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Cues and pseudocues in surgical multiple choice questions from the German state examination

Multiple choice questions (MCQs) are the most common written test item in medical examinations. Writing MCQs is difficult and cues can decrease test validity. The aim of this article is to describe the prevalence and pattern of cues in surgical MCQs in the central German medical examination questions from 2000-2011. All surgical questions were entered into a database. The questions were reviewed for cues and pseudocues independently by three students of different academic background and one clinical physician. Initially, 1014 questions were included, 22 questions were not rated uniformly by the reviewers and 3 questions were excluded because no consensus could be reached. Overall 15.2 % of the questions analyzed contained some type of cue or pseudocue. Of the total questions 0.2 % contained type A cues (i.e. disruption of grammatical flow), 6.5 % contained type B cues (i.e. heterogeneous length or differentiation), 4.0 % contained type C cues (two or more answers described closely related topics, serving to focus attention), 0.6 % contained type D convergence cues (i.e. answers with the most items in common with distractors are correct), 0.7 % contained type E verbal association cues (i.e. connection in the use of words leading to the correct answer) and 1.0 % contained type F cues (i.e. answers with absolute terms). Pseudocues were found in 3.7 % of the questions. The proportion of questions that contained cues or pseudocues should lead to further efforts to avoid such factors compromising test reliability by specific attention in the process of question design and review. Cues are still an important consideration in designing MCQs and are present in considerable numbers in medical state examination questions. Pseudocues should be explicitly avoided so as not to compromise validity and reliability.

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Nailing versus plating for comminuted fractures of the distal femur: a comparative biomechanical in vitro study of three implants.

The purpose of our study was to determine the biomechanical properties of three different implants utilized for internal fixation of a supracondylar femur fracture. The retrograde supracondylar nail (SCN), the less invasive stabilization system plate (LISS) and the distal femoral nail (DFN) were tested and their biomechanical properties compared. Twenty pairs of fresh-frozen human femura were used. Each femur was osteotomised to simulate a comminuted supracondylar fracture (AO/OTA 33.A3) and then randomized to fracture fixation with either SCN (n=9) or LISS (n=9). Each contralateral femur was stabilized with DFN as a control (n=18). Two femur pairs were spent on pretesting. All femura were subjected to axial (10-500N) and torsional (0.1-14Nm) loading. Eighteen matched femur pairs were analyzed. The post-loading median residual values were 49.78, 41.25 and 33.51% of the axial stiffness of the intact femur and 59.04, 62.37 and 46.72% of the torsional stiffness of the intact femur in the SCN, LISS and DFN groups. There were no significant differences between the three implants concerning axial and torsional stiffness. All implants had sufficient biomechanical stability under physiological torsional and axial loading. All three implants have different mechanisms for distal locking. The SCN nail with the four-screw distal interlocking had the best combined axial and torsional stiffness whereas the LISS plate had the highest torsional stiffness.

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Carotid artery stenting: Do procedural complications relate to the side intervened upon?

To determine the influence of the side intervened upon on outcomes during carotid artery stenting (CAS). Anatomic and technical aspects may influence the results of CAS. The value of the side intervened upon has not been analyzed yet. We analyzed data from the Carotid Artery Stent (CAS)-Registry. A total of 3,165 CAS procedures, 1,613 (51%) at the left and 1,552 (49%) at the right carotid artery were included. There was a higher proportion of patients treated for symptomatic stenoses when CAS was performed at the left carotid artery (50.1% versus 45.8%, P = 0.016) and more patients already had prior carotid endarterectomy (8.5% versus 5.8%, P = 0.003). Interventions at the left side took 3 min longer than interventions at the right side (46.6 +/- 24.3 versus 43.8 +/- 23.6, P = 0.003). In patients treated at the left carotid artery amaurosis fugax (0.7% versus 0.1%, P = 0.005), ipsilateral stroke (3.1% versus 1.8%, P = 0.017), and the primary endpoint of in-hospital death or stroke (4.1% versus 2.3%, P = 0.005) occurred significantly more often. Even after adjusting for confounding parameters, CAS procedures performed at the left carotid arteries remained an independent predictor of death or stroke (OR = 1.77, 95% CI: 1.15-2.72, P = 0.009). In current clinical practice, CAS is performed frequently at the right carotid artery as at the left carotid artery. CAS interventions have a higher in-hospital complication rate if performed at the left carotid artery. Technical improvements might help to overcome this situation.

