GB1485681A - Knee joint prostheses - Google Patents

Abstract

1485681 Endoprosthetic elbow or knee joint H KAUFER L S MATTHEWS D A SONSTEGARD and I P MURRAY 20 Jan 1975 [6 Feb 1974] 2468/75 Heading A5R An endoprosthetic knee joint comprises a femoral component 16 having an attachment stem 30 and a pair of spaced, parallel, spheroidally curved condyle runners 22 straddling a hollow central housing, the runners having at one end 26 a larger radius of curvature than at the other end and bearing on a pair of sliding shoes 38 formed on a tibial component 18 having an attachment stem 48. The shoes have a radius of curvature corresponding to that of the ends 26 of the runners such that when the joint is flexed there is clearance between the shoes and runners allowing controlled twisting of the joint. The components are connected by a ball and socket joint, the ball 34 being mounted on a stem 44 extending upwardly from a base 46 of the tibial component and engaging a plastics socket 36 located in the hollow housing. The socket is formed of two segments 36A, 36B each with a slot 68, 62 to provide for movement of the stem during pivoting of the joint. The segments are inserted at right angles to their final position to enable a flat on one segment to clear an overhang of the housing cavity 60, a tool with projecting pins then rotating the segments to their final position and locking them above the overhang.