Greger Lønne

Minimally invasive decompression versus open laminectomy for central stenosis of the lumbar spine: pragmatic comparative effectiveness study

Objective To test the equivalence for clinical effectiveness between microdecompression and laminectomy in patients with central lumbar spinal stenosis. Design Multicentre observational study. Setting Prospective data from the Norwegian Registry for Spine Surgery. Participants 885 patients with central stenosis of the lumbar spine who underwent surgery at 34 Norwegian orthopaedic or neurosurgical departments. Patients were treated from October 2006 to December 2011. Interventions Laminectomy and microdecompression. Main outcome measures The primary outcome was change in Oswestry disability index score one year after surgery. Secondary endpoints were quality of life (EuroQol EQ-5D), perioperative complications, and duration of surgical procedures and hospital stays. A blinded biostatistician performed predefined statistical analyses in unmatched and propensity matched cohorts. Results The study was powered to detect a difference between the groups of eight points on the Oswestry disability index at one year. 721 patients (81%) completed the one year follow-up. Equivalence between microdecompression and laminectomy was shown for the Oswestry disability index (difference 1.3 points, 95% confidence interval −1.36 to 3.92, P<0.001 for equivalence). Equivalence was confirmed in the propensity matched cohort and full information regression analyses. No difference was found between groups in quality of life (EQ-5D) one year after surgery. The number of patients with complications was higher in the laminectomy group (15.0% v 9.8%, P=0.018), but after propensity matching for complications the groups did not differ (P=0.23). The duration of surgery for single level decompression was shorter in the microdecompression group (difference 11.2 minutes, 95% confidence interval 4.9 to 17.5, P<0.001), but after propensity matching the groups did not differ (P=0.15). Patients in the microdecompression group had shorter hospital stays, both for single level decompression (difference 1.5 days, 95% confidence interval 1.7 to 2.6, P<0.001) and two level decompression (0.8 days, 1.0 to 2.2, P=0.003). Conclusion At one year the effectiveness of microdecompression is equivalent to laminectomy in the surgical treatment of central stenosis of the lumbar spine. Favourable outcomes were observed at one year in both treatment groups. Trial registration ClinicalTrials.gov NCT02006901.

Minimally invasive decompression versus x-stop in lumbar spinal stenosis: a randomized controlled multicenter study.

Study Design. Prospective randomized controlled multicenter study. Objective. To compare the effect of X-Stop with minimally invasive decompression (MID) in patients with neurogenic intermittent claudication due to lumbar spinal stenosis. Summary of Background Data. Lumbar spinal stenosis is the most common indication for operative treatment in elderly. Laminectomy has been the “gold standard,” but MID is now widely used. Another minimally invasive surgery option is X-Stop showing good result compared with nonoperative treatment, but showing higher reoperation rate than laminectomy. Methods. We enrolled 96 patients aged 50 to 85 years, with symptoms of neurogenic intermittent claudication within 250-m walking distance and 1- or 2-level lumbar spinal stenosis, randomized to either MID or X-Stop. Primary outcome was Zurich Claudication Questionnaire in this intention-to-treat analysis. Secondary outcome was Oswestry Disability Index, EuroQol 5-dimensional questionnaire, numerical rating scale 11 for lower back pain and leg pain, and risk for secondary surgery and complications. Results. No significant differences were found in Zurich Claudication Questionnaire between the groups at any follow-ups. Both groups had a statistical and clinical significant improvement at 6 weeks and throughout the 2-year observation period. The number of patients having secondary surgery due to persistent or recurrent symptoms was significantly higher in the X-Stop group, odds ratio (95% confidence interval) = 6.5 (1.3–31.9). Complication rate was similar and low, but more severe for MID. Conclusion. Both MID and X-Stop led to significant symptom improvements. There were no significant clinical differences in effect between the methods at any of the follow-up time points. X-Stop had significant higher risk of secondary surgery. Complication was more severe for MID. Level of Evidence: 2

Comparing cost-effectiveness of X-Stop with minimally invasive decompression in lumbar spinal stenosis: a randomized controlled trial.

