ABSTRACT
Due to the often late detection and the neurological disability as a consequence of the disease, leprosy plays an important role in the public health system of emerging countries with the highest prevalence such as India and Brazil. The National Leprosy Control Program of the Ministry of Health and the Health Institutions of the Federal States in Brazil has implemented a strategy to ensure successful treatment of people in rural areas both at the preventive and curative level. A successful screening program, timely treatment of patients according to the stage of disease, and the introduction of preventive measures have significantly reduced the prevalence of leprosy in Brazil over the last 20 years. Due to limited medical care and socioeconomic weakness in the Amazon region in Brazil, the early eradication of leprosy does not seem to be currently realistic.
Subject(s)
Endemic Diseases/prevention & control , Health Promotion/organization & administration , Leprosy/diagnosis , Mass Screening , Public Health , Brazil , Humans , Program EvaluationABSTRACT
OBJECT: The authors measured relevant quantitative anatomical parameters to define safety zones for the placement of C-1 posterior screws. METHODS: Nineteen linear, two angular, and four surface parameters of 20 dried atlantal specimens were evaluated. The Optotrak 3020 system was used to define the working area. Ideal angles for screw positioning were measured using digital radiographs and a free image-processing program. Six silicone-injected cadaveric heads were dissected bilaterally to study related neurovascular anatomy. The depth (range 5.2-9.4 mm, mean 7.2 +/- 1.1 mm) and width (range 5.2-8.1 mm, mean 6.5 +/- 0.9 mm) of the transverse foramen varied considerably among specimens. The mean posterior working area was 43.3 mm2. All specimens accommodated 3.5-mm-diameter screws, and 93% accepted 4-mm-diameter screws. In 10 specimens (50%), partial removal of the posterior arch was necessary to accommodate a 4-mm screw. The mean maximum angle of medialization was 16.7 +/- 1.3 degrees; the mean maximum superior angulation was 21.7 +/- 4.7 degrees. CONCLUSIONS: The anatomical configuration of the atlas and vertebral artery (VA) varied considerably among the cadaveric specimens. The heights of the C-1 pedicle, posterior arch, and posterior lamina determine the posterior working area available for screw placement. The inferior insertion of the posterior arch may have to be drilled to increase this working area, but doing so risks injury to the VA. A dense venous plexus with multiple anastomoses may cover the screw entry site, potentially obscuring the operative view and increasing the risk of hemorrhage.