Medial congruent polyethylene design show different tibiofemoral kinematics and enhanced congruency compared to a standard symmetrical cruciate retaining design for total knee arthroplasty-an in vivo randomized controlled study of gait using dynamic radiostereometry.

PURPOSE: New total knee arthroplasty implant designs attempt to normalize kinematics patterns that may improve functional performance and patient satisfaction. It was hypothesized that a more medial congruent (MC) anatomic bearing design (1) influences the tibiofemoral kinematics and (2) enhances articular congruency compared to a standard symmetrical cruciate retaining (CR) bearing design. METHODS: In this double-blinded randomized study, 66 patients with knee osteoarthritis were randomly included in two groups: MC (n = 31) and CR (n = 33). Clinical characteristics such as knee ligament lesions and knee osteoarthritis scores were graded on preoperative magnetic resonance imaging and radiography. At the 1-year follow-up, dynamic radiostereometric analysis was used to assess tibiofemoral joint kinematics and articulation congruency. Patient-reported outcome measures, Oxford Knee Score, the Forgotten Joint Score, and the Knee Osteoarthritis Outcome Score, were assessed preoperatively and at the 1-year follow-up. RESULTS: Compared to the CR bearing, the MC bearing displayed an offset with approximately 3 mm greater anterior tibial drawer (p < 0.001) during the entire motion, and up to approximately 3.5 degrees more tibial external rotation (p = 0.004) from mid-swing to the end of the gait cycle at the 1-year follow-up. Furthermore, the congruency area in the joint articulation was larger during approximately 80% of the gait cycle for the MC bearing compared to the CR. The patient-reported outcome measures improved (p < 0.001), but there were no differences between groups. In addition, there were no differences in clinical characteristics and there were no knee revisions or recognized deep infections during follow-up. CONCLUSION: The study demonstrates that the MC-bearing design changes tibiofemoral kinematics and increases the area of congruency towards more native knee kinematics than the CR bearing. In perspective this may contribute to a more stabilized knee motion, restoring the patient's confidence in knee function during daily activities.

The national child odontology registry (SCOR): a valuable resource for odontological and public health research.

BACKGROUND: Since 1972 The National Child Odontology Registry has collected data on the oral health of most of all Danish children and adolescents. However, comprehensive information on the registry has not previously been available, making it difficult to approach and use the registry for research purposes. METHODS: By combining historical documentation and simple descriptive statistics we provide an overview of major events in the timeline of The National Child Odontology Registry and discuss how they impact the available data. We provide a broad overview of the dental variables in the registry, and how the registration criteria for some of the core dental variables (gingivitis, periodontitis, and dental caries) have changed over time. We then provide examples of how aggregate variables for the core dental diseases, allowing for comparison across registration criteria, can be created. RESULTS: Most of the Danish population born during or after 1965 have a least one entry in the National Child Odontology Registry, with 68% having entries spanning their entire childhood and adolescence. The prevalence of gingivitis and periodontitis seem to increase significantly in the years immediately following changes in how registration criteria for these variables, raising questions as to whether these diseases are generally underreported, or subject to overreporting in the years following the registration changes. The mandatory ages of registration instituted in 2003, do not appear to have had a strong impact on the ages at which registrations are made. For variables not directly comparable across datasets due to changes in registration criteria aggregate variables of measurements can be computed in most cases. CONCLUSIONS: The National Child Odontology Registry provides a unique opportunity to study the impact of childhood oral health on life trajectories, but using the registry is not without issues, and we strongly recommend consulting with experts in the field of odontology to ensure the best use of available data.

Exome sequencing reveals the first intragenic deletion in ABCA5 underlying autosomal recessive hypertrichosis.