Study Design. Randomized clinical trial with 2-year follow-up. Objective. To compare the cost-effectiveness of X-stop to minimally invasive decompression in patients with symptomatic lumbar spinal stenosis. Summary of Background Data. Lumbar spinal stenosis is the most common indication for operative treatment in elderly. Although surgery is more costly than nonoperative treatment, health outcomes for more than 2 years were shown to be significantly better. Surgical treatment with minimally invasive decompression is widely used. X-stop is introduced as another minimally invasive technique showing good results compared with nonoperative treatment. Methods. We enrolled 96 patients aged 50 to 85 years, with symptoms of neurogenic intermittent claudication within 250-m walking distance and 1- or 2-level lumbar spinal stenosis, randomized to either minimally invasive decompression or X-stop. Quality-adjusted life-years were based on EuroQol EQ-5D. The hospital unit costs were estimated by means of the top-down approach. Each cost unit was converted into a monetary value by dividing the overall cost by the amount of cost units produced. The analysis of costs and health outcomes is presented by the incremental cost-effectiveness ratio. Results. The study was terminated after a midway interim analysis because of significantly higher reoperation rate in the X-stop group (33%). The incremental cost for X-stop compared with minimally invasive decompression was &OV0556;2832 (95% confidence interval: 1886–3778), whereas the incremental health gain was 0.11 quality-adjusted life-year (95% confidence interval: −0.01 to 0.23). Based on the incremental cost and effect, the incremental cost-effectiveness ratio was &OV0556;25,700. Conclusion. The majority of the bootstrap samples displayed in the northeast corner of the cost-effectiveness plane, giving a 50% likelihood that X-stop is cost-effective at the extra cost of &OV0556;25,700 (incremental cost-effectiveness ratio) for a quality-adjusted life-year. The significantly higher cost of X-stop is mainly due to implant cost and the significantly higher reoperation rate. Level of Evidence: 2

Comparative effectiveness of microdecompression and laminectomy for central lumbar spinal stenosis: study protocol for an observational study

Introduction This observational study is designed to test the equivalence between the clinical effectiveness of microdecompression and laminectomy in the surgical treatment of central lumbar spinal stenosis. Lumbar spinal stenosis is the most frequent indication for spinal surgery in the elderly, and as the oldest segment of the population continues to grow its prevalence is likely to increase. However, data on surgical outcomes are limited. Open or wide decompressive laminectomy, often combined with medial facetectomy and foraminotomy, was formerly the standard treatment. In recent years a growing tendency towards less invasive decompressive procedures has emerged. At present, many spine surgeons perform microdecompression for central lumbar spinal stenosis. Methods and analysis Prospectively registered treatment and outcome data are obtained from the Norwegian Registry for Spine Surgery. The primary outcome measure is change in Oswestry disability index between baseline and 12-month follow-up. Secondary outcome measures are changes in health-related quality of life measured by the Euro-Qol-5D between baseline and 12-month follow-up, perioperative complications, and duration of surgical procedures and length of hospital stay. Ethics and dissemination The study has been evaluated and approved by the regional committee for medical research in central Norway and all participants provided written informed consent. The findings of this study will be disseminated through peer-reviewed publications. Trial registration number Clinicaltrials.gov (NCT02006901).

Variation in selection criteria and approaches to surgery for Lumbar Spinal Stenosis among patients treated in Boston and Norway

OBJECTIVES There are no uniform guidelines regarding when to operate or the ideal surgical intervention in Lumbar Spinal Stenosis (LSS). Understanding the presence of practice-based variation between different localities is critical. We sought to compare patient-reported pre-operative pain, disability, and health-related quality of life as indications for surgery between Boston and Norway, and the use of decompression alone vs. decompression and arthrodesis. PATIENTS AND METHODS This study included 3826 patients; 1886 from Boston and 1940 from Norway. Eligible patients were 50 years or older who received surgery for the diagnosis of LSS. Data were retrieved from a centralized clinical database in Boston and a national spine registry in Norway based on reported diagnosis and procedure. We evaluated patient-reported pre-operative pain, disability, and health-related quality of life as indications for surgery. A propensity score match was performed for the generation of comparable cohorts. RESULTS There were no significant differences in demographics between the unadjusted cohorts. The rates of obesity (39.4% vs. 25.4%; p<0.001) and patients with ASA ≥3 (34.8% vs. 22.1%; p<0.001) were higher in the Boston cohort, while smokers were less frequent (9.6% vs. 19.3%; p<0.001). These differences were accounted for in the propensity score matching. Pre-operative ODI was slightly higher among patients in Boston (43.3 [95% CI 41.5, 45.1] vs. 40.7 [95% CI 40.0, 41.4]; p=0.005), but did not reach the minimal clinically important difference. No statistical difference was encountered between pre-operative EQ-5D (0.339 [95% CI 0.304, 0.374] vs. 0.366 [95% CI 0.351, 0.381]; p=0.16). Fifty-one percent of patients treated in Boston received a decompression and arthrodesis, as compared to only 13.9% of those in Norway (p<0.001). In the matched cohort, counting 294 in each group, the overall conclusions were the same. CONCLUSIONS The results demonstrate that indications for intervention were very similar in comparable patient populations with LSS in Boston and Norway. The use of supplemental arthrodesis was significantly greater in Boston. The etiology behind this finding is likely multifactorial but may represent medico-legal concerns in the US, or the phenomenon of provider inducement.

