La forme de la cavité glénoïdale de la scapula humaine: variabilité et hypothèse fonctionnelle

Abstract

The glenoid cavity of the scapula can be sorted according to its shape in lateral view: pear-shaped cavities are more frequent than egg-shaped ones, elliptic shapes being the rarest. The morphology of the glenoid cavities is usually the same on both sides of a given individual, but when asymmetrical, pear-shaped cavities are more often present on the right, the other shapes being more frequent on the left. Elliptic and egg-shaped cavities are more common in men than in women. Elliptic glenoid cavities and the associated humeral heads are usually of big size, suggesting that they could be well adapted to sustain significant loads. No other functional particularity stood out from the analysis of the shape of the glenoid fossa. By contrast, egg-shaped and mainly elliptic types much more frequently show a remodelled border. This suggests that those shapes could be the result of a secondary deformation of the pear-shaped type under the action of loads applied on the scapulohumeral joint. Either their intensity or their direction would determine the shape acquired by the glenoid cavity at the time of death.