<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>2306-4102</journal-id>
<journal-title><![CDATA[Acta ortopédica mexicana]]></journal-title>
<abbrev-journal-title><![CDATA[Acta ortop. mex]]></abbrev-journal-title>
<issn>2306-4102</issn>
<publisher>
<publisher-name><![CDATA[Colegio Mexicano de Ortopedia y Traumatología A.C.]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S2306-41022023000400237</article-id>
<article-id pub-id-type="doi">10.35366/113619</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Asimilación atlantoidea: malformación, compensación o deformidad. ¿Es parte de la invaginación basilar?]]></article-title>
<article-title xml:lang="en"><![CDATA[Atlantoid assimilation: malformation, compensation or deformity. Is it part of basilar invagination?]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Alemán-Iñiguez]]></surname>
<given-names><![CDATA[JM]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Astudillo-Pacheco]]></surname>
<given-names><![CDATA[PD]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[De la Torre]]></surname>
<given-names><![CDATA[JS]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad San Francisco de Quito  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Ecuador</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Universidad de Santiago de Chile  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Chile</country>
</aff>
<aff id="Af3">
<institution><![CDATA[,Hospital Metropolitano de Quito  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Ecuador</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>08</month>
<year>2023</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>08</month>
<year>2023</year>
</pub-date>
<volume>37</volume>
<numero>4</numero>
<fpage>237</fpage>
<lpage>243</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S2306-41022023000400237&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S2306-41022023000400237&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S2306-41022023000400237&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen:  Introducción:  la asimilación atlantoidea puede presentarse sola o asociada a otras malformaciones y deformidades de la unión craneocervical, los mecanismos etiológicos y patológicos no están esclarecidos.  Presentación de caso:  paciente de la sexta década de vida, quien fue atendida en el Hospital de Especialidades «Eugenio Espejo», con datos clínicos piramidales asimétricos, posteriores a mecanismo de lesión de caída con cinética de baja energía. La sintomatología revirtió con manejo conservador. En la actualidad, la paciente está bajo observación periódica.  Conclusión:  la asimilación atlantoidea es una malformación congénita muchas veces asintomática y parte de una compensación embriológica cuando está asociada a otras malformaciones. Es necesaria la aparición de deformidad para llegar a la inestabilidad atlantoaxoidea que no es temprana. El conocimiento y poder diferenciar los conceptos de las anormalidades de la unión craneocervical permiten indicar el mejor tratamiento y así obtener los resultados más adecuados con la individualización de cada caso.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract:  Introduction:  atlas assimilation can occur alone or in association with other craniocervical junction malformations and deformities. The etiological and pathological mechanisms are not clear.  Case presentation:  patient in her sixth decade of life, who was treated at the «Eugenio Espejo» Hospital, with asymmetric pyramidal symptoms after a low-energy kinetic fall. The condition completely reverted with conservative management. The patient is currently under periodic observation.  Conclusion:  the atlas assimilation, a congenital malformation, often asymptomatic; it is part of an embryological compensation when it is associated with other malformations. The appearance of deformity is necessary to reach atlantoaxial instability that it is not early. The knowledge of the concepts and distinction of the craniocervical junction abnormalities allows to indicate the best treatment in order to obtain the most suitable results with the individualization of each case.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[asimilación atlantoidea]]></kwd>
<kwd lng="es"><![CDATA[tratamiento]]></kwd>
<kwd lng="es"><![CDATA[inestabilidad atlantoaxoidea]]></kwd>
<kwd lng="es"><![CDATA[cirugía]]></kwd>
<kwd lng="es"><![CDATA[fijación]]></kwd>
<kwd lng="es"><![CDATA[columna cervical]]></kwd>
<kwd lng="en"><![CDATA[atlantoid assimilation]]></kwd>
<kwd lng="en"><![CDATA[treatment]]></kwd>
<kwd lng="en"><![CDATA[atlantoaxial instability]]></kwd>
<kwd lng="en"><![CDATA[surgery]]></kwd>
<kwd lng="en"><![CDATA[fixation]]></kwd>
<kwd lng="en"><![CDATA[cervical spine]]></kwd>
</kwd-group>
</article-meta>
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