Articulated spacer provides long-term knee improvement after two-stage reimplantation

Purpose: The purpose of this study was to determine the long-term outcome in patients who underwent two-stage reimplantation with an articulated spacer following a chronic periprosthetic knee infection. The hypothesis was that the use of an articulated spacer provides significant improvement of clinical results and knee functionality through a long follow-up period, and therefore a durable revision TKA. Methods: Forty-six consecutive patients (46 knees) who underwent two-stage reimplantation with an articulated spacer for a chronic periprosthetic knee infection were retrospectively analysed. An articulated cement spacer, moulded in surgery room, was implanted in all cases. Patients were followed for a median period of 12 (range 6–16) years, and no patients were lost to follow-up. Patients were assessed preoperatively and postoperatively through the IKS knee and function scores and ROM. Results: Two-stage reimplantation was successful in controlling the infection in 91.3 % of patients. In the 42 patients with a successful two-stage revision, the median IKS knee and function scores were 36 (range 16–56) points and 25 (range 15–35) points, respectively, before the operation, and 76 (range 52–94) points and 70 (range 55–90) points (p < 0.001) at the last follow-up. The median ROM increased from 80 (range 60–110) degrees preoperatively to 115 (range 100–128) degrees (p < 0.01) at the last follow-up. Conclusions: Two-stage septic revision with an articulated cement spacer provided a significant long-term improvement of preoperative clinical and functional knee scores and therefore a durable revision TKA. Level of evidence: Retrospective case series, Level IV.