Trends in arthroscopy-documented cartilage injuries of the knee and repair procedures among 15-60-year-old patients

We validated a registry-based method of identifying patients with knee cartilage injury and estimated temporal changes in the incidence of arthroscopy-documented cartilage injuries of the knee and the proportion leading to repair procedures in Denmark. After excluding patients with diagnosed osteoarthritis, we identified 21,392 patients aged 15-60 years with a first recorded procedure code indicating knee cartilage injury in the Danish National Registry of Patients (DNRP) from 1996 to 2011. Using the surgical descriptions of arthroscopy findings in medical records as gold standard, the positive and negative predictive value of procedure codes for knee cartilage injury was 88% and 99%, respectively. The arthroscopy-documented overall incidence of cartilage injury of the knee was 40/100,000 person-years (py) [95% confidence interval (CI): 39.5-40.6] during the period 1996-2011. The arthroscopy-documented age-standardized annual incidence of knee cartilage injury increased from 22 (95% CI: 20.5-23.7) in 1996 to 61 (95% CI: 58.7-64.0) in 2011, per 100,000 py. An increase occurred in all age groups and both sexes. Only 1/6 (17%) patients with knee cartilage injury had a repair procedure. The validity of procedure codes for knee cartilage injury in the DNRP is high. The arthroscopy-documented incidence of knee cartilage injuries increased substantially during the 15-year period.

The association between BMI and hospitalization for heart failure in 83,021 persons with Type 2 diabetes: a population-based study from the Swedish National Diabetes Registry

AIM'S

The aim was to To study the relationship between BMI and hospitalization for heart failure in people with Type 2 diabetes.

METHODS

We identified 83 021 individuals with Type 2 diabetes from the Swedish National Diabetes Registry during 1998-2003, who were followed until hospitalization for heart failure, death or end of follow-up on 31 December 2009. Cox regression analyses were performed, adjusting for age, sex, HbA(1c), blood pressure, diabetes duration, smoking, microalbuminuria, cardiac co-morbidities, glucose-lowering and anti-hypertensive medications.

RESULTS

During a median follow-up of 7.2 years, 10 969 patients (13.2%) were hospitalized with heart failure. By categories of BMI, with BMI 20 to < 25 kg/m(2) as the reference, hazard ratios for patients during follow-up were 1.07 (95% CI 0.91-1.26) for a mean BMI of < 20 kg/m(2), 1.04 (95% CI 0.98-1.11) for BMI 25 to < 27.5 kg/m(2), 1.22 (95% CI 1.15-1.30) for BMI 27.5 to < 30 kg/m(2), 1.54 (95% CI 1.45-1.63) for BMI 30 to < 35 kg/m(2), 2.16 (95% CI 2.00-2.33) for BMI 35 to < 40 kg/m(2) and 3.22 (95% CI 2.88-3.60) for BMI 40 kg/m(2) or higher. There was a significant interaction between BMI and sex (P = 0.0006), with numerically higher hazard ratios for hospitalization for heart failure within each BMI category for men than for women.

CONCLUSIONS

Obesity is strongly related to hospitalization for heart failure in people with Type 2 diabetes, and the relationship is somewhat stronger for men than for women. Preventing weight gain and promoting weight loss may be crucial in reducing the incidence of future hospitalizations for heart failure in this population.

