Past incidence and future demand for knee arthroplasty in Sweden: A report from the Swedish Knee Arthroplasty Register regarding the effect of past and future population changes on the number of arthroplasties performed

By combining data from the Swedish Knee Arthroplasty Register and Swedish census registers we have calculated the past age-specific incidence of primary knee arthroplasties and predicted the demand. During the last 20 years, osteoarthrosis has accounted for the largest increase in number of knee arthroplasties while operations for rheumatoid arthritis remained constant. The mean yearly number of operations between the periods 1976-1980 and 1996-1997 increased more than five-fold, while only 6% of that increase could be explained by changes in the age-profile of the population. Most operations were performed on persons of 65 years and older who also had the largest increase in incidence. By using the incidences for 1996 and 1997 and taking into account the expected future changes in the age profile of the Swedish population, we estimate that, in the absence of an effective preventive treatment, the number of knee arthroplasties will increase by at least one third until 2030.     

Neuroendocrine assessment of serotonergic, dopaminergic, and noradrenergic functions in alcohol-dependent individuals

Background: Alcohol dependence has been associated with reduced function of serotonin, dopamine as well as noradrenaline activities in several neuroendocrine studies. To our knowledge, there is, however, no study investigating all these 3 systems with the use of neuroendocrine methods in one and the same alcohol‐dependent individual. Methods: Alcohol‐dependent individuals (n = 42) and controls (n = 28) participated in the neuroendocrine test series. Central serotonergic neurotransmission was assessed by the prolactin (PRL) response to citalopram (CIT). The postsynaptic DRD2 function was measured by the growth hormone (GH) response to apomorphine (APO) and the postsynaptic α2‐adrenoceptor function by GH response to clonidine (CLON). Results: In the alcohol‐dependent individuals, the PRL concentrations were significantly lower at the time points 240 minutes and 300 minutes after CIT administration and mean delta PRL value was significantly reduced by 45% in comparison with controls. There were no significant differences in APO‐GH and CLON‐GH concentrations at any time points or in mean delta GH values between the groups. An impaired monoaminergic profile, including all 3 systems, was significantly more frequent in alcohol‐dependent individuals than controls (43% vs. 6% respectively). Conclusions: The monoaminergic dysfunction was restricted to an impairment of the serotonergic system, suggesting that this system is especially vulnerable to long‐term and excessive alcohol consumption. Moreover, impaired monoaminergic profiles, including low responses in 2 or 3 systems, were more frequently observed in alcohol‐dependent individuals than in controls. Such impaired profiles may be of clinical importance, but further studies are needed.     

Mental health at population level during an economic recession in Finland

The aim of this study was to investigate the prevalence of mental disorder and associated factors during an economic recession. Random samples of Finnish general population were collected in 3 consecutive years, 1993-95. The prevalence of mental disorders was assessed by means of the 12-item General Health Questionnaire (GHQ). The prevalence of mental disorders varied among Finnish men from 15.6% to 19.2% and among women from 21 to 24.5%. Mental disorder was more common among women than among men in every study year. Mental disorder was more common among the unemployed than among other respondents both in women and men in every year. Subjective poor health, suicidal thoughts and poor economic situation were constantly associated with mental disorder in both sexes every year. Using logistic regression analyses, problems with a partner, uncertain future orientation and use of psychoactive drugs, in particular, were found to be fairly permanent independent risk factors in relation to mental disorder. As studied by gender no major changes occurred in the mental health status of Finns during economic recession, although in many specific groups mental disorder was markedly more common than in the general population.     

Elevated cerebrospinal fluid F2-isoprostane levels indicating oxidative stress in healthy siblings of multiple sclerosis patients

Lipid peroxidation has been implicated in the pathogenesis of multiple sclerosis (MS). Isoprostanes, isomers of prostaglandins, are produced by free radical-mediated peroxidation of fatty acids in vivo and can be quantified in biological fluids. This study examines the levels of cerebrospinal fluid (CSF) F2-isoprostanes (F2-iPs) in MS patients (n=46), their healthy siblings (n=46) and unrelated controls (n=50). The median CSF F2-iP concentration (range) was significantly higher in siblings of MS patients, as compared to healthy controls (40.0 [7.1-68.7] and 29.1 [6.4-60.3] pg/mL, respectively, p=0.031). MS patients demonstrated F2-iP levels intermediate between siblings and controls. F2-iP levels in MS patients and siblings correlated significantly (R=0.360, p=0.012). These results suggest that siblings of MS patients have an increased oxidative stress response to environmental and/or genetic factors that may be involved in MS pathogenesis.     

What Are the Interobserver and Intraobserver Variability of Gap and Stepoff Measurements in Acetabular Fractures?

