| 1. |
- Eskilsson, Karin, et al.
(author)
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Pedicle subtraction osteotomy: a comprehensive analysis in 104 patients. Does the cause of deformity influence the outcome?
- 2017
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In: Journal of Neurosurgery-Spine. - : Journal of Neurosurgery Publishing Group (JNSPG). - 1547-5654. ; 27:1, s. 56-62
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Journal article (peer-reviewed)abstract
- OBJECTIVE The clinical outcomes and complications of patients who underwent pedicle subtraction osteotomy (PSO) for various diagnoses were compared. More specifically, the purpose was to identify if outcomes differed between patients with flat-back syndrome after lumbar fusion (FBS-LF) versus patients who underwent surgery for adult spinal deformity (ASD). METHODS A retrospective analysis of 104 patients who underwent a PSO for sagittal plane imbalance was performed. There were 28 patients with FBS-LF and 76 patients with various forms of ASD. Outcome was measured using visual analog scale (VAS)-back, VAS-leg, Oswestry Disability Index (ODI) (range 0-100 for all scales), and EQ-5D scores (range 0-1). Patients also rated their global outcomes as much better, better, unchanged, or worse at follow-up. The minimum follow-up was 1 year (range 1-4 years). Clinical outcomes and complications were compared between the 2 groups of patients. RESULTS The most common level of PSO was L-3 and L-2; 100 single and 4 double PSOs were performed. The average local correction by PSO itself was 27.2 degrees. The sagittal vertical axis (SVA) improved from a mean preoperative value of 74 +/- 23 mm to 49 +/- 20 mm at the final follow-up. The VAS -back, ODI, and EQ:5D scores improved significantly for the entire group by 33, 16, and 0.31 points, respectively. In total, 57% of patients reported that they were "much better" or "better" than before surgery. Preoperatively, as well as postoperatively, the FBS-LF patients reported significantly worse VAS scores.. According to VAS -back results, the ASD group improved by 34 points compared with 29 points in FBS-LF patients. ODI scores were similar between the 2 groups preoperatively but improved significantly more in the ASD group (18 points) compared with the FBS-LF group (13 points). The EQ-5D scores improved from 0.07 to 0.35 in FBS-LF patients, and from 0.21 to 0.56 on average in ASD patients. Similarly, a "much better" or "better" outcome compared with before surgery was reported by 72% of patients in the ASD group compared with 24% of patients in the FBS-LF group (p < 0.001). The overall reoperation rate was 31%: 46% of patients in the FBS-LF group compared with 25% of patients in the ASD group. There were 19 (18%) dural tears, 14 (13.5%) surgical site infections, 12 (11.5%) instances of pseudarthrosis, 15 (14%) proximal junctional failures, and 2 distal junctional failures. The 12 (11%) neurological complications were dominated by partial weakness of hip flexion and knee extension, and all but 2 of these were temporary. CONCLUSIONS PSO is a safe and effective method for correcting sagittal plane imbalance due to multiple etiologies. The authors found patient satisfaction to be high, and health-related quality of life was greatly improved by the procedure in patients with ASD. In contrast, in FBS-LF patients, a suboptimal outcome was observed and the cautious use of PSO seems warranted in this subset of patients.
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| 2. |
- Eskilsson, Karin, et al.
(author)
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The impact of spinopelvic morphology on the short-term outcome of pedicle subtraction osteotomy in 104 patients
- 2017
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In: Journal of Neurosurgery-Spine. - : Journal of Neurosurgery Publishing Group (JNSPG). - 1547-5654. ; 27:1, s. 74-80
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Journal article (peer-reviewed)abstract
- OBJECTIVE Pedicle subtraction osteotomy (PSO) is commonly performed for correction of spinal sagittal plane deformities. The PSO results in complex, multiple changes of the spinopelvic alignment. The influence of the variability of individual pelvic morphology has not been fully analyzed in previous outcome studies of sagittal imbalance. The aim of this study was to define radiological variables affecting the outcome after PSO in adult spinal deformities, with special emphasis on the variability of pelvic morphology. METHODS Clinical and radiographic outcomes were analyzed in a retrospective analysis of 104 patients who underwent a PSO at a single center. The radiographic variables studied were sagittal vertical axis (SVA), T1SPI (T-1 spinopelvic inclination), lumbar lordosis (LL), thoracic kyphosis (TK), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). To control for the individual variation of pelvic morphology, the LL/PI, PT/PI, and SS/PI ratios were calculated. Clinical outcome was assessed using the visual analog scale for pain, Oswestry Disability Index, and EQ-5D preoperatively and at a minimum 1 -year follow-up. Correlation coefficients were calculated between each individual radiographic variable and the outcome measures. The importance of LL mismatch to TK, reflecting the importance of a harmonious spine, was analyzed by comparing the outcome of patients with a TK+LL+PI 5 45 to those with a sum > 45. RESULTS SVA and T1SPI demonstrated the strongest correlation with the clinical outcome scores (r = 0.4-0.5, p < 0.001). LL correlated weakly with the clinical outcome (r = 0.2-0.3, p < 0.003). Mismatch of LL to PI, however, did not correlate significantly with the outcome. Similarly, only weak and inconsistent correlation was observed between PT, SS, PT/PI, SS/PI, and functional outcome. Patients with a TK+LL+PI _5 45 had a significantly lower ODI score (33 vs 44) and a significantly higher EQ-5D score (0.64 vs 0.40) than patients with a sum > 45 (LL is a negative value). CONCLUSIONS PSO resulted in a substantial correction of sagittal imbalance and improved outcome in most patients in this study. Correction of the global sagittal balance appears to be a necessary precondition for a good outcome. A harmonious spine with a TK and an LL of similar magnitude seems to add to a positive outcome.
