Postoperative stability following a triple pelvic osteotomy is affected by implant configuration: a finite element analysis

BackgroundThe triple pelvic osteotomy is an established surgical method with multiple modifications regarding surgical technique and choice of implant. The stability of the osteotomy is affected by numerous factors, and among these, the three-dimensional implant configuration is a scientifically less explored aspect.MethodsWe used a finite element model of a hemi-pelvis with a standardized triple osteotomy to calculate relative flexibility for loads in all translational degrees of freedom for five different implant configurations. Two of the configurations used entry points only feasible when implant removal was not necessary.ResultsThe stability of the osteotomy improved with an increased distance between the implants in the plane of the osteotomy as well as for a more perpendicular angle relative to the osteotomy plane. The implant configurations with more entry points available made this easier to adhere to.ConclusionThe use of bioabsorbable implants may provide better opportunities for optimal implant constructs which can, to a certain degree, compensate for the lesser mechanical stiffness of bioabsorbable polymers as compared to metal implants

Bioabsorbable Screws for Pelvic Osteotomies in Children

Multiple conditions, with developmental dysplasia of the hip being a prime example, affect the congruity of the pediatric hip joint. A Salter osteotomy (SO) or a triple pelvic osteotomy (TPO) can be used to address suboptimal biomechanical conditions in the hip joint by improving containment and load distribution. Traditionally these osteotomies use metal implants to stabilize the osteotomy of the ilium, necessitating a second surgery for implant removal. If Kirschner-wires are used there are also risks related to wire migration and lack of stability. The general aim of this thesis was to explore the novel use of poly lactic-co-glycolic acid (PLGA) screws for osteotomy fixation in SO and TPO. The feasibility of this concept was examined regarding the stability of fixation as well as the biocompatibility of the implants. Bioabsorbable screws negate the need for implant removal which would be a major benefit for children. Study I reported on a novel surgical method for SO using PLGA screws instead of metal implants. A case series of 21 patients was reported on and the stability of the osteotomy fixation was evaluated using the post-operative radiographs. Migration percentage, acetabular index and center-edge angle were used to decide if an osteotomy collapsed or remained stable. In all patients but one the osteotomy remained stable and healed with maintained perioperative correction. There were no local reactions to the bioabsorption of the screws. Study II presented a retrospective analysis of the bioabsorption of 4.5mm PLGA screws as interpreted on Magnetic Resonance Imaging (MRI). Twelve patients who had undergone a SO or TPO with PLGA screws as the method of fixation were included. Eighteen MRIs were performed 0.5-4.5 years postoperatively and were analyzed according to eight parameters. After 2-4.5 years all screw canals were replaced with >90% bone with one exception where most, but not 90%, was replaced with bone. The local reactions seen during the bioabsorption were minor. Study III described a modified surgical method for TPO utilizing PLGA screws for the ilium osteotomy. A case series of 11 patients was reported on and the postoperative stability of the osteotomy was evaluated using migration percentage, acetabular index, center-edge angle as well as Sharp’s angle. The osteotomy angle (OA) was, as an addendum, suggested as a parameter to evaluate the integrity of an osteotomy. All patients maintained the initial correction and there were no signs of implant failure nor any local reactions to the implants. In Study IV the finite element method was used to analyze how different screw configurations affect stability in a TPO. Relative flexibility for loads in all translational degrees of freedom was calculated for five different screw configurations in a standardized hemi-pelvis. In two of these configurations the entry points used are only viable options if bioabsorbable implants are used. The screw configurations with a more perpendicular angle to the osteotomy and with a greater spread in the osteotomy plane between the screws resulted in increased stability. The use of bioabsorbable implants enables entry points that can provide improved biomechanical stability in a TPO. In summary, the presented studies support that 4.5 mm PLGA screws provide sufficient stability in SO and TPO in children with no major local reactions to the implants. After bioabsorption the screw canals were mostly replaced by bone and the use of bioabsorbable implants enables fixation configurations that seems to improve stability of the osteotomy. The use of bioabsorbable screws for pelvic osteotomies can eliminate suffering associated with a second surgery and save resources

Daily habitat shifts by the neotroplcal butterfly Manataria maculata (Nymphalidae: Satyrinae) is driven by predation

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Low carbohydrate high fat-diet in real life assessed by diet history interviews

Background: Low carbohydrate high fat (LCHF) diet has been a popular low carbohydrate diet in Sweden for 15 years. Many people choose LCHF to lose weight or control diabetes, but there are concerns about the effect on long-term cardiovascular risks. There is little data on how a LCHF diet is composed in real-life. The aim of this study was to evaluate the dietary intake in a population with self-reported adherence to a LCHF diet. Methods: A cross-sectional study of 100 volunteers that considered themselves eating LCHF was conducted. Diet history interviews (DHIs) and physical activity monitoring for validation of the DHIs were performed. Results: The validation shows acceptable agreement of measured energy expenditure and reported energy intake. Median carbohydrate intake was 8.7 E% and 63% reported carbohydrate intake at potentially ketogenic levels. Median protein intake was 16.9 E%. The main source of energy was dietary fats (72.0 E%). Intake of saturated fat was 32 E% and cholesterol was 700 mg per day, both of which exceeded the recommended upper limits according to nutritional guidelines. Intake of dietary fiber was very low in our population. The use of dietary supplements was high, and it was more common to exceed the recommended upper limits of micronutrients than to have an intake below the lower limits. Conclusions: Our study indicates that in a well-motivated population, a diet with very low carbohydrate intake can be sustained over time and without apparent risk of deficiencies. High intake of saturated fats and cholesterol as well as low intake of dietary fiber remains a concern

Mental health problems, sleep quality and overuse injuries in advanced Swedish rock-climbers - the CLIMB study.

