A Randomized, Controlled Trial of Fusion Surgery for Lumbar Spinal Stenosis.

BACKGROUND: The efficacy of fusion surgery in addition to decompression surgery in patients who have lumbar spinal stenosis, with or without degenerative spondylolisthesis, has not been substantiated in controlled trials. METHODS: We randomly assigned 247 patients between 50 and 80 years of age who had lumbar spinal stenosis at one or two adjacent vertebral levels to undergo either decompression surgery plus fusion surgery (fusion group) or decompression surgery alone (decompression-alone group). Randomization was stratified according to the presence of preoperative degenerative spondylolisthesis (in 135 patients) or its absence. Outcomes were assessed with the use of patient-reported outcome measures, a 6-minute walk test, and a health economic evaluation. The primary outcome was the score on the Oswestry Disability Index (ODI; which ranges from 0 to 100, with higher scores indicating more severe disability) 2 years after surgery. The primary analysis, which was a per-protocol analysis, did not include the 14 patients who did not receive the assigned treatment and the 5 who were lost to follow-up. RESULTS: There was no significant difference between the groups in the mean score on the ODI at 2 years (27 in the fusion group and 24 in the decompression-alone group, P=0.24) or in the results of the 6-minute walk test (397 m in the fusion group and 405 m in the decompression-alone group, P=0.72). Results were similar between patients with and those without spondylolisthesis. Among the patients who had 5 years of follow-up and were eligible for inclusion in the 5-year analysis, there were no significant differences between the groups in clinical outcomes at 5 years. The mean length of hospitalization was 7.4 days in the fusion group and 4.1 days in the decompression-alone group (P<0.001). Operating time was longer, the amount of bleeding was greater, and surgical costs were higher in the fusion group than in the decompression-alone group. During a mean follow-up of 6.5 years, additional lumbar spine surgery was performed in 22% of the patients in the fusion group and in 21% of those in the decompression-alone group. CONCLUSIONS: Among patients with lumbar spinal stenosis, with or without degenerative spondylolisthesis, decompression surgery plus fusion surgery did not result in better clinical outcomes at 2 years and 5 years than did decompression surgery alone. (Funded by an Uppsala institutional Avtal om Läkarutbildning och Forskning [Agreement concerning Cooperation on Medical Education and Research] and others; Swedish Spinal Stenosis Study ClinicalTrials.gov number, NCT01994512.).

Predicting clinical outcome and length of sick leave after surgery for lumbar spinal stenosis in Sweden: a multi-register evaluation.

PURPOSE: Lumbar spinal stenosis (LSS) can be surgically treated, with variable outcome. Studies have linked socioeconomic factors to outcome, but no nation-wide studies have been performed. This register-based study, including all patients surgically treated for LSS during 2008-2012 in Sweden, aimed to determine predictive factors for the outcome of surgery. METHODS: Clinical and socioeconomic factors with impact on outcome in LSS surgery were identified in several high-coverage registers, e.g., the national quality registry for spine surgery (Swespine, FU-rate 70-90%). Multivariate regression analyses were conducted to assess their effect on outcome. Two patient-reported outcome measures, Global Assessment of leg pain (GA) and the Oswestry Disability Index (ODI), as well as length of sick leave after surgery were analyzed. RESULTS: Clinical and socioeconomic factors significantly affected health outcome (both GA and ODI). Some predictors of a good outcome (ODI) were: being born in the EU, reporting no back pain at baseline, a high disposable income and a high educational level. Some factors predicting a worse outcome were previous surgery, having had back pain more than 2 years, having comorbidities, being a smoker, being on social welfare and being unemployed. CONCLUSIONS: The study highlights the relevance of adding socioeconomic factors to clinical factors for analysis of patient-reported outcomes, although the causal pathway of most predictors' impact is unknown. These findings should be further investigated in the perspective of treatment selection for individual LSS patients. The study also presents a foundation of case mix algorithms for predicting outcome of surgery for LSS. These slides can be retrieved under Electronic Supplementary Material.

Recurrent Versus Primary Lumbar Disc Herniation Surgery: Patient-reported Outcomes in the Swedish Spine Register Swespine.