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| 3. |
- Jalalpour, Kourosh, et al.
(author)
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A Randomized Controlled Trial Comparing Transforaminal Lumbar Interbody Fusion and Uninstrumented Posterolateral Fusion in the Degenerative Lumbar Spine.
- 2015
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In: Global spine journal. - : SAGE Publications. - 2192-5682 .- 2192-5690. ; 5:4, s. 322-8
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Journal article (peer-reviewed)abstract
- Study DesignRandomized controlled trial. ObjectiveDespite a large number of publications of outcomes after spinal fusion surgery, there is still no consensus on the efficacy of the several different fusion methods. The aim of this study was to determine whether transforaminal lumbar interbody fusion (TLIF) results in an improved clinical outcome compared with uninstrumented posterolateral fusion (PLF) in the surgical treatment for chronic low back pain. MethodsThis study included 135 patients with degenerative disk disease (n=96) or postdiskectomy syndrome (n=39). Inclusion criteria were at least 1year of back pain with or without leg pain in patients aged 20 to 65 with one- or two-level disease. Exclusion criteria were sequestration of disk hernia, psychosocial instability, isthmic spondylolisthesis, drug abuse, and previous spine surgery other than diskectomy. Pain was assessed by visual analog scale (pain index). Functional disability was quantified by the disability rating index and Oswestry Disability Index. The global outcome was assessed by the patient and classified as much better, better, unchanged, or worse. The patients were randomized to conventional uninstrumented PLF (n=67) or TLIF (n=68). PLF was performed in a standardized fashion using autograft. TLIF was performed with pedicle titanium screw fixation and a porous tantalum interbody spacer with interbody and posterolateral autograft. The clinical outcome measurements were obtained preoperatively and at 12 and 24 months postoperatively. The 2-year follow-up rate was 98%. ResultsThe two treatment groups improved significantly from preoperatively to 2 years' follow-up. At final follow-up, the results in the TLIF group were significantly superior to those in the PLF group in pain index (2.0 versus 3.9, p=0.007) and in disability rating index (22 versus 36, p=0.003). The Oswestry Disability Index was better in the TLIF group (20 versus 28, p=0.110, not significant). The global assessment was clearly superior in the TLIF group: 63% of patients scored "much better" in the TLIF group as compared with 48% in the PLF group (p=0.017). ConclusionsThe results of the current study support the use of TLIF rather than uninstrumented PLF in the surgical treatment of the degenerative lumbar spine. The less optimal outcome after uninstrumented PLF may be explained by the much higher reoperation rate.
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| 4. |
- Johansson, Inger, 1953, et al.