BACKGROUND: Hereditary hypertrichosis (HH) is characterized by excessive hair growth on various body areas, which is independent of the individual's age. This rare hair disorder has been classified by its origin (genetic or acquired), age of onset, breadth of hair distribution (universal or localized) and the affected body areas. HH is often linked to several additional congenital abnormalities involving teeth, heart and bones. Human HH is associated with heterozygous genomic duplications and deletions in the chromosomal region 17q24.2-q24.3, containing genes such as ABCA5, ABCA6, ABCA10 and MAP2K6. Recently, a homozygous splice-site variant in ABCA5 has been reported to cause autosomal recessive congenital generalized hypertrichosis terminalis (CGHT; OMIM 135400). AIM: To investigate the clinical and genetic basis of autosomal recessive hypertrichosis in a large consanguineous Pakistani family. METHODS: In the present study, we characterized a family of Pakistani origin segregating CGHT in an autosomal recessive pattern, using whole exome sequencing followed by Sanger sequencing. RESULTS: We identified a novel 2-bp intragenic deletion [NM_172232.4(ABCA5);c.977_978delAT] causing a frameshift variant (p.His326ArgfsTer5) in ABCA5. CONCLUSIONS: To our knowledge, this is the first intragenic deletion in ABCA5 underlying CGHT. The findings further validate the involvement of ABCA5 in hair development. The study will facilitate genetic counselling of families carrying CGHT-related features in Pakistani and other populations.

Cemented and cementless dual mobility cups show similar fixation, low polyethylene wear, and low serum cobalt-chromium in elderly patients: a randomized radiostereometry study with 6 years' follow-up.

BACKGROUND AND PURPOSE: Dual mobility (DM) articulation total hip arthroplasty (THA) is used increasingly to reduce dislocation risk. We investigated cup fixation, polyethylene (PE) wear, serum chromium and cobalt ions, and their correlation to physical activity in patients with DM cups at 6-year follow-up. PATIENTS AND METHODS: In a patient-blinded RCT, 60 patients with hip osteoarthritis at a median age of 74 years (70-82) were randomly allocated to cemented (n = 30) or cementless hydroxyapatite-coated (n = 30) fixation of Avantage DM THA with a highly-crosslinked vitamin-E PE liner. Cup migration and PE wear were measured with radiostereometric analysis (RSA), chromium and cobalt ions were measured in serum, and physical activity was measured with accelerometers. RESULTS: At 6-year follow-up, proximal cup migration was similar: 0.14 mm (95% CI 0.01-0.28) for cemented cups and 0.21 mm (0.02-0.39) for cementless cups. The PE wear rate from 1- to 6-year follow-up was also similar: 0.06 mm/year (0.04-0.09) for cemented cups and 0.07 mm/year (0.04-0.11) for cementless cups. Serum metal ion levels were undetectable or very low. Physical activity was mainly low intensity and did not correlate to PE wear rate or cup migration. CONCLUSION: Cemented and cementless DM cups with highly crosslinked vitamin-E infused liners have similar cup migration and PE wear when used for primary THA surgery.

Gestational diabetes and the human salivary microbiota: a longitudinal study during pregnancy and postpartum.

BACKGROUND: An aberrant composition of the salivary microbiota has been found in individuals with type 2 diabetes, and in pregnant women salivary microbiota composition has been associated with preeclampsia and pre-term birth. Pregnant women, who develop gestational diabetes (GDM), have a high risk of developing type 2 diabetes after pregnancy. In the present study we assessed whether GDM is linked to variation in the oral microbial community by examining the diversity and composition of the salivary microbiota. METHOD: In this observational study the salivary microbiota of pregnant women with GDM (n = 50) and normal glucose regulation (n = 160) in third trimester and 9 months postpartum was assessed by 16S rRNA gene amplicon sequencing of the V1-V3 region. GDM was diagnosed in accordance with the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criteria. Cross-sectional difference in alpha diversity was assessed using Student's t-test and longitudinal changes were assessed by mixed linear regression. Cross-sectional and longitudinal difference in beta diversity was assessed by permutational multivariate analyses of variance. Differentially abundant genera and OTUs were identified by negative binomial regression. RESULTS: In the third trimester, two species-level operational taxonomic units (OTUs), while eight OTUs postpartum were differentially abundant in women with GDM compared with normoglycaemic women. OTU richness, Shannon diversity and Pielou evenness decreased from late pregnancy to 9 months after delivery regardless of glycaemic status. CONCLUSION: GDM is associated with a minor aberration of the salivary microbiota during late pregnancy and postpartum. For unknown reasons richness of the salivary microbiota decreased from late pregnancy to postpartum, which might be explained by the physiological changes of the immune system during human pregnancy.

