Morphology and morphometric study of occipital condyles

Abstract

Introduction: The occipital condyles are undersurface protruberances of the occipital bone in vertebrates, which articulate with the superior facets of the atlas vertebra. The condyles are oval or reniform in shape, and their anterior extremities directed forward and medially and are closer together than the posterior end. Aim: The aim of the study is to provide important anatomical parameters for lateral transcondylar approach. Materials and Methods: 200 occipital condyles in 100 dry human skulls ( 73 males and 27 females) were studied. The measured parameters included length, width, height, shape, anterior and posterior intercondylar distance, distance between basion and opesthion, distance from anterior tip of the condyle to the basion and opestion and distance from posterior tip to the basion and opesthion. Measurements were made using Vernier Callipers. Results: The mean length, width and height of the occipital condyles in males is greater than females. The anterior intercondylar distance is more in females whereas posterior intercondylar distance is more in males. The mean distance from basion to opesthion / anteroposteriordiamerer of foramen magnum is more in males than in females. The mean distance between the anterior tip of occipital condyles to basion is more in females than in males on both the sides. Conclusion: The knowledge of condylar anatomy helps the surgeon in making important decisions regarding extent and direction of condylar drilling and minimizing injury and retraction of neural structures. KEY WORDS: Occipital Condyles, Foramen Magnum, Intercondylar distance, Basion, Opesthion.

Morphological analysis and morphometry of the occipital condyle and its relationship to the foramen magnum, jugular foramen, and hypoglossal canal: implications for craniovertebral junction surgery

“…A detailed knowledge of the morphology and morphometry of OC, as well as its relationship to the surrounding bony structures including the FM, the orifices of HC and the JF in dry skull was evaluated to provide essential data to improve surgical outcomes. The most prevalent shape of OC in this study was oval-like condyle or type I, which agreed with previous findings in Indians [ 14 , 19 , 26 ], and Turks [ 20 , 27 ]. In contrast, Aragão et al [ 13 ] and Bayat et al [ 28 ], reported that the most common shape in Brazilians was S-like condyle or type III and kidney-like condyle or type II in Iranians.…”

“…Moreover, the average OC-H was 7.4±1.1 mm, which was lesser than those reported previously [ 1 , 30 ]. This data can be used to determine how deep the OC must be drilled [ 14 ] and the successful insertion of screws during occipitocervical fixation [ 30 ].…”

“…This process increases the angle of exposure, greater visualization, and enhances access to the ventrolateral and ventral aspects of CVJ [ 5 , 11 , 12 ]. The morphological or morphometric analysis of OC has been described in a majority of CVJ anatomical and biomechanical studies [ 1 , 13 - 15 ]. The stability of CVJ depends mainly on the length of OC.…”

Morphological analysis and morphometry of the occipital condyle and its relation to surrounding structures: implication in craniovertebral junction surgery

“…Therefore, removing the same amount of bone stock results in greater O-C1 joint instability in shorter condyles compared to longer ones, whereas a longer condyle may necessitate more widespread resection for optimum visualization (23,27,28). In addition, the thickness of OC also matters during condylectomy as one should know how deep of the OC must be drilled (21) . The greater thickness of OC may facilitate the successful screw placement during occipitocervical fixation (23).…”

“…A patient with a large OC has limited exposure to the ventral aspect of the CVJ (40). The height of the OC is also important during condylectomy because it is necessary to determine how deep the OC must be drilled (21). Furthermore, the higher thickness of OC may improve in the successful insertion of screws during occipitocervical fixation (23).…”