(author)
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Cytomegalovirus infection and disease reduce 10-year cardiac allograft vasculopathy-free survival in heart transplant recipients
- 2015
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In: Bmc Infectious Diseases. - : Springer Science and Business Media LLC. - 1471-2334. ; 15
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Journal article (peer-reviewed)abstract
- Background: Cytomegalovirus (CMV) is associated with an increased risk of cardiac allograft vasculopathy (CAV), the major limiting factor for long-term survival after heart transplantation (HTx). The purpose of this study was to evaluate the impact of CMV infection during long-term follow-up after HTx. Methods: A retrospective, single-centre study analyzed 226 HTx recipients (mean age 45 +/- 13 years, 78 % men) who underwent transplantation between January 1988 and December 2000. The incidence and risk factors for CMV infection during the first year after transplantation were studied. Risk factors for CAV were included in an analyses of CAV-free survival within 10 years post-transplant. The effect of CMV infection on the grade of CAV was analyzed. Results: Survival to 10 years post-transplant was higher in patients with no CMV infection (69 %) compared with patients with CMV disease (55 %; p = 0.018) or asymptomatic CMV infection (54 %; p = 0.053). CAV-free survival time was higher in patients with no CMV infection (6.7 years; 95 % CI, 6.0-7.4) compared with CMV disease (4.2 years; CI, 3.2-5.2; p < 0.001) or asymptomatic CMV infection (5.4 years; CI, 4.3-6.4; p = 0.013). In univariate analysis, recipient age, donor age, coronary artery disease (CAD), asymptomatic CMV infection and CMV disease were significantly associated with CAV-free survival. In multivariate regression analysis, CMV disease, asymptomatic CMV infection, CAD and donor age remained independent predictors of CAV-free survival at 10 years post-transplant. Conclusions: CAV-free survival was significantly reduced in patients with CMV disease and asymptomatic CMV infection compared to patients without CMV infection. These findings highlight the importance of close monitoring of CMV viral load and appropriate therapeutic strategies for preventing asymptomatic CMV infection.
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| 5. |
- Johansson, Örjan, et al.
(author)
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Land sharing is essential for snow leopard conservation
- 2016
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In: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 203, s. 1-7
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Journal article (peer-reviewed)abstract
- Conserving large carnivores in an increasingly crowded planet raises difficult challenges. A recurring debate is whether large carnivores can be conserved in human used landscapes (land sharing) or whether they require specially designated areas (land sparing). Here we show that 40% of the 170 protected areas in the global range of the snow leopard (Panthera uncia) are smaller than the home range of a single adult male and only 4-13% are large enough for a 90% probability of containing 15 or more adult females. We used data from 16 snow leopards equipped with GPS collars in the Tost Mountains of South Gobi, Mongolia, to calculate home range size and overlap using three different estimators: minimum convex polygons (MCP), kernel utility distributions (Kernel), and local convex hulls (LoCoH). Local convex hull home ranges were smaller and included lower proportions of unused habitats compared to home ranges based on minimum convex polygons and Kernels. Intra-sexual home range overlap was low, especially for adult males, suggesting that snow leopards are territorial. Mean home range size based on the LoCoH estimates was 207 km(2) +/- 63 SD for adult males and 124 km(2) +/- 41 SD for adult females. Our estimates were 6-44 times larger than earlier estimates based on VHF technology when comparing similar estimators, i.e. MCP. Our study illustrates that protected areas alone will not be able to conserve predators with large home ranges and conservationists and managers should not restrict their efforts to land sparing. (C) 2016 Elsevier Ltd. All rights reserved.
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| 6. |
- Johansson, Örjan, et al.
(author)
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Sex-specific seasonal variation in puma and snow leopard home range utilization
- 2018
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In: Ecosphere. - : Wiley. - 2150-8925. ; 9
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Journal article (peer-reviewed)abstract
- Territory size is often larger for males than for females in species without biparental care. For large solitary carnivores, this is explained by males encompassing a set of female territories to monopolize their reproduction during mating (area maximization). However, males are expected to behave more like females outside of breeding, with their area utilization being dependent on the range required to secure food resources (area minimization). To examine how male and female solitary carnivores adjust their spatial organization during the year as key resources (mates and prey) change, we radio-collared 17 pumas (Puma concolor; nine males and eight females) and 14 snow leopards (Panthera uncia; seven males and seven females) and estimated home range size and overlap on two temporal scales (annual vs. monthly). Contrary to expectation, we found no evidence that males monopolized females (the mean territory overlap between females and the focal male during the mating season was 0.28 and 0.64 in pumas and snow leopards, respectively). Although male-male overlap of annual home ranges was comparatively high (snow leopards [0.21] vs. pumas [0.11]), monthly home range overlaps were small (snow leopards [0.02] vs. pumas [0.08]) suggesting strong territoriality. In pumas, both males and females reduced their monthly home ranges in winter, and at the same time, prey distribution was clumped and mating activity increased. In snow leopards, females showed little variation in seasonal home range size, following the seasonal stability in their primary prey. However, male snow leopards reduced their monthly home range utilization in the mating season. In line with other studies, our results suggest that female seasonal home range variation is largely explained by changes in food resource distribution. However, contrary to expectations, male territories did not generally encompass those of females, and males reduced their home ranges during mating. Our results show that male and female territorial boundaries tend to intersect in these species, and hint at the operation of female choice and male mate guarding within these mating systems.
