Just then, whether it was the cold of the morning that was now approaching, or that he had eaten something laxative at supper, or that it was only natural (as is most likely), Sancho felt a desire to do what no one could do for him; but so great was the fear that had penetrated his heart, he dared not separate himself from his master by as much as the black of his nail; to escape doing what he wanted was, however, also impossible; so what he did for peace's sake was to remove his right hand, which held the back of the saddle, and with it to untie gently and silently the running string which alone held up his breeches, so that on loosening
it they at once fell down round his feet like fetters; he then raised his shirt as well as he could and bared his hind quarters, no slim ones.
Radiographically, all patients in Group 1 were stable, and there were no cases of acetabular loosening or revision of the acetabular shell.
Revision rates due to aseptic loosening of 11.9% were reported for HA-coated cups at 8-year follow-up.
The purpose of this investigation was to corroborate early studies and confirm through a multicenter study that the addition of an AD HA coating to an acetabular shell resolved the problem of early acetabular loosening. The rougher surface of the arc deposited (AD) coating, as hypothesized, provided better initial stability, leading to excellent intermediate results and the potential for long-term biologic fixation.
No patients in Group 1 required revision of any of the components for loosening, mechanical failure, or osteolysis.
The five patients with acetabular loosening were revised at 3.8, 4.0, 4.3, 4.4, and 4.6 years after the index procedure.
Postoperatively, there was no acetabular erosion at 5 years; however, shell migration was observed in three patients by 60 months postoperatively prior to revision for acetabular loosening. Among the nonrevised shells, there were no patients with radiolucencies in all three DeLee and Charnley zones, nor were there any radiolucent lines greater than 2 mm wide in any zone at 5 years postoperatively (Table 2).
There were no revisions for aseptic loosening or evidence of radiographic instability in AD HA Group 1 at a minimum of 5 years (mean, 5.5 years), while there were five revisions for aseptic loosening (three with acetabular migration) at 5 years in Group 2 (p < 0.01).
Udomkiat and colleagues (21) previously reported several criteria that are predictive of loosening for a cementless acetabular device.
In Group 2, three of the five components revised for acetabular loosening had evidence of component migration in a radiographic examination prior to revision.
The absence of radiolucent lines and component migration may be predictive of a long-term low revision rate due to aseptic loosening. Radiographic signs of shell migration and clinical loosening of the acetabular components, seen in the first-generation design are absent at an identical time frame in a similarly designed multicenter study with other parameters being on par.