UNIVERSAL BIPOLAR BIT FOR PREPARING THE MECHANICAL LOCKING OF THE CENTROMEDULLARY NAILS OF THE DESCENDERS AND ASCENDANTS OF THE FEMUR

摘要

The multipurpose double-pole trephine (Figure 8/13) is an instrument for drilling from inside an end of the medullary canal based on a standard trephination (from outside inwards) carried out at its other end. Said trephine is a hollow cylinder longer than the thigh bone (3). In its axis slides a perforating mandrin (5, 17) longer than the trephine properly speaking. Said mandrin perforates from inside outwards the end of the canal which is not yet open. A nozzle-shaped drill (16) slides on the mandrin (17) after it has passed through the teguments opposite the top of the patella ( in the case of descending or anterograde roding). Then the trephine is pushed outwards. The mandrin is removed. A conducting rod (6) screwed at the end of the trephine (18) replaces the latter and comes out at the trochanterian region once the trephine has been removed, Then an assembly comprising successively the conducting rod screwed to the guide perforator (8), the pin, the adapter (9) replaces the rod which comes out at the infra-patellar incision. A multipurpose interlocking guide is adapted successively to the perforating guide (21) and to the adapter (22). Then the perforator and the adapter can be removed. A retrograde or ascending roding can be carried out in the same way as an anterograde roding ( the subject of the figure). The different manoeuvres are carried out in reverse.