Abstract: A surgical instrument (100) and system incorporating such instruments, the instrument comprising: a stem (112), the stem having a proximal end (116) and having a distal end (110); a handle portion (114), the handle portion being provided towards the proximal end of the stem; and a guide element (108), the guide element being provided towards the distal end of the stem, wherein the guide element provides: a body element (131) defining a guide channel (128), the guide channel having a longitudinal axis (X-X) and being open at both ends along the longitudinal axis; and one or more positioning elements (130a, 130b). The instrument and system are suited to the removal of a polyethylene acetabular liner (25) from an implanted shell (27), for instance to remove that liner and replace it with another, whilst minimising the risk of damage to the shell holding it.

Abstract: A surgical instrument system includes a commonly-sized orthopaedic surgical instrument assembly for use in implanting a femoral component, along with a number of orthopaedic surgical instrument assemblies having varying sizes of instruments of use in implanting a tibial tray component and a patella component.

Abstract: A medical implant comprising: ?an implant body configured for use as a medical implant, ?a surface on the implant body, ?wherein the surface comprises a plurality of projections (40), each projection having a base proximal to the implant body, a peak distal to the implant body, and a side wall extending from the base to the peak, ?wherein the surface has a peak density in a range 50 to 500 peaks per 11 m2, and ?wherein the projections are tapered such that a width at the peak of each projection is less than a width at the base of each projection.