Benefit of Cup Medialization in Total Hip Arthroplasty is Associated With Femoral Anatomy.

BACKGROUND: Medialization of the cup with a respective increase in femoral offset has been proposed in THA to increase abductor moment arms. Insofar as there are potential disadvantages to cup medialization, it is important to ascertain whether the purported biomechanical benefits of cup medialization are large enough to warrant the downsides; to date, studies regarding this question have disagreed. QUESTIONS/PURPOSES: The purpose of this study was to quantify the effect of cup medialization with a compensatory increase in femoral offset compared with anatomic reconstruction for patients undergoing THA. We tested the hypothesis that there is a (linear) correlation between preoperative anatomic parameters and muscle moment arm increase caused by cup medialization. METHODS: Fifteen patients undergoing THA were selected, covering a typical range of preoperative femoral offsets. For each patient, a finite element model was built based on a preoperative CT scan. The model included the pelvis, femur, gluteus minimus, medius, and maximus. Two reconstructions were compared: (1) anatomic position of the acetabular center of rotation, and (2) cup medialization compensated by an increase in the femoral offset. Passive abduction-adduction and flexion-extension were simulated in the range of normal gait. Muscle moment arms were evaluated and correlated to preoperative femoral offset, acetabular offset, height of the greater trochanter (relative to femoral center of rotation), and femoral antetorsion angle. RESULTS: The increase of muscle moment arms caused by cup medialization varied among patients. Muscle moment arms increase by 10% to 85% of the amount of cup medialization for abduction-adduction and from -35% (decrease) to 50% for flexion-extension. The change in moment arm was inversely correlated (R(2) = 0.588, p = 0.001) to femoral antetorsion (anteversion), such that patients with less femoral antetorsion gained more in terms of hip muscle moments. No linear correlation was observed between changes in moment arm and other preoperative parameters in this series. CONCLUSIONS: The benefit of cup medialization is variable and depends on the individual anatomy. CLINICAL RELEVANCE: Cup medialization with compensatory increase of the femoral offset may be particularly effective in patients with less femoral antetorsion. However, cup medialization must be balanced against its tradeoffs, including the additional loss of medial acetabular bone stock, and eventual proprioceptive implications of the nonanatomic center of rotation and perhaps joint reaction forces. Clinical studies should better determine the relevance of small changes of moment arms on function and joint reaction forces.

Is spinal stenosis assessment dependent on slice orientation? A magnetic resonance imaging study.

INTRODUCTION: Lumbar spinal stenosis (LSS) treatment is based primarily on the clinical criteria providing that imaging confirms radiological stenosis. The radiological measurement more commonly used is the dural sac cross-sectional area (DSCA). It has been recently shown that grading stenosis based on the morphology of the dural sac as seen on axial T2 MRI images, better reflects severity of stenosis than DSCA and is of prognostic value. This radiological prospective study investigates the variability of surface measurements and morphological grading of stenosis for varying degrees of angulation of the T2 axial images relative to the disc space as observed in clinical practice. MATERIALS AND METHODS: Lumbar spine TSE T2 three-dimensional (3D) MRI sequences were obtained from 32 consecutive patients presenting with either suspected spinal stenosis or low back pain. Axial reconstructions using the OsiriX software at 0°, 10°, 20° and 30° relative to the disc space orientation were obtained for a total of 97 levels. For each level, DSCA was digitally measured and stenosis was graded according to the 4-point (A-D) morphological grading by two observers. RESULTS: A good interobserver agreement was found in grade evaluation of stenosis (k = 0.71). DSCA varied significantly as the slice orientation increased from 0° to +10°, +20° and +30° at each level examined (P < 0.0001) (-15 to +32% at 10°, -24 to +143% at 20° and -29 to +231% at 30° of slice orientation). Stenosis definition based on the surface measurements changed in 39 out of the 97 levels studied, whereas the morphology grade was modified only in two levels (P < 0.01). DISCUSSION: The need to obtain continuous slices using the classical 2D MRI acquisition technique entails often at least a 10° slice inclination relative to one of the studied discs. Even at this low angulation, we found a significantly statistical difference between surface changes and morphological grading change. In clinical practice, given the above findings, it might therefore not be necessary to align the axial cuts to each individual disc level which could be more time-consuming than obtaining a single series of axial cuts perpendicular to the middle of the lumbar spine or to the most stenotic level. In conclusion, morphological grading seems to offer an alternative means of assessing severity of spinal stenosis that is little affected by image acquisition technique.