BACKGROUND: Lumbar disc herniation (LDH) is a common indication for lumbar spine surgery. The proportion of patients having a second surgery within 2 years varies in the literature between 0.5% and 24%, with recurrent herniation being the most common cause. Several studies have not found any relevant outcome differences between patients undergoing surgery for primary LDH and patients undergoing reoperation for a recurrent LDH, but these studies have limitations, including small sample size and retrospective design. QUESTIONS/PURPOSES: We (1) compared patient-reported outcomes between patients operated on for primary LDH and patients reoperated on for recurrent LDH within 1 year after index surgery and (2) determined risk factors for worse outcomes. METHODS: We obtained data from the Swedish National Spine Register, Swespine, where patient-reported outcomes are collected using mailed protocols at 1, 2, 5, and 10 years after surgery. Of the 13,562 patients identified who underwent LDH between January 2000 and May 2011, 13,305 (98%) underwent primary surgery for LDH and 257 (2%) underwent reoperation for a recurrent LDH within the first year. Patient-reported outcomes at 1 to 2 years were available for 8497 patients (63%), 8350 of 13,305 (63%) in the primary LDH group and 147 of 257 (57%) in the recurrent LDH group (p = 0.068). We compared leg and back pain (VAS: 0-100), function (Oswestry Disability Index [ODI]: 0-100), quality of life (EQ-5D: -0.59 to 1.0), patient satisfaction, and global assessment of leg pain between groups. We also analyzed rsik factors for worse global assessment and satisfaction. RESULTS: Mean (95% CI) differences in improvement between groups favoring patients with primary LDH were VAS leg pain 9 (4-14), ODI 6 (3-9), and EQ-5D 0.09 (0.04-0.15). While statistically significant, these effect sizes may be lower than the minimal clinically important differences often referred to. Percentage of satisfied patients was 79% and 58% in the primary and recurrent LDH groups, respectively (p < 0.001), and percentage of patients with no or better leg pain (global assessment) was 74% and 65%, respectively (p = 0.008). Reoperation for recurrent LDH represented the largest independent risk for dissatisfaction; this factor and smoking represented similar risks for less improvement in leg pain. CONCLUSIONS: Repeat surgery for a recurrent LDH was performed with good probability for improvement, although not as good as for primary LDH surgery, and patients undergoing repeated surgery were less satisfied. Studies on risk factors for recurrence are warranted. LEVEL OF EVIDENCE: Level II, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Decompression alone or decompression with fusion for lumbar spinal stenosis: five-year clinical results from a randomized clinical trial.

Aims: We compared decompression alone to decompression with fusion surgery for lumbar spinal stenosis, with or without degenerative spondylolisthesis (DS). The aim was to evaluate if five-year outcomes differed between the groups. The two-year results from the same trial revealed no differences. Methods: The Swedish Spinal Stenosis Study was a multicentre randomized controlled trial with recruitment from September 2006 to February 2012. A total of 247 patients with one- or two-level central lumbar spinal stenosis, stratified by the presence of DS, were randomized to decompression alone or decompression with fusion. The five-year Oswestry Disability Index (ODI) was the primary outcome. Secondary outcomes were the EuroQol five-dimension questionnaire (EQ-5D), visual analogue scales for back and leg pain, and patient-reported satisfaction, decreased pain, and increased walking distance. The reoperation rate was recorded. Results: Five-year follow-up was completed by 213 (95%) of the eligible patients (mean age 67 years; 155 female (67%)). After five years, ODI was similar irrespective of treatment, with a mean of 25 (SD 18) for decompression alone and 28 (SD 22) for decompression with fusion (p = 0.226). Mean EQ-5D was higher for decompression alone than for fusion (0.69 (SD 0.28) vs 0.59 (SD 0.34); p = 0.027). In the no-DS subset, fewer patients reported decreased leg pain after fusion (58%) than with decompression alone (80%) (relative risk (RR) 0.71 (95% confidence interval (CI) 0.53 to 0.97). The frequency of subsequent spinal surgery was 24% for decompression with fusion and 22% for decompression alone (RR 1.1 (95% CI 0.69 to 1.8)). Conclusion: Adding fusion to decompression in spinal stenosis surgery, with or without spondylolisthesis, does not improve the five-year ODI, which is consistent with our two-year report. Three secondary outcomes that did not differ at two years favoured decompression alone at five years. Our results support decompression alone as the preferred method for operating on spinal stenosis.

