Clinical Performance With HHS Clinical Trial
Official title:
Primary Uncemented Total Hip Prosthesis With Pure Ti With and Without HA, and Alumina-on-alumina Articulation
Both HA coated and certain uncoated femoral stems have good results in general. On the cup
side the results are more variable, either with or without HA. HA may delaminate from the
prosthesis, damage the articulation, witch may lead to osteolysis and aseptic loosening.
The investigators are investigating whether a well working uncemented hip prosthesis design
with HA coating, will perform without HA in the long run, when the investigators use pure Ti
macrostructure and alumina on alumina articulation.
Hypothesis: The bone ingrowth will be equal when the surface has almost equal roughness in Ti
and HA version. This means that HA on Ti is not necessary with a well functioning prosthesis
design.
0-hypothesis:The two prosthesis perform equal in survival, clinically (HHS),radiographic and
in patient satisfaction at 2, 5, 10, 15 and 20 years.
Investigate survival of the implants and possible biological consequences. Clinical outcome
with Harris Hip Score. Radiographic outcome with a modified protocol after JRC, JBJS 1990.
Patient satisfaction with the hip prosthesis (five categories).
Grit blasted TiAL6V4 + pure Ti versus grit blasted TiAL6V4 + pure Ti +HA, with almost the
same roughness. Screw cup, double tapered stem, partly double coated cup, proximally double
coated stem.
Prospective RCT. Multicenter ( Three hospitals). Selected surgeons. Non-inferiority-design.
At present 569 hips (391 patients, 178 bilateral) are randomized into the study. Inclusion of
patients into the study stopped in January 2013.
548 hips have completed follow ups at an average of 2 years, 301 hips have completed follow
ups at an average of 5 years and 60 hips at 8-10 years.
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