Inter- and Intraobserver Agreement of Morphological Grading for Central Lumbar Spinal Stenosis on Magnetic Resonance Imaging.

Study Design Validation study of a morphological grading system for central lumbar spinal stenosis. Objective To evaluate and validate the inter- and intraobserver agreement of a morphological grading system for central lumbar spinal stenosis on magnetic resonance imaging between neurosurgeons and radiologists. Methods Two neurosurgeons and two radiologists independently assessed the morphological grading of lumbar spinal stenosis on pretreatment magnetic resonance imaging of 84 patients. Inter- and intrarater agreements were calculated by comparing the observers’ evaluations level to level on the grading method. The results of both clinicians were compared with the assessment of both radiologists. Results On axial magnetic resonance images, 189 lumbar disk levels were evaluated for the grade of stenosis. The interobserver agreement between the clinicians was substantial. The interobserver agreement between clinician 1 and both radiologists was substantial, and it was moderate between clinician 2 and both radiologists. The clinicians’ intraobserver agreement was almost perfect, and the radiologists’ intraobserver agreement was substantial. Conclusions The interobserver agreement of this morphological grading for lumbar spinal stenosis was high between both the clinicians and radiologists, whereas the intraobserver agreement was almost perfect. Experienced clinicians may safely evaluate lumbar magnetic resonance images using this morphological grading for central lumbar spinal stenosis.

Surgery for Refractory Coccygodynia: Operative Versus Nonoperative Treatment

Study Design. This is a retrospective cohort study. Objective. To evaluate the long-term outcomes for patients with refractory coccygodynia treated with coccygectomy compared to a nonsurgical regimen of sitting aids, physical therapy, medications, and injections. Summary of Background Data. The surgical treatment of coccygodynia remains controversial. To date, there has only been one small comparative study of surgical versus nonsurgical treatment. Methods. From 2004 to 2014, 109 patients presenting with coccygodynia were treated with either total coccygectomy or a nonsurgical course of sitting aids, physical therapy, anti-inflammatory medications, and injections. All had at least 2 years of symptoms before surgery. The patient principally made the treatment decision, counseled by the treating physician. Before surgery, all subjects underwent at least 2 years of conservative treatment and three-dimensional imaging (computed tomography and/or magnetic resonance imaging). Subjects completed visual analog pain scales, EuroQol five-dimension, components of the PROMIS measure, and a novel Coccygodynia Disability Index evaluation. Work status, complications, and satisfaction were recorded. Results. A total of 61 patients received nonsurgical care; eight declined participation and five could not be located. Forty-eight patients underwent total coccygectomy; three declined participation and five could not be located. At an average 4.8 years of follow-up (range: 2–9), the nonsurgical visual analog pain scales was 5 and the surgical 2 (P = 0.001); 79% of surgically treated patients were improved at 2 years versus 43% for the nonsurgical group. EuroQol five-dimension (P = 0.002), Coccygodynia Disability Index (0.01), and PROMIS Pain interference scores (0.02) were also significantly improved in the surgical group. Eleven surgical patients (26%) had complications, all wound related with successful resolution; seven treated with dressing changes and four with surgical debridement. Conclusion. Total coccygectomy is a safe and effective surgical treatment of coccygodynia refractory to nonoperative care. Patient-reported outcome measures were improved after surgery compared with nonsurgical management. Postoperative wound care remains a concern. Level of Evidence: 4

Lumbar spinal stenosis: comparison of surgical practice variation and clinical outcome in three national spine registries

