Bengt Sandén - Academia.edu (original) (raw)
Papers by Bengt Sandén
BMJ Open
IntroductionSymptomatic lumbar spinal stenosis is the most common indication for spinal surgery. ... more IntroductionSymptomatic 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 analysisUppSten 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 Spine Journal
BACKGROUND CONTEXT: Proper patient selection is of utmost importance in the surgical treatment of... more 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.
Journal of orthopaedic surgery and research, Jan 21, 2016
The aim of this study was to examine whether reduced distal radius fractures can be treated with ... more The aim of this study was to examine whether reduced distal radius fractures can be treated with early mobilisation without affecting the radiographic results. 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). 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 wi...
The New England journal of medicine, Jan 11, 2016
The New England journal of medicine, Jan 14, 2016
The efficacy of fusion surgery in addition to decompression surgery in patients who have lumbar s... more 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. 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...
Spine, 2015
Study Design. A prospective cohort study that used a Swedish nationwide occupational surveillance... more Study Design. A prospective cohort study that used a Swedish nationwide occupational surveillance program for construction workers (period of registration from 1971-1992). In all, 364 467 participants (mean age at baseline 34 years) were included in the study. To determine whether overweight and obesity are associated with a higher risk of lumbar spinal stenosis (LSS). During recent decades, LSS has become the most common indication for spine surgery, a change that coincides with a higher prevalence of obesity. 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. At baseline, 65% had normal weight (BMI 18.5 to 24.99 kg/m), 29% were overweight (BMI 25 to 29.99 kg/m), 5% were obese (BMI≥30 kg/m) and 2% were underweight (BMI&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;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 (CI), 1.87 to 2.53) for LSS and overweight workers had an IRR of 1.68 (95% CI, 1.54 to 1.83). Workers who were underweight halved their risk of LSS (IRR 0.52, 95% CI 0.30 to 0.90). Obese and overweight persons are at a higher risk of developing LSS. Further, our results indicate that obesity might be a novel explanation for the increased number of patients with clinical LSS.
Journal of orthopaedic surgery and research, Jan 21, 2015
Recombinant human platelet-derived growth factor BB (rhPDGF-BB) combined with an osteoconductive ... more Recombinant human platelet-derived growth factor BB (rhPDGF-BB) combined with an osteoconductive scaffold (β-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/β-TCP (Augment®) in acute wrist fractures. 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/β-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. 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...
Läkartidningen, Jan 26, 1996
Spine, Jan 15, 2014
SWESPINE, the Swedish Spine Register, was used for this cohort study. Our primary aim was to dete... more SWESPINE, the Swedish Spine Register, was used for this cohort study. 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). 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. 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). 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) aft...
Läkartidningen, Jan 22, 1998
International Journal of Nano and Biomaterials, 2012
ABSTRACT The early fixation of pedicle screws is crucial for improving spinal stabilisation. Firm... more ABSTRACT The early fixation of pedicle screws is crucial for improving spinal stabilisation. Firm and immediate fixation between pedicle screws and bone prevents aseptic loosening and implant failure. Coating with hydroxyapatite is a possible method to improve the fixation of metallic implants in bone. In this study, scanning transmission electron microscopy (STEM) has been used to investigate the ultrastructure of the plasma-sprayed hydroxyapatite coating and human bone interface in detail. Focused ion beam sample preparation also enabled the investigation of the bone-lacunae interface. An intimate contact and elemental analysis between bone and HA coatings suggests bioactive fixation. Therefore, coating with hydroxyapatite leads to enhanced biocompatibility at the ultrastructural level and may lead to improved early and long-term fixation of pedicle screws.
The Bone & Joint Journal, 2013
Whether to combine spinal decompression with fusion in patients with symptomatic lumbar spinal st... more Whether to combine spinal decompression with fusion in patients with symptomatic lumbar spinal stenosis remains controversial. We performed a cohort study to determine the effect of the addition of fusion in terms of patient satisfaction after decompressive spinal surgery in patients with and without a degenerative spondylolisthesis. The National Swedish Register for Spine Surgery (Swespine) was used for the study. Data were obtained for all patients in the register who underwent surgery for stenosis on one or two adjacent lumbar levels. A total of 5390 patients fulfilled the inclusion criteria and completed a two-year follow-up. Using multivariable models the results of 4259 patients who underwent decompression alone were compared with those of 1131 who underwent decompression and fusion. The consequence of having an associated spondylolisthesis in the operated segments pre-operatively was also considered. At two years there was no significant difference in patient satisfaction bet...
Spine, 2013
A cohort study based on the Swedish Spine Register. To determine the association between body mas... more A cohort study based on the Swedish Spine Register. To determine the association between body mass index (BMI) and outcome of lumbar spine surgery for spinal stenosis. 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. 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. 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. 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.
