Shoulder joint prosthetic system

摘要

In a first aspect the invention provides a glenoid prosthesis assembly for use in a shoulder joint arthroplasty. The assembly comprises a first shell component 40 to be affixed to a scapula and a smaller second component 35 having a surface for articulation 36 with a humeral head. The first component 40 may be affixed to at least two of the glenoid, acromion and coracoid processes of the scapula and the second component 35 may be cemented within the first component allowing initial adjustment of the second component 35 relative to the first component 40. A second aspect provides a modular proximal humeral prosthesis for articulation with a glenoid mounted prosthesis with a stem and with convex 11 or concave 7 demountable upper parts. Alternatively the humeral prosthesis may have a head part 11, an upper part 4 and a stem, with a recess or projection formed on the upper part for coupling with the head part. In another alternative the upper part has a projecting flange or fin to which soft tissues may attach and anchor. The modular proximal humeral prosthesis may have convex or concave demountable heads. Further there is a glenoid prosthesis 5 which comprises a head part 30 with a convex articulating surface and a body part 28 with a frustroconical taper with a screw formation. Alternatively the glenoid prosthesis has a concave articulating surface 15 having a tray or plate shaped base part 24 with an integral screw formation 26 there being an intermediate annular part 20 with lugs 21 to project into the glenoid for stabilisation.