Efficacy of total knee arthroplasty (TKA) revision surgery depends upon the indication for revision : a systematic review.

The number of revision total knee arthroplasty (TKA) surgeries has increased over the years and it is expected that its number will keep rising. Most frequent reasons for revision are known to be aseptic loosening, infection, instability, periprosthetic frac- ture, arthrofibrosis and component malposition. The influence of the indication for revision on the outcome scores is not fully understood. Therefore, this work will evaluate and review the existing literature regarding outcome scores after revision TKA surgery. We conducted a sensitive and comprehensive search for published and unpublished studies relevant to the review question. We restricted our search to English studies published between January 2008 and December 2018. Our systematic review was done according to PRISMA guidelines. We withheld 19 studies (1419 knees) for inclusion. Of these, 9 papers reported outcome scores after TKA revision for aseptic loosening, 10 reported on revision for instability, 10 reported on stiffness or arthrofibrosis and 4 papers reported on component malposition. Although we found some papers suggesting that there is no difference in postoperative outcome scores depending on the aetiology of revision surgery, the majority of the included studies suggest differently. This review suggests there is a tendency for relative higher outcome scores after revision for aseptic loosening. Revision for malrotation might give comparable postoperative outcome scores and satisfaction ratios. Revision for instability tends to give lower postoperative outcome scores than aseptic loosening, although certain subgroups of instability show comparable results. Lowest postoperative scores might be found after revision for stiffness and arthrofibrosis.