Distribution and evolution of het gene homologs in the basidiomycota

In filamentous fungi a system known as somatic incompatibility (SI) governs self/non-self recognition. SI is controlled by a regulatory signaling network involving proteins encoded at the het (heterokaryon incompatible) loci. Despite the wide occurrence of SI, the molecular identity and structure of only a small number of het genes and their products have been characterized in the model fungi Neurospora crassa and Podospora anserina. Our aim was to identify and study the distribution and evolution of putative het gene homologs in the Basidiomycota. For this purpose we used the information available for the model fungi to identify homologs of het genes in other fungi, especially the Basidiomycota. Putative het-c, het-c2 and un-24 homologs, as well as sequences containing the NACHT, HET or WD40 domains present in the het-e, het-r, het-6 and het-d genes were identified in certain members of the Ascomycota and Basidiomycota. The widespread phylogenetic distribution of certain het genes may reflect the fact that the encoded proteins are involved in fundamental cellular processes other than SI. Although homologs of het-S were previously known only from the Sordariomycetes (Ascomycota), we also identified a putative homolog of this gene in Gymnopus luxurians (Basidiomycota, class Agaricomycetes). Furthermore, with the exception of un-24, all of the putative het genes identified occurred mostly in a multi-copy fashion, some with lineage and species-specific expansions. Overall our results indicated that gene duplication followed by gene loss and/or gene family expansion, as well as multiple events of domain fusion and shuffling played an important role in the evolution of het gene homologs of Basidiomycota and other filamentous fungi.

Mortality trends in patients with and without diabetes in Ontario, Canada and the UK from 1996 to 2009: a population-based study

AIMS/HYPOTHESIS

The aim of this study was to determine the contemporary rate ratio of mortality and changes over time in individuals with vs without diabetes.

METHODS

Annual age- and sex-adjusted mortality rates were compared for adults (>20 years) with and without diabetes in Ontario, Canada, and the UK from January 1996 to December 2009 using The Health Improvement Network (THIN) and Ontario databases. The total number of individuals evaluated increased from 8,757,772 in 1996 to 12,696,305 in 2009.

RESULTS

The excess risk of mortality for individuals with diabetes in both cohorts was significantly lower during later vs earlier years of the follow-up period (1996-2009). In Ontario the diabetes mortality rate ratio decreased from 1.90 (95% CI 1.86, 1.94) in 1996 to 1.51 (1.48, 1.54) in 2009, and in THIN from 2.14 (1.97, 2.32) to 1.65 (1.57, 1.72), respectively. In Ontario and THIN, the mortality rate ratios among diabetic patients in 2009 were 1.67 (1.61, 1.72) and 1.81 (1.68, 1.94) for those aged 65-74 years and 1.11 (1.10, 1.13) and 1.19 (1.14, 1.24) for those aged over 74 years, respectively. Corresponding rate ratios in Ontario and THIN were 2.45 (2.36, 2.54) and 2.64 (2.39, 2.89) for individuals aged 45-64 years, and 4.89 (4.35, 5.45) and 5.18 (3.73, 6.69) for those aged 20-44 years.

CONCLUSIONS/INTERPRETATION

The excess risk of mortality in individuals with vs without diabetes has decreased over time in both Canada and the UK. This may be in part due to earlier detection and higher prevalence of early diabetes, as well as to improvements in diabetes care.

Isolation of native soil microorganisms with potential for breaking down biodegradable plastic mulch films used in agriculture

Fungi native to agricultural soils that colonized commercially available biodegradable mulch (BDM) films were isolated and assessed for potential to degrade plastics. Typically, when formulations of plastics are known and a source of the feedstock is available, powdered plastic can be suspended in agar-based media and degradation determined by visualization of clearing zones. However, this approach poorly mimics in situ degradation of BDMs. First, BDMs are not dispersed as small particles throughout the soil matrix. Secondly, BDMs are not sold commercially as pure polymers, but rather as films containing additives (e.g. fillers, plasticizers and dyes) that may affect microbial growth. The procedures described herein were used for isolates acquired from soil-buried mulch films. Fungal isolates acquired from excavated BDMs were tested individually for growth on pieces of new, disinfested BDMs laid atop defined medium containing no carbon source except agar. Isolates that grew on BDMs were further tested in liquid medium where BDMs were the sole added carbon source. After approximately ten weeks, fungal colonization and BDM degradation were assessed by scanning electron microscopy. Isolates were identified via analysis of ribosomal RNA gene sequences. This report describes methods for fungal isolation, but bacteria also were isolated using these methods by substituting media appropriate for bacteria. Our methodology should prove useful for studies investigating breakdown of intact plastic films or products for which plastic feedstocks are either unknown or not available. However our approach does not provide a quantitative method for comparing rates of BDM degradation.