Spine, 2001
An in vivo sheep model with loaded pedicle screws was used, wherein each animal served as its own... more An in vivo sheep model with loaded pedicle screws was used, wherein each animal served as its own control. To examine the effects of hydroxyapatite (HA) coating on the bone-to-implant interface in loaded spinal instrumentations. Spinal instrumentation improves the healing rate in spinal fusion, but screw loosening constitutes a problem. HA coating of other implants has resulted in favorable effects on the bone-to-implant interface. Nine sheep were operated on with destabilizing laminectomies at two levels: L2-L3 and L4-L5. Each level was stabilized separately with a four-screw instrumentation. Uncoated screws (stainless steel) or the same type of screws coated with plasma-sprayed HA were used in either the upper or the lower instrumentation in a randomized fashion. The animals were killed at 6 or 12 weeks after surgery. The specimens were embedded in resin, ground to approximately 10 microm, and stained with toluidine blue. Histomorphometric evaluation was carried out in a Leitz Aristoplan (Wetzlar, Germany) light microscope equipped with a Leitz Microvid unit. The average percentage of bone-to-implant contact after 6 weeks was 69 +/- 10 for the HA-coated screws and 18 +/- 11 for the uncoated screws (P < 0.03), and after 12 weeks 64 +/- 31 (HA-coated) and 9 +/- 13 (uncoated, P < 0.02). The average bone volume in the area close to the screw was significantly higher for the HA-coated screws at both 6 and 12 weeks. HA coating improved the bone-to-implant interface significantly, indicating that HA coating can become useful for improving the purchase of pedicle screws.
Spine, 2011
A cohort study based on the Swedish Spine Register. To determine the relation between smoking sta... more A cohort study based on the Swedish Spine Register. To determine the relation between smoking status and disability after surgical treatment for lumbar spinal stenosis. 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. 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. 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 &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001), EuroQol (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) or Short Form (36) Health Survey (SF-36) BP and SF-36 PF (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). The differences in results between smokers and nonsmokers were evident, irrespective of whether the decompression was done with or without spinal fusion. Smoking is an important predictor for 2-year results after surgery for lumbar spinal stenosis. Smokers had less improvement after surgery than nonsmokers.
Patient Safety in Surgery, 2013
Background: Ankylosing spondylitis (AS) is a rheumatoid disease leading to progressive ossificati... more 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.
BMJ Open
IntroductionSymptomatic lumbar spinal stenosis is the most common indication for spinal surgery. ... more IntroductionSymptomatic 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 analysisUppSten 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 Spine Journal
BACKGROUND CONTEXT: Proper patient selection is of utmost importance in the surgical treatment of... more 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.
Journal of orthopaedic surgery and research, Jan 21, 2016
The aim of this study was to examine whether reduced distal radius fractures can be treated with ... more The aim of this study was to examine whether reduced distal radius fractures can be treated with early mobilisation without affecting the radiographic results. 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). 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 wi...
The New England journal of medicine, Jan 11, 2016
The New England journal of medicine, Jan 14, 2016
The efficacy of fusion surgery in addition to decompression surgery in patients who have lumbar s... more 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. 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...
Spine, 2015
Study Design. A prospective cohort study that used a Swedish nationwide occupational surveillance... more Study Design. A prospective cohort study that used a Swedish nationwide occupational surveillance program for construction workers (period of registration from 1971-1992). In all, 364 467 participants (mean age at baseline 34 years) were included in the study. To determine whether overweight and obesity are associated with a higher risk of lumbar spinal stenosis (LSS). During recent decades, LSS has become the most common indication for spine surgery, a change that coincides with a higher prevalence of obesity. 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. At baseline, 65% had normal weight (BMI 18.5 to 24.99 kg/m), 29% were overweight (BMI 25 to 29.99 kg/m), 5% were obese (BMI≥30 kg/m) and 2% were underweight (BMI&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;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 (CI), 1.87 to 2.53) for LSS and overweight workers had an IRR of 1.68 (95% CI, 1.54 to 1.83). Workers who were underweight halved their risk of LSS (IRR 0.52, 95% CI 0.30 to 0.90). Obese and overweight persons are at a higher risk of developing LSS. Further, our results indicate that obesity might be a novel explanation for the increased number of patients with clinical LSS.
Journal of orthopaedic surgery and research, Jan 21, 2015
Recombinant human platelet-derived growth factor BB (rhPDGF-BB) combined with an osteoconductive ... more Recombinant human platelet-derived growth factor BB (rhPDGF-BB) combined with an osteoconductive scaffold (β-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/β-TCP (Augment®) in acute wrist fractures. 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/β-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. 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...