Swespine: the Swedish spine register : the 2012 report.

INTRODUCTION: Swespine, the Swedish National Spine Register, has existed for 20 years and is in general use within the country since over 10 years regarding degenerative lumbar spine disorders. Today there are protocols for registering all disorders of the entire spinal column. MATERIALS AND METHODS: Patient-based pre- and postoperative questionnaires, completed before surgery and at 1, 2, 5 and 10 years postoperatively. Among patient-based data are VAS pain, ODI, SF-36 and EQ-5D. Postoperatively evaluation of leg and back pain as compared to preoperatively ("global assessment"), overall satisfaction with outcome and working conditions are registered in addition to the same parameters as preoperatively evaluation. A yearly report is produced including an analytic part of a certain topic, in this issue disc prosthesis surgery. More than 75,000 surgically treated patients are registered to date with an increasing number yearly. The present report includes 7,285 patients; 1-, 2- and 5-year follow-up data of previously operated patients are also included for lumbar disorders as well as for disc prosthesis surgery. RESULTS: For the degenerative lumbar spine disorders (disc herniation, spinal stenosis, spondylolisthesis and DDD) significant improvements are seen in all aspects as exemplified by pronounced improvement regarding EQ-5D and ODI. Results seem to be stable over time. Spinal stenosis is the most common indication for spine surgery. Disc prosthesis surgery yields results on a par with fusion surgery in disc degenerative pain. The utility of spine surgery is well documented by the results. CONCLUSION: Results of spine surgery as documented on a national basis can be utilized for quality assurance and quality improvement as well as for research purposes, documenting changes over time and bench marking when introducing new surgical techniques. A basis for international comparisons is also laid.

Instrumentation in lumbar fusion improves back pain but not quality of life 2 years after surgery. A study of 1,310 patients with degenerative disc disease from the Swedish Spine Register SWESPINE.

BACKGROUND AND PURPOSE: Instrumented and non-instrumented methods of fusion have been compared in several studies, but the results are often inconsistent and conflicting. We compared the 2-year results of 3 methods of lumbar fusion when used in degenerative disc disease (DDD), using the Swedish Spine Register (SWESPINE). METHODS: All patients registered in SWESPINE for surgical treatment of DDD between January 1, 2000 and October 1, 2007 were eligible for the study. Patients who had completed the 2-year follow-up were included in the analysis. The outcomes of 3 methods of surgical fusion were assessed. RESULTS: Of 1,310 patients enrolled, 115 had undergone uninstrumented fusion, 620 instrumented posterolateral fusion, and 575 instrumented interbody fusion. Irrespective of the surgical procedure, quality of life (QoL) improved and back pain diminished. Change in QoL and functional disability and return to work was similar in the 3 groups. Patients who had undergone uninstrumented fusion had more back pain than the patients with instrumented interbody fusion at the 2-year follow-up (p = 0.02), although the difference was only 7 visual analog scale (VAS) units (95% CI: 1-13) on a 100-point scale. Moreover, 83% of the patients with uninstrumented fusion used analgesics at the end of follow-up as compared to 68% of the patients who had undergone surgery with one of the 2 instrumented fusion techniques. INTERPRETATION: In comparison with instrumented interbody fusion, uninstrumented fusion was associated with higher levels of back pain 2 years after surgery. We found no evidence for differences in QoL between uninstrumented fusion and instrumented interbody fusion.

Decompression alone or decompression with fusion for lumbar spinal stenosis: a randomized clinical trial with two-year MRI follow-up.