Infrequent attention to dietary and physical activity behaviours in conversations in Swedish child health services

AIM

To investigate conversations between nurses and parents in Swedish child health services and to assess to what extent attention is directed towards dietary and physical activity behaviours in children.

METHODS

Twenty-three nurses audio-recorded one session each. Recordings were assessed and topics were classified according to predetermined categories.

RESULTS

The three most frequent topics of conversation concerned physical examinations of the child (30% of session time), talking to the child to establish or maintain contact and interest (15%), and development of language skills (12%). Dietary habits came on fourth place (10%), and physical activity ranked 14 (4%).

CONCLUSION

Attention to dietary and physical activity behaviours in children is infrequent in Swedish child health services. Concern is raised about the efficacy of prevention efforts against childhood obesity.

The relationship between glycaemic control and heart failure in 83,021 patients with type 2 diabetes

AIMS/HYPOTHESIS

The aim of this study was to examine the relationship between glycaemic control and hospitalisation for heart failure in patients with type 2 diabetes.

METHODS

Patients included in the Swedish National Diabetes Register (NDR) during 1998-2003 were followed until hospitalisation for heart failure, death or 31 December 2009. Unadjusted and adjusted incidence rates for heart failure were estimated by Poisson regression and relative risk was estimated by Cox regression.

RESULTS

In 83,021 patients with type 2 diabetes, 10,969 (13.2%) were hospitalised with a primary or secondary diagnosis of heart failure during a mean follow-up of 7.2 years. The incidence increased by male sex (p < 0.001), older age (p < 0.001) and longer diabetes duration (p < 0.001). In Cox regression adjusting for risk factors of heart failure the HR per each percentage unit higher HbA(1c) (10 mmol/mol) for heart-failure hospitalisation was 1.12 (95% CI 1.10, 1.14). By category of HbA(1c) the HR for heart failure hospitalisation was: HbA(1c) 6.0 to <7.0% (42 to <53 mmol/mol), 0.91 (95% CI 0.84, 0.98); HbA(1c) 7.0 to <8.0% (53 to <64 mmol/mol), 0.99 (95% CI 0.91, 1.07); HbA(1c) 8.0 to <9.0% (64 to < 75 mmol/mol), 1.10 (95% CI 1.01, 1.20); HbA(1c) 9.0 to <10.0% (75 to <86 mmol/mol), 1.27 (95% CI 1.15, 1.41); HbA(1c) ≥ 10.0 % (≥ 86 mmol/mol), 1.71 (1.51, 1.93) (reference HbA(1c) <6% [42 mmol/mol]). The HR for patients with HbA(1c) 7.0 to <8.0% (53 to < 64 mmol/mol) compared with patients with HbA(1c) 6.0 to <7.0% (42 to <53 mmol/mol) was 1.09 (95% CI 1.03, 1.14).

CONCLUSIONS/INTERPRETATION

Poor glycaemic control (HbA(1c) >7% [53 mmol/mol]) is associated with an increased risk of hospitalisation for heart failure in patients with type 2 diabetes.

Availability of insulin pump therapy in clinical practice

AIM

To examine the availability of insulin pump therapy in patients with Type 1 diabetes.

METHODS

Patients using insulin pumps among a cohort of 7224 patients with Type 1 diabetes were studied.

RESULTS

In logistic regression, used to evaluate variables not changing over time among the total cohort, use of insulin pumps varied by outpatient clinic (P<0.001) and sex (P<0.001). Cox regression analysis in 5854 patients with detailed patient data prior to use of an insulin pump showed higher HbA(1c) (P<0.0001), lower creatinine (P=0.002), high and low insulin doses (P<0.0001), younger age (P<0.0001) and female sex (P<0.0001) to be associated with use of an insulin pump. Women were 1.5-fold more likely to start using an insulin pump (hazard ratio 1.52, 95% confidence interval 1.29-1.79) and patients in the 20- to 30-years age range were more than twice as likely to begin use of an insulin pump than patients aged 40-50 years (hazard ratio 8.63, 95% confidence interval 5.91-12.59 and hazard ratio 3.98, 95% confidence interval 2.80-5.64, respectively). A 10-μmol/l higher level of creatinine was associated with a hazard ratio of 0.56 (95% confidence interval 0.39-0.81) of starting use of an insulin pump.

