Minor influence of humeral component size on torsional stiffness of the Souter-Strathclyde total elbow prosthesis

The use of Souter-Strathclyde total elbow prostheses is a well-studied replacement therapy for reconstruction of the elbow, but loosening of the humeral component is still of concern at long-term follow-up. In this study we looked at the effect of humeral component size and bone mineral density with respect to the bone size, torsional stiffness and torque to failure in cadaveric bones. Fourteen cadaveric humeri were available for testing purposes and four different humeral component size categories were used. First, we calculated the bone quality using dual-energy X-ray absorptiometry (DEXA). The torsional stiffness of the prosthetic humeri was measured during two mechanical tests: Firstly, the applied torque was recorded during a torsion fatigue test. The change of torsional stiffness between the tenth and last cycle was calculated. Secondly, a simple torsion test was performed and the torque to failure was recorded. No significant differences in outcome were seen between sizes of humeral components, even after correction for the bone size. Torsional stiffness and torque to failure were significantly correlated with bone mineral density and not with component size. In conclusion, bone quality seems to be a major eminent factor in the fixation of the humeral component in elbow replacement surgery

Long-term outcomes of slipped capital femoral epiphysis treated with in situ pinning

PURPOSE: Slipped capital femoral epiphysis (SCFE) is the commonest hip disorder in adolescents. In situ pinning is commonly performed, yet lately there has been an increase in procedures with open reduction and internal fixation. These procedures, however, are technically demanding with relatively high complication rates and unknown long-term outcomes. Nevertheless, reports on long-term results of in situ fixation are not equivocal. This study evaluates the possible higher risk of worse outcome after in situ pinning of SCFE. METHODS: All patients treated for SCFE with in situ fixation between 1980 and 2002 in four different hospitals were asked to participate. Patients were divided into three groups, based on severity of the slip. Patients were invited to the outpatient clinic for physical examination and X-rays, and to fill out the questionnaires HOOS, EQ5D, and SF36. ANOVA and chi-squared tests were used to analyze differences between groups. RESULTS: Sixty-one patients with 78 slips filled out the questionnaires. Patients with severe slips had worse scores on HOOS, EQ5D, and SF36. 75 % of patients with severe slips had severe osteoarthritis, compared to 2 % of mild and 11 % of moderate slips. CONCLUSION: Hips with mild and moderate SCFE generally had good functional and radiological outcome at a mean follow-up of 18 years, and for these hips there seems to be no indication for open procedures. However, severe slips have a significantly worse outcome, and open reduction and internal fixation could therefore be considered

CT angiography and CT perfusion improve prediction of infarct volume in patients with anterior circulation stroke

Introduction: We investigated whether baseline CT angiography (CTA) and CT perfusion (CTP) in acute ischemic stroke could improve prediction of infarct presence and infarct volume on follow-up imaging. Methods: We analyzed 906 patients with suspected anterior circulation stroke from the prospective multicenter Dutch acute stroke study (DUST). All patients underwent baseline non-contrast CT, CTA, and CTP and follow-up non-contrast CT/MRI after 3 days. Multivariable regression models were developed including patient characteristics and non-contrast CT, and subsequently, CTA and CTP measures were added. The increase in area under the curve (AUC) and R2 was assessed to determine the additional value of CTA and CTP. Results: At follow-up, 612 patients (67.5 %) had a detectable infarct on CT/MRI; median infarct volume was 14.8 mL (interquartile range (IQR) 2.8–69.6). Regarding infarct presence, the AUC of 0.82 (95 % confidence interval (CI) 0.79–0.85) for patient characteristics and non-contrast CT was improved with addition of CTA measures (AUC 0.85 (95 % CI 0.82–0.87); p < 0.001) and was even higher after addition of CTP measures (AUC 0.89 (95 % CI 0.87–0.91); p < 0.001) and combined CTA/CTP measures (AUC 0.89 (95 % CI 0.87–0.91); p < 0.001). For infarct volume, adding combined CTA/CTP measures (R2 = 0.58) was superior to patient characteristics and non-contrast CT alone (R2 = 0.44) and to addition of CTA alone (R2 = 0.55) or CTP alone (R2 = 0.54; all p < 0.001). Conclusion: In the acute stage, CTA and CTP have additional value over patient characteristics and non-contrast CT for predicting infarct presence and infarct volume on follow-up imaging. These findings could be applied for patient selection in future trials on ischemic stroke treatment