AIMS: The aims of this study were first, to determine if adding fusion to a decompression of the lumbar spine for spinal stenosis decreases the rate of radiological restenosis and/or proximal adjacent level stenosis two years after surgery, and second, to evaluate the change in vertebral slip two years after surgery with and without fusion. METHODS: The Swedish Spinal Stenosis Study (SSSS) was conducted between 2006 and 2012 at five public and two private hospitals. Six centres participated in this two-year MRI follow-up. We randomized 222 patients with central lumbar spinal stenosis at one or two adjacent levels into two groups, decompression alone and decompression with fusion. The presence or absence of a preoperative spondylolisthesis was noted. A new stenosis on two-year MRI was used as the primary outcome, defined as a dural sac cross-sectional area ≤ 75 mm2 at the operated level (restenosis) and/or at the level above (proximal adjacent level stenosis). RESULTS: A total of 211 patients underwent surgery at a mean age of 66 years (69% female): 103 were treated by decompression with fusion and 108 by decompression alone. A two-year MRI was available for 176 (90%) of the eligible patients. A new stenosis at the operated and/or adjacent level occurred more frequently after decompression and fusion than after decompression alone (47% vs 29%; p = 0.020). The difference remained in the subgroup with a preoperative spondylolisthesis, (48% vs 24%; p = 0.020), but did not reach significance for those without (45% vs 35%; p = 0.488). Proximal adjacent level stenosis was more common after fusion than after decompression alone (44% vs 17%; p < 0.001). Restenosis at the operated level was less frequent after fusion than decompression alone (4% vs 14%; p = 0.036). Vertebral slip increased by 1.1 mm after decompression alone, regardless of whether a preoperative spondylolisthesis was present or not. CONCLUSION: Adding fusion to a decompression increased the rate of new stenosis on two-year MRI, even when a spondylolisthesis was present preoperatively. This supports decompression alone as the preferred method of surgery for spinal stenosis, whether or not a degenerative spondylolisthesis is present preoperatively.Cite this article: Bone Joint J 2022;104-B(12):1343-1351.

Study protocol for a randomised controlled trial with clinical, neurophysiological, laboratory and radiological outcome for surgical versus non-surgical treatment for lumbar spinal stenosis: the Uppsala Spinal Stenosis Trial (UppSten).

INTRODUCTION: Symptomatic lumbar spinal stenosis is the most common indication for spinal surgery. However, more than one-third of the patients undergoing surgery for lumbar stenosis report dissatisfaction with the results. On the other hand, conservative treatment has shown positive results in some cases. This trial will compare the outcomes of surgical versus non-surgical treatment for lumbar stenosis. The study includes a multidimensional follow-up, aiming to study the association between outcome and other studied parameters, mainly electromyography and nerve conduction. Moreover, it may contribute to a better understanding of the pathophysiology of lumbar stenosis and to the development of future pharmacological treatments. METHODS AND ANALYSIS: UppSten is a single-centre randomised controlled trial in which 150 patients with symptomatic lumbar spinal stenosis will be randomised into one of two treatment arms. The patients in the surgical arm will undergo laminectomy; the patients in the non-surgical arm will be given a structured physical training programme. The primary outcome of the study will be the Oswestry Disability Index. Secondary outcomes will include motor amplitude and degree of denervation activity obtained by means of nerve conduction studies and electromyography. Patient-reported outcome measures will be also used as secondary outcomes. Blood sample analysis and the investigation of potential inflammation markers are the additional secondary outcome parameters. Laboratory evaluation will include blood sample collection before the treatment initiation and after 6 months. Flavum ligament biopsies will be performed in the surgical group. Finally, tertiary outcomes will include neurophysiological measures, the objective walking ability and radiological evaluation. ETHICS AND DISSEMINATION: The study is approved by the Local Ethics Committee (Dnr 2017-506), the Hospital's Clinical Trials Committee (2018-0001) and the National Biobank Council and Uppsala Biobank (BbA-827-2018-025). The results will be presented in peer-reviewed journals and at international conferences. TRIAL REGISTRATION NUMBER: NCT03495661.

Motion Analysis in Lumbar Spinal Stenosis With Degenerative Spondylolisthesis: A Feasibility Study of the 3DCT Technique Comparing Laminectomy Versus Bilateral Laminotomy.

