摘要 |
A finger joint has first and second hollow anchorage shafts (2, 3) which can be implanted in finger tubular bones with a hinge joint (4) arranged between them. The first hollow shaft (2) can be connected with a ball cage (5) of the hinge joint (4) in which a spherical part (6) is mounted, on which a protruding stem (7) is formed. This stem (7) passes through the ball cage (5), and indeed through a slit (8) provided therefor in the wall of the ball cage (5). The slit (8) in the ball cage (5) widens continuously from the point (P) at which the stem (7) passes through the ball cage (5) in the extended position of the joint (4) to the point (M) at which the stem (7) passes through the ball cage (5) in the flexed position of the joint. In this manner, additional play is allowed to the joint in the flexed position, which largely corresponds to the physiological coordinated movement of a finger joint.
|