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· DOS Abstracts
What do surgeons consider as optimal acetabular
component positioning during primary total hip
arthroplasty?
Dana Cotong, Anders Troelsen, Henrik Husted, Kirill Gromov
Dept. of Orthopaedic Surgery, Copenhagen University Hospital Hvidovre
Background:
Dislocation is a well-known complication following total hip ar-
throplasty (THA). The Lewinnek and Callanan “safe zones”, respectively, have
been widely used to minimize dislocation frequency. However, recent studies
have questioned the association between “safe zones” and lower dislocation
rates.
Purpose / Aim of Study:
The purpose of this study is to investigate (1) if
Danish hip surgeons agree on a specific “safe zone” for cup positioning and (2)
surgeons’ surgical practice patterns concerning recurring instability in primary
THA.
Materials and Methods:
A survey was performed among attending hip sur-
geons during the 2015 Annual Meeting of the Danish Orthopaedic Society. The
questionnaire contained questions regarding optimal component positioning,
operative practice patterns in primary THA, indications for revision THA and
surgical techniques used in revisions for dislocation.
Findings / Results:
42 questionnaires were gathered, 2 were excluded, thus
leaving 40 for analyses. 97 % of the surgeons indicated optimum cup ante-
version within both the Lewinnek and Callanan “safe zones”, while 97 % and
83 % reported optimum cup inclination within the Lewinnek and Callanan “safe
zones”, respectively. Reported range on optimal cup positioning varied from
30-55° of inclination and 15-30° of anteversion. Minimum and maximum ac-
cepted inclination and anteversion angles within the Lewinnek “safe zone” were
68 % and 67 %, respectively.
Conclusions:
Danish hip surgeons agree that optimum cup positioning should
lie within the Lewinnek “safe zone”, but do not agree on exact optimal cup po-
sitioning concerning inclination and anteversion. Current surgical practice pat-
terns among the majority of surgeons are supported by existing literature.
However, as 1/3 of the accepted “safe zones” are outside the Lewinnek “safe
zone”, behavioural changes through education are advised
No conflicts of interest reported
73.