Clinical evaluation of a radio-protective cream for the hands of the pediatric interventional cardiologist.

OBJECTIVES: The aim of this study was to evaluate the effectiveness of UltraBLOX™ radiation attenuating hand cream during lengthy cardiac catheterization procedures in children. BACKGROUND: The hands of interventional cardiologists receive high doses of radiation due to their proximity to the X-ray beam. Radiation attenuating gloves have about a 26% attenuation rate, but reduce dexterity and tactile sensation. The UltraBLOX™ cream is a new FDA-approved X-ray attenuating cream that can be applied to the operator's hands for radio-protection. METHODS: Two nanoDot™ dosimeters were secured side by side on the dorsum of the operator's (n = 2) left hand close to the wrist. One dosimeter and the rest of the hand were covered with 0.2 mm layer of the cream. The other dosimeter was unshielded. Procedures were performed using 110 kVp fluoroscopy at 15 pulses/sec. The measurements were categorized into four groups dependent on the duration of the procedure. The patients in all four groups were well matched for age and size. RESULTS: Procedural and cumulative hand radiation doses were higher with longer procedural duration. The overall % attenuation by the cream was 39.7% (28.6-51.5) and was unaffected by the length of the procedure (median: 40.9% at 30 min and 41.4% at 180 min; P = 0.66) or the dose of radiation. The kappa statistic for interobserver agreement for good tactile sensitivity was 0.82. CONCLUSIONS: UltraBLOX™ cream provides a new option for radio-protection for the hands of interventional cardiologists without impairing tactile sensitivity. There was no decrease in attenuation up to 180 min. © 2016 Wiley Periodicals, Inc.

Fabrication and testing of silicon nitride bearings in total hip arthroplasty: winner of the 2007 "HAP" PAUL Award.

Total hip arthroplasty (THA) bearings were fabricated from silicon nitride (Si(3)N(4)) powder. Mechanical testing showed that Si(3)N(4) had improved fracture toughness and fracture strength over modern alumina (Al(2)O(3)) ceramic. When tested with Si(3)N(4) cups in a hip simulator, both cobalt-chromium (CoCr) and Si(3)N(4) femoral heads produced low wear rates that were comparable to Al(2)O(3)-Al(2)O(3) bearings in THA. This study offers experimental support for a novel metal-ceramic THA bearing couple that combines the reliability of CoCr femoral heads with the wear advantages of ceramic surfaces.

Testing of silicon nitride ceramic bearings for total hip arthroplasty.

Modern ceramic bearings used in total hip arthroplasty (THA) consist of a femoral head (ball) articulating inside a hemispherical acetabular cup (socket); the ball and socket are made of alumina (Al(2)O(3)) and Al(2)O(3)-based composite materials. In the present study, total hip bearings were made from a different ceramic material, silicon nitride (Si(3)N(4)), by sintering and hot isostatic pressing of powders. The resulting material had improved mechanical properties over modern Al(2)O(3) THA bearings, with a flexural strength of 920 +/- 70 MPa, a Weibull modulus of 19, and a fracture toughness of 10 +/- 1 MPa m(1/2). Unlike zirconia-based ceramics that have also been used in THA, accelerated aging of Si(3)N(4) did not adversely affect the flexural strength. In simulated wear tests, Si(3)N(4) acetabular cups produced low-volumetric wear whether articulating against Si(3)N(4) or cobalt-chromium (CoCr) femoral heads. The results of this investigation suggest that Si(3)N(4) may allow improved THA bearings that combine the reliability of metal femoral heads with the low wear advantages of ceramic materials.