REVISION OF THE ACETABULAR COMPONENT WITHOUT CEMENT AFTER TOTAL HIP-ARTHROPLASTY - 3-YEAR TO 6-YEAR FOLLOW-UP

One hundred and thirty-eight consecutive revisions of an acetabular co mponent were performed in 132 patients between 1983 and 1986. The revi sion prosthesis was a hemispherical component that was coated with por ous titanium mesh and was secured to the pelvis with a variable number of screws. There were seventy-five women and fifty-seven men, and the mean age at the time of the revision was fifty-two years (range, twen ty to seventy-nine years). Due to defects in the acetabulum, 80 per ce nt of the hips were treated with bone grafts, usually a mixture of loc al autogenous graft and freeze-dried allograft. One hundred and twenty -four patients (129 hips) were available for follow-up, at a mean of f orty-four months (range, thirty-six to eighty months). Seven hips (5 p er cent) were revised again: four because of infection and three becau se of instability. There were no revisions for loosening without infec tion, and none of the components migrated in the absence of infection. Radiolucent lines were common and usually corresponded to regions in which allograft had been used. All bone grafts united by twelve months . Non-contained medial grafts underwent a phenomenon of resorption, co nsolidation, and remodeling to a sclerotic rim by twenty-four months. There were no complications related to placement of the screws. The re sults in this series were superior to results of revisions of acetabul ar components with the use of cement, which were associated with rates of failure of almost 10 per cent after a similar duration of follow-u p. The technique of maximization of host-bone coverage and of packing of all defects with cancellous autogenous graft or allograft, or both, was successful for all classes of acetabular deficiencies.