The Applied Anatomy Of The C0-C1-C2 Complex

Objective: Through anatomizing the cadavers, measure the ligaments, find out the shape, structure of the ligaments, the function and mode when the joint is moving. Measuring the correlate data's of the atlas, establishing the formula, understanding the displacement of points, the variety of the canal sectional area and dimensions of the canal when the joint is rotating. In the clinic, appraising the sufferer of the atlas and axis disease correctly, taking more appropriate methods conveniently.Material and methods: (1) 30 atlas specimens of adults. Twenty are male, the others are female. No matter their race and age, excluding deformity and torn in aspect. Establishing the formula, understanding the displacement of points, the variety of the canal sectional area and dimensions of the canal when the joint is rotating. (2) Nine human skull and neck cadaveric specimens fixated by formalin, all are male. Measuring the length and width of the ligaments, analyzing the datas.Results: (1) The formula of calculating the displacement of the points is: d=2a×sm(α/2). The formula of calculating the areas of the shadow is: s= ( π-α π /180-sin α ) r~2 ( α is the angle of the rotating and r is the half of the arrowy diameter of the atlas. ) (2) The length and width of the transverse ligaments are 20.41 ±0.48mm and 9.74 ±0.45mm. The length and width of the alar ligaments are 11.65±0.50mm and 6.65 ± 0.32mm.The length of the apical ligaments are 22.72± 0.84mm.Conclusions: There are complexity in the construction and uniformity in the motion among the occipito-atlanto-axial complex. When the atlanto-axial joint is rotating, the facts of limiting the motion are transvers ligments and alar ligments. If the facts are lost, it can induce rotational dislocation, and then can lead to death. This method provides academic foundation for knowing and treating the dislocation of the atlantoaxial and injuries of the ligaments of the atlas in the clinic.