We prospectively studied the results of 411 consecutive total hip
arthroplasties with a Mecring screw-ring acetabular component inserted
without cement combined with a Stanmore femoral stem inserted with cement.
The duration of follow-up ranged from three to seven years (mean, four
years and six months). Three hundred and thirty-one patients (378 hips)
were available for physical examination and had a complete set of
radiographs. The clinical result was good or excellent for 82 per cent
(309) of the 378 hips. However, the rate of radiographic loosening of the
acetabular component, as evidenced by migration at the most recent
follow-up examination, was alarmingly high: 25 per cent (ninety-five) of
the 378 hips. In general, these patients did not have serious clinical
symptoms. The cups in women migrated significantly more often (p = 0.003)
than those in men. Migration was also more frequent in patients who were
less than fifty-one years old and in patients in whom the index procedure
was a revision arthroplasty, but these differences were not significant.
Twenty-one (6 per cent) of the acetabular cups were revised for aseptic
loosening. The high rate of radiographic loosening has led us to abandon
the use of the Mecring screw-ring acetabular component.