The geometrical shapes of the Durom Cup and head, the nature of the backside coating, the deformation of the cup upon impaction during installation, and the inherent difficulty in orientating and seating the cup itself all contribute to the failure of bone to integrate into the cup.
Analyses of retrievals of Durom Cup components removed surgical revision procedures all exhibited poor to no evidence of bone on the fixation surface.
Clinical presentations of patients 1 to 4 years post implantation with a failed Durom Cup prosthesis were essentially the same across different studies. These included:
Helping Defective Hip Replacement Recipients In Wisconsin
- No continuous radiolucent lines seen on xrays
- Radiographic assessment failed to reveal any significant migration or osteolysis
- Persistent, severe, unexplained groin pain that is worse with activity
- No infection (normal C reactive protein and Sed rates)
- Durom Cups were not grossly loose at revision, however, in all cases, the cups were easily removed as soon as the peripheral rim fins were disengaged
- Bone scans did not demonstrate increased uptake around acetabular or femoral components, although in some patients the bone scans did show increased uptake
- Small amount of periarticular fluid