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DOS Kongressen 2017 ·
157
Does year of surgery influence revision risk of ce-
mented primary total hip arthroplasty – results
from the Danish Hip Arthroplasty Register (DHR)
Graversen Anders Elneff, Varnum Claus, Pedersen Alma Becic, Overgaard Søren
Dept. of Orthopaedic Surgery and Traumatology, Odense University Hospital ;
Dept. of Orthopaedic Surgery, Vejle Hospital; Department of Clinical Epidemiol-
ogy, Aarhus University Hospital; Dept. of Orthopaedic Surgery and Traumatol-
ogy & Department of Clinical Research, Odense University Hospital & University
of Southern Denmark
Background:
The percentage of patients who received cemented total hip
arthroplasty (THA) in Denmark decreased by 60 % from 1995 to 2015. This
could affect the outcome of cemented THA due to less experience with the
cementing technique.
Purpose / Aim of Study:
We aimed to compare the revision risk of cemented
THA operated in 4 different time periods from 1995 to 2015 in order to explore
time trends in revision risk.
Materials and Methods:
All cemented THA registered in the DHR (n=44,254)
were included. Dual mobility cups (n=1,731), cancers (n=535), and missing
data on confounders (n=61) were excluded. We defined 4 time periods: 1995-
1999 (Period 1=reference), 2000-2004 (Period 2), 2005-2009 (Period 3),
and 2010-2015 (Period 4). Using regression with the pseudo-value approach
with death as a competing risk we estimated the relative risk (RR) of any revi-
sion with 95% confidence intervals at 3-months and 6–years follow-up. RRs
were adjusted for sex, age, primary diagnosis, femoral head size, and duration
of surgery.
Findings / Results:
We included 14,366 (34%), 12,210 (29%), 9,442 (22%),
and 5,925 (14%) THAs in Periods 1-4, respectively. The cumulative incidences
of any revision at 6-years follow-up were 3.5% (3.2-3.8), 2.9% (2.7-3.3),
3.7% (3.3-4.1), and 4.3% (3.8-5.0) for Periods 1-4, respectively. At 3-months
follow-up, the adjusted RRs of any revision were 1.67 (1.03- 2.72); 2.80
(1.67-4.69); and 4.36 (1.87-10.2) for Periods 2-4 compared to Period 1. At
6-years follow- up, the adjusted RRs were 0.89 (0.76-1.04) for Period 2; 1.20
(1.02-1.42) for Period 3; and 1.53 (1.18-2.01) for Period 4.d 4.
Conclusions:
The RR for any revision was increased for the recent time peri-
ods in the immediate postoperative phase and decreased for Periods 2-4 with
longer follow-up. The findings may be a result of less experience with cemented
THA and possible unmeasured confounding.
No conflicts of interest reported
109.