Decompression with or without Fusion in Degenerative Lumbar Spondylolisthesis.

BACKGROUND: In patients with lumbar spinal stenosis and degenerative spondylolisthesis, it is uncertain whether decompression surgery alone is noninferior to decompression with instrumented fusion. METHODS: We conducted an open-label, multicenter, noninferiority trial involving patients with symptomatic lumbar stenosis that had not responded to conservative management and who had single-level spondylolisthesis of 3 mm or more. Patients were randomly assigned in a 1:1 ratio to undergo decompression surgery (decompression-alone group) or decompression surgery with instrumented fusion (fusion group). The primary outcome was a reduction of at least 30% in the score on the Oswestry Disability Index (ODI; range, 0 to 100, with higher scores indicating more impairment) during the 2 years after surgery, with a noninferiority margin of -15 percentage points. Secondary outcomes included the mean change in the ODI score as well as scores on the Zurich Claudication Questionnaire, leg and back pain, the duration of surgery and length of hospital stay, and reoperation within 2 years. RESULTS: The mean age of patients was approximately 66 years. Approximately 75% of the patients had leg pain for more than a year, and more than 80% had back pain for more than a year. The mean change from baseline to 2 years in the ODI score was -20.6 in the decompression-alone group and -21.3 in the fusion group (mean difference, 0.7; 95% confidence interval [CI], -2.8 to 4.3). In the modified intention-to-treat analysis, 95 of 133 patients (71.4%) in the decompression-alone group and 94 of 129 patients (72.9%) in the fusion group had a reduction of at least 30% in the ODI score (difference, -1.4 percentage points; 95% CI, -12.2 to 9.4), showing the noninferiority of decompression alone. In the per-protocol analysis, 80 of 106 patients (75.5%) and 83 of 110 patients (75.5%), respectively, had a reduction of at least 30% in the ODI score (difference, 0.0 percentage points; 95% CI, -11.4 to 11.4), showing noninferiority. The results for the secondary outcomes were generally in the same direction as those for the primary outcome. Successful fusion was achieved with certainty in 86 of 100 patients (86.0%) who had imaging available at 2 years. Reoperation was performed in 15 of 120 patients (12.5%) in the decompression-alone group and in 11 of 121 patients (9.1%) in the fusion group. CONCLUSIONS: In this trial involving patients who underwent surgery for degenerative lumbar spondylolisthesis, most of whom had symptoms for more than a year, decompression alone was noninferior to decompression with instrumented fusion over a period of 2 years. Reoperation occurred somewhat more often in the decompression-alone group than in the fusion group. (NORDSTEN-DS ClinicalTrials.gov number, NCT02051374.).

Prospects of returning to work after lumbar spine surgery for patients considering disability pension: a nationwide study based on data from the Norwegian Registry for Spine Surgery.

OBJECTIVES: To assess the odds for not returning to work (non-RTW) 1 year after treatment among patients who had applied for or were planning to apply for disability pension (DP-applicant) prior to an operation for degenerative disorders of the lumbar spine. METHODS: This population-based cohort study from the Norwegian Registry for Spine surgery included 26 688 cases operated for degenerative disorders of the lumbar spine from 2009 to 2020. The primary outcome was RTW (yes/no). Secondary patient-reported outcome measures (PROMs) were the Oswestry Disability Index, Numeric Rating Scales for back and leg pain, EuroQoL five-dimension and the Global Perceived Effect Scale. Logistic regression analysis was used to investigate associations between being a DP-applicant prior to surgery (exposure), possible confounders (modifiers) at baseline and RTW 12 months after surgery (outcome). RESULTS: The RTW ratio for DP-applicants was 23.1% (having applied: 26.5%, planning to apply 21.1%), compared with 78.6% among non-applicants. All secondary PROMs were more favourable among non-applicants. After adjusting for all significant confounders (low expectations and pessimism related to working capability, not feeling wanted by the employer and physically demanding work), DP-applicants with under 12 months preoperative sick leave had 3.8 (95% CI 1.8 to 8.0) higher odds than non-applicants for non-RTW 12 months after surgery. The subgroup having applied for disability pension had the strongest impact on this association. CONCLUSION: Less than a quarter of the DP-applicants returned to work 12 months after surgery. This association remained strong, also when adjusted for the confounders as well as other covariates related RTW.

The Norwegian registry for spine surgery (NORspine): cohort profile.

