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- Halvorsen, V., et al.
(författare)
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Outcome of 881 total hip arthroplasties in 747 patients 21 years or younger: data from the Nordic Arthroplasty Register Association (NARA) 1995-2016
- 2019
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Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3674 .- 1745-3682. ; 90:4, s. 331-337
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose - The literature is scarce on the outcome of the youngest patients with total hip arthroplasties (THAs). We analyzed register data, revision risk, and related factors in patients 21 years or younger with THAs in the Nordic Arthroplasty Register Association (NARA). Patients and methods - We included all THA patients 21 years or younger reported during 1995 through 2016 to the Danish, Finnish, Norwegian, and Swedish hip arthroplasty registers and merged these into the NARA dataset. Primary outcome was any implant revision. Results - We identified 881 THAs in 747 patients. Mean age at primary surgery was 18 years (9-21). The indications for THA were pediatric hip diseases (33%), systemic inflammatory disease (23%), osteoarthritis (4%), avascular necrosis (12%), hip fracture sequelae (7%), and other diagnoses (21%). Unadjusted 10-year survival for all THAs was 86%. Comparison between indications showed no differences in survival. Uncemented implants were used most frequently. Survival for uncemented and cemented implants was the same adjusted for sex, indication, head size, and time period for primary surgery. Aseptic loosening was the main cause of revision. Interpretation - Both cemented and uncemented fixations seem to be a viable option in this age group, but with a lower implant survival than in older patient groups.
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| 6. |
- Kaastad, T S, et al.
(författare)
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Effect of intensive training on lower leg structural strength: an in vivo study in ovariectomized rats
- 1997
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Ingår i: Scandinavian Journal of Medicine & Science in Sports. - : Wiley. - 1600-0838 .- 0905-7188. ; 7:4, s. 220-225
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the effect of training on the in vivo tibial structural strength during the development of post-ovariectomy osteoporosis. Seventeen mature Wistar rats (215 g) were ovariectomized and randomized into two groups. The sedentary control group was kept cage confined, while 3 days postoperatively the trained group started treadmill running with high intensity for 1 h 5 days a week. All were given a low calcium diet (Ca 0.01%). After 8 weeks the animals were anaesthetized and the right lower legs fractured during muscle contraction in three-point ventral bending. The left legs were fractured at the same level after removal of all soft tissues. Histomorphometry of the meta- and diaphysis of the distal tibiae was performed. Weight-gain was higher in sedentary (108 g) than in trained (61 g) rats (P<0.0001). There were no significant differences in mechanical results between the groups at in vivo or in vitro fracture. Correcting for weight-gain differences did not change these results. Histomorphometry showed no differences between the groups. Corticosterone was higher in trained than in sedentary rats (P<0.02), and corticosterone may have had a negative influence both on muscle and bone. The study could not show an effect of high intensity training in the early phase after ovariectomy on in vivo or in vitro fracture strength.
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| 7. |
- Kaastad, T S, et al.
(författare)
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Effects of clodronate on cortical and trabecular bone in ovariectomized rats on a low calcium diet
- 1997
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 1432-0827 .- 0171-967X. ; 61:2, s. 158-164
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate the contribution of a low calcium diet to the cortical and trabecular osteoporosis seen in ovariectomized rats after 7 weeks on a low calcium diet and to investigate the effects of the bisphosphonate clodronate on this development of osteoporosis. Thirty-six mature, female Wistar rats were randomized into four groups: Ovx-B (bisphosphonate) and Ovx-C (control) were ovariectomized, and Sham-Ca (low calcium) and Sham+Ca (normal calcium) were sham operated. The first three groups were fed a low calcium diet (0.01%) and Sham+Ca normal rat chow (Ca 1.1%). The Ovx-B received 10 mg/kg s.c. clodronate daily for nine weeks, and Ovx-C, Sham-Ca, and Sham+Ca received the same volumes of saline. Bone mineral turnover measured as 85Sr-uptake was increased in all low calcium groups compared to Sham+Ca. The Sham+Ca femora had higher dry weight and ash weight than the other groups, and Ovx-C had higher dry weight compared with Ovx-B and Sham-Ca. Calcium content was lower in both Ovx groups compared to both Sham groups. Magnesium was lower in all groups compared to Sham+Ca and higher in Ovx-B compared with Ovx-C. In the femoral shaft, Sham+Ca had significantly higher ultimate bending moment, energy absorption, and deflection compared to the other three groups. Ultimate bending moment was higher in Sham-Ca than in Ovx-C. Stiffness was increased in both Sham+Ca and Ovx-B compared to Ovx-C. The maximum stress in the femoral midshaft was higher in Sham+Ca than in the other groups, and higher in Ovx-B than in Ovx-C. Histomorphometry showed increased medullary area in all low calcium groups compared to Sham+Ca and larger cortical area in Sham+Ca and Ovx-B compared to Ovx-C. Compared to Sham+Ca the trabecular bone volume was decreased to 30% in Sham-Ca and to 9% in Ovx-C, but was unchanged in Ovx-B. The low calcium diet generally increased bone mineral turnover and reduced the tibial bone volume. Femoral changes led to a reduction of cortical fracture strength and maximal stress. Ovariectomy in addition to a low calcium diet reduced femoral strength even more. Daily injections of clodronate to ovariectomized rats on a low calcium diet increased femoral shaft stiffness and maximum stress, and clodronate preserved both trabecular and cortical tibial bone volume completely.
