摘要:
A tibial knee joint prosthesis for attachment to a suitably prepared tibial bone, providing bearing portions in the lateral and medial compartments. The lateral and medial bearing surfaces of the component are inclined at different angles in the anterior to posterior direction of the knee, so that when mounted to the tibia, the lateral bearing surface of the prosthesis is higher than the medial bearing surface to the posterior side of the knee. In this way the lateral ligament is tightened progressively more than the medial ligament as the knee moves from extension to flexion, resulting in increased stability in the lateral compartment.
摘要:
A drill guide comprising: a body comprising a hole extending therethrough for guiding a drill; and an alignment tool, the alignment tool being operable to connect the body to an intramedullary rod, such that the orientation of the body is fixable with respect to the intramedullary rod in an anteroposterior plane and in a transverse plane.
摘要:
The invention concerns prosthetic knee joint devices, in particular of the meniscal type having femoral, tibial and meniscal components co-operable to allow congruence of the interfacing articulation surfaces while allowing close simulation of the natural joint in flexion-extension. The device features meniscal and tibial components each of one-piece bicompartmental construction having a pair of mutually spaced portions respectively defining condylar articulation surfaces, such portions being joined by way of an intercondylar portion, and the tibial and meniscal intercondylar portions being interengageable by means of complementary elements of a rib-and-groove joint arranged substantially in the antero-posterior direction, both the rib and the groove having curved side faces to allow limited long axis rotation between the components, and the groove being open at at least one end. With appropriate dimensioning, the device allows movement of the meniscal component in the antero-posterior direction, limited movement in the medio-lateral direction and limited long-axis rotation. It also provides in a simple and effective manner a securement against tibio-meniscal dislocation.
摘要:
A drill guide comprising: a body comprising a hole extending therethrough for guiding a drill; and an alignment tool, the alignment tool being operable to connect the body to an intramedullary rod, such that the orientation of the body is fixable with respect to the intramedullary rod in an anteroposterior plane and in a transverse plane.
摘要:
The invention concerns endoprosthetic knee joint devices of the so called `meniscal knee`variety.A device is provided of the above type wherein the mutually engaging bearing surfaces of the tibial platform and the meniscal component have a part-cylindrical shaping to allow rotation therebetween about an antero-posterior axis, the superior bearing surface of the tibial platform preferably being convex.Movements of the natural joint can still be closely simulated and full congruency can be retained throughout the natural range of movement, but there is an additional degree of restraint at the tibio-meniscal interface. Unrestricted antero-posterior relative movement is allowed, as in the conventional meniscal knee, but the part-cylindrical interface shaping serves to reduce the risk of lateral or medial dislocation.
摘要:
A prosthetic joint device is provided with first and second components respectively providing convex and relatively flat articulatory bearing surfaces, and a third component is located between the former components and has two surfaces which are complementary to and engage the convex and flat surfaces. Preferably the two pairs of engaged surfaces are suitably respectively spherically shaped and planar. The device can move under natural muscular and ligamentous control, in a varying manner closely simulating that of a natural joint which maintains uniform load distribution. Initial development centered on the provision of a knee joint endoprosthesis, but the mechanics of the device are well suited to other joints, particularly of non-congruous form, and also to joints in exoprostheses.
摘要:
A stylus assembly (10) adapted to align a surgical tool with a bone, the stylus assembly (10) comprising: a mounting element (12,18); a tool guide (50) adjustably mounted relative to the mounting element (12,18); a stylus (16) adjustably mounted relative to the mounting element (12,18) and having a curved portion for engagement with a predetermined part of the bone; and a lockable retaining member (14) for simultaneously locking the surgical tool guide (50) and the stylus (16) to the mounting element (12,18).
摘要:
A kit of parts for use in unicondylar meniscal bearing knee replacement comprises a plurality of meniscal bearings, each meniscal bearing comprising a body defining a dished first bearing surface on one side thereof and a second surface on an opposing side of the body. Each meniscal bearing has an entrapment between 3.2 mm and 3.8 mm. Meniscal bearings and methods of performing unicondylar meniscal bearing replacements are also described.
摘要:
A femoral extension prosthetic component for use in a unicondylar meniscal bearing unicompartmental knee replacement is described. The femoral component comprises a securing element and a bearing surface, the securing element adapted to abut and be connected to a distal end of a femur bone, and the bearing surface adapted to abut a meniscal bearing. The femoral component includes an entrapment portion adapted to extend beyond the meniscal bearing. Tibial components and meniscal bearings are also described, as well as methods of using such components.
摘要:
A rotary mill is disclosed comprising a body portion (4) having a milling surface (10) and a central bore (20) extending along an axis of rotation (18) of the body portion (4); and a guide portion (6) having a guide body (22) and a guide peg (24) extending from the guide body (22), the guide peg (24) operable to be received in the central bore (20) of the body portion (4), the guide body (22) having at least one alignment feature (28, 30) which is the same as that of a prosthesis component. A method of implanting a unicondylar femoral component is also disclosed, the method comprising, a) reaming the femoral condylar surface to accept the unicondylar femoral component; b) drilling peg holes for affixing the unicondylar femoral component; c) affixing a guide portion of a rotary mill onto the prepared condylar surface using the drilled peg holes; d) reaming a portion of bone anterior to the affixed guide portion; e) removing the guide portion from the bone; and f) affixing a unicondylar femoral component to the prepared condylar surface.