PURPOSE: To review and describe the development, methods and cohort of the lumbosacral part of the Norwegian registry for spine surgery (NORspine). METHODS: NORspine was established in 2007. It is government funded, covers all providers and captures consecutive cases undergoing operations for degenerative disorders. Patients' participation is voluntary and requires informed consent. A set of baseline-, process- and outcome-variables (3 and 12 months) recommended by the International Consortium for Health Outcome Measurement is reported by surgeons and patients. The main outcome is the Oswestry disability index (ODI) at 12 months. RESULTS: We show satisfactory data quality assessed by completeness, timeliness, accuracy, relevance and comparability. The coverage rate has been 100% since 2016 and the capture rate has increased to 74% in 2021. The cohort consists of 60,647 (47.6% women) cases with mean age 55.7 years, registered during the years 2007 through 2021. The proportions > 70 years and with an American Society of Anaesthesiologists' Physical Classification System (ASA) score > II has increased gradually to 26.1% and 19.3%, respectively. Mean ODI at baseline was 43.0 (standard deviation 17.3). Most cases were operated with decompression for disc herniation (n = 26,557, 43.8%) or spinal stenosis (n = 26,545, 43.8%), and 7417 (12.2%) with additional or primary fusion. The response rate at 12 months follow-up was 71.6%. CONCLUSION: NORspine is a well-designed population-based comprehensive national clinical quality registry. The register's methods ensure appropriate data for quality surveillance and improvement, and research.

The Norwegian degenerative spondylolisthesis and spinal stenosis (NORDSTEN) study: study overview, organization structure and study population.

PURPOSE: To provide an overview of the The Norwegian Degenerative spondylolisthesis and spinal stenosis (NORDSTEN)-study and the organizational structure, and to evaluate the study population. METHODS: The NORDSTEN is a multicentre study with 10 year follow-up, conducted at 18 public hospitals. NORDSTEN includes three studies: (1) The randomized spinal stenosis trial comparing the impact of three different decompression techniques; (2) the randomized degenerative spondylolisthesis trial investigating whether decompression surgery alone is as good as decompression with instrumented fusion; (3) the observational cohort tracking the natural course of LSS in patients without planned surgical treatment. A range of clinical and radiological data are collected at defined time points. To administer, guide, monitor and assist the surgical units and the researchers involved, the NORDSTEN national project organization was established. Corresponding clinical data from the Norwegian Registry for Spine Surgery (NORspine) were used to assess if the randomized NORDSTEN-population at baseline was representative for LSS patients treated in routine surgical practice. RESULTS: A total of 988 LSS patients with or without spondylolistheses were included from 2014 to 2018. The clinical trials did not find any difference in the efficacy of the surgical methods evaluated. The NORDSTEN patients were similar to those being consecutively operated at the same hospitals and reported to the NORspine during the same time period. CONCLUSION: The NORDSTEN study provides opportunity to investigate clinical course of LSS with or without surgical interventions. The NORDSTEN-study population were similar to LSS patients treated in routine surgical practice, supporting the external validity of previously published results. TRIAL REGISTRATION: ClinicalTrials.gov; NCT02007083 10/12/2013, NCT02051374 31/01/2014 and NCT03562936 20/06/2018.

Characteristics and outcomes of patients who did not respond to a national spine surgery registry.

BACKGROUND: Loss to follow-up may bias outcome assessments in medical registries. This cohort study aimed to analyze and compare patients who failed to respond with those that responded to the Norwegian Registry for Spine Surgery (NORspine). METHODS: We analyzed a cohort of 474 consecutive patients operated for lumbar spinal stenosis at four public hospitals in Norway during a two-year period. These patients reported sociodemographic data, preoperative symptoms, and Oswestry Disability Index (ODI), numerical rating scales (NRS) for back and leg pain to NORspine at baseline and 12 months postoperatively. We contacted all patients who did not respond to NORspine after 12 months. Those who responded were termed responsive non-respondents and compared to 12 months respondents. RESULTS: One hundred forty (30%) did not respond to NORspine 12 months after surgery and 123 were available for additional follow-up. Sixty-four of the 123 non-respondents (52%) responded to a cross-sectional survey done at a median of 50 (36-64) months after surgery. At baseline, non-respondents were younger 63 (SD 11.7) vs. 68 (SD 9.9) years (mean difference (95% CI) 4.7 years (2.6 to 6.7); p = < 0.001) and more frequently smokers 41 (30%) vs. 70 (21%) RR (95%CI) = 1.40 (1.01 to 1.95); p = 0.044. There were no other relevant differences in other sociodemographic variables or preoperative symptoms. We found no differences in the effect of surgery on non-respondents vs. respondents (ODI (SD) = 28.2 (19.9) vs. 25.2 (18.9), MD (95%CI) = 3.0 ( -2.1 to 8.1); p = 0.250). CONCLUSION: We found that 30% of patients did not respond to NORspine at 12 months after spine surgery. Non-respondents were somewhat younger and smoked more frequently than respondents; however, there were no differences in patient-reported outcome measures. Our findings suggest that attrition bias in NORspine was random and due to non-modifiable factors.

