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· DOS Abstracts
The survival of total knee arthroplasties depends on
the need for additional component supplementation
– A Danish population-based study including 52.876
patients
Anders El-Galaly, Steffen Haldrup Andersen, Alma Becic Pedersen, Andreas
Kappel, Poul Torben Nielsen, Michael-Ulrich Jensen
Department of Orthopaedic Surgery, Aalborg University Hospital; Department
of Economics and Business Economics, Aarhus University; Department of
Epidemiology, Aarhus University Hospital; Department of Orthopaedic Surgery,
Aalborg University Hospital; Department of Orthopaedic Surgery, Aalborg
University Hospital; Department of Orthopaedic Surgery, Aalborg University
Hospital
Background:
Previous minor studies have reported an inferior survival of total
knee arthroplasties (TKA) inserted due to post-traumatic osteoarthritis (PTA)
when compared to TKA inserted due to primary osteoarthritis (OA).
Purpose / Aim of Study:
We conducted a population-based study with the
aim of confirming the previous findings on a larger cohort. In addition, we hy-
pothesize that the need for additional component supplementation (CS) during
surgery were more pronounced in patients with PTA and that this might be as-
sociated with the inferior survival.
Materials and Methods:
52.876 primary TKAs inserted between 1997 and
2013 were withdrawn from the Danish Knee Arthroplasty Registry. 1.423 were
inserted due to PTA and 51.453 were inserted due to OA. We examined short-
(0-1 year), mid- (1-5 years) and long term (+5 years) implant survival using
cumulative incidence and adjusted hazard ratio (HR) with revision as endpoint
and death as competing risk. The analyses were repeated after dividing the pa-
tients by the need for additional CS.
Findings / Results:
An inferior survival of TKAs inserted due PTA was present
in all follow-ups. The five-year cumulative incidence was 9% in the PTA-group
and 4% in the OA-group, with a corresponding adjusted HR of 1,93. Additional
CS was needed in 22% of the PTA-group and in 4% of the OA-group, and the
five-year cumulative incidence in these cases were 33% and 40%, respectively.
An adjusted HR of 2,41 was calculated for TKAs inserted with the need for ad-
ditional CS. All reported results were significant with p<0,001.
Conclusions:
The study confirmed the inferior survival of TKAs inserted due
to PTA, and found that this is strongly related to the need for additional CS. To
our knowledge this relationship has not previous been described and should be
remembered when informing the patient prior and following surgery.
No conflicts of interest reported
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