Inferior stabilization of cementless compared with cemented dual-mobility cups in elderly osteoarthrosis patients: a randomized controlled radiostereometry study on 60 patients with 2 years' follow-up.

Background and purpose - Elderly patients may benefit from a dislocation low-risk dual-mobility (DM) articulation in total hip arthroplasty, but the best cup fixation method is unknown. We compared cup migration for cemented and cementless DM cups using radiostereometry.Patients and methods - In a patient-blinded randomized trial, 60 patients (33 female) with osteoarthritis were allocated to cemented (n = 30) or cementless (n = 30) Avantage DM cup fixation. Criteria were age above 70 years, and T-score above -4. We investigated cup migration, periprosthetic bone mineral density (BMD), and patient-reported outcome measures (PROMs) until 24 months postoperative follow-up.Results - At 24 months mean proximal cup migration was 0.11 mm (95% CI 0.00-0.23) for cemented cups and 0.09 mm (CI -0.09 to 0.28) for cementless cups. However, cementless cups generally migrated more than cemented cups at 12 and 24 months. Cemented cups had no measurable migration from 3 months' follow-up, while cementless cups had not yet stabilized at 24 months in all rotations. Cementless cups showed statistically significantly more maximum total point motion (MTPM) at 12- and 24-month follow-up compared with cemented cups in patients with low systemic BMD (p = 0.01). Periprosthetic BMD changes did not statisticially significantly correlate to proximal migration in either cup fixation group (p > 0.05). PROMs improved similarly in both groups.Interpretation - Cemented cups were well fixed at 3 months. The cementless cups migrated more in patients with low BMD, showed an inconsistent pattern of migration, and migrated in different directions during the first and second year without tendency to stabilization. Cemented fixation of the Avantage DM cup seems safer in elderly patients.

Dietary modulation of the gut microbiota--a randomised controlled trial in obese postmenopausal women.

The gut microbiota has been implicated in obesity and its progression towards metabolic disease. Dietary interventions that target the gut microbiota have been suggested to improve metabolic health. The aim of the present study was to investigate the effect of interventions with Lactobacillus paracasei F19 or flaxseed mucilage on the gut microbiota and metabolic risk markers in obesity. A total of fifty-eight obese postmenopausal women were randomised to a single-blinded, parallel-group intervention of 6-week duration, with a daily intake of either L. paracasei F19 (9.4 × 1010 colony-forming units), flaxseed mucilage (10 g) or placebo. Quantitative metagenomic analysis of faecal DNA was performed to identify the changes in the gut microbiota. Diet-induced changes in metabolic markers were explored using adjusted linear regression models. The intake of flaxseed mucilage over 6 weeks led to a reduction in serum C-peptide and insulin release during an oral glucose tolerance test (P< 0.05) and improved insulin sensitivity measured by Matsuda index (P< 0.05). Comparison of gut microbiota composition at baseline and after 6 weeks of intervention with flaxseed mucilage showed alterations in abundance of thirty-three metagenomic species (P< 0.01), including decreased relative abundance of eight Faecalibacterium species. These changes in the microbiota could not explain the effect of flaxseed mucilage on insulin sensitivity. The intake of L. paracasei F19 did not modulate metabolic markers compared with placebo. In conclusion, flaxseed mucilage improves insulin sensitivity and alters the gut microbiota; however, the improvement in insulin sensitivity was not mediated by the observed changes in relative abundance of bacterial species.

Genome-wide association study identifies host genetic variants influencing oral microbiota diversity and metabolic health.