Anterior surgical treatment for cervical degenerative radiculopathy: a prediction model for non-success.

PURPOSE: By using data from the Norwegian Registry for Spine Surgery, we wanted to develop and validate prediction models for non-success in patients operated with anterior surgical techniques for cervical degenerative radiculopathy (CDR). METHODS: This is a multicentre longitudinal study of 2022 patients undergoing CDR surgery and followed for 12 months to find prognostic models for non-success in neck disability and arm pain using multivariable logistic regression analysis. Model performance was evaluated by area under the receiver operating characteristic curve (AUC) and a calibration test. Internal validation by bootstrapping re-sampling with 1000 repetitions was applied to correct for over-optimism. The clinical usefulness of the neck disability model was explored by developing a risk matrix for individual case examples. RESULTS: Thirty-eight percent of patients experienced non-success in neck disability and 35% in arm pain. Loss to follow-up was 35% for both groups. Predictors for non-success in neck disability were high physical demands in work, low level of education, pending litigation, previous neck surgery, long duration of arm pain, medium-to-high baseline disability score and presence of anxiety/depression. AUC was 0.78 (95% CI, 0.75, 0.82). For the arm pain model, all predictors for non-success in neck disability, except for anxiety/depression, were found to be significant in addition to foreign mother tongue, smoking and medium-to-high baseline arm pain. AUC was 0.68 (95% CI, 0.64, 0.72). CONCLUSION: The neck disability model showed high discriminative performance, whereas the arm pain model was shown to be acceptable. Based upon the models, individualized risk estimates can be made and applied in shared decision-making with patients referred for surgical assessment.

Non-respondents do not bias outcome assessment after cervical spine surgery: a multicenter observational study from the Norwegian registry for spine surgery (NORspine).

BACKGROUND: The Norwegian registry for spine surgery (NORspine) is a national clinical quality registry which has recorded more than 10,000 operations for degenerative conditions of the cervical spine since 2012. Registries are large observational cohorts, at risk for attrition bias. We therefore aimed to examine whether clinical outcomes differed between respondents and non-respondents to standardized questionnaire-based 12-month follow-up. METHODS: All eight public and private providers of cervical spine surgery in Norway report to NORspine. We included 334 consecutive patients who were registered with surgical treatment of degenerative conditions in the cervical spine in 2018 and did a retrospective analysis of prospectively collected register data and data on non-respondents' outcomes collected by telephone interviews. The primary outcome measure was patient-reported change in arm pain assessed with the numeric rating scale (NRS). Secondary outcome measures were change in neck pain assessed with the NRS, change in health-related quality of life assessed with EuroQol 5 Dimensions (EQ-5D), and patients' perceived benefit of the operation assessed by the Global Perceived Effect (GPE) scale. RESULTS: At baseline, there were few and small differences between the 238 (71.3%) respondents and the 96 (28.7%) non-respondents. We reached 76 (79.2%) non-respondents by telephone, and 63 (65.6%) consented to an interview. There was no statistically significant difference between groups in change in NRS score for arm pain (3.26 (95% CI 2.84 to 3.69) points for respondents and 2.77 (1.92 to 3.63) points for telephone interviewees) or any of the secondary outcome measures. CONCLUSIONS: The results indicate that patients lost to follow-up were missing at random. Analyses of outcomes based on data from respondents can be considered representative for the complete register cohort, if patient characteristics associated with attrition are controlled for.

Return to work after surgery for degenerative cervical myelopathy: a nationwide registry-based observational study.

