Acetabular System for Modular Dual-Motion Total Hip Replacement

Abstract

The invention relates to a modular dual-action acetabular system for use in total hip arthroplasty. The system comprises an acetabular cup (1), a rigid acetabular liner (3) that locks into the acetabular cup (1) via conical attachment surfaces (2, 4), an alignment element (5) that limits off-axis placement of the liner, a highly cross-linked polyethylene insert (8), a femoral head (11), and a femoral neck and stem (12). The geometry of the acetabular cup (1) and the rigid acetabular liner (3) is arranged to create a nominal 0.4 mm gap on the opposing surfaces, excluding the conical locking zones. This gap limits the wide contact of different metal surfaces and mechanical interference with angled screw heads. Additional fixation can be achieved in revision applications using perforated, flexible and cuttable acetabular cup wings (16) and an acetabular cup attachment (17).The double articulation and eccentric insert geometry contribute to both range of motion and stability.