Prediction of outcome in patients with suspected acute ischaemic stroke with CT perfusion and CT angiography: The Dutch acute stroke trial (DUST) study protocol

Background: Prediction of clinical outcome in the acute stage of ischaemic stroke can be difficult when based on patient characteristics, clinical findings and on non-contrast CT. CT perfusion and CT angiography may provide additional prognostic information and guide treatment in the early stage. We present the study protocol of the Dutch acute Stroke Trial (DUST). The DUST aims to assess the prognostic value of CT perfusion and CT angiography in predicting stroke outcome, in addition to patient characteristics and non-contrast CT. For this purpose, individualised prediction models for clinical outcome after stroke based on the best predictors from patient characteristics and CT imaging will be developed and validated.Methods/design: The DUST is a prospective multi-centre cohort study in 1500 patients with suspected acute ischaemic stroke. All patients undergo non-contrast CT, CT perfusion and CT angiography within 9 hours after onset of the neurological deficits, and, if possible, follow-up imaging after 3 days. The primary outcome is a dichotomised score on the modified Rankin Scale, assessed at 90 days. A score of 0-2 represents good outcome, and a score of 3-6 represents poor outcome. Three logistic regression models will be developed, including patient characteristics and non-contrast CT (model A), with addition of CT angiography (model B), and CT perfusion parameters (model C). Model derivation will be performed in 60% of the study population, and model validation in the remaining 40% of the patients. Additional prognostic value of the models will be determined with the area under the curve (AUC) from the receiver operating characteristic (ROC) curve, calibration plots, assessment of goodness-of-fit, and likelihood ratio tests.Discussion: This study will provide insight in the added prognosti

Temporal profile of body temperature in acute ischemic stroke: Relation to infarct size and outcome

Background: High body temperatures after ischemic stroke have been associated with larger infarct size, but the temporal profile of this relation is unknown. We assess the relation between temporal profile of body temperature and infarct size and functional outcome in patients with acute ischemic stroke. Methods: In 419 patients with acute ischemic stroke we assessed the relation between body temperature on admission and during the first 3 days with both infarct size and functional outcome. Infarct size was measured in milliliters on CT or MRI after 3 days. Poor functional outcome was defined as a modified Rankin Scale score ≥3 at 3 months. Results: Body temperature on admission was not associated with infarct size or poor outcome in adjusted analyses. By contrast, each additional 1.0 °C in body temperature on day 1 was associated with 0.31 ml larger infarct size (95% confidence interval (CI) 0.04-0.59), on day 2 with 1.13 ml larger infarct size(95% CI, 0.83-1.43), and on day 3 with 0.80 ml larger infarct size (95% CI, 0.48-1.12), in adjusted linear regression analyses. Higher peak body temperatures on days two and three were also associated with poor outcome (adjusted relative risks per additional 1.0 °C in body temperature, 1.52 (95% CI, 1.17-1.99) and 1.47 (95% CI, 1.22-1.77), respectively). Conclusions: Higher peak body temperatures during the first days after ischemic stroke, rather than on admission, are associated with larger infarct size and poor functional outcome. This suggests that prevention of high temperatures may improve outcome if continued for at least 3 days

No relation between body temperature and arterial recanalization at three days in patients with acute ischaemic stroke

