Abstract
Background: A knee functional spacer made of antibiotic-loaded acrylic cement was used for treatment of infected TKA with two-stage exchange arthroplasty procedure.
Materials and Methods: 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 preformed in 3 sizes (commercial name Spacer K, Tecres), with standardised mechanical and pharmacological performances, was implanted in 20 consecutive patients affected by early (12) and late (8) infection according Segawa classification. Infection was caused by CoNs (14 cases), MSSA (2), 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). .
Results: Minimum F.U. was 6 months, maximum 51. Healing of infection process was observed in all patients. The KSS score, after definitive reimplantation, has been excellent or good in more than 70% of patients as well as the functional score. Pain was absent but in 1 patient (mild); ROM remained unchanged between first and second stage or improved after definitive reimplantation; patients judged the result excellent or good in 85%. The walk ability was good in 60%, excellent in 15%. Seventy seven per cent of patients went on only cructh, but of these at least, one third could walk without anything. the patient’s judgement has been excellent. Neither breakage, or macroscopic wear signs were detected. No complications related to the use of the device were observed. (one case of dislocation due to pre-existing insufficiency of the extensor apparatus)
Conclusions: In a reasoned costs benefits ratio, the use of an articulated knee spacer in two-stage septic revisions should be considered the preferred option.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
