Articulating spacers compared to fixed spacers for the treatment of infected knee arthroplasty: A follow-up of 37 cases

BACKGROUND: The standard treatment of a periprosthetic infection after TKA involves a two-stage reimplantation with the intermittent implantation of spacers. Different designs of spacers have been described; currently articulating spacers and fixed spacers are used. The aim of the present study is to compare the advantages/disadvantages of the different spacers. PATIENTS AND METHODS: In this retrospective study we analyzed 37 cases after revision surgery of infected TKA. All patients that received spacers as part of the two-stage reimplantation were included. Exclusion criteria were massive bone loss prior to revision, because the implantation of a mobile spacer would not have been possible. RESULTS: The average ROM was 98.0 (+/- 14.9) degrees in the articulating spacer group (group 1) and 79.3 (+/- 22.5) in the group that received the fixed spacers (group 2) before revision surgery started. At a late follow up the average ROM for group 1 was 102.0 (+/- 8.4) and 79.0 (+/- 26) for group 2. CONCLUSION: The use of articulating spacers in the two-stage revision for infected total knee arthroplasty is a safe alternative to fixed spacers, that equally preserves ligament balancing and has equal infection eradication rates. A long term improvement of the range of motion following reimplantation of the new joint was, however, not observed.