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Humeral nailing revisited

Unreamed interlocked humeral nailing for stabilisation of acute humeral fractures was introduced a decade ago. Antegrade and retrograde nail insertion are equally popular. The role of nailing as opposed to plating of humeral fractures is the subject of continuous debate. Between 1997 and 2005, 99 acute fractures of the humeral shaft were treated operatively with the unreamed humeral nail (UHN, Synthes) in our Level I Trauma Centre. The mean age of the patients was 63 years. Only eight patients (8.1%) were polytraumatised, nine patients had an open fracture (9.1%), five had a primary radial nerve palsy (5.1%). There were 54 antegrade and 45 retrograde nailings. The procedures were performed by 19 different surgeons, who carefully followed a detailed operation protocol. There were 6 adverse events: 3 secondary radial nerve palsies (3%), 2 fissures at the insertion point (2%) and one false placement of a locking screw (1%). Three patients developed pseudarthrosis (3%). Eight further operation were necessary (8.1%): 3 exploration of the radial nerve, 3 for treatment of pseudarthrosis, one replacement of a locking screw and one wound revision for superficial wound infection. Ninety patients (92 fractures) were evaluated after bone healing. Shoulder function was assessed using the Constant Score, elbow function with the Mayo Elbow Score. 91.3% and 5.4% of patients had an excellent or good shoulder function, 81.5% and 14.1% had an excellent or good elbow function. All patients with a functional deficit of the shoulder joint had antegrade, all patients with a deficit at the elbow joint retrograde nailing. Motor function recovered in all radial nerve palsies. 93.5% of patients had an excellent or good functional end result. Unreamed humeral nailing is a valid therapeutic option for stabilisation of acute humeral shaft fractures. Antegrade and retrograde nailing are associated with specific but different complications. By strictly adhering to the operation technique, the number and severity of complications can be reduced. When good fracture alignment and stability are obtained, uneventful bone healing with good functional outcome is the rule.

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Glycoprotein IIb/IIIa antagonists during carotid artery stenting:

Glycoprotein II b/IIIa antagonists (GPII b/IIIa-A) lower the periprocedural rate of ischemic events during high risk percutaneous coronary interventions. Their clinical impact on carotid artery stenting (CAS) remains to be determined. We analyzed data from the Carotid Artery Stent (CAS) Registry. From 01/ 2000 to 06/2005 1322 CAS interventions were registered. In 94 (7.1%) procedures a GPII b/IIIa-A was used: abciximab in 8 cases (8.6%), tirofiban in 53 cases (57%) and eptifibatide in 32 cases (34.4%). The use of a GPII b/IIIa-A during CAS decreased significantly over time: from 17.6% in 2000 to 3% in 2005, p for trend <0.0001. The mean use of a GPII b/IIIa-A at the hospitals was 5.2%. More than 50% of the hospitals never used a GPII b/IIIa-A. There were no significant differences in baseline characteristics and concomitant diseases in CAS patients treated with GPII b/IIIa-A compared to those without GPII b/IIIa-A. A bilateral intervention was performed more often in patients treated with GPII b/IIIa-A (2.1 vs 0.2%, p = 0.04), a thrombus was more often visible (27 vs 12.4%, p <0.001) and an ulcer more frequently diagnosed (50 vs 37.5%, p = 0.03). There was no significant difference in the combined death or stroke rate between the two groups (5.3 vs 3.0%, p = 0.22, OR = 1.81, 95% CI: 0.69-4.72), which was confirmed by logistic regression analysis after adjusting for possible confounders (OR = 1.67, 95% CI: 0.62-4.46, p = 0.31). Our data neither demonstrate a significant benefit nor a significant risk with the use of GPIIb/IIIa-A during CAS. However, only an adequately sized randomized controlled clinical trial could establish the real value of GPII b/IIIa-A during CAS. Until then, considering the potential increase in cerebral hemorrhage, we should not use GPII b/ IIIa-A routinely during CAS.

