Catastrophic deformations of weller endoprosthesis heads

Catastrophic deformations of Weller endoprosthesis metal heads, done on account of penetration of bone cement molecules, which forced to surface of polyethylene cup and head are described in the paper. The deep and continuous scratch was about fifty times deeper and not very deep and discontinuous was about four times deeper in compare with the biggest high of irregularities of head surface occurring without presented changes. Conclusion shows that bone cement molecules, which forced to surface of polyethylene cup and head, produce some scratches on the metal heads of Weller endoprosthesis. Observed scratches on the heads surface were considerably deeper in compare with the basic roughness of surface. The direction of scratches is coincident with the vector of displacements on the surfaces of polyethylene cup and head contact