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| 7. |
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| 8. |
- Nilsson, Jan-Eric, 1952-, et al.
(author)
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Tidtabelläggning : principer, tumregler och utfall
- 2015
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Reports (other academic/artistic)abstract
- Denna rapport består av tre delar som ur olika perspektiv handlar om kapacitetstilldelning på järnväg. I rapportens första del beskrivs de principer och tumregler som används i avsaknad av det ideala instrumentet för att ta fram en tidtabell för varje nytt år. Ett centralt tillvägagångssätt för att hantera denna komplexa uppgift är att så långt som möjligt utgå från existerande tidtabell eftersom denna visat sig fungera i praktiken. Intervjuer pekar på att förhandskunskapen om denna prioriteringsordning kan påverka de ansökningar som lämnas, det vill säga att den eller de operatörer som från början vet att man kommer att ha lägre prioritet anpassar sina önskemål efter detta faktum.Rapportens andra del behandlar den del av prioriteringarna som avser balansgången mellan önskemål om att få bedriva trafik i förhållande till behovet av att få tillgång till banan för underhåll. En aspekt på denna del av problematiken är att Trafikverket tar på sig en central roll för att definiera behovet av tillgång till banan.Den tredje delen av rapporten använder data från tågplaneringsprocessen. Den centrala analysen syftar till att undersöka i vilken utsträckning olika operatörer och olika tågslag (person- eller godståg) beviljas de tåglägen som söks. Analysen indikerar att en stor del av de tåglägen som sökts i tågplanearbetet de senaste två åren också har beviljats.En avslutande diskussion pekar på att det kan finnas skäl att under vissa förutsättningar skapa utrymme för att också operatörer och entreprenörer kommunicerar direkt med varandra.
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| 9. |
- Svanström, Rune, et al.
(author)
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Gradually losing one’s foothold : A fragmented existence when living alone with dementia
- 2015
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In: Dementia. - : Sage Publications. - 1471-3012 .- 1741-2684. ; 14:2, s. 145-163
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Journal article (peer-reviewed)abstract
- The number of persons with dementia who lives at home for a longer period of time after diagnosis is increasing. Even if the literature in the dementia field is growing, there is a need for more knowledge about everyday life of persons with a dementia disease; particularly the lived perspective of persons who live alone. The aim of this study was to elucidate the phenomenon of living alone with dementia and having a manifest care need. This phenomenological study was carried out from a reflective lifeworld approach. The data material in the study consisted of field notes from 32 visits and transcriptions from 11 tape-recorded conversations with six participants. The results reveal that the person with dementia who lives alone ends up in a vague existence where they cannot survive alone. The person’s level of activity comes to a halt and body movement becomes slower. Daily life becomes more difficult to manage and the person’s earlier natural way of relating to the world and the people around them is gradually lost. This is followed by a loneliness and forgetfulness that cloud the meaning of life. This study highlights the importance of the patient’s perspective needed to better understand the inner life of a person who suffers from dementia. This understanding is important in the organization of help and care as well as for caregivers to better understand these individuals and their needs.
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| 10. |
- Westin, Jonas, et al.
(author)
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Analyzing model uncertainty and economies of scale of the Swedish National Freight model to changes in transport demand
- 2016
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In: European Journal of Transport and Infrastructure Research. - : Editorial Board EJTIR. - 1567-7133 .- 1567-7141. ; 16:4, s. 619-632
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Journal article (peer-reviewed)abstract
- The purpose of the paper is to analyze model uncertainty and economies of scale of the Swedish national freight transport model system Samgods to changes in its zone-to-zone base matrices. Even though economies of scale is important for freight transport, few studies analyze model uncertainty and economies of scale at a national level. Compared to many large scale network-based freight models working on aggregated transport flows, an important feature in Samgods is that it simulates logistics behavior at a disaggregated firm level. The paper studies effects on total tonne- and vehicle-kilometre, modal split, consolidation and logistics costs when the base matrices are scaled up and down and estimates economies of scale for Swedish freight transports. The results indicate that the logistics model can find new logistics solutions for larger demand volumes, mainly by shifting freight to sea transport. If transport volume increases with one percent, average logistics cost per tonne is reduced by around 0.5 percent. Part of the cost reduction comes from increased consolidation of shipments due to larger transport volumes. The results derived in the paper can serve as a reference for empirical validation and comparisons with other large scale freight models. The paper is a first contribution that tries to fill the knowledge gap on the impact of base matrices on transport model outcomes, such as economies of scale, in the context of a full-fledged real-world freight transport model.
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