Function of the supraspinatus muscle: Abduction of the humerus studied in cadavers

We evaluated the function of the supraspinatus tendon with a dynamic shoulder model. Active glenohumeral joint motion was simulated in 10 cadaveric shoulder specimens with hydrodynamic cylinder forces at the deltoid muscle and at the rotator cuff. Computerized regulation initiated standardized cycles of glenohumeral joint motion, where the isolated effect of the supraspinatus muscle could be studied. The efficacy of the supraspinatus muscle on elevation of the glenohumeral joint was measured with an ultrasonic sensor system. Pressures underneath the coracoa-cromial vault were recorded with capacitive sensors, as an indicator of the impingement at the shoulder. Elimination of force of the supraspinatus muscle led to a 6 percent decrease in elevation of the glenohumeral joint. The deltoid muscle was able to reverse this loss of elevation by a force increase of one third of the lost supraspinatus force. If no force was applied to the supraspinatus muscle, average pressures underneath the coracoacromial vault decreased 8 percent. It was concluded that the supraspinatus produces less torque and more glenohumeral joint compression than the deltoid. However, the supraspinatus has no effect on depression of the humeral head during elevation.

The clinical consequence of our observations is that operative closure of supraspinatus tendon defects is not mandatory.     

Peripheral venous pressure predicts central venous pressure poorly in pediatric patients

Purpose: Using peripheral venous pressure (PVP) instead of central venous pressure (CVP) as a volume monitor decreases patient risks and costs, and is convenient. This study was undertaken to determine if PVP predicts CVP in pediatric patients. METHODS: With ethical approval and informed consent, 30 pediatric patients aged neonate to 12 yr requiring a central venous line were studied prospectively in a tertiary care teaching hospital. In the supine position, PVP and CVP were simultaneously transduced. Ninety-six paired recordings of CVP and PVP were made. Correlation and Bland-Altman analysis of agreement of end-expiratory measurements were performed. RESULTS: The mean (SD; range) CVP was 10.0 mmHg (6.0; -1.0 to 27.0); the mean PVP was 13.7 mmHg (6.3; 0.0 to 33.0); offset (bias) of PVP > CVP was 3.7 mmHg with SD 2.6. The 95% confidence intervals (CI) for the bias were 3.2 to 4.1 mmHg. In the Bland-Altman analysis, lower and upper limits of agreement (LOA; CI in parentheses) were -1.5 (-2.3 to -0.7) and 8.8 (8.1 to 9.6) mmHg. Eight of 96 points were outside the limits of agreement. The correlation of PVP on CVP was r = 0.92, P < 0.0001. For a subset of ten patients (20 simultaneous recordings) with iv catheters proximal to the hand, limits of agreement were better - offset: 3.8 mmHg (+/- 1.4); lower LOA: 1.2 mmHg (0.25 to 2.1); upper LOA: 6.6 mmHg (5.7 to 7.5). CONCLUSION: Peripheral venous pressure measured from an iv catheter in the hand predicts CVP poorly in pediatric patients.     

Rotigotine transdermal patch in early Parkinson's disease: a randomized, double-blind, controlled study versus placebo and ropinirole.

Rotigotine is a new, non-ergot dopamine agonist formulated in a transdermal delivery system. The present study was to investigate the efficacy and safety of the rotigotine transdermal patch in the treatment of early Parkinson's disease. Patients (n = 561) were randomized to rotigotine, ropinirole, or placebo. The titration period was up to 13 weeks, and there was a minimum dose-maintenance period of 24 weeks for ropinirole and 33 weeks for rotigotine. The primary endpoint was the proportion of patients with a minimum of 20% decrease in the combined Unified Parkinson's Disease Rating Scale Part II and Part III scores. The responder rate in the rotigotine group was significantly higher than in the placebo group (52% vs. 30%, P < 0.0001). Transdermal rotigotine at doses < or =8 mg/24 h did not show noninferiority to ropinirole at doses < or =24 mg/day. In a post-hoc subgroup analysis, rotigotine < or =8 mg/24 hours had a similar efficacy to ropinirole at doses < or =12 mg/day. The rotigotine transdermal patch was well tolerated. The most common adverse events were application-site reactions, nausea, and somnolence. Application-site reactions were predominantly mild or moderate in intensity. In conclusion, the rotigotine transdermal patch represents an effective and safe option for the treatment of patients with early Parkinson's disease.     

Ueber eine neue Vorrichtung zur raschen Beruhigung schwingender Magnete in Spiegelboussolen

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