BACKGROUND: Few studies of high quality exist on return to work (RTW) rate after surgery for degenerative cervical myelopathy (DCM). This study aims to examine the RTW rate in patients undergoing surgery for DCM. METHODS: Nationwide prospectively collected data were obtained from the Norwegian Registry for Spine Surgery and the Norwegian Labour and Welfare Administration. The primary outcome was return to work, defined as being at work at a given time postoperatively without any medical income-compensation benefits. Secondary endpoints included the neck disability index (NDI) and quality of life measured by EuroQol-5D (EQ-5D). RESULTS: Among 439 patients operated for DCM between 2012 and 2018, 20% of the patients received a medical income-compensation benefit one year before surgery. This number increased steadily towards the operation at which timepoint 100% received benefits. By 12 months after surgery, 65% had returned to work. By 36 months, 75% had returned to work. Patients that returned to work were more likely to be non-smokers and to have a college education. They had less comorbidity, more were without benefit 1-year pre-surgery, and significantly more patients were employed at operation date. Average days of sick leave in the year before surgery were significantly less in the RTW group, and they had a significantly lower baseline NDI and EQ-5D All PROMs reached statistical significance at 12 months, in favor of the group that achieved RTW. CONCLUSION: At 12 months following surgery, 65% had returned to work. At the end of the 36-month follow-up period, 75% had returned to work, 5% less than the working percentage in the beginning of the follow-up period. This study demonstrates that a large percentage of patients return to work after surgical treatment for DCM.

Is the presence of foraminal stenosis associated with outcome in lumbar spinal stenosis patients treated with posterior microsurgical decompression.

BACKGROUND: We aim to investigate associations between preoperative radiological findings of lumbar foraminal stenosis with clinical outcomes after posterior microsurgical decompression in patients with predominantly central lumbar spinal stenosis (LSS). METHODS: The study was an additional analysis in the NORDSTEN Spinal Stenosis Trial. In total, 230 men and 207 women (mean age 66.8 (SD 8.3)) were included. All patients underwent an MRI including T1- and T2-weighted sequences. Grade of foraminal stenosis was dichotomized into none to moderate (0-1) and severe (2-3) category using Lee's classification system. The Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ), and numeric rating scale (NRS) for back and leg pain were collected at baseline and at 2-year follow-up. Primary outcome was a reduction of 30% or more on the ODI score. Secondary outcomes included the mean improvement on the ODI, ZCQ, and NRS scores. We performed multivariable regression analyses with the radiological variates foraminal stenosis, Pfirrmann grade, Schizas score, dural sac cross-sectional area, and the possible plausible confounders: patients' gender, age, smoking status, and BMI. RESULTS: The cohort of 437 patients presented a high degree of degenerative changes at baseline. Of 414 patients with adequate imaging of potential foraminal stenosis, 402 were labeled in the none to moderate category and 12 in the severe category. Of the patients with none to moderate foraminal stenosis, 71% achieved at least 30% improvement in ODI. Among the patients with severe foraminal stenosis, 36% achieved at least 30% improvement in ODI. A significant association between severe foraminal stenosis and less chance of reaching the target of 30% improvement in the ODI score after surgery was detected: OR 0.22 (95% CI 0.06, 0.83), p=0.03. When investigating outcome as continuous variables, a similar association between severe foraminal stenosis and less improved ODI with a mean difference of 9.28 points (95%CI 0.47, 18.09; p=0.04) was found. Significant association between severe foraminal stenosis and less improved NRS pain in the lumbar region was also detected with a mean difference of 1.89 (95% CI 0.30, 3.49; p=0.02). No significant association was suggested between severe foraminal stenosis and ZCQ or NRS leg pain. CONCLUSION: In patients operated with posterior microsurgical decompression for LSS, a preoperative severe lumbar foraminal stenosis was associated with higher proportion of patients with less than 30% improvement in ODI. TRIAL REGISTRATION: The study is registered at ClinicalTrials.gov (22.11.2013) under the identifier NCT02007083.

Accuracy and agreement of national spine register data for 474 patients compared to corresponding electronic patient records.

PURPOSE: Data quality is essential for all types of research, including health registers. However, data quality is rarely reported. We aimed to assess the accuracy of data in a national spine register (NORspine) and its agreement with corresponding data in electronic patient records (EPR). METHODS: We compared data in NORspine registry against data in (EPR) for 474 patients operated for spinal stenosis in 2015 and 2016 at four public hospitals, using EPR as the gold standard. We assessed accuracy using the proportion correctly classified (PCC) and sensitivity. Agreement was quantified using Kappa statistics or interaclass correlation coefficient (ICC). RESULTS: The mean age (SD) was 66 (11) years, and 54% were females. Compared to EPR, surgeon-reported perioperative complications displayed weak agreement (kappa (95% CI) = 0.51 (0.33-0.69)), PCC of 96%, and a sensitivity (95% CI) of 40% (23-58%). ASA classification had a moderate agreement (kappa (95%CI) = 0.73 (0.66-0.80)). Comorbidities were underreported in NORspine. Perioperative details had strong to excellent agreements (kappa (95% CI) ranging from 0.76 ( 0.68-0.84) to 0.98 (0.95-1.00)), PCCs between 93% and 99% and sensitivities (95% CI) between 92% (0.84-1.00%) and 99% (0.98-1.00%). Patient-reported variables (height, weight, smoking) had excellent agreements (kappa (95% CI) between 0.93 (0.89-0.97) and 0.99 (0.98-0.99)). CONCLUSION: Compared to electronic patient records, NORspine displayed weak agreement for perioperative complications, moderate agreement for ASA classification, strong agreement for perioperative details, and excellent agreement for height, weight, and smoking. NORspine underreported perioperative complications and comorbidities when compared to EPRs. Patient-recorded data were more accurate and should be preferred when available.