STUDY DESIGN: This was a randomized radiologic biomechanical pilot study in vivo. OBJECTIVE: The objectives of this study was to evaluate if 3-dimensional computed tomography is a feasible tool in motion analyses of the lumbar spine and to study if preservation of segmental midline structures offers less postoperative instability compared with central decompression in patients with lumbar spinal stenosis with degenerative spondylolisthesis. SUMMARY OF BACKGROUND DATA: The role of segmental instability after decompression is controversial. Validated techniques for biomechanical evaluation of segmental motion in human live subjects are lacking. METHODS: In total, 23 patients (mean age, 68 y) with typical symptoms and magnetic resonance imaging findings of spinal stenosis with degenerative spondylolisthesis (>3 mm) in 1 or 2 adjacent lumbar levels from L3 to L5 were included. They were randomized to either laminectomy (LE) or bilateral laminotomy (LT) (preservation of the midline structures). Documentation of segmental motion was made preoperatively and 6 months postoperatively with CT in provoked flexion and extension. Analyses of movements were performed with validated software. The accuracy for this method is 0.6 mm in translation and 1 degree in rotation. Patient-reported outcome measures were collected from the Swespine register preoperatively and 2-year postoperatively. RESULTS: The mean preoperative values for 3D rotation and translation were 6.2 degrees and 1.8 mm. The mean increase in 3D rotation 6 months after surgery was 0.25 degrees after LT and 0.7 degrees after LE (P=0.79) while the mean increase in 3D translation was 0.15 mm after LT and 1.1 mm after LE (P=0.42). Both surgeries demonstrated significant improvement in patient-reported outcome measures 2 years postoperatively. CONCLUSIONS: The 3D computed tomography technique proved to be a feasible tool in the evaluation of segmental motion in this group of older patients. There was negligible increase in segmental motion after decompressive surgery. LE with removal of the midline structures did not create a greater instability compared with when these structures were preserved.

Women do not fare worse than men after lumbar fusion surgery: Two-year follow-up results from 4,780 prospectively collected patients in the Swedish National Spine Register with lumbar degenerative disc disease and chronic low back pain.

BACKGROUND CONTEXT: Proper patient selection is of utmost importance in the surgical treatment of degenerative disc disease (DDD) with chronic low back pain (CLBP). Among other factors, gender was previously found to influence lumbar fusion surgery outcome. PURPOSE: This study investigates whether gender affects clinical outcome after lumbar fusion. STUDY DESIGN: This is a national registry cohort study. PATIENT SAMPLE: Between 2001 and 2011, 2,251 men and 2,521 women were followed prospectively within the Swedish National Spine Register (SWESPINE) after lumbar fusion surgery for DDD and CLBP. OUTCOME MEASURES: Patient-reported outcome measures (PROMs), visual analog scale (VAS) for leg and back pain, Oswestry Disability Index (ODI), quality of life (QoL) parameter EQ5D, and labor status and pain medication were collected preoperatively, 1 and 2 years after surgery. METHODS: Gender differences of baseline data and PROM improvement from baseline were analyzed. The effect of gender on clinically important improvement of PROM was determined in a multivariate logistic regression model. Furthermore, gender-related differences in return-to-work were investigated. RESULTS: Preoperatively, women had worse leg pain (p<.001), back pain (p=.002), lower QoL (p<.001), and greater disability than men (p=.001). Postoperatively, women presented greater improvement 2 years from baseline for pain, function, and QoL (all p<.01). Women had better chances of a clinically important improvement than men for leg pain (odds ratio [OR]=1.39, 95% confidence interval [CI]: 1.19-1.61, p<.01) and back pain (OR=1.20,95% CI:1.03-1.40, p=.02) as well as ODI (OR=1.24, 95% CI:1.05-1.47, p=.01), but improved at a slower pace in leg pain (p<.001), back pain (p=.009), and disability (p=.008). No gender differences were found in QoL and return to work at 2 years postoperatively. CONCLUSIONS: Swedish women do not have worse results than men after spinal fusion surgery. Female patients present with worse pain and function preoperatively, but improve more than men do after surgery.

Radiographic results after plaster cast fixation for 10 days versus 1 month in reduced distal radius fractures: a prospective randomised study.

