Morphological analysis of occipital condyles and foramen magnum as a guide for lateral surgical approaches

Objectives Surgical approaches to the craniovertebral junction CVJ are associated with a high mortality and morbidity when undertaken without detailed morphologic analysis of the region In spite of the clinical importance of this area there are only few anatomical reports are available in the literature The aim of the present study was to present the detailed anatomy of the foramen magnum FM and occipital condyle OC for surgical approaches to the CVJ region Methods Morphometric analysis was performed on dried human occipital bones of unknown sex and age from Turkish population Four parameters were measured for FM and eleven parameters for OC FM shapes were classified FM index was calculated Results The anteroposterior and transverse diameters of FM were plusmn mm and plusmn mm respectively Anterior and posterior intercondylar distances were plusmn mm and plusmn mm Anteroposterior and transverse diameters of OC were plusmn mm and plusmn mm Sagittal intercondylar angle was plusmn degrees on the right and plusmn degrees on the left side OC anterior tip opisthion distance was plusmn mm on the right and plusmn mm on the left side there was a significant difference between the right and left side for these two parameters p lt FM was classified into seven morphological shapes tetragonal shape was the most commonly observed Conclusion This study gives a detailed morphological analysis of the CVJ showing that most of the CVJ parameters are variable Each surgical approach to this area has advantages disadvantages limitations and potential risks Anatomical structures must be well known and clinical and radiological diagnostic procedures like plain radiography computed tomography and magnetic resonance imagining should be performed before surgery nbsp