The reliability of the patellotrochlear index on magnetic resonance imaging for measuring patellofemoral height.

BACKGROUND: The purpose of this study was to determine the inter- and intra-observer reliability of the patellotrochlear index (PTI) on magnetic resonance images (MRI) in patients with patellofemoral pain. The correlation between the PTI measured on MRI and the modified Insall-Salvati (MIS) ratio measured on radiographs was also assessed. METHODS: The PTI was assessed on MRI images and the MIS ratio on radiographs of 66 knees of 62 patients. Assessment was performed by two orthopaedic surgeons, one orthopaedic surgery registrar, two radiologists and one radiology registrar. Correlation coefficients, standard errors of measurement and limits of agreement were calculated for the PTI. To assess the association between the PTI and the MIS ratio, the Pearson's correlation coefficient was calculated. RESULTS: The PTI showed good interobserver reliability (intraclass correlation coefficient (ICC) 0.79; 95% confidence interval (CI) 0.73-0.85) and excellent intra-observer reliability (ICC 0.90; 95% CI 0.89-0.91). The standard error of measurement was 0.05 and limits of agreement with the mean ± 0.09. A very weak and not significant correlation was found between the PTI and the MIS (r = 0.02; P = 0.77). CONCLUSIONS: The PTI showed good interobserver reliability and excellent intra-observer reliability. In order to conclude which measurement method of assessing patellar height is truly the most reliable, future studies should investigate agreement parameters (standard error of measurement, limits of agreement) besides solely correlation coefficients. We found a very weak correlation between the PTI and the MIS which suggests that at least one index has poor validity. Future validity studies on indices to assess patellar height are necessary.

Linking employee burnout to medical aid provider expenditure.

BACKGROUND: Healthcare has become a major expense. Burnout and its connection with psychological and physical health is well researched, yet little research has been done on the connection between burnout and financial outcomes, specifically as indicated by the costs incurred by medical aid providers as a result of members' claims. OBJECTIVE: To investigate the connection between employee burnout and medical aid claims and expenditure data in a sample from the private sector. METHOD: A cross-sectional design was used. The sample comprised 3 182 participants. The available objective medical aid expenditure data connected with each participant were: total insured benefits, general practitioner visits, specialist visits, general practitioner insured benefits, and claims for medicine. A low and a high burnout group were extracted, based on comorbidity of the two core components of burnout. Analysis of covariance (ANCOVA) was then applied to investigate the differences in estimated marginal means of the expenditures on the low and the high burnout contrast groups, while controlling for age and gender. RESULTS: The high burnout group frequented a general practitioner more often, and the medical aid provider expenditure was nearly double that of the low burnout group, on all the variables. Specialist visits did not show a significant result. CONCLUSION: High burnout is associated with a higher expenditure by a medical aid provider, compared with low burnout, per member. Stakeholders should therefore address burnout to reduce expenditure and promote health.

Relation between coronary artery stenosis and myocardial purine metabolism, histology and regional function in humans.

In 54 patients undergoing elective or emergency aortocoronary bypass grafting, angiographic and electrocardiographic changes were studied. Five patients with unstable angina and five patients with evolving myocardial infarction were included. High energy phosphate metabolism and the histologic appearance of the myocardium were analyzed in transmural biopsy specimens acquired at the time of surgery. In patients without anterior infarction on the electrocardiogram, severe stenosis of the left anterior descending coronary artery resulted in a reduction of anterior wall motion that was associated with a partial depletion of the adenylate pool. Mitochondrial function, however, remained intact: the adenosine diphosphate/adenosine triphosphate ratio, the energy charge and the creatine phosphate/adenosine triphosphate ratio were in the normal range. Histologic assessment demonstrated viable myocardium with a high incidence of atrophic cells. In evolving myocardial infarction, 170 minutes of acute coronary artery obstruction resulted in anterior wall akinesia associated with a decrease of the sum of the adenylates to 52% and of creatine phosphate to 16% of their normal value (p less than 0.05). The nucleosides accumulated; their major fraction (91%) was inosine. The adenosine diphosphate/adenosine triphosphate ratio increased from 0.14 +/- 0.04 to 0.49 +/- 0.20 (p less than 0.01) and the energy charge decreased from 0.924 +/- 0.021 to 0.660 +/- 0.169 (p less than 0.01). Ultrastructure examination revealed irreversible cell damage in at least the subendocardial layer. These results suggest that the energetic base of reduced contractility due to severe coronary artery stenosis is different from that in acute coronary obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Drug-induced antibodies: interaction of the drug with a polymorphic platelet-antigen.

Preincubation of donor platelets with ticarcillin will prevent the reactivity of a platelet antibody against these platelets, whereas no influence was observed on antisera against HLA, 5A, 5b and ZWa. The implications for the mechanism of drug-induced antibodies with restricted specificity will be discussed.