RADIAL head arthroplasty: does ligaments repair influence outcomes? A minimum two years follow-up radiographic multi-center study.

PURPOSE: The current indication for comminuted radial head fractures is radial head arthroplasty (RHA). The main purpose of this study was to investigate any statistical differences in terms of prosthesis revision or removal and radiographic degenerative changes by comparing patients who underwent RHA and ligaments repair to those who underwent only RHA implant at minimum two years follow-up. The secondary aim was to delineate a trend profile of RHA implants. METHODS: All patients who underwent RHA surgery for traumatic pathology between January 2012 and December 2017 were eligible. Two researchers independently and retrospectively reviewed the patients' charts and collected the following data: type of prosthesis, associated surgical procedures and revision surgery. They also looked for any radiographic sign of prosthesis loosening, overstuffing, capitellar osteopenia, heterotopic ossification and degenerative changes. No clinical evaluation was performed. RESULTS: In 6 years, 124 RHA were implanted (74 female, 50 male, mean age 56). The main diagnoses were: terrible triad, trans-olecranon fracture and isolated radial head fracture. It was found no significant statistical difference between the 2 groups; nevertheless, the cohort of patients that underwent ligaments repair had a lower revision rate in comparison with the other. Suture of the annular ligament seems to be critical. The overall revision rate was 10.5%. CONCLUSION: This multi-center study found no evidence that ligaments repair, as an associated surgical procedure, improves RHA longevity, except for annular ligament. Nevertheless, it seems to prevent degenerative changes at midterm follow-up.

Adsorption sites and ligand effect for CO on an alloy surface: a direct view.

CO adsorption on a PtCo(111) surface was studied by scanning tunneling microscopy. Comparison of images with chemical contrast of Pt and Co and images showing the CO molecules indicates that CO resides exclusively on top of Pt sites and never on Co. CO bonding is highly sensitive to the chemical environment. The probability to find CO on a Pt atom increases drastically with the number of its Co nearest neighbors. Ab initio calculations show that this ligand effect is due to different positions of the center of the Pt d band.

[An estimation of the prevalence of hanseniasis by research in non-specific demand for health services]. / Estimativa da prevalência da hanseníase pela investigação em demanda inespecífica de agências de saúde.

In view of the importance of knowing the prevalence and incidence rates of a disease to learn about its behavior and control at the collective level, a study was undertaken to determine the occurrence of hanseniasis among the clients of health agencies and to explore the use of this methodology for estimating the epidemiologic "iceberg" of the disease, i.e., the total number of cases including those that are not officially reported. The city of Taubaté in the Paraíba Valley, State of S. Paulo, Brazil, was chosen for the study. All clients aged 15 years or older were screened regardless of variables such as sex, age, social condition or marital status. The study was based on what is known about the populational distribution of the disease and the characteristics of health services. In view of the local peculiarities of operationalization (e.g., identity of the different clientele, availability of offices, hours of greatest flux), the sampling process used was simple randomization. The patients with active disease detected, 40 of the 10,013 persons examined, correspond to a prevalence of 3.99/1000, with a confidence interval (at the 5% level of reliability) of 3,365 to 4,625/1000, indicating that the minimum estimated increase of prevalence is of the order of 52% and the maximum estimated increase is of the order of 109%.(ABSTRACT TRUNCATED AT 250 WORDS)