CONCLUSIONS

At 10 hospital outpatient clinics in Sweden, use of insulin pumps therapy varied by clinic. A higher proportion of women began using insulin pumps. Younger patients and patients with fewer complications were also more likely to start using an insulin pump. Further research is needed to confirm these findings in other geographical regions and to understand whether the availability of insulin pumps today is optimized.

Von Willebrand factor predicts major bleeding and mortality during oral anticoagulant treatment

AIMS

Oral anticoagulation (OAC), predominantly with warfarin, is an effective treatment to prevent thromboembolic events. Serious bleeding is a frequent and feared treatment complication. In this longitudinal cohort study of OAC-treated patients, we aimed to evaluate the relationship between von Willebrand factor (VWF) levels and risk of bleeding complications, cardiovascular mortality and all-cause mortality.

METHODS AND RESULTS

A total of 719 patients receiving warfarin treatment were observed for a mean duration of 4.2 years. All bleeding complications causing hospitalization were registered and classified into clinically relevant bleeding (CRB) and major bleeding. Ischaemic stroke, peripheral arterial embolism, myocardial infarction, and death were also recorded. We identified 113 cases of CRB and 73 of major bleeding. In total, 161 deaths occurred during follow-up with cardiovascular disease identified as the cause of death in 110 patients. Patients in the highest tertile of VWF had a significantly increased risk of bleeding complications: hazard ratio (HR) 2.53 (95% CI 1.41-4.56) for major bleeding and HR 2.19 (95% CI 1.38-3.48) for CRB. VWF, expressed either in tertiles or as a continuous variable, showed a significant association with cardiovascular mortality (HR 1.68, 95% CI 1.40-2.01) and all-cause mortality (HR 1.77, 95% CI 1.52-2.05). In multivariate Cox regression analysis, the findings remained significant after adjusting for age, high-sensitivity C-reactive protein and creatinine.

CONCLUSIONS

Patients with high levels of VWF had an increased risk of bleeding complications, cardiovascular mortality and all-cause mortality during OAC treatment. Our findings imply that the use of VWF as a risk marker for thromboembolic events is complicated by the association of VWF with bleeding complications.

Mechanical stability of the femoral fixation for single- and double-bundle ACL reconstruction in an in vitro experimental model

Anterior cruciate ligament ACL reconstruction using the double-bundle (DB) technique is gaining popularity. A possible weak link in the DB technique could be that two tendon grafts of smaller diameters are used. The purpose of this study was to test different femoral fixation methods and graft diameters representing single-bundle (SB) and DB ACL reconstructions and compare their biomechanical properties. We hypothesized that SB 6-mm graft constructs had inferior biomechanical properties than SB 9-mm grafts or DB 2 × 6-mm grafts. Furthermore, we hypothesized that interference (IF) screw fixation would demonstrate less elongation and a higher stiffness than Endobutton (Smith & Nephew®, Inc., Andover, Massachusetts, USA) fixation (EBF). We performed an in vitro study using porcine knees and extensor tendons. The mechanical test consisted of a cyclic test followed by a load-to-failure test. We found that 6-mm graft constructs had an ultimate failure load that was up to 40% less than both the 9-mm and 2 × 6-mm graft constructs, despite the fixation method (P-values ≥ 0.004). Comparing fixation methods, EBF was superior to IF concerning maximum load to failure (P < 0.001); IF resulted in a higher stiffness of the femur/graft complex than the EBF (P < 0.001) but no significant difference in elongation between fixation methods. Since the two graft strands are subjected to different loads in different knee flexion angles, the reduced strength of the individual graft strands in DB ACL reconstruction could be a concern.