The association between preoperative MRI findings and clinical improvement in patients included in the NORDSTEN spinal stenosis trial.

PURPOSE: To investigate potential associations between preoperative MRI findings and patient reported outcome measures (PROMs) after surgery for lumbar spinal stenosis (LSS). METHODS: The NORDSTEN trial included 437 patients. We investigated the association between preoperative MRI findings such as morphological grade of stenosis (Schizas grade), quantitative grade of stenosis (dural sac cross-sectional area), disc degeneration (Pfirrmann score), facet joint tropism and fatty infiltration of the multifidus muscle, and improvement in patient reported outcome measures (PROMs) 2 years after surgery. We dichotomized each radiological parameter into a moderate or severe category. PROMs i.e., Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ) and Numeric rating scale (NRS) for back and leg pain were collected before surgery and at 2 year follow-up. In the primary analysis, we investigated the association between MRI findings and ODI score (dichotomized to ≥ 30% improvement or not). In the secondary analysis, we investigated the association between MRI findings and the mean improvement on the ODI-, ZCQ- and NRS scores. We used multivariable regression models adjusted for patients' gender, age, smoking status and BMI. RESULTS: The primary analysis showed that severe disc degeneration (Pfirrmann score 4-5) was significantly associated with less chance of achieving a 30% improvement on the ODI score (OR 0.54, 95% CI 0.34, 0.88). In the secondary analysis, we detected no clinical relevant associations. CONCLUSION: Severe disc degeneration preoperatively suggest lesser chance of achieving 30% improvement in ODI score after surgery for LSS. Other preoperative MRI findings were not associated with patient reported outcome.

Clinical and MRI findings in lumbar spinal stenosis: baseline data from the NORDSTEN study.

PURPOSE: The aim was to describe magnetic resonance imaging findings in patients planned for lumbar spinal stenosis surgery. Further, to describe possible associations between MRI findings and patient characteristics with patient reported disability or pain. METHODS: The NORDSTEN spinal stenosis trial included 437 patients planned for surgical decompression of LSS. The following MRI findings were evaluated before surgery: morphological (Schizas) and quantitative (cross-sectional area) grade of stenosis, disk degeneration (Pfirrmann), facet joint tropism and fatty infiltration of the multifidus muscle. Patients were dichotomized into a moderate or severe category for each radiological parameter classification. A multivariable linear regression analysis was performed to investigate the association between MRI findings and preoperative scores for Oswestry Disability Index, Zurich Claudication Questionnaire and Numeric rating scale for back and leg pain. The following patient characteristics were included in the analysis: gender, age, smoking and weight. RESULTS: The percentage of patients with severe scores was as follows: Schizas (C + D) 71.3%, cross-sectional area (< 75 mm2) 86.8%, Pfirrmann (4 + 5) 58.1%, tropism (≥ 15°) 11.9%, degeneration of multifidus muscle (2-4) 83.7%. Regression coefficients indicated minimal changes in severity of symptoms when comparing the groups with moderate and severe MRI findings. Only gender had a significant and clinically relevant association with ODI score. CONCLUSION: In this cross-sectional study, the majority of the patients had MRI findings classified as severe LSS changes, but the findings had no clinically relevant association with patient reported disability and pain at baseline. Patient characteristics have a larger impact on disability and pain than radiological findings. TRIAL REGISTRATION: www. CLINICALTRIALS: gov identifier: NCT02007083, registered December 2013.

Surgery for degenerative cervical myelopathy in the elderly: a nationwide registry-based observational study with patient-reported outcomes.

