CEMENTLESS CUP ANCHORAGE IN TOTAL HIP SYS TEMS - COMPARATIVE-STUDY OF3 DIFFERENT ACETABULAR COMPONENTS WITH TITANIUM SURFACES

A wealth of commercially available hip endoprotheses makes it difficul t for the practitioner to choose the best implant for each individual case. In a multi-centre study, in which 22 hospitals took part, a ceme ntless stem was used 1172 times and was combined with 3 different ceme ntless cup components. The follow up period ranged from 1-8 years. In 321 cases the spherical Mecring cup, in 208 cases the spherical CLS-ex pansion cup and in 643 cases the conical Weill-ring was implanted. The predominant indication for the THR was primary coxarthrosis (767 pati ents). Evaluation of clinical results was based on the Merle d'Aubigne score. Good or excellent results were found in 82% for the Mecring, i n 85% for the Weill-ring and in 91% when the CLS-expansion cup was use d. Whereas 88% of the patients with the Mecring or Weill-ring had mini mal or no pain, 94% of the patients had minimal or no pain when the CL S-expansion cup was implanted. Aseptic loosening was found in 1,25% fo r the Mecring and 1,5% with the Weill-ring. In the CLS-expansion cup g roup, 2 cases with radiological signs of loosening were seen, but neit her patient required revision. The CLS-expansion-cup with the press fi t system shows better medium follow-up results in this study, than the Mecring or Weill-ring systems.