Abstracts Posters SICOT-SOF meeting Gothenburg 2010 _2_

Poster
Topic: Navigation
Abstract number: 23697
THE UTILITY OF KINEMATIC NAVIGATION SYSTEM OF TKA FOR THE
UNSTABLE OR DESTRUCTED RA KNEE
Katsuya KANESAKI 1 , Kimiaki YOKOSUKA 1 , Takateru KAIEDA 1 , Yasuhiro MITSUI 1 ,
Kensei NAGATA 2
1 Nagata Orthopaedic Hospital, Omuta (JAPAN), 2 Kurume University, Kurume
(JAPAN)
Introduction: Final state of RA is a “stiff knee”. Degenerative change is added on to
the RA change at weight bearing joints, which is the sclerotic change of the
subcondral bone. This will generate an unstable knee with loosened and
dysfunctional ligament. Total knee arthroplasty (TKA) is indicated for unstable knees
with ADL disturbance. In general, constrained TKA is indicated for such unstable
knee like RA, since it is necessary to achieve a good ligament balance with
dysfunctional cruciate ligament and collateral ligament. Usually, we perform TKA
using kinematic navigation system (OrthoPilot TKA ver.4.2) with e-motion FP
manufactured by Aesculap Germany. This paper reports on our short-term results
and its favorable outcomes using the fore-mentioned surgery, indicated for unstable
RA knee. Material and Methods: 40 cases of TKA for unstable RA knee were studied.
All cases had over 10 degrees of instability in full extension on navigation display,
just after registration. There were 9 knees of male and 31 knees of female. Average
age at the time of operation was 70.1 years (range, 64-85 years). We evaluated
range of motion and patient satisfaction level three months post-operatively. Results:
The average malalignment of the mechanical axis, under valgus or varus stress in
extension, became from 13.92 degrees just after registration to -2.3 degrees after
implantation. Patients were very satisfied and regained nearly normal gait three
months post-operatively, and there was no limping gait due to knee dysfunction.
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