Fifteen cases of trapezio-metacarpal dislocations are reported. The authors recommend a surgical procedure which, alone, allows a reduction and a stabilisation in the right place of this joint. This stabilisation is ensured by a dorsal ligament reconstruction, which allows an elastic stability of the first metacarpal. An anatomical study proved the worth of the dorsal ligamentous apparatus, the lesion of which enables the dorso-radial dislocation of the first metacarpal. These lesions were found as much in the course of cadavers experimentation as in the course of clinical experience. The follow-up of the authors cases confirms the value of the surgical procedure and the superiority of their technique as opposed to others ligamentous reconstructions. This dorsal approach, easy to perform, ensures in a trice the "resting position" of the thumb and the articular congruity. At last, it protects a good stability without perturbing the normal laxity of this joint.