PREFORMED ARTICULATING KNEE SPACER IN TWO-STAGE REVISION FOR THE INFECTED TOTAL KNEE ARTHROPLASTY

Abstract

Two-stage exchange technique is currently considered the standard treatment for the infected total knee arthroplasty, but the clinical outcomes associated with the use of articulating bone cementspacers are not well established. Spacer-K is a pre-formed articulatingspacer made of genta-micin-impregnated acrylic cement. The aim of this prospective study was to assess safety and effectiveness of Spacer-K for the management of the infected total knee arthroplasty.

Twenty-two consecutive patients were operated on in two centres. Infection was caused by Coagulase neg. Staphylococcus (11cases), Staphylococcus aureus (3), and others (5). In 3 cases microorganisms were not identified. The mean implantation time of the spacer was 11 weeks(range, 7 to 28 weeks). The rehabilitation program between stages consistedin early range of motion exercises and partial weight-bearing. In one patient removal of the spacer and insertion of a molded cement block with vancomycin was necessary because of insurgence of MRSA.

The mean follow-up of 21 knees after removal of the spacer and insertion of the new prosthesis was 28 months (6 to 45 months). In one patient removal of the spacer and insertion of a molded cement block with vancomycin was necessary following insurgence of methi-cillin-resistant Staphylococcus aureus isolated between stages. No patient had recurrence of infection at latest follow-up. The mean Knee Society functional score during spacer management was rated 76 points (range 55 to 80 points) and was rated 86 points (range, 76 to 90 points) at latest follow-up. Preoperative range of motion improved markedly after removal of the infected pros-thesis and insertion of the spacer. Neither breakage, nor clinically relevant wear of the spacer were detected, and no complications related to the device were observed

The Spacer-K is safe and effective for the management of the infected total knee arthroplasty.