Abstract: An improved polyaxial mechanism is disclosed. The mechanism preferably works in conjunction with a bone plate and fixation mechanism, such as a screw, rod, or the like. The improved polyaxial mechanism increases the strength of the locking among the locking mechanism, fixation mechanism, and bone plate. In addition, the improved polyaxial mechanism allows for easy locking among the elements, as well as more difficulty in unlocking the elements. A method for utilizing the improved polyaxial mechanism is also disclosed.

Abstract: A polymeric external fixator element, such as a rod or a pin or a clamp, has at least one contacting surface. At least one of the contacting surfaces of the element responsible to establish connection between the element and a different external fixator element is provided with a rough ablated structure. The clamping can be improved if one of the polymeric elements comprise fibers having fiber parts protruding above the surface.

Abstract: A memory management device includes circuits having a DCh base activate in a set of N circular commands, h successive commands among the set of commands. A device DCh activates h columns among K: S.sub.0, . . . , S.sub.K-1. A device DC2 activates two line sections among 2L: S'.sub.0, S".sub.0, . . . , S'.sub.L-1, S".sub.L-1. The device DC2 is dependent upon a condition C.sub.d which indicates if a limit d is exceeded by the activated columns, in which case the activation goes from S'.sub.i and S".sub.i and S'.sub.i+1, or else from S".sub.i and S'.sub.i+1 to S'.sub.i+1 and S".sub.i+1 and so on. Selection of groups of memory cells in a matrix-organized field is by high and low addresses transmitted to the devices DC2 and DCh by means of buses B.sub.L and B.sub.K.