Läkartidningen, Jan 26, 1996
Spine, Jan 15, 2014
SWESPINE, the Swedish Spine Register, was used for this cohort study. Our primary aim was to dete... more SWESPINE, the Swedish Spine Register, was used for this cohort study. 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). 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. 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). 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) aft...
Läkartidningen, Jan 22, 1998
International Journal of Nano and Biomaterials, 2012
ABSTRACT The early fixation of pedicle screws is crucial for improving spinal stabilisation. Firm... more ABSTRACT The early fixation of pedicle screws is crucial for improving spinal stabilisation. Firm and immediate fixation between pedicle screws and bone prevents aseptic loosening and implant failure. Coating with hydroxyapatite is a possible method to improve the fixation of metallic implants in bone. In this study, scanning transmission electron microscopy (STEM) has been used to investigate the ultrastructure of the plasma-sprayed hydroxyapatite coating and human bone interface in detail. Focused ion beam sample preparation also enabled the investigation of the bone-lacunae interface. An intimate contact and elemental analysis between bone and HA coatings suggests bioactive fixation. Therefore, coating with hydroxyapatite leads to enhanced biocompatibility at the ultrastructural level and may lead to improved early and long-term fixation of pedicle screws.
The Bone & Joint Journal, 2013
Whether to combine spinal decompression with fusion in patients with symptomatic lumbar spinal st... more Whether to combine spinal decompression with fusion in patients with symptomatic lumbar spinal stenosis remains controversial. We performed a cohort study to determine the effect of the addition of fusion in terms of patient satisfaction after decompressive spinal surgery in patients with and without a degenerative spondylolisthesis. The National Swedish Register for Spine Surgery (Swespine) was used for the study. Data were obtained for all patients in the register who underwent surgery for stenosis on one or two adjacent lumbar levels. A total of 5390 patients fulfilled the inclusion criteria and completed a two-year follow-up. Using multivariable models the results of 4259 patients who underwent decompression alone were compared with those of 1131 who underwent decompression and fusion. The consequence of having an associated spondylolisthesis in the operated segments pre-operatively was also considered. At two years there was no significant difference in patient satisfaction bet...
Spine, 2013
A cohort study based on the Swedish Spine Register. To determine the association between body mas... more A cohort study based on the Swedish Spine Register. To determine the association between body mass index (BMI) and outcome of lumbar spine surgery for spinal stenosis. 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. 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. 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. 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.
Spine, 2001
An in vivo sheep model with loaded pedicle screws was used, wherein each animal served as its own... more An in vivo sheep model with loaded pedicle screws was used, wherein each animal served as its own control. To examine the effects of hydroxyapatite (HA) coating on the bone-to-implant interface in loaded spinal instrumentations. Spinal instrumentation improves the healing rate in spinal fusion, but screw loosening constitutes a problem. HA coating of other implants has resulted in favorable effects on the bone-to-implant interface. Nine sheep were operated on with destabilizing laminectomies at two levels: L2-L3 and L4-L5. Each level was stabilized separately with a four-screw instrumentation. Uncoated screws (stainless steel) or the same type of screws coated with plasma-sprayed HA were used in either the upper or the lower instrumentation in a randomized fashion. The animals were killed at 6 or 12 weeks after surgery. The specimens were embedded in resin, ground to approximately 10 microm, and stained with toluidine blue. Histomorphometric evaluation was carried out in a Leitz Aristoplan (Wetzlar, Germany) light microscope equipped with a Leitz Microvid unit. The average percentage of bone-to-implant contact after 6 weeks was 69 +/- 10 for the HA-coated screws and 18 +/- 11 for the uncoated screws (P < 0.03), and after 12 weeks 64 +/- 31 (HA-coated) and 9 +/- 13 (uncoated, P < 0.02). The average bone volume in the area close to the screw was significantly higher for the HA-coated screws at both 6 and 12 weeks. HA coating improved the bone-to-implant interface significantly, indicating that HA coating can become useful for improving the purchase of pedicle screws.
Spine, 2011
A cohort study based on the Swedish Spine Register. To determine the relation between smoking sta... more A cohort study based on the Swedish Spine Register. To determine the relation between smoking status and disability after surgical treatment for lumbar spinal stenosis. 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. 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. 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 &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001), EuroQol (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) or Short Form (36) Health Survey (SF-36) BP and SF-36 PF (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). The differences in results between smokers and nonsmokers were evident, irrespective of whether the decompression was done with or without spinal fusion. Smoking is an important predictor for 2-year results after surgery for lumbar spinal stenosis. Smokers had less improvement after surgery than nonsmokers.
Patient Safety in Surgery, 2013
Background: Ankylosing spondylitis (AS) is a rheumatoid disease leading to progressive ossificati... more 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.