BACKGROUND: The aim of this study was to examine whether reduced distal radius fractures can be treated with early mobilisation without affecting the radiographic results. METHODS: In a prospective randomised study, 109 patients (mean age 65.8 (range 50-92)) with moderately displaced distal radius fractures were treated with closed reduction and plaster cast fixation for about 10 days (range 8-13 days) followed by randomisation to one of two groups: early mobilisation (n = 54, active group) or continued plaster cast fixation for another 3 weeks (n = 55, control group). RESULTS: For three patients in the active group (6%), treatment proved unsuccessful because of severe displacement of the fracture (n = 2) or perceived instability (n = 1). From 10 days to 1 month, i.e. the only period when the treatment differed between the two groups, the active group displaced significantly more in dorsal angulation (4.5°, p < 0.001), radial angulation (2.0°, p < 0.001) and axial compression (0.5 mm, p = 0.01) compared with the control group. However, during the entire study period (i.e. from admission to 12 months), the active group displaced significantly more than the controls only in radial angulation (3.2°, p = 0.002) and axial compression (0.7 mm, p = 0.02). CONCLUSIONS: Early mobilisation 10 days after reduction of moderately displaced distal radius fractures resulted in both an increased number of treatment failures and increased displacement in radial angulation and axial compression as compared with the control group. Mobilisation 10 days after reduction cannot be recommended for the routine treatment of reduced distal radius fractures. TRIAL REGISTRATION: ClinicalTrail.gov, NCT02798614 . Retrospectively registered 16 June 2016.

Prospective randomized feasibility trial to assess the use of rhPDGF-BB in treatment of distal radius fractures.

BACKGROUND: Recombinant human platelet-derived growth factor BB (rhPDGF-BB) combined with an osteoconductive scaffold (ß-TCP) has been demonstrated to increase bone formation, but rhPDGF-BB has not been studied in human fractures. The purpose of this study was to evaluate the safety and potential use of locally administered rhPDGF-BB/ß-TCP (Augment®) in acute wrist fractures. METHODS: Forty patients with unstable distal radial fracture were randomized to closed reduction and external fixation alone (n = 20) or combined with injection of rhPDGF-BB/ß-TCP (Augment®) into the fracture (n = 20). All patients were followed for 24 weeks. Outcome was based on adverse events, fracture displacement on radiographs, fracture healing, range of motion, grip strength, pain, and the disability of the arm, shoulder and hand (DASH) score. RESULTS: There were no serious adverse events in the study, but the pin tract infection rate was significantly lower in the Augment® group. There was no difference between the groups in fracture healing time, based on number of healed cortices or fracture displacement. The Augment® group had an early temporary significant decrease in wrist flexion, but no difference in range of motion at 24 weeks. There were no differences between the two treatment groups for any other outcome variables. CONCLUSION: rhPDGF-BB/ß-TCP (Augment®) is safe and convenient for local administration into wrist fractures. In this pilot study, we could not detect any reduced healing time in the Augment® group although potential efficacy should be addressed in larger studies. CLINICAL TRIAL REGISTRATION NUMBER: The clinical trial registration number for the study protocol is BMPI-2014-02-E.

Body Mass Index and Risk for Clinical Lumbar Spinal Stenosis: A Cohort Study.

STUDY DESIGN: A prospective cohort study that used a Swedish nationwide occupational surveillance program for construction workers (period of registration from 1971 to 1992). In all, 364,467 participants (mean age at baseline 34 yr) were included in the study. OBJECTIVE: To determine whether overweight and obesity are associated with a higher risk of lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA: During recent decades, LSS has become the most common indication for spine surgery, a change that coincides with a higher prevalence of obesity. METHODS: A diagnosis of LSS was collected through individual linkage to the Swedish National Patient Register through December 31, 2011. Poisson regression models were employed to estimate multivariable-adjusted incidence rate ratios (IRRs) for LSS. RESULTS: At baseline, 65% had normal weight (BMI [body mass index]: 18.5-24.99 kg/m), 29% were overweight (BMI: 25-29.99 kg/m), 5% were obese (BMI ≥30 kg/m), and 2% were underweight (BMI <18.5 kg/m). During 11,190,944 person-years of follow-up, with a mean of 31 years, 2381 participants were diagnosed with LSS. Compared with normal weight individuals, obese workers had an IRR of 2.18 (95% confidence interval, 1.87-2.53) for LSS and overweight workers had an IRR of 1.68 (95% confidence interval, 1.54-1.83). Workers who were underweight halved their risk of LSS (IRR: 0.52, 95% confidence interval, 0.30-0.90). CONCLUSION: Obese and overweight persons are at a higher risk of developing LSS. Furthermore, our results indicate that obesity might be a novel explanation for the increased number of patients with clinical LSS. LEVEL OF EVIDENCE: 3.