BACKGROUND CONTEXT Decompression surgery for lumbar spinal stenosis (LSS) is the most common spinal procedure in the elderly. To avoid persisting low back pain, adding arthrodesis has been recommended, especially if there is a coexisting degenerative spondylolisthesis. However, this strategy remains controversial, resulting in practice-based variation. PURPOSE The present study aimed to evaluate in a pragmatic study if surgical selection criteria and variation in use of arthrodesis in three Scandinavian countries can be linked to variation in treatment effectiveness. STUDY DESIGN This is an observational study based on a combined cohort from the national spine registries of Norway, Sweden, and Denmark. PATIENT SAMPLE Patients aged 50 and older operated during 2011-2013 for LSS were included. OUTCOME MEASURES Patient-Reported Outcome Measures (PROMs): Oswestry Disability Index (ODI) (primary outcome), Numeric Rating Scale (NRS) for leg pain and back pain, and health-related quality of life (Euro-Qol-5D) were reported. Analysis included case-mix adjustment. In addition, we report differences in hospital stay. METHODS Analyses of baseline data were done by analysis of variance (ANOVA), chi-square, or logistic regression tests. The comparisons of the mean changes of PROMs at 1-year follow-up between the countries were done by ANOVA (crude) and analysis of covariance (case-mix adjustment). RESULTS Out of 14,223 included patients, 10,890 (77%) responded at 1-year follow-up. Apart from fewer smokers in Sweden and higher comorbidity rate in Norway, baseline characteristics were similar. The rate of additional fusion surgery (patients without or with spondylolisthesis) was 11% (4%, 47%) in Norway, 21% (9%, 56%) in Sweden, and 28% (15%, 88%) in Denmark. At 1-year follow-up, the mean improvement for ODI (95% confidence interval) was 18 (17-18) in Norway, 17 (17-18) in Sweden, and 18 (17-19) in Denmark. Patients operated with arthrodesis had prolonged hospital stay. CONCLUSIONS Real-life data from three national spine registers showed similar indications for decompression surgery but significant differences in the use of concomitant arthrodesis in Scandinavia. Additional arthrodesis was not associated with better treatment effectiveness.

Decompressive surgery for lumbar spinal stenosis across the Atlantic: a comparison of preoperative MRI between matched cohorts from the US and Norway

BackgroundThere are no uniform guidelines regarding when to operate for Lumbar Spinal Stenosis (LSS). As we apply findings from clinical research from one population to the next, elucidating similarities or differences provides important context for the validity of extrapolating clinical outcomes. The aim of this study was to compare the morphological severity of lumbar spinal stenosis on preoperative MRI in patients undergoing decompressive surgery in Boston, USA, and Trondheim, Norway.MethodsIn this observational retrospective study, we compared morphological severity on MRI before surgical treatment between two propensity score-matched patient populations with single or two-level symptomatic LSS. We assessed the radiographic severity of LSS utilizing the Schizas classification (grade A to D).ResultsFollowing propensity score matching, demographics are balanced. In the Trondheim cohort, two levels decompression were present in 36.2% of the patients vs. 41.9% in Boston, (p = 0.396). There was no significant difference in grades A to D concerning central stenosis (p = 0.075). When dichotomized in mild/moderate (A/B) and severe /extreme (C/D), there were no significant differences in the rate of levels operated for high-grade stenosis (C/D), 67.6% in the Boston group compare to 78.1% in the Trondheim group (p = 0.088).ConclusionsTrondheim, Norway, and Boston, US, have similar radiographic thresholds of LSS for offering surgery.

Surgical management of lumbar spinal stenosis: a survey among Norwegian spine surgeons

BackgroundSymptomatic lumbar spinal stenosis (LSS) is the most common reason for lumbar surgery in the elderly. There is growing evidence that decompressive surgery offers an advantage over non-surgical management for selected patients with persistent severe symptoms. Based on treatment traditions, open laminectomy has been the gold standard surgical treatment, but various other surgical and non-surgical treatments for LSS are widely used in clinical practice. Therefore, we conducted a survey study to capture potential diversities in surgeons’ management of LSS in Norway.MethodsAll spine surgeons in Norway were contacted by e-mail and asked to answer a 20-item questionnaire by using an Internet-based survey tool. We asked eight questions about the respondent (gender, surgical specialty, workplace, experience, number of surgeries performed per year, use of magnification devices) and 12 questions about different aspects of the surgical treatment of LSS (indication for surgery and preoperative imaging, different surgical techniques, clinical outcome).ResultsThe questionnaire was answered by 51 spine surgeons (47% response rate). The preferred surgical technique for LSS in Norway is microdecompression via a unilateral approach and crossover technique, followed by microdecompression via a bilateral approach. Other techniques are not much used in Norway.ConclusionsMost Norwegian spine surgeons use minimally invasive decompression techniques in the surgical treatment of LSS, and unilateral microsurgical decompression with crossover decompression is the preferred technique. Where evidence is lacking (e.g., fusion procedures), there is a larger variation of opinions and preferred procedures among Norwegian spine surgeons.