BACKGROUND: The aim of this study was to investigate whether clinical outcomes in patients aged ≥ 70 undergoing decompressive surgery for degenerative cervical myelopathy (DCM) differ from those of younger patients (50-70 years) at 1 year. METHODS: Data were obtained from the Norwegian Registry for Spine Surgery (NORspine). Among 651 patients included, 177 (27.2%) were ≥ 70 years old. The primary outcome was change in the Neck Disability Index (NDI). Secondary outcomes were changes in the European Myelopathy Score (EMS), quality of life (EuroQoL EQ-5D), numeric rating scales (NRS) for headache, neck pain, and arm pain, and complications. RESULTS: Significant improvements in all patient-reported outcomes (PROMs) were detected for both age cohorts at 1 year. For the two age cohorts combined, there was a statistically significant improvement in the NDI score (mean 9.2, 95% CI 7.7 to 10.6, P < 0.001). There were no differences between age cohorts in mean change of NDI (- 8.9 vs. - 10.1, P = 0.48), EQ-5D (0.13 vs. 0.17, P = 0.37), or NRS pain scores, but elderly patients experienced a larger improvement in EMS (0.7 vs. 1.3, P = 0.02). A total of 74 patients (15.6%) in the younger cohort and 43 patients (24.3%) in the older cohort experienced complications or adverse effects within 3 months of surgery, mainly urinary and respiratory tract infections. CONCLUSION: Surgery for DCM was associated with significant improvement across a wide range of PROMs for both younger and elderly patients. Surgery for DCM should not be denied based on age alone.

Surgery for degenerative cervical myelopathy in patients with rheumatoid arthritis and ankylosing spondylitis: a nationwide registry-based study with patient-reported outcomes.

PURPOSE: To compare patient-reported outcomes (PROMs) following surgery for degenerative cervical myelopathy (DCM) among patients with rheumatoid arthritis (RA) or ankylosing spondylitis (AS) versus those without rheumatic diseases. METHODS: Data were obtained from the Norwegian Registry for Spine Surgery. The primary outcome was change in the Neck Disability Index (NDI) at 1 year. Secondary endpoints included the European Myelopathy Score (EMS), quality of life (EuroQoL-5D [EQ-5D]), numeric rating scales (NRS) for headache, neck pain, and arm pain, and complications. RESULTS: Among 905 participants operated between 2012 and 2018, 35 had RA or AS. There were significant improvements in all PROMs at 1 year and no statistically significant difference between the cohorts in mean change in NDI (- 0.64, 95% CI - 8.1 to 6.8, P = .372), EQ-5D (0.10, 95% CI - 0.04 to 0.24, P = .168), NRS neck pain (- 0.8, 95% CI - 2.0 to 0.4, P = .210), NRS arm pain (- 0.6, 95% CI - 1.9 to 0.7, P = .351), and NRS headache (- 0.5, 95% CI - 1.7 to 0.8, P = .460). DISCUSSION AND CONCLUSION: Our study adds to the limited available evidence that surgical treatment cannot only arrest further progression of myelopathy but also improve functional status, neurological outcomes, and quality of life in patients with rheumatic disease.

Effect of Spinal Cord Burst Stimulation vs Placebo Stimulation on Disability in Patients With Chronic Radicular Pain After Lumbar Spine Surgery: A Randomized Clinical Trial.

Importance: The use of spinal cord stimulation for chronic pain after lumbar spine surgery is increasing, yet rigorous evidence of its efficacy is lacking. Objective: To investigate the efficacy of spinal cord burst stimulation, which involves the placement of an implantable pulse generator connected to electrodes with leads that travel into the epidural space posterior to the spinal cord dorsal columns, in patients with chronic radiculopathy after surgery for degenerative lumbar spine disorders. Design, Setting, and Participants: This placebo-controlled, crossover, randomized clinical trial in 50 patients was conducted at St Olavs University Hospital in Norway, with study enrollment from September 5, 2018, through April 28, 2021. The date of final follow-up was May 20, 2022. Interventions: Patients underwent two 3-month periods with spinal cord burst stimulation and two 3-month periods with placebo stimulation in a randomized order. Burst stimulation consisted of closely spaced, high-frequency electrical stimuli delivered to the spinal cord. The stimulus consisted of a 40-Hz burst mode of constant-current stimuli with 4 spikes per burst and an amplitude corresponding to 50% to 70% of the paresthesia perception threshold. Main Outcomes and Measures: The primary outcome was difference in change from baseline in the self-reported Oswestry Disability Index (ODI; range, 0 points [no disability] to 100 points [maximum disability]; the minimal clinically important difference was 10 points) score between periods with burst stimulation and placebo stimulation. The secondary outcomes were leg and back pain, quality of life, physical activity levels, and adverse events. Results: Among 50 patients who were randomized (mean age, 52.2 [SD, 9.9] years; 27 [54%] were women), 47 (94%) had at least 1 follow-up ODI score and 42 (84%) completed all stimulation randomization periods and ODI measurements. The mean ODI score at baseline was 44.7 points and the mean changes in ODI score were -10.6 points for the burst stimulation periods and -9.3 points for the placebo stimulation periods, resulting in a mean between-group difference of -1.3 points (95% CI, -3.9 to 1.3 points; P = .32). None of the prespecified secondary outcomes showed a significant difference. Nine patients (18%) experienced adverse events, including 4 (8%) who required surgical revision of the implanted system. Conclusions and Relevance: Among patients with chronic radicular pain after lumbar spine surgery, spinal cord burst stimulation, compared with placebo stimulation, after placement of a spinal cord stimulator resulted in no significant difference in the change from baseline in self-reported back pain-related disability. Trial Registration: ClinicalTrials.gov Identifier: NCT03546738.