The microbial communities of the oral cavity are important elements of oral and systemic health. With emerging evidence highlighting the heritability of oral bacterial microbiota, this study aimed to identify host genome variants that influence oral microbial traits. Using data from 16S rRNA gene amplicon sequencing, we performed genome-wide association studies with univariate and multivariate traits of the salivary microbiota from 610 unrelated adults from the Danish ADDITION-PRO cohort. We identified six single nucleotide polymorphisms (SNPs) in human genomes that showed associations with abundance of bacterial taxa at different taxonomical tiers (P < 5 × 10-8). Notably, SNP rs17793860 surpassed our study-wide significance threshold (P < 1.19 × 10-9). Additionally, rs4530093 was linked to bacterial beta diversity (P < 5 × 10-8). Out of these seven SNPs identified, six exerted effects on metabolic traits, including glycated hemoglobin A1c, triglyceride and high-density lipoprotein cholesterol levels, the risk of type 2 diabetes and stroke. Our findings highlight the impact of specific host SNPs on the composition and diversity of the oral bacterial community. Importantly, our results indicate an intricate interplay between host genetics, the oral microbiota, and metabolic health. We emphasize the need for integrative approaches considering genetic, microbial, and metabolic factors.

Combination of zoledronic Acid and targeted therapy is active but may induce osteonecrosis of the jaw in patients with metastatic renal cell carcinoma.

PURPOSE: To investigate the efficacy and safety of zoledronic acid (ZA) combined with targeted therapy (TT). MATERIALS AND METHODS: A retrospective study was performed in patients with metastatic renal cell carcinoma treated with ZA and TT. RESULTS: Twenty-one patients received ZA and TT to prevent skeletal-related events and no pretherapy oral and maxillofacial (OM) examination (cohort A). Six patients (29%) developed osteonecrosis of the jaw (ONJ), which was observed only in patients receiving sunitinib and ZA. Sixteen patients received TT and ZA for hypercalcemia and no pretherapy OM examination (cohort B). In these patients, no ONJ was observed. Nine patients received ZA and TT and pretherapy OM examination (cohort C). One patient (11%) developed ONJ during sunitinib and ZA treatment. Mean skeletal morbidity rates were 0.8 for cohort A and 1.2 for cohort C. In the combined cohort (A plus C; n = 30), 47% developed skeletal-related events, 7% pathologic fracture, 7% medullary compression, and 37% progression of bone metastases. Patients who developed ONJ had a significantly improved median survival of 31.6 months compared with 14.5 months in patients without ONJ (P = .039). CONCLUSION: The combination of ZA and TT resulted in high, clinically meaningful activity. ONJ may be exacerbated by concomitant ZA and sunitinib. Regular OM examinations before and during treatment are recommended.

Early detection of childhood overweight and related complications in a Danish population-based cohort aged 2-8 years.

BACKGROUND: Overweight in early childhood often tracks into adolescence and adulthood and early childhood is a critical period for developing sustained overweight. This study aims to investigate the early detection of childhood overweight (including obesity) and related cardiometabolic complications in a Danish population-based cohort of children aged 2.5-8 years in collaboration with primary care municipal dental clinics and public health nurses. METHODS: In this prospective population-based cohort study, 335 pre-school children (age 2.5 and 5 years) were recruited from municipal dental clinics, and 657 school children (age 6-8 years) by public health nurses. A subgroup of 392 children (40%) participated in additional hospital-based examinations including blood pressure measurement and a blood sample. Children were re-examined approximately one year later. RESULTS: The prevalence of overweight was 13.73% in pre-school children and 13.69% in school children at baseline. In the pre-school children, differences in cardiometabolic risk markers between children with and without overweight were minor, whereas in school children with overweight, cardiometabolic derangements were manifest including significantly higher levels of fasting glucose, insulin, homoeostasis model of assessment for insulin resistance, triglycerides, and alanine aminotransferase and lower levels of high-density lipoprotein cholesterol. During follow-up the prevalence of overweight did not change in pre-school children but increased to 17.0% in school children. CONCLUSIONS: Existing contacts with the primary health care sector, including dental care, can successfully be used for detection of overweight. This study suggests that early detection should be initiated at pre-school ages since overweight-related complications are already established by school ages.