A phase II trial evaluating two schedules of sagopilone (ZK-EPO), a novel epothilone, in patients with platinum-resistant ovarian cancer

BACKGROUND

Sagopilone, the first fully synthetic epothilone, has shown promising preclinical activity in tumour models. This open-label randomised phase II study investigated two infusion schedules of sagopilone in women with ovarian cancer.

PATIENTS AND METHODS

Women with ovarian cancer recurring within 6 months of end of last platinum-containing treatment received sagopilone 16 mg/m(2) as a 3- or 0.5-h i.v. infusion every 21 days for up to 6 weeks.

RESULTS

Sixty-three patients received sagopilone as a 3-h (n=38) or 0.5-h (n=25) infusion. There were nine confirmed tumour responses [by modified RECIST (n=8) and by Gynecologic Cancer Intergroup CA-125 criteria (n=1)] in 57 patients assessable for efficacy overall [three (13%) with 0.5-h and six (18%) with 3-h infusions]. The 0.5-h arm was closed when it failed to meet its target efficacy. Main drug-related adverse events were peripheral sensory neuropathy (73%; 16% grade 3), nausea (37%; 2% grade 3), fatigue (35%; 3% grade 3) and arthralgia (30%; 5% grade 3). Overall incidence of peripheral sensory neuropathy was similar in both treatment arms, with no grade 4 neuropathy events. No acute allergic infusion reactions were observed.

CONCLUSION

Sagopilone is effective, with balanced tolerability, in patients with recurrent platinum-resistant ovarian cancer.

The combination of radiostereometric analysis and the telos stress device results in poor precision for knee laxity measurements after anterior cruciate ligament reconstruction

PURPOSE

Several devices for measuring knee laxity following anterior cruciate ligament ACL reconstruction exist, but the precision of the methods has never been optimal. Therefore, a new standardized protocol (NSP) was made, aiming at ensuring a reliable positioning of the Telos Stress Device (TSD) which theoretically could result in precise knee laxity measurements when using radiostereometric analysis (RSA) in combination with TSD.

METHOD

The TSD was applied to the knee of 30 healthy persons, using both the NSP and the official company instructions. The position of the stress arms of the TSD was marked following each measurement. The reliability of each protocol was calculated as the difference in length between the first and second markings. The NSP for the TSD was then used in a clinical study. Thirty-five patients underwent ACL reconstruction. Double measurements of knee laxity by RSA were performed at a 3-month follow-up.

RESULTS

Using the NSP for TSD positioning, the prediction interval at the marking sites ranged from ±0.4 to ±1.1 mm. Following the company instructions, the prediction interval ranged from ±0.8 to ±3.9 mm depending on marking site. Thus, the precision of positioning the stress arms of the TSD was improved at all marking sites using the NSP compared with the original company protocol. The double measurements of the knee laxity in the clinical study resulted in a mean difference of 0.0 mm and a prediction interval of ±5.2 mm.

CONCLUSION

Even though the NSP improved the positioning of the TSD on patients' extremities, the combination of NSP-TSD and RSA was not able to provide acceptable knee laxity measurements in a clinical setting compared with published precision data for other devices on the market. Therefore, the Telos Stress Device is not recommendable for use in knee laxity measurements following ACL reconstruction.

The shape of the metabolic memory of HbA1c: re-analysing the DCCT with respect to time-dependent effects

AIMS/HYPOTHESIS

We determined the shape of the metabolic memory of HbA1c and its contribution to retinopathy, as well as the importance of reducing HbA1c to prevent progression of retinopathy.

METHODS

The relative risk contribution of HbA1c values at different points in time to current progression of retinopathy was determined in the DCCT patients.

RESULTS

HbA1c 2 to 3 years earlier had the greatest relative risk contribution to current progression of retinopathy. HbA1c up to 5 years earlier made a greater contribution than current values, while values from 8 years earlier still had an important impact. When HbA1c had been at 8% for a long period and was subsequently lowered to 7%, the salutary effects did not begin to appear until 2 to 3 years after lowering. The hazard function for a constant level of HbA1c increased with time. The numbers needed to treat when reducing HbA1c from 8.3% to 8% from diagnosis was estimated to be 1,688 for the first 3 years and 13 for the period 9 to 12 years. Survival functions when reducing HbA1c from 8% to 7% show that pre-study glycaemic control dominates the effect on progression of retinopathy during the first years of a trial.