Cervical spine surgery in the Northern Norway Regional Health Authority area in 2014-18. / Nakkekirurgi i Helse Nord 2014­18.

BACKGROUND: Knowledge about the variation in treatment rates is needed to assess whether the access to health services is equitable. The objective of this study was to investigate the rates of surgical treatment of degenerative cervical spine disease in Norway and the Northern Norway Regional Health Authority area and the local coverage in the Northern Norway Regional Health Authority area, and to assess the activity in the region. MATERIAL AND METHOD: We included cervical spine procedures recorded in the Norwegian Patient Registry from the years 2014-18 and estimated age-standardised treatment rates for Norway, the health regions and health trusts in Northern Norway Regional Health Authority. We estimated the local coverage as the proportion of patients resident in the Northern Norway Regional Health Authority area who had undergone surgery at the University Hospital of North Norway in Tromsø. RESULTS: The treatment rate remained stable at an average of 29.6 surgical procedures per 100 000 inhabitants (aged 18-105) per year. The rate for residents in the Northern Norway Regional Health Authority area was 23.0 procedures per 100 000 inhabitants per year (78 % of the national average). The rates in Finnmark and the areas of residence served by the University Hospital of North Norway were close to the national average. Residents in the Nordland and Helgeland areas had lower rates in each year of the study period, with an average of 16.6 and 18.1 procedures per 100 000 inhabitants per year respectively. This corresponds to 56 % and 61 % of the national average. Local coverage in the Northern Norway Regional Health Authority area increased from 69 % in 2014 to 91 % in 2018. INTERPRETATION: The treatment rate for degenerative cervical spine disease was lower in the Northern Norway Regional Health Authority area than in the rest of Norway. For this to be compensated and the local coverage to be increased to 100 %, we have estimated that the activity needs to be increased by approximately 35 surgical procedures per year.

A prognostic model for failure and worsening after lumbar microdiscectomy: a multicenter study from the Norwegian Registry for Spine Surgery.

OBJECTIVE: To develop a prognostic model for failure and worsening 1 year after surgery for lumbar disc herniation. METHODS: This multicenter cohort study included 11,081 patients operated with lumbar microdiscectomy, registered at the Norwegian Registry for Spine Surgery. Follow-up was 1 year. Uni- and multivariate logistic regression analyses were used to assess potential prognostic factors for previously defined cut-offs for failure and worsening on the Oswestry Disability Index scores 12 months after surgery. Since the cut-offs for failure and worsening are different for patients with low, moderate, and high baseline ODI scores, the multivariate analyses were run separately for these subgroups. Data were split into a training (70%) and a validation set (30%). The model was developed in the training set and tested in the validation set. A prediction (%) of an outcome was calculated for each patient in a risk matrix. RESULTS: The prognostic model produced six risk matrices based on three baseline ODI ranges (low, medium, and high) and two outcomes (failure and worsening), each containing 7 to 11 prognostic factors. Model discrimination and calibration were acceptable. The estimated preoperative probabilities ranged from 3 to 94% for failure and from 1 to 72% for worsening in our validation cohort. CONCLUSION: We developed a prognostic model for failure and worsening 12 months after surgery for lumbar disc herniation. The model showed acceptable calibration and discrimination, and could be useful in assisting physicians and patients in clinical decision-making process prior to surgery.

Comparable increases in dural sac area after three different posterior decompression techniques for lumbar spinal stenosis: radiological results from a randomized controlled trial in the NORDSTEN study.