Elektra trapeziometacarpal prosthesis for treatment of osteoarthrosis of the basal joint of the thumb.

The first reports about treating osteoarthrosis of the trapeziometacarpal (TMC) joint with the Elektra prosthesis were encouraging. Based on those, we operated on 17 hands in 16 patients with Eaton stage 3+4 osteoarthritis of the TMC joint using the Elektra hydroxyapatite-coated uncemented TMC prosthesis. There were 15 women and one man, mean age 54 years (range 40-70). At follow-up after 35 months (range 22-52), four patients had been reoperated on because of aseptic loosening of the screw cup with migration and progressive pain. Two other patients have been revised because the implant had to be removed for other reasons. At radiological follow-up in the 11 other patients, one cup had migrated and was clearly loose, leaving 10 implants with no sign of failure. Part of this mediocre result may be explained by the learning curve, but more studies are needed to confirm the excellent results obtained elsewhere with the Elektra prosthesis, and we advise others to monitor their results carefully when using this implant. Studies comparing joint replacement with resection arthroplasty are also needed.

Impact of a vegan diet on the human salivary microbiota.

Little is known about the effect of long-term diet patterns on the composition and functional potential of the human salivary microbiota. In the present study, we sought to contribute to the ongoing elucidation of dietary effects on the oral microbial community by examining the diversity, composition and functional potential of the salivary microbiota in 160 healthy vegans and omnivores using 16S rRNA gene amplicon sequencing. We further sought to identify bacterial taxa in saliva associated with host inflammatory markers. We show that compositional differences in the salivary microbiota of vegans and omnivores is present at all taxonomic levels below phylum level and includes upper respiratory tract commensals (e.g. Neisseria subflava, Haemophilus parainfluenzae, and Rothia mucilaginosa) and species associated with periodontal disease (e.g. Campylobacter rectus and Porphyromonas endodontalis). Dietary intake of medium chain fatty acids, piscine mono- and polyunsaturated fatty acids, and dietary fibre was associated with bacterial diversity, community structure, as well as relative abundance of several species-level operational taxonomic units. Analysis of imputed genomic potential revealed several metabolic pathways differentially abundant in vegans and omnivores indicating possible effects of macro- and micro-nutrient intake. We also show that certain oral bacteria are associated with the systemic inflammatory state of the host.

Higher UHMWPE wear-rate in cementless compared with cemented cups with the Saturne® Dual-Mobility acetabular system.

INTRODUCTION: Dual mobility (DM) total hip arthroplasty (THA) may reduce dislocation risk, but might increase the risk of high polyethylene (PE) wear due to double wearing surfaces. METHODS: 127 patients (97 female) with 129 hips operated with THA after displaced femoral neck fracture FNF between 2005 and 2011, were seen for a cross-sectional clinical follow-up. Acetabular components were Saturne® DM cups with 28mm chrome-cobalt heads in UHMWPE. Cementless cups (n = 73) were hydroxyapatite coated. Radiographs were obtained for analysis of cup placement, 2D polyethylene wear and wear-rate (PolyWare 3D), and further radiological evaluation. Activity measurements included Timed Up and Go test (TUG) and walking distance from Harris Hip Score (HHS). RESULTS: At a mean follow-up of 2.83 (1.0-7.7) years the mean wear was 0.82 mm (range 0.17-4.51, SD 0.50), and the wear-rate was 0.37 mm (range 0.06-1.90, SD 0.29). Wear-rate of 0.43 mm/year (SD 0.30) in cementless cups was higher (p = 0.004) than 0.30 mm/year (SD 0.27) in cemented cups. Mean age at time of surgery was 75.1 years (range 30-95). There was no correlation between age at time of surgery and wear (p = 0.56). There was no correlation between cup inclination and wear-rate (p = 0.35). TUG was mean 13.4 seconds (range 4.5-30.1) and correlated with wear rate (p = 0.03). CONCLUSIONS: At short term follow-up, the mean wear-rate in old and low demand patients was high, correlated to activity, and was above the generally accepted osteolysis threshold (0.1 mm/yr.). Cementless HA-coated cups had higher wear-rate than cemented cups.

