Abstract: A patellar component 91) for use in conjunction with a prosthetic knee joint of the type comprising a femoral component and a tibial component comprises a metal disc (2) embedded within an ultra-high molecular weight polyethylene disc (3). The polyethylene disc completely surrounds the edge of the metal disc such that the metal disc is flush with the polyethylene disc on one surface of the component. The metal disc may be provided with a knurl or serrations (20) which key into the polyethylene disc to prevent rotation of the two discs. The component (1) is fixed to the patella by means of a central peg (4) and a number of spikes (10).

Abstract: There is disclosed a surgical instrument for use in preparing a bone cavity for the subsequent implantation of a joint replacement prosthesis, and especially for the enlargement of a medullary cavity of a femur prior to the implantation of a femoral component of a hip prosthesis. The instrument comprises a shank (2) having serrations (4) on at least a part of its outer surface and a handle (3) mounted at one end of the shank, in which the shank is divided into a main body member (5) and at least one sliding member (6) which is engageable with the main body member in such a way as to allow relative sliding motion between the sliding member and the main body member during use of the instrument, so that the serrations can shape the interior surface of the bone cavity.

Abstract: A knee prosthesis comprises tibial, meniscal and femoral components. Subluxation and/or rotation of the meniscal component with respect to the tibial component is controlled by means of a control peg 21 fitted between the tibial and meniscal components, and a bar 5 spanning the intercondylar notch of the femoral component provides posterior stabilization by bearing against a cam surface 8 of a protrusion extending upwardly from the center of the meniscal component.

Abstract: A hip prosthesis having a stem (1) for introduction into the medullary cavity of a femur (13) and a head (2) which replaces a natural femoral head is characterized in that a plate-like anchoring member (3) is movably mounted at or near to the proximal end. The anchoring member is movable from an inoperative position in which it is housed within the general confines of the stem for the purpose of introducing the stem into the medullary cavity, to an operative position in which the member projects laterally of the stem to engage and anchor itself in adjacent cancellous bone.

Abstract: Instruments for use in the surgical implanation of a knee prosthesis including a femoral alignment rod for insertion into the medulla of a femur through an access hole located between the femoral condyles. The rod is resiliently deformable so that once the rod is fully inserted within the medulla the portion of the rod located within the medulla contacts the inner walls of the bone defining the medulla and is thus caused to bend. The access hole through which the rod is inserted is sufficiently larger than the diameter of the rod so as to impose no physical constraint on the rod for allowing the portion of the rod which protrudes from the access hole to extend linearly along an axis the position of which is determined by points of contact within the medulla between the rod and the inner walls of the medulla.

Abstract: This invention relates to endo-prosthetic knee joint devices.A knee prosthesis according to the invention comprises a femoral component for attachment to the femur and having a bearing surface including a first inferior curved portion and a second posterior portion contiguous with and of relatively lesser curvature than said first portion, a tibial component for attachment to the tibia and having a concave bearing surface and a meniscal component to lie between the femoral and tibial components and having bearing surfaces complementary to said first portion of the bearing surface of the femoral component and to the bearing surface of the tibial component.