difference of 125 percentage points 1008 125
Our dataset contains NORspine data at baseline 3 months one year and long-term follow-up performed at 7 to 15 years NCT03469791 NORspine also provides dates of death for all deceased patients The Norwegian Patient Registry NPR will serve as an external data source providing data about all reoperations until August 31st 2023 and the baseline Charlson Comorbidity Index CCI NPR data will ensure follow-up of 8 to 16 years concerning reoperations For these cases we will review the electronic health records to validate NPR data regarding classification of reoperation level indication surgical technique total number of reoperations spinal cord stimulation reoperations within 90 days after the index operation participation in other studies
In the short-term follow-up study 5NCT03469791 propensity score matching PSM was performed to reduce the risk of allocation bias We will reuse this matching PSM is used to make the distribution of observed baseline patient characteristics in the micro-decompression and instrumented fusion group as similar as possible The following parameters were included in the calculation of the propensity score Age Gender American Society of Anaesthesiologists ASA grade Body Mass Index BMI Smoking Oswestry Disability Index ODI Numeric Rating Scale for leg pain and back pain Euroqol 5D EQ-5D-3L foraminal stenosis degenerative disc disease predominating back pain number of levels operated on and neurological palsy The propensity scores were derived from a logistic regression model and reflected a patients theoretical baseline probability for being instrumentally fused Using the 11 matching without replacement method pairs of fused and non-fused patients with a difference in propensity scores less than 02 in the logit of the standard deviation were formed Statistical Package for the Social Sciences SPSS version 24 was used for propensity score matching For comparison complete case analyses will also be performed
In this non-inferiority designed study with one sided testing our primary outcome is the occurrence of a reoperation defined as new lumbar spine operation more than 90 days after the index operation during the observation period ie from 90 days after index operation until August 31st 2023 years range from 8 to 16 years We will use survival analysis to detect whether the probability for reoperation during the first 10 postoperative years is more than 125 higher non-inferiority margin in the micro-decompression group than in the decompression and instrumented fusion group This is to be tested by deriving a 90 confidence interval CI for the difference of the survival function St at 10 years between the groups St in decompression and instrumented fusion group - St in micro-decompression group where t 10 years and rejected if the lower limit of the CI is above -0125 If this is rejected the conclusion will be that in the setting of everyday clinical practice micro-decompression is non-inferior to decompression and instrumented fusion regarding the risk of reoperation We will further report the survival functions and observed reoperation rates at multiple timepoints 2 5 and 10 years hazard ratio HR for reoperation at 2 5 and 10 years if the proportional hazard assumption in violated as well as complications including reoperations within 90 days We will also investigate the indication for reoperation surgical techniques used and risk factors associated with reoperation
For the power analysis conducted with PASS 2019 we made two assumptions 1 Expected reoperation rate Based on NORspine data about 271 of lumbar surgical procedures are performed on patients previously operated on in the lumbar spine We use this as a proxy for the expected probability of the event reoperation in the total cohort 2 HR 16 decompression and instrumented fusion as baseline approximates the event ratio between the groups This non-inferiority margin choosing a type 1 error 005 and power 08 gives sample size 269 per group Our sample size is 285 per group and since our data source are national administrative registries and patients health records we do not expect substantial loss to follow-up
We will employ SAS Enterprise Guide 83 for analyses including descriptive statistics tests for data distribution cross-tabulations with χ2 test Student t-tests and Mann-Whitney U tests Reoperation survival hazard and rates will be assessed by stratified log-rank test cox regression modelling time-dependent if the proportional hazard assumption is violated Kaplan-Meier plots and multivariable regression analyses
1 Herkowitz HN Kurz LT Degenerative lumbar spondylolisthesis with spinal stenosis A prospective study comparing decompression with decompression and intertransverse process arthrodesis J Bone Joint Surg Am 1991736802-8
2 Bridwell KH Sedgewick TA OBrien MF Lenke LG Baldus C The role of fusion and instrumentation in the treatment of degenerative spondylolisthesis with spinal stenosis J Spinal Disord 199366461-72
3 Ghogawala Z Dziura J Butler WE Dai F Terrin N Magge SN et al Laminectomy plus Fusion versus Laminectomy Alone for Lumbar Spondylolisthesis N Engl J Med 2016374151424-34
4 Försth P Ólafsson G Carlsson T Frost A Borgström F Fritzell P et al A Randomized Controlled Trial of Fusion Surgery for Lumbar Spinal Stenosis N Engl J Med 2016374151413-23
5 Austevoll IM Gjestad R Solberg T Storheim K Brox JI Hermansen E et al Comparative Effectiveness of Microdecompression Alone vs Decompression Plus Instrumented Fusion in Lumbar Degenerative Spondylolisthesis JAMA Netw Open 202039e2015015
6 Austevoll IM Hermansen E Fagerland MW Storheim K Brox JI Solberg T et al Decompression with or without Fusion in Degenerative Lumbar Spondylolisthesis N Engl J Med 20213856526-38
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None