| 1. |
- Alriksson, Björn, et al.
(author)
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Fish feed from wood
- 2014
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In: Cellulose Chemistry and Technology. - 0576-9787. ; 48, s. 843-848
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Journal article (peer-reviewed)abstract
- Increased demand of fish in combination with overexploitation of the fish stocks of the oceans has led to an increased production of fish through aquaculture. Today, fishmeal is the main protein source in fish feed for most aquaculture species. However, fishmeal is soon expected to fall short of demand as its production is associated with environmental problems. This shortage must therefore be met by sustainable alternative protein sources. Protein-rich microorganisms (i.e. Single cell protein) is an interesting option as a fishmeal substitute in fish feed which, in addition, can be produced as an important co-product in wood-based biorefineries. In the current study, four different microorganisms were cultivated on five different residual streams from Swedish wood-based biorefineries. Screening experiments were carried out in shake flasks, optimization experiments in benchtop bioreactors, and scale-up experiments were performed in a 50-litre pilot bioreactor. In addition, a demo-scale experiment was carried out in the Swedish Biorefinery Demo Plant. Microbial biomass from the scale-up experiments was collected and used for production of different fish feed formulations which, in turn, were used in feeding trials of the freshwater fish Tilapia. Fishes fed with feed, in which part of the fishmeal had been substituted with Single cell protein, showed similar or better growth than fishes fed with a fishmeal-based control feed.
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| 2. |
- Gudnason, Asgeir, et al.
(author)
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All-Polyethylene Versus Metal-Backed Tibial Components-An Analysis of 27,733 Cruciate-Retaining Total Knee Replacements from the Swedish Knee Arthroplasty Register.
- 2014
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In: Journal of Bone and Joint Surgery. American Volume. - 1535-1386 .- 0021-9355. ; 96A:12, s. 994-999
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Journal article (peer-reviewed)abstract
- Currently, the use of metal-backed tibial components is more common than the use of all-polyethylene components in total knee arthroplasty. However, the available literature indicates that all-polyethylene tibial components are not inferior to the metal-backed design. We hypothesized that there would be no difference in the ten-year survival rate between all-polyethylene and metal-backed tibial components of a specific design in a large nationwide cohort.METHODS: In the Swedish Knee Arthroplasty Register, we identified 27,733 cruciate-retaining total knee replacements using the press-fit condylar prosthesis with either metal-backed or all-polyethylene tibial components inserted from 1999 to 2011. Unadjusted survival functions were calculated with the end points of revision for any reason, revision due to infection, and revision due to reasons other than infection, and the differences between the groups were investigated with the log-rank test. Cox proportional hazard models were fitted to analyze the influence of various covariates on the adjusted relative risk of revision.RESULTS: The median duration of follow-up was 4.5 years (range, zero to 12.9 years). Of all total knee replacements, 16,896 (60.9%) were in women and 10,837 (39.1%) were in men. Metal-backed components were used in 16,011 total knee arthroplasties (57.7%) and all-polyethylene in 11,722 total knee arthroplasties (42.3%). With revision for any reason as the end point, the all-polyethylene tibial component had slightly superior, unadjusted ten-year survival compared with the metal-backed component: 97.2% (95% confidence interval [CI], 96.7% to 97.7%) compared with 96.6% (95% CI, 96.2% to 96.9%; p = 0.002). Cox multiple regression analysis adjusting for age group, sex, and patellar resurfacing showed that all-polyethylene components had a reduced risk of revision for any reason (relative risk = 0.75; 95% CI, 0.64 to 0.89) and a reduced risk of revision due to infection (relative risk = 0.63; 95% CI, 0.46 to 0.86). Patellar resurfacing and male sex increased the risk of revision due to infection (relative risk = 2.22 [95% CI, 1.37 to 3.62] and 2.21 [95% CI, 1.66 to 2.94], respectively).CONCLUSIONS: These all-polyethylene tibial components were at least as good as or superior to metal-backed tibial components with respect to implant survivorship at ten years in cruciate-retaining total knee replacements. We concluded that these less expensive all-polyethylene tibial components can be safely and effectively used in total knee arthroplasty.LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
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| 3. |
- Gudnason, Asgeir, et al.
(author)
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Implant survival and outcome after rotating-hinge total knee revision arthroplasty : a minimum 6-year follow-up
- 2011
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In: Archives of Orthopaedic and Trauma Surgery. - : Springer Science and Business Media LLC. - 0936-8051 .- 1434-3916. ; 131:11, s. 1601-1607
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Journal article (peer-reviewed)abstract
- Introduction: Data on long-time survival and clinical function of rotating hinge knee prostheses used in revision total knee arthroplasty (TKA) are scarce. Method: We evaluate the outcome of 42 revision TKA in 38 patients using the Endo-model rotating hinge total knee prosthesis after a minimum of 6 years, with 10-year implant survival as our primary outcome measure. Only revision TKAs performed due to aseptic loosening were included, and the Swedish Knee Arthroplasty Register was consulted in order to ensure that patients unavailable for clinical follow-up had not been revised elsewhere. Mean follow-up was after 8.8 (6-18) years, mean age at revision surgery was 72 (55-88) years, and most patients had severe medical comorbidities (n = 31). Results: At follow-up, four knees had been re-revised due to aseptic loosening, and five further knees underwent re-revision due to other reasons. With implant revision due to aseptic loosening as the endpoint, 10-year survival was 89.2%, and with implant revision due to any reason 10-year survival was 65.1%. 11 patients (13 knees) eligible for clinical follow-up were evaluated according to the Hospital for Special Surgery score (HSSS), the Knee Society scores (KSS), and by plain radiography. Mean HSSS was 67 (36-90), mean KSS-knee was 85 (73-96), and mean KSS-function was 29 (0-100). Radiography showed that no implant was in need of revision. Conclusion: Our results indicate that revision arthroplasty of the knee with this rotating hinge prosthesis can be performed with satisfactory or good results in an elderly population with severe comorbidities.
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| 4. |
- Gudnason, Asgeir, et al.
(author)
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Tibial component rotation around the transverse axis measured by radiostereometry predicts aseptic loosening better than maximal total point motion A follow-up of 116 total knee arthroplasties after at least 15 years
- 2017
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In: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3674 .- 1745-3682. ; 88:3, s. 282-287
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Journal article (peer-reviewed)abstract
- Background and purpose - Maximal total point motion (MTPM) measured by radiostereometry (RSA) is widely used as a predictor of total knee arthroplasty (TKA) loosening. We compared the ability of different RSA measurements at different time points to predict loosening of tibial TKA components in the long term. Patients and methods - 116 TKAs in 116 patients were included in our analysis. 16 (14.8-17.4) years after surgery, 5 tibial components had been revised due to aseptic loosening. Receiver operating characteristic curves were calculated in order to investigate the specificity and sensitivity of different RSA parameters at different thresholds. Results - Rotation around the transverse (x-) axis measured 2 years postoperatively had the best predictive value of all parameters, with an area under the curve (AUC) of 80%. Using a threshold of 0.8 degrees, a specificity of 85% and a sensitivity of 50% were reached. The AUC for tibial component distal translation was 79% and it was 77% for proximal translation, whereas it was only 68% for MTPM. Interpretation - Rotation of the cemented tibial component around the transverse axis, proximal translation, and distal translation are slightly better at predicting aseptic loosening than MTPM, and tibial component migration measured after 2 years gives a good prediction of aseptic loosening up to 15 years.
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