Abstract: An instrument including a cutter (2) mountable on a cutter 32 spindle (1) and shaped in such a way that it also acts as a test cup 33 engageable by a test head of a femoral prosthesis. The cutter (2) may be attached to the pelvis (34) by means of nails (29), and the cutter position is detected by sighting means (32) on the cutter spindle (1). The sighting means (32) are then used to arrange the final cup in the same position as the cutter (2) so that the position of the final cup may be selected in such a way that the risk of joint dislocation is reduced.

Abstract: The prosthesis of the invention comprises a shaft (1) with its upper end (3) linked to a neck (2) connecting it to a spherical joint head. The shaft (1) comprises a proximal area (H1, H2) with a reversed spiral double twist, over a length substantially equal to one third or half of the length (H) of the shaft (1). The proximal segment (H2) of the proximal area and the distal area (H3) are generally rectilinear in the antero-posterior plane, while the distal segment (H1) of the proximal area is curved with the center offset frontwards. The invention provides a prosthesis that fits more effectively in the medullary channel and does not need cement to fix it.

Abstract: The hollow tubular implant of the invention comprises an internal cavity delimited by a peripheral wall open at its first end and having a generally circular cross-section external surface. Two side surfaces are solid and top and bottom surfaces have communicating holes in them. Annular external ribs prevent retrograde movement and rotation of the implant when inserted between two adjacent vertebrae. The implant achieves good fastening together of the two vertebrae and fusion thereof by means of a bone graft inserted in the implant before fitting.