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.