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Comparison of Inhospital Outcomes of Patients With Versus Without Previous Carotid Endarterectomy Undergoing Carotid Stenting (from the German ALKK CAS Registry)

Repeat carotid endarterectomy (CEA) for recurrent stenosis remains a challenging treatment option associated with high morbidity and mortality. Carotid artery stenting (CAS) is an attractive alternative management option for these patients. However, data about the effectiveness and safety of CAS in a large number of unselected patients are less known. We evaluated 3,070 patients who underwent CAS enrolled in a German registry from 1996 to 2006 at 31 sites. We compared clinical and angiographic features and in-hospital outcomes of patients with and without previous CEA who underwent CAS. Of 3,070 patients in the registry, 223 (7.3%) underwent CAS for restenosis after previous CEA. Median age was similar in patients with and without previous CEA (70 years, interquartile range 64 to 76 vs 71 years, interquartile range 65 to 76). Ipsilateral neurologic symptoms occurred in approximately 1/2 the patients in both groups. Other co-morbid conditions and angiographic or procedural factors did not differ between the 2 groups. In-hospital events including death (0% vs 0.4%), ipsilateral major stroke (1.4% vs 1.5%), death or major ipsilateral stroke (1.4% vs 1.7%), ipsilateral transient ischemic attack (1.9% vs 2.8%), myocardial infarction (0.4% vs 0.1%), and reintervention (0.7% vs 0.4%) were all low and not significantly different between those with and without previous CEA (p >0.05 for all comparisons). In conclusion, our data for a large number of patients who underwent CAS in a recent contemporary community-based practice attests to the low risk of periprocedural events in patients with recurrent stenosis after previous CEA. This low risk along with the less invasive nature of the procedure should make CAS an attractive and perhaps preferred option for the treatment of these patients.

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Biventricular Versus Conventional Right Ventricular Stimulation for Patients With Standard Pacing Indication and Left Ventricular Dysfunction: The Homburg Biventricular Pacing Evaluation (HOBIPACE)

The Homburg Biventricular Pacing Evaluation (HOBIPACE) is the first randomized controlled study that compares the biventricular (BV) pacing approach with conventional right ventricular (RV) pacing in patients with left ventricular (LV) dysfunction and a standard indication for antibradycardia pacing in the ventricle. In patients with LV dysfunction and atrioventricular block, conventional RV pacing may yield a detrimental effect on LV function. Thirty patients with standard indication for permanent ventricular pacing and LV dysfunction defined by an LV end-diastolic diameter > or =60 mm and an ejection fraction < or =40% were included. Using a prospective, randomized crossover design, three months of RV pacing were compared with three months of BV pacing with regard to LV function, N-terminal pro-B-type natriuretic peptide (NT-proBNP) serum concentration, exercise capacity, and quality of life. When compared with RV pacing, BV stimulation reduced LV end-diastolic (-9.0%, p = 0.022) and end-systolic volumes (-16.9%, p < 0.001), NT-proBNP level (-31.0%, p < 0.002), and the Minnesota Living with Heart Failure score (-18.9%, p = 0.01). Left ventricular ejection fraction (+22.1%), peak oxygen consumption (+12.0%), oxygen uptake at the ventilatory threshold (+12.5%), and peak circulatory power (+21.0%) were higher (p < 0.0002) with BV pacing. The benefit of BV over RV pacing was similar for patients with (n = 9) and without (n = 21) atrial fibrillation. Right ventricular function was not affected by BV pacing. In patients with LV dysfunction who need permanent ventricular pacing support, BV stimulation is superior to conventional RV pacing with regard to LV function, quality of life, and maximal as well as submaximal exercise capacity.

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