Background: Recanalization of an occluded intracranial artery is influenced by temperature-dependent enzymes, including alteplase. We assessed the relation between body temperature on admission and recanalization. Methods: We included 278 patients with acute ischaemic stroke within nine hours after symptom onset, who had an intracranial arterial occlusion on admission CT angiography, in 13 participating centres. We calculated the relation per every 0.1°Celsius increase in admission body temperature and recanalization at three days. Results: Recanalization occurred in 80% of occluded arteries. There was no relation between body temperature and recanalization at three days after adjustments for age, NIHSS score on admission and treatment with alteplase (adjusted odds ratio per 0.1°Celsius, 0.99; 95% confidence interval, 0.94-1.05; p = 0.70). Results for patients treated or not treated with alteplase were essentially the same. Conclusions: Our findings suggest that in patients with acute ischaemic stroke there is no relation between body temperature on admission and recanalization of an occluded intracranial artery three days later, irrespective of treatment with alteplase

Genetic and lifestyle risk factors for MRI-defined brain infarcts in a population-based setting.

OBJECTIVE: To explore genetic and lifestyle risk factors of MRI-defined brain infarcts (BI) in large population-based cohorts. METHODS: We performed meta-analyses of genome-wide association studies (GWAS) and examined associations of vascular risk factors and their genetic risk scores (GRS) with MRI-defined BI and a subset of BI, namely, small subcortical BI (SSBI), in 18 population-based cohorts (n = 20,949) from 5 ethnicities (3,726 with BI, 2,021 with SSBI). Top loci were followed up in 7 population-based cohorts (n = 6,862; 1,483 with BI, 630 with SBBI), and we tested associations with related phenotypes including ischemic stroke and pathologically defined BI. RESULTS: The mean prevalence was 17.7% for BI and 10.5% for SSBI, steeply rising after age 65. Two loci showed genome-wide significant association with BI: FBN2, p = 1.77 × 10-8; and LINC00539/ZDHHC20, p = 5.82 × 10-9. Both have been associated with blood pressure (BP)-related phenotypes, but did not replicate in the smaller follow-up sample or show associations with related phenotypes. Age- and sex-adjusted associations with BI and SSBI were observed for BP traits (p value for BI, p [BI] = 9.38 × 10-25; p [SSBI] = 5.23 × 10-14 for hypertension), smoking (p [BI] = 4.4 × 10-10; p [SSBI] = 1.2 × 10-4), diabetes (p [BI] = 1.7 × 10-8; p [SSBI] = 2.8 × 10-3), previous cardiovascular disease (p [BI] = 1.0 × 10-18; p [SSBI] = 2.3 × 10-7), stroke (p [BI] = 3.9 × 10-69; p [SSBI] = 3.2 × 10-24), and MRI-defined white matter hyperintensity burden (p [BI] = 1.43 × 10-157; p [SSBI] = 3.16 × 10-106), but not with body mass index or cholesterol. GRS of BP traits were associated with BI and SSBI (p ≤ 0.0022), without indication of directional pleiotropy. CONCLUSION: In this multiethnic GWAS meta-analysis, including over 20,000 population-based participants, we identified genetic risk loci for BI requiring validation once additional large datasets become available. High BP, including genetically determined, was the most significant modifiable, causal risk factor for BI

Limited influence of prosthetic position on aseptic loosening of elbow replacements: 125 elbows followed for an average period of 5.6 years

Aseptic loosening of elbow replacements, seen in long-term follow-up, remains a problem. In this study, we attempted to determine the influence of cementing technique, prosthetic position, different component sizes, use of a bone plug, and intraoperative fractures on the development and progression of radiolucent lines and aseptic loosening. We studied standard radiographs of 125 primary Souter-Strathclyde total elbow prostheses using the Wrightington method. Additionally, 104 preoperative radiographs were available for analysis. We used a Markow statistical model to detect relationships between all factors described above. After a mean follow-up time of 5.5 (2-19) years, 21 (17%) prostheses had loosened radiographically (10-year survival: 65%). When the humeral component was tilted more medially or more anteriorly, we found development of radiolucent lines at the medial condyle and at the posterior side of the humeral component. However, the progression of these lines was not influenced by these positions. No other prognostic factors for radiolucent lines or aseptic loosening were found. Despite the small number of elbows studied, the weak influence of prosthetic position on aseptic loosening gives more ground for a multifactorial cause for aseptic loosening of the Souter-Strathclyde total elbow prosthesi