OBJECTIVES: To examine the prevalence of mental health problems (depression, anxiety, and stress), sleep quality, and disability due to overuse injuries in advanced and elite rock-climbers. The rock-climbers were compared to a group of non-climbing controls. METHODS: A self-selected sample of advanced and elite Swedish rock-climbing athletes was recruited through the Swedish Rock-climbing Federation, local rock-climbing gyms and through social media. A control group, matched in size was recruited. Participants in the control group answered an online survey of validated questionnaires, examining symptoms of stress, anxiety, depression, sleep quality. The climbing participants answered the same survey as the non-climbing controls but with additional questions regarding musculoskeletal problems and disabilities related to these. Outcome measures used were the Depression Anxiety Stress Scale, Pittsburgh Sleep Quality Index and The Oslo Sports Trauma Research Center Overuse Injury Questionnaire. RESULTS: A total of 183 participants were included in the rock-climbing group, and 180 participants in the control group. In the rock-climbing group the mean age (SD) was 28.2 (8.3) years among women and 30.5 (9.6) years in men. The mean BMI of women was 21.2 (2.2) and 22.8 (2.1) in men. A total of 30.6% of the rock-climbing group (26.7% of men, 35.9% of women) reported at least moderate levels of symptoms of depression and 23.1% (17.2% men, 30.8% women) at least moderate levels of symptoms of anxiety. A total of 48.4% of rock-climbers (39.1% men, and 61.6% women) reported at least moderate levels of symptoms of stress. Among the rock-climbers, 45.0% reported having poor sleep quality. There were no statistical significant differences (p = 0.052-0.96) in mental health problems or sleeping problems between the rock-climbers and the controls. Among rock-climbers, reports of one-week prevalence of injury related problems was: Finger and hand (49.5%), Shoulder (35.2%), Knee (29.1%), Lumbar back (26.4%), Arm (25.3%), Thoracic back and neck (17.0%), and Foot and lower leg (12.1%). CONCLUSION: The overall results indicate high levels of symptoms of mental health problems and poor sleep quality in both rock-climbers and controls. Although no significant differences between the climbing group and the control group was displayed, symptoms that warrant clinical attention is high. Overuse injuries were commonly reported among the rock-climbers in all examined injury locations. Previous studies reporting mental health problems to be more prevalent among athletes were contradicted in this study. The results display the need for a broader perspective regarding climbers general health and the need to provide structured care and adequate support in order to come to terms with these concerns

Protocol for a 2-year longitudinal study of eating disturbances, mental health problems and overuse injuries in rock climbers (CLIMB).

INTRODUCTION: Rock climbing is a rapidly growing sport in which performance may be affected by participant's weight and leanness, and there may be pressure on athletes with respect to their eating behaviour and body weight. However, there is sparse research performed on climbers, constituting a knowledge gap which the present study aims to fill. The primary outcomes of the study are to examine disordered eating and overuse injuries in rock climbers. Secondary variables are body image, indicators of relative energy deficiency, mental health problems, compulsive training, perfectionism, sleep quality and bone density. METHOD AND ANALYSIS: This prospective longitudinal study aims to recruit Swedish competitive rock climbers (>13 years) via the Swedish Climbing Federation. A non-athlete control group will be recruited via social media (n=equal of the climbing group). Data will be collected using streamlined validated web-based questionnaires with three follow-ups over 2 years. Inclusion criteria for rock climbers will be a minimum advanced level according to International Rock-Climbing Research Association. The non-athlete control group is matched for age and gender. Exclusion criteria are having competed at an elite level in any sport as well as training more often than twice per week. Statistical analyses will include multinominal logistic regression, multivariate analysis of variance (MANOVA) and structural equation modelling (SEM). We will assess effect measure modification when relevant and conduct sensitivity analyses to assess the impact of lost to follow-up. ETHICS AND DISSEMINATION: The Rock-Climbers' Longitudinal attitudes towards Injuries, Mental health and Body image study, CLIMB, was approved by the Swedish ethics authority (2021-05557-01). Results will be disseminated through peer-reviewed research papers, reports, research conferences, student theses and stakeholder communications. TRIAL REGISTRATION NUMBER: NCT05587270

Association of frequent consumption of fatty fish with prostate cancer risk is modified by COX‐2 polymorphism

AbstractDietary intake of marine fatty acids from fish may protect against prostate cancer development. We studied this association and whether it is modified by genetic variation in cyclooxygenase (COX)‐2, a key enzyme in fatty acid metabolism and inflammation. We assessed dietary intake of fish among 1,499 incident prostate cancer cases and 1,130 population controls in Sweden. Five single nucleotide polymorphisms (SNPs) were identified and genotyped in available blood samples for 1,378 cases and 782 controls. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by multivariate logistic regression. Multiplicative and additive interactions between fish intake and COX‐2 SNPs on prostate cancer risk were evaluated. Eating fatty fish (e.g., salmon‐type fish) once or more per week, compared to never, was associated with reduced risk of prostate cancer (OR: 0.57, 95% CI: 0.43–0.76). The OR comparing the highest to the lowest quartile of marine fatty acids intake was 0.70 (95% CI: 0.51–0.97). We found a significant interaction (p < 0.001) between salmon‐type fish intake and a SNP in the COX‐2 gene (rs5275: +6365 T/C), but not with the 4 other SNPs examined. We found strong inverse associations with increasing intake of salmon‐type fish among carriers of the variant allele (OR for once per week or more vs. never = 0.28, 95% CI: 0.18–0.45; ptrend < 0.01), but no association among carriers of the more common allele. Frequent consumption of fatty fish and marine fatty acids appears to reduce the risk of prostate cancer, and this association is modified by genetic variation in the COX‐2 gene. © 2006 Wiley‐Liss, Inc