PURPOSE: To investigate changes in dural sac area after three different posterior decompression techniques in patients undergoing surgery for lumbar spinal stenosis. Decompression of the nerve roots is the main surgical treatment for lumbar spinal stenosis. The aim of this study was to radiologically investigate three commonly used posterior decompression techniques. METHODS: The present study reports data from one of two multicenter randomized trials included in the NORDSTEN study. In the present trial, involving 437 patients undergoing surgery, we report radiological results after three different midline retaining posterior decompression techniques: unilateral laminotomy with crossover (UL) (n = 146), bilateral laminotomy (BL) (n = 142) and spinous process osteotomy (SPO) (n = 149). MRI was performed before and three months after surgery. The increase in dural sac area and Schizas grade at the most stenotic level was evaluated. Three different predefined surgical indicators of substantial decompression were used: (1) postoperative dural sac area of > 100 mm2, (2) increase in the dural sac area of at least 50% and (3) postoperative Schizas grade A or B. RESULTS: No differences between the three surgical groups were found in the mean increase in dural sac area. Mean values were 66.0 (SD 41.5) mm2 in the UL-group, 71.9 (SD 37.1) mm2 in the BL-group and 68.1 (SD 41.0) mm2 in the SPO-group (p = 0.49). No differences in the three predefined surgical outcomes between the three groups were found. CONCLUSION: For patients with lumbar spinal stenosis, the three different surgical techniques provided the same increase in dural sac area. CLINICAL TRIAL REGISTRATION: The study is registered at ClinicalTrials.gov reference on November 22th 2013 under the identifier NCT02007083.

Associations between utilization rates and patients' health: a study of spine surgery and patient-reported outcomes (EQ-5D and ODI).

BACKGROUND: A vast body of literature has documented regional variations in healthcare utilization rates. The extent to which such variations are "unwarranted" critically depends on whether there are corresponding variations in patients' needs. Using a unique medical registry, the current paper investigated any associations between utilization rates and patients' needs, as measured by two patient-reported outcome measures (PROMs). METHODS: This observational panel study merged patient-level data from the Norwegian Patient Registry (NPR), Statistics Norway, and the Norwegian Registry for Spine Surgery (NORspine) for individuals who received surgery for degenerative lumbar spine disorders in 2010-2015. NPR consists of hospital administration data. NORspine includes two PROMs: the generic health-related quality of life instrument EQ-5D and the disease-specific, health-related quality of life instrument Oswestry Disability Index (ODI). Measurements were assessed at baseline and at 3 and 12 months post-surgery and included a wide range of patient characteristics. Our case sample included 15,810 individuals. We analyzed all data using generalized estimating equations. RESULTS: Our results show that as treatment rates increase, patients have better health at baseline. Furthermore, increased treatment rates are associated with smaller health gain. CONCLUSION: The correlation between treatment rates and patients health indicate the presence of unwarranted variation in treatment rates for lumbar spine disorders.

Surgery for herniated lumbar disc in private vs public hospitals: A pragmatic comparative effectiveness study.

BACKGROUND: There is limited evidence on the comparative performance of private and public healthcare. Our aim was to compare outcomes following surgery for lumbar disc herniation (LDH) in private versus public hospitals. METHODS: Data were obtained from the Norwegian registry for spine surgery. Primary outcome was change in Oswestry disability index (ODI) 1 year after surgery. Secondary endpoints were quality of life (EuroQol EQ-5D), back and leg pain, complications, and duration of surgery and hospital stays. RESULTS: Among 5221 patients, 1728 in the private group and 3493 in the public group, 3624 (69.4%) completed 1-year follow-up. In the private group, mean improvement in ODI was 28.8 points vs 32.3 points in the public group (mean difference - 3.5, 95% CI - 5.0 to - 1.9; P for equivalence < 0.001). Equivalence was confirmed in a propensity-matched cohort and following mixed linear model analyses. There were differences in mean change between the groups for EQ-5D (mean difference - 0.05, 95% CI - 0.08 to - 0.02; P = 0.002) and back pain (mean difference - 0.2, 95% CI - 0.2, - 0.4 to - 0.004; P = 0.046), but after propensity matching, the groups did not differ. No difference was found between the two groups for leg pain. Complication rates was lower in the private group (4.5% vs 7.2%; P < 0.001), but after propensity matching, there was no difference. Patients operated in private clinics had shorter duration of surgery (48.4 vs 61.8 min) and hospital stay (0.7 vs 2.2 days). CONCLUSION: At 1 year, the effectiveness of surgery for LDH was equivalent in private and public hospitals.