Kaplan-Meier survival analysis was performed with the type of cup as the independent factor and revision for any reason as the endpoint.
Get about one cup of any type of flour per child/person and any color of food coloring, and also get one cup of water per child/person.
This type of cup dosimeter was used earlier (Kobeissi et al. 2008) so the team was experienced in its use and confident of its performance.
Because of this potential bias, the type of cup fixation (cemented or uncemented) was introduced as a covariate.
In contrast, the risk of revision due to deep infection is not influenced by the type of cup coating.
There were no differences regarding age at surgery, side, bilateral THAs, followup, type of cup used, cup inner diameter, and body mass index between the two groups.
In an exploratory analysis, we found no evidence that the type of cup fixation (cemented or uncemented) influenced the risk of dislocation (data not shown).
In Sweden, this type of cup has only recently been introduced, and, with few exceptions, only one design has been inserted (Avantage; Biomet, Warsaw, IN).
However, the regression model indicated that the type of cup fixation did not influence the risk of revision of the stem for any reason as the endpoint (Table 4).
A Cox proportional hazards model including the type of coating, age at index revision, sex, cause of cup revision, cup design, the use of bone graft at the revision procedure, and the type of cup fixation at primary THA were used to calculate adjusted risk ratios (RRs with 95% CI) for re-revision for any reason or due to aseptic loosening.