CONCLUSIONS/INTERPRETATION

The most harmful effect of hyperglycaemia on progression of retinopathy in type 1 diabetes initially increases, but declines after roughly 5 years. The salutary effect of reducing HbA1c accelerates with time and becomes greater in clinical practice than has been previously understood. Clinical trials should preferably be designed for long periods or include patients with low previous glycaemic exposure to distinguish trial effects from those of the metabolic memory.

Three-dimensional microstructural properties of regenerated mineralizing tissue after PTH (1-34) treatment in a rabbit tibial lengthening model

Since the approval of parathyroid hormone (PTH) as treatment for osteoporosis, PTH has increasingly been investigated for bone repair and regeneration. The aim of the study was to investigate the effects of intermittent PTH treatment on the microstructure of regenerated mineralizing tissue after distraction osteogenesis in rabbits. After tibial mid-diaphyseal osteotomy the callus was distracted 1 mm/day for 10 days. 72 rabbits were divided in to 3 groups, which daily received a PTH (1-34) 25 microg/kg injection for 30 days; a saline injection for 10 days and a PTH injection for 20 days; or a saline injection for 30 days. The microstructure of the regenerate was assessed by micro computed tomography (microCT). In all 51 obtained specimens were evaluated morphometrically using three different volumes of interests. The results showed that treatment with PTH during distraction osteogenesis resulted in a significantly higher trabecular number, a more isotropic trabecular orientation, a higher connectivity density, and a higher mineralizing tissue mass. We also found that distraction calluses treated with PTH were more mature than the non-treated.

CONCLUSION

treatment with PTH resulted in an enhanced microstructure of the newly regenerated mineralizing tissue indicating that PTH has a potential role as a stimulating agent during distraction osteogenesis.

Usability laboratory test of a novel mobile homecare application with experienced home help service staff

Using participatory design, we developed and deployed a mobile Virtual Health Record (VHR) on a personal digital assistant (PDA) together with experienced homecare staff. To assess transferability to a second setting and usability when used by novice users with limited system education the application was tested in a usability lab. Eight participants from another homecare district performed tasks related to daily homecare work using the VHR. Test protocols were analyzed with regard to effectiveness, potential usability problems and user satisfaction. Usability problems having impact on system performance and contextual factors affecting system transferability were uncovered. Questionnaires revealed that the participants frequently used computers, but never PDAs. Surprisingly there were only minor differences in input efficiency between novice and experienced users. The participants were overall satisfied with the application. However, transfer to another district can not be performed, unless by means of careful field observations of contextual differences.

Osteogenic protein-1 increases the fixation of implants grafted with morcellised bone allograft and ProOsteon bone substitute: an experimental study in dogs

Impacted bone allograft is often used in revision joint replacement. Hydroxyapatite granules have been suggested as a substitute or to enhance morcellised bone allograft. We hypothesised that adding osteogenic protein-1 to a composite of bone allograft and non-resorbable hydroxyapatite granules (ProOsteon) would improve the incorporation of bone and implant fixation. We also compared the response to using ProOsteon alone against bone allograft used in isolation. We implanted two non-weight-bearing hydroxyapatite-coated implants into each proximal humerus of six dogs, with each implant surrounded by a concentric 3 mm gap. These gaps were randomly allocated to four different procedures in each dog: 1) bone allograft used on its own; 2) ProOsteon used on its own; 3) allograft and ProOsteon used together; or 4) allograft and ProOsteon with the addition of osteogenic protein-1. After three weeks osteogenic protein-1 increased bone formation and the energy absorption of implants grafted with allograft and ProOsteon. A composite of allograft, ProOsteon and osteogenic protein-1 was comparable, but not superior to, allograft used on its own. ProOsteon alone cannot be recommended as a substitute for allograft around non-cemented implants, but should be used to extend the volume of the graft, preferably with the addition of a growth factor.