Trapeziectomy or revision into a cemented polyethylene cup in failed trapeziometacarpal total joint arthroplasty.

OBJECTIVES: Total joint replacement as treatment of osteoarthritis of the trapeziometacarpal joint may lead to excellent short-term results, but also with a high risk of failure of the trapezium component. The aim of this study was to compare revision using trapeziectomy with a revision into a cemented trapezium cup. METHODS: Thirty-four patients with a mean follow-up time of 47 months were included in a case control study with 17 hands revised with a cemented cup and 21 trapeziectomy. RESULTS: At follow-up, no significant difference was found in self-reported outcome, with pain at rest or activity and in grip strength comparing patients revised using trapeziectomy with patients revised with insertion of a new cup. There was, however, a high risk of re-revision in patients treated with insertion of a new cup and at the follow-up 4/17 cups had been re-revised and 5/17 cups had radiological signs of implant loosening. CONCLUSION: IT was found that trapeziectomy should be the standard salvage procedure after a failed trapezium implant and revision of cup loosening with a cemented cup has an unacceptable failure rate.

Higher wear-rate of third-generation metal-backed Reflection cups with eto-sterilised UHMWPE at a mean 13 years follow-up.

Polyethylene (PE) wear and osteolysis is a recognised problem with non-cross linked PE liners and first generation modular cup designs. Wear particles induce osteolysis leading to aseptic loosening. We retrospectively compared the linear PE wear and implant survival and revision rates of the Reflection Cup and the Duraloc 300. After a mean clinical follow-up of 13 years (range 11-15 years), the 2D linear PE wear-rate of the Reflection liner (n = 68) was 0.23 mm/year, with a mean total wear of 3.14 mm (1.04-7.36), SD 1.45. The wear-rate of the Duraloc 300 cups (n = 32) was 0.14 mm/year, with a mean total wear of 1.84 mm (0.55-4.63), SD 1.07. The difference in PE wear-rate as well as mean total wear was highly significant (p = 0.0001). There was a positive correlation between wear-rate and both Oxford Hip Score and Harris Hip Score (p = 0.02). Large acetabular cup size (>54 mm), HA coating on the stem and age <50 years did not influence PE wear. The higher wear-rate in the Reflection liners could be related to the EtO sterilisation. Intermediate and long-term follow-up is advisable.

Acceptable long-term results after Boneloc hip arthroplasty.

INTRODUCTION: As the only femoral stem, the Exeter stem has shown acceptable results with Boneloc cement, but no long-term results have been published. The aim of this study was to evaluate the 20-year performance of Boneloc-cemented primary Exeter hip arthroplasty. MATERIAL AND METHODS: From March 1992 to June 1994, a total of 200 consecutive Boneloc-cemented primary hip arthroplasties were performed in 183 patients aged 26-90 years, mean 71 years. At follow-up after 18-20 years, the primary endpoint was prosthetic survival assessed by the Kaplan-Meier analysis. Secondary endpoints were clinical and radiographic follow-up examination. RESULTS: After a mean 18.4 (17.6-19.6)-year period, 27 patients/32 hips had been revised. At endpoint revision for any reason the 20-year cumulative overall survival was 73% (95% confidence interval (CI): 49-89%); at endpoint revision for aseptic loosening the 20-year cumulative survival was 84% (95% CI: 68-96%) for the stem and 76% (95% CI: 61-92%) for the cup. Cementing technique, implant size and metal backing of the cup were not associated with revision rates. A total of 23 patients/24 hips had clinical/radiographic examination, and 10 patients/12 hips were assessed by telephone. According to patient reported evaluation, all were very satisfied or satisfied. Radiographs showed loosening of two cups and possible loosening of two stems. CONCLUSION: This study provides the first long-term results on Boneloc-cemented primary hip arthroplasty. The Exeter prosthesis, especially the stem, maintains the previously published acceptable survival and results despite the documented inferior quality of the cement. FUNDING: not relevant. TRIAL REGISTRATION: not relevant.