Predictors of political orientation among US-born Mexican Americans: cultural identification, acculturation attitudes and socioeconomic status

With each passing election, U.S. political campaigns have renewed their efforts in courting the “Latino vote,” yet the Latino population is not a culturally homogenous voting bloc. This study examined how cultural identifications and acculturation attitudes in U.S. born Mexican Americans interacted with socioeconomic status (SES) to predict political orientation. Individuals who held stronger Mexican identity and supported biculturalism as an acculturation strategy had a more liberal orientation, while belonging to a higher SES group and holding stronger assimilation attitudes predicted a less liberal orientation. Mexican cultural identification interacted with SES such that those who held a weaker Mexican identity, but came from a higher social class were less liberal and more moderate in their political orientation. Weak Mexican identification and higher SES also predicted weaker endorsement of bicultural acculturation attitudes, which in turn, mediated the differences in political orientation. The acceptance of one’s ethnic identity and endorsement of bicultural attitudes predicted a more liberal political orientation. In light of these findings, political candidates should be cautious in how they pander to Latino constituents—referencing the groups’ ethnic culture or customs may distance constituents who are not strongly identified with their ethnic culture.

Health Information and the Choice of Fish Species: An Experiment Measuring the Impact of Risk and Benefit Information, April 2006

An experiment was conducted in France to evaluate the impact of health information on consumers’ choice between two different types of fish. Successive messages revealing risks (methylmercury) and benefits (omega-3s) of consuming the fish, along with consumption recommendations, were delivered. Results show a significant difference of reaction according to the order and type of information. The information about risks had a larger marginal impact on change in willingness to pay (WTP) than did the information about benefits. While the results show that detailed messages on risks/benefits, including recommendations for nutrition behavior, matter in the modification of WTP, 40% of respondents did not change their initial choices after the revelation of health information.

Iowa Certified Nursing Assistants Wage and Benefit Survey

Iowa Certified Nursing Assistants Wage and Benefit Survey

Home Care Workers Wage and Benefit Survey

Study to determine the wage and benefit status of Iowa's Home Care Workers.

Orientation Center Newsletter, Winter 2004

The Orientation Center newsletter is produced three times a year, and includes articles written by students, staff, and former students. It also contains news about what is happening to other students who have been in the Center.

Orientation Center Newsletter, Summer 2003

The Orientation Center newsletter is produced three times a year, and includes articles written by students, staff, and former students. It also contains news about what is happening to other students who have been in the Center.

Orientation Center Newsletter, Summer 2004

The Orientation Center newsletter is produced three times a year, and includes articles written by students, staff, and former students. It also contains news about what is happening to other students who have been in the Center.

Orientation Center Newsletter, Summer 2005

The Orientation Center newsletter is produced three times a year, and includes articles written by students, staff, and former students. It also contains news about what is happening to other students who have been in the Center.

Orientation Center Newsletter, Summer 2006

The Orientation Center newsletter is produced three times a year, and includes articles written by students, staff, and former students. It also contains news about what is happening to other students who have been in the Center.

Ultra-early intravenous stroke thrombolysis: do all patients benefit similarly?

BACKGROUND AND PURPOSE: We previously reported increased benefit and reduced mortality after ultra-early stroke thrombolysis in a single center. We now explored in a large multicenter cohort whether extra benefit of treatment within 90 minutes from symptom onset is uniform across predefined stroke severity subgroups, as compared with later thrombolysis. METHODS: Prospectively collected data of consecutive ischemic stroke patients who received IV thrombolysis in 10 European stroke centers were merged. Logistic regression tested association between treatment delays, as well as excellent 3-month outcome (modified Rankin scale, 0-1), and mortality. The association was tested separately in tertiles of baseline National Institutes of Health Stroke Scale. RESULTS: In the whole cohort (n=6856), shorter onset-to-treatment time as a continuous variable was significantly associated with excellent outcome (P<0.001). Every fifth patient had onset-to-treatment time≤90 minutes, and these patients had lower frequency of intracranial hemorrhage. After adjusting for age, sex, admission glucose level, and year of treatment, onset-to-treatment time≤90 minutes was associated with excellent outcome in patients with National Institutes of Health Stroke Scale 7 to 12 (odds ratio, 1.37; 95% confidence interval, 1.11-1.70; P=0.004), but not in patients with baseline National Institutes of Health Stroke Scale>12 (odds ratio, 1.00; 95% confidence interval, 0.76-1.32; P=0.99) and baseline National Institutes of Health Stroke Scale 0 to 6 (odds ratio, 1.04; 95% confidence interval, 0.78-1.39; P=0.80). In the latter, however, an independent association (odds ratio, 1.51; 95% confidence interval, 1.14-2.01; P<0.01) was found when considering modified Rankin scale 0 as outcome (to overcome the possible ceiling effect from spontaneous better prognosis of patients with mild symptoms). Ultra-early treatment was not associated with mortality. CONCLUSIONS: IV thrombolysis within 90 minutes is, compared with later thrombolysis, strongly and independently associated with excellent outcome in patients with moderate and mild stroke severity.