Patellar Button and knee prothesis for resisting medial and lateral forces

摘要

Femoral component 10 comprises lateral 11 and medial 12 condynes, open intercondylar area 13, patella flange 15 and patella groove 16 extending from the open area 13 to a free end of the flange; the flange surface for patella contact is, from a distance extending inwardly from the free end configured to resist medial to lateral forces - flange 15 has a twist or roller coaster shape. Patella component 22 (Figure 13) has off-set dome (23) with respective lateral and medial facets (24, 25). Also independently claimed is a device (Figure 39 onward) for intra-operative checking of patellar tracking to allow correct insertion of the femoral and patellar components, comprising a first part (29) having a polymeric patella component matching a femoral component, and an extension member for registering with a second part (30) having a portion sized to a cut surface of the patella and with means to engage the cut surface; a further member registers with the first part, with sliding between the parts.