[Injuries of the trapezo-metacarpal joint].

The trapezo-metacarpal joint has a complex structure with specific anatomical, physiological, radiological and clinical characteristics. Several anatomical descriptions of this joint are available, and we believe one should know it well in order to understand its radiological problems. For instance a wrong projection may lead to overlook a fracture, especially in the trapezium. Several mechanisms have been suggested to explain the lesions of the base of the first metacarpal and of the trapezium. The therapeutic consequences of these considerations are not very important. Regardless of the lesion, two methods seem to yield the best results: Iselin's double pinning; oblique traction as suggested by L. Thoren. A perfect reduction is most important in both methods, as is usually the case fort any articular structure. This will reduce the risk of trapezo-metacarpal arthritis which still remains an unpredictable complication.