DOS 2016

DOS Kongressen 2016 ·

195

High two-year revision rates after primary

knee arthroplasty – causes and implemented

interventions for improvement

Martin Lindberg-Larsen, Mette Hornsleth, Jens Bagger

Department of Orthopaedic Surgery, Copenhagen University Hospital Bispebjerg

Background:

Data from the Danish Knee Arthroplasty Register (DKR) has re-

vealed high 2-year revision rates after primary knee arthroplasty performed in

2012 and 2013 in Copenhagen University Hospital Bispebjerg.

Purpose / Aim of Study:

To investigate causes of early revisions in order to

implement a strategy for improvement of outcome after primary knee arthro-

plasty.

Materials and Methods:

A retrospective single center investigation of all pri-

mary knee arthroplasties performed in 2012 and 2013. During the first 15

months the Zimmer NexGen CR-Flex (n=225) was used as the standard pri-

mary knee prosthesis and in the remaining 9 months the DePuySynthes SIGMA

(n=158) was used. 17 uni- compartmental prosthesis were implanted.

Findings / Results:

197 primary knee arthroplasties were performed in 2012

and 21(10.7%) were revised within 2 years, whereas 203 were performed in

2013 and 22 (10.8%) were revised within 2 years. The main cause of early

revision was instability (n=20) resulting in 10 liner exchanges, 3 revisions of

femoral component to posterior stabilized and 7 total revision procedures. 6 of

the instability cases were fall-related and the remaining 14 were surgical proce-

dure related. Other main causes of early revision were aseptic loosening of the

tibial component (n=10) and secondary insertion of patella component (n=4).

Conclusions:

Some of the early revisions (liner exchanges) due to instability

could be explained by the learning curve after change of the standard pros-

thesis and a decrease in these revisions are expected with an increased intra-

operative focus on balancing. The revisions due to aseptic loosening have led

to a change in cementation technique of the tibial component. Finally, patella

resurfacing is now performed as a standard procedure. With implementation of

these interventions the early revision rate is expected to decrease significantly.

No conflicts of interest reported

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