Metal-backed Acetabular Cups Research Articles

The use of photoelastic coatings to investigate the pelvic strain variations resulting from the introduction of cementless metal backed acetabular cups

An in vitro photoelastic coating study was initiated to investigate the influence of metal backed cementless acetabular cups on pelvic strain conditions in the immediately post operative state, for comparison with those related to normal hip joint conditions. A single dried bone hemipelvis was loaded to simulate the pelvic orientation at both the 47% stance and single leg stance. The problems associated with use of the photoelastic coating technique are discussed, particularly in relation to the analysis of the anisotropic pelvic bone. A number of critical areas were highlighted on the pelvis where high shearing strains occurred after the introduction of cementless metal backed acetabular cups.

Metal-backed acetabular cups in total hip arthroplasty.

Metal backing for the acetabular component of a total hip replacement, initially designed to allow replacement of the polyethylene liner, has since been universally accepted as a means of decreasing peak stresses at the interfaces of bone and cement. We studied the results of 238 total hip replacements that had been performed between 1980 and 1983 and that differed only in that 138 of the acetabular components had a metal backing and 100 were made of polyethylene only. Kaplan-Meier survival analysis, with three different modes of failure (radiolucency, loosening, and revision), showed a significant increase in the rate of failure of the metal-backed acetabular cup compared with the all-polyethylene cup: radiolucency, 39 compared with 23 per cent (p less than 0.0001); loosening, 4 compared with 2 per cent (p less than 0.0001); and revision, 6 compared with 2 per cent (p less than 0.0034). It was concluded that metal backing cannot be recommended for a cemented acetabular component of a total hip-replacement system.

Fracture of a metal-backed acetabular cup: A case report

In this case of fracture of a metal-backed polyethylene acetabular component after a total hip arthroplasty, there was no history of difficulties prior to the component fracture and no history of trauma.

Tri-LockTM metal-backed acetabular cups available for an improved implant/cement interface

Tri-LockTM metal-backed acetabular cups available for an improved implant/cement interface