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| 8. |
- Kaastad, T S, et al.
(författare)
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Vitamin D deficiency and ovariectomy reduced the strength of the femoral neck in rats
- 2001
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Ingår i: Calcified Tissue International. - : Springer Science and Business Media LLC. - 1432-0827 .- 0171-967X. ; 69:2, s. 102-108
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Tidskriftsartikel (refereegranskat)abstract
- Vitamin D (vit D) deficiency is common in the elderly, and the aim of this study was to investigate whether vit D deprivation in ovariectomized (ovx) and normal rats would reduce fracture strength. Forty mature female Wistar rats were randomized into four groups: two were ovariectomized (ovx) and two were sham-operated (sham). One ovx and one sham group were fed a vit D-deficient diet (Ovx-D and Sham-D), and the control groups were fed normal rat chow (Ovx and Sham) for 12 weeks. Vit D deficiency was substantiated after 12 weeks by undetectable serum concentrations of 25OHD in the Sham-D and Ovx-D groups. 85Sr activity was lower in Sham-D than in the other groups (P < 0.005). Tibial and femoral weights and lengths showed no differences. Distal tibial trabecular bone volume was reduced in both ovx groups compare with sham (P < 0.005). Bone mineral density (BMD) was higher in sham than in Sham-D and both ovx groups (P < 0.005). Femoral area moment of inertia increased and ultimate stress decreased in Ovx-D compared with ovx (P < 0.05). Other biomechanical properties of the femoral shafts did not differ significantly. The femoral neck was significantly weaker in Ovx-D than in the other groups. In conclusion, ovx decreased tibial trabecular bone volume and both ovx and vit D depletion reduced femoral BMD in rats. Vit D depletion reduced the ultimate stress in the femoral shaft, and the combined depletion of estrogen and vit D significantly reduced the fracture strength in the femoral neck. This fits well with clinical evidence of how postmenopausal status combined with vit D deficiency lead to an increased risk of hip fractures, making this animal model a possible tool for investigating measures to prevent such fractures.
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| 9. |
- Marlevi, David, doktorand, et al.
(författare)
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Altered Aortic Hemodynamics and Relative Pressure in Patients with Dilated Cardiomyopathy
- 2021
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Ingår i: Journal of Cardiovascular Translational Research. - : Springer Nature. - 1937-5387 .- 1937-5395.
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Tidskriftsartikel (refereegranskat)abstract
- Ventricular-vascular interaction is central in the adaptation to cardiovascular disease. However, cardiomyopathy patients are predominantly monitored using cardiac biomarkers. The aim of this study is therefore to explore aortic function in dilated cardiomyopathy (DCM). Fourteen idiopathic DCM patients and 16 controls underwent cardiac magnetic resonance imaging, with aortic relative pressure derived using physics-based image processing and a virtual cohort utilized to assess the impact of cardiovascular properties on aortic behaviour. Subjects with reduced left ventricular systolic function had significantly reduced aortic relative pressure, increased aortic stiffness, and significantly delayed time-to-pressure peak duration. From the virtual cohort, aortic stiffness and aortic volumetric size were identified as key determinants of aortic relative pressure. As such, this study shows how advanced flow imaging and aortic hemodynamic evaluation could provide novel insights into the manifestation of DCM, with signs of both altered aortic structure and function derived in DCM using our proposed imaging protocol. Graphic Abstractr: [Figure not available: see fulltext.].
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