Obese patients report modest weight loss after surgery for lumbar spinal stenosis: a study from the Swedish spine register.

STUDY DESIGN: SWESPINE, the Swedish Spine Register, was used for this cohort study. OBJECTIVE: Our primary aim was to determine weight change in obese patients after surgery for lumbar spinal stenosis (LSS). Our secondary aim was to study any possible associations between weight loss after surgery and improvement in patient-related outcome measures (PROMs). SUMMARY OF BACKGROUND DATA: Only meager evidence is available as to how surgery for LSS affects weight and whether weight loss is associated with improvement in PROMs after surgery for LSS. METHODS: All obese patients who underwent surgery for LSS from January 1, 2006 through June 30, 2008 with a completed 2-year follow-up in SWESPINE were included. Data for weight were collected before surgery and then 1 and 2 years after surgery. The cohort was divided into 3 subclasses (weight stable, weight loss, or weight gain). RESULTS: Totally, 538 obese patients were enrolled. Mean weight loss was 1.9 kg (95% confidence interval, 1.5-2.3) 1 year after surgery and 2.0 kg (95% confidence interval, 1.5-2.4) after 2 years after surgery. Only 8% of the patients reported a clinically important weight loss (≥10%). No significant differences in PROMs were observed. The weight-stable group reported a mean improvement of 0.22 (standard deviation, 0.36) in EQ-5D, 14 (18) units in the Oswestry Disability Index, 18 (33) units in back pain (visual analogue scale), and 23 (36) units in leg pain (visual analogue scale). The corresponding changes in the weight-loss group were 0.23 (0.35) in EuroQol 5D, 15 (19) in Oswestry Disability Index, 27 (29) in back pain, and 31 (36) in leg pain. CONCLUSION: Modest weight loss was reported 1 and 2 years postsurgery; a small proportion (8%) of these patients reported a clinically important weight loss at the 2-year follow-up. The weight loss was unrelated to changes in PROMs. LEVEL OF EVIDENCE: 3.

Increased occurrence of spinal fractures related to ankylosing spondylitis: a prospective 22-year cohort study in 17,764 patients from a national registry in Sweden.

BACKGROUND: Ankylosing spondylitis (AS) is a rheumatoid disease leading to progressive ossification of the spinal column. Patients suffering from AS are highly susceptible to unstable vertebral fractures and often require surgical stabilisation due to long lever arms. Medical treatment of these patients improved during the last decades, but until now it is unknown whether the annual number of spinal fractures changed during the last years. Since the annual count of fracture is an effective measure for efficacy of injury prevention and patient safety in AS patients, the current recommendations of activity have to be revised accordingly. METHODS: Data for all patients with AS treated as inpatients between 01/01/1987 and 31/12/2008 were extracted from the Swedish National Hospital Discharge Registry (SNHDR). The data in the registry are collected prospectively, recording all inpatient admissions throughout Sweden. The SNHDR uses the codes for diagnoses at discharge according to the Swedish versions of the International Classification of Diseases (ICD-9 and ICD-10). RESULTS: During the years from 1987 to 2008 17,764 patients with AS were treated as inpatients; of these 724 patients were treated due to spinal fractures. The annual number of cervical, thoracic and lumbar fractures in the registry increased until 2008 (r = 0.94). CONCLUSIONS: Despite the improved treatment of AS the annual number of vertebral fractures requiring inpatient care increased during the last two decades. Possible explanations are population growth, greater awareness of fractures, improved diagnostics, improved emergency care reducing fatalities, and a higher activity level of patients receiving modern medical therapy. Obviously the improvement of medical treatment did not reduce the susceptibility of these patients to unstable fractures. Thus the restrictive injury prevention recommendations for patients with AS cannot be defused, but must be critically revised to improve patient safety.