BackgroundGap and stepoff values in the treatment of acetabular fractures are correlated with clinical outcomes. However, the interobserver and intraobserver variability of gap and stepoff measurements for all imaging modalities in the preoperative, intraoperative, and postoperative phase of treatment is unknown. Recently, a standardized CT-based measurement method was introduced, which provided the opportunity to assess the level of variability.Questions/purposes(1) In patients with acetabular fractures, what is the interobserver variability in the measurement of the fracture gaps and articular stepoffs determined by each observer to be the maximum one in the weightbearing dome, as measured on pre- and postoperative pelvic radiographs, intraoperative fluoroscopy, and pre- and postoperative CT scans? (2) What is the intraobserver variability in these measurements?MethodsSixty patients with a complete subset of pre-, intra- and postoperative high-quality images (CT slices of < 2 mm), representing a variety of fracture types with small and large gaps and/or stepoffs, were included. A total of 196 patients with nonoperative treatment (n = 117), inadequate available imaging (n = 60), skeletal immaturity (n = 16), bilateral fractures (n = 2) or a primary THA (n = 1) were excluded. The maximum gap and stepoff values in the weightbearing dome were digitally measured on pelvic radiographs and CT images by five independent observers. Observers were free to decide which gap and/or stepoff they considered the maximum and then measure these before and after surgery. The observers were two trauma surgeons with more than 5 years of experience in pelvic surgery, two trauma surgeons with less than 5 years of experience in pelvic surgery, and one surgical resident. Additionally, the final intraoperative fluoroscopy images were assessed for the presence of a gap or stepoff in the weightbearing dome. All observers used the same standardized measurement technique and each observer measured the first five patients together with the responsible researcher. For 10 randomly selected patients, all measurements were repeated by all observers, at least 2 weeks after the initial measurements. The intraclass correlation coefficient (ICC) for pelvic radiographs and CT images and the kappa value for intraoperative fluoroscopy measurements were calculated to determine the inter- and intraobserver variability. Interobserver variability was defined as the difference in the measurements between observers. Intraobserver variability was defined as the difference in repeated measurements by the same observer.ResultsPreoperatively, the interobserver ICC was 0.4 (gap and stepoff) on radiographs and 0.4 (gap) and 0.3 (stepoff) on CT images. The observers agreed on the indication for surgery in 40% (gap) and 30% (stepoff) on pelvic radiographs. For CT scans the observers agreed in 95% (gap) and 70% (stepoff) of images. Postoperatively, the interobserver ICC was 0.4 (gap) and 0.2 (stepoff) on radiographs. The observers agreed on whether the reduction was acceptable or not in 60% (gap) and 40% (stepoff). On CT images the ICC was 0.3 (gap) and 0.4 (stepoff). The observers agreed on whether the reduction was acceptable in 35% (gap) and 38% (stepoff). The preoperative intraobserver ICC was 0.6 (gap and stepoff) on pelvic radiographs and 0.4 (gap) and 0.6 (stepoff) for CT scans. Postoperatively, the intraobserver ICC was 0.7 (gap) and 0.1 (stepoff) on pelvic radiographs. On CT the intraobserver ICC was 0.5 (gap) and 0.3 (stepoff). There was no agreement between the observers on the presence of a gap or stepoff on intraoperative fluoroscopy images (kappa -0.1 to 0.2).ConclusionsWe found an insufficient interobserver and intraobserver agreement on measuring gaps and stepoffs for supporting clinical decisions in acetabular fracture surgery. If observers cannot agree on the size of the gap and stepoff, it will be challenging to decide when to perform surgery and study the results of acetabular fracture surgery.Level of EvidenceLevel III, diagnostic study.     

Elevated Concentrations of Neurofilament Light Chain in the Cerebrospinal Fluid of Bipolar Disorder Patients

Bipolar disorder (BD) is characterized by mood swings between manic and depressive states. The etiology and pathogenesis of BD is unclear, but many of the affected cognitive domains, as well as neuroanatomical abnormalities, resemble symptoms and signs of small vessel disease. In small vessel disease, cerebrospinal fluid (CSF) markers reflecting damages in different cell types and subcellular structures of the brain have been established. Hence, we hypothesized that CSF markers related to small vessel disease may also be applicable as biomarkers for BD. To investigate this hypothesis, we sampled CSF from 133 patients with BD and 86 healthy controls. The concentrations of neurofilament light chain (NF-L), myelin basic protein (MBP), S100B, and heart-type fatty acid binding protein (H-FABP) were measured in CSF and analyzed in relation to diagnosis, clinical characteristics, and ongoing medications. Hereby we found an elevation of the marker of subcortical axonal damage, NF-L, in bipolar subjects. We also identified positive associations between NF-L and treatment with atypical antipsychotics, MBP and lamotrigine, and H-FABP and lithium. These findings indicate axonal damage as an underlying neuropathological component of bipolar disorder, although the clinical value of elevated NF-L remains to be validated in follow-up studies. The associations between current medications and CSF brain injury markers might aid in the understanding of both therapeutic and adverse effects of these drugs.