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

Abstract

A knee functional spacer made of antibiotic-loaded acrylic cement was used for treatment of infected TKA with two-stage exchange arthroplasty procedure.

The Spacer K is a preformed articulated spacer with the characteristics of an ultra-congruent condylar knee-prosthesis, made of acrylic cement impregnated with antibiotic (gentamicin). The device, industrially pre-formed in 3 sizes (Spacer K, Tecres), with standardised mechanical and pharmacological performances, was implanted in 21 consecutive patients all affected by late (8) infection according Segawa classification. Infection was caused by CoNs (16 cases), MSSA (1), Micrococcus spp (1), Enterococcus spp. (1). In 2 cases the germ was not detected. All knees presented the integrity of extensor apparatus and of peripheral ligaments (medial), furthermore type I & II bone loss according to Engh’s classification. Mean implantation time was 12 wks. Post-op following std. rehabilitation program as with primary TKR. We evaluated: healing of infection (clinical parameters, CPR, ESR, biopsy); clinical results and functional outcome (KSS); mechanical device behaviour (breakage, wear: macro – and microscopic surface evaluation, histological examination of peri-prosthetic tissues); possible related complications (bone loss, instability or dislocation, loosening: intra- and postoperative evaluation, x-ray study). The results obtained shows that the spacer K is effective and safe.