Obesity is associated with inferior results after surgery for lumbar spinal stenosis: a study of 2633 patients from the Swedish spine register.

STUDY DESIGN: A cohort study based on the Swedish Spine Register. OBJECTIVE: To determine the association between body mass index (BMI) and outcome of lumbar spine surgery for spinal stenosis. SUMMARY OF BACKGROUND DATA: Several small studies have sought to evaluate the importance of obesity in relation to results after surgery for lumbar spinal stenosis (LSS), but the findings are inconsistent and relatively weak. METHODS: All patients who underwent surgery for LSS from January 1, 2006, to June 30, 2008, with a completed 2-year follow-up in the Swedish Spine Register were included. Logistic regression was used to assess the association between BMI and different outcomes. RESULTS: Of the 2633 patients enrolled, 819 (31%) had normal weight, 1208 (46%) were overweight, and 606 (23%) were obese. On average, all 3 BMI groups achieved significant improvements after surgery. A higher BMI, however, was associated with greater odds of dissatisfaction after surgery and inferior results at the 2-year follow-up. After adjusting for differences in baseline characteristics, the obese group demonstrated inferior function and quality of life as measured by the Oswestry Disability Index (ODI) and the EuroQol Group Index (EQ-5D), respectively. At the 2-year follow-up, obese patients had a mean ODI of 33 (95% confidence interval [CI], 31-34) and mean EQ-5D of 0.56 (95% CI, 0.54-0.59) compared with a mean ODI of 25 (95% CI, 24-26) and mean EQ-5D of 0.64 (95% CI, 0.62-0.66) in the normal weight group. When compared with the normal weight patients, the adjusted odds ratio for dissatisfaction was 1.73 in the obese group (95% CI, 1.36-2.19). Differences between the normal weight and overweight groups were modest and therefore could not be considered clinically relevant. CONCLUSION: Obese patients achieved significant pain reduction, better walking ability, and improved quality of life after surgical treatment of LSS. Nevertheless, obesity was associated with a higher degree of dissatisfaction and poorer outcomes after surgery for LSS.

Smokers show less improvement than nonsmokers two years after surgery for lumbar spinal stenosis: a study of 4555 patients from the Swedish spine register.

STUDY DESIGN: A cohort study based on the Swedish Spine Register. OBJECTIVE: To determine the relation between smoking status and disability after surgical treatment for lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA: Smoking and nicotine have been shown to inhibit lumbar spinal fusion and promote disc degeneration. No association, however, has previously been found between smoking and outcome after surgery for lumbar spinal stenosis. A large prospective study is therefore needed. METHODS: All patients with a completed 2-year follow-up in the Swedish Spine Register operated for central lumbar stenosis before October 1, 2006 were included. Logistic regression was used to assess the association between smoking status and outcomes. RESULTS: Of 4555 patients enrolled, 758 (17%) were current smokers at the time of surgery. Smokers had an inferior health-related Quality of Life at baseline. Nevertheless, adjusted for differences in baseline characteristics, the odds ratio (OR) for a smoker to end up dissatisfied at the 2-year follow-up after surgery was 1.79 [95% confidence interval (CI) 1.51-2.12]. Smokers had more regular use of analgesics (OR 1.86; 95% CI 1.55-2.23). Walking ability was less likely to be significantly improved in smokers with an OR of 0.65 (95% CI 0.51-0.82). Smokers had inferior Quality of Life also after taking differences before surgery into account, either when measured with the Oswestry Disability Index (ODI; P < 0.001), EuroQol (P < 0.001) or Short Form (36) Health Survey (SF-36) BP and SF-36 PF (P < 0.001). The differences in results between smokers and nonsmokers were evident, irrespective of whether the decompression was done with or without spinal fusion. CONCLUSION: Smoking is an important predictor for 2-year results after surgery for lumbar spinal stenosis. Smokers had less improvement after surgery than nonsmokers.