CUSTOM HAND MADE ARTICULATING SPACERS IN TWO STAGE REVISION FOR INFECTED TOTAL KNEE ARTHROPLASTY: DO-IT-YOURSELF

Abstract

35 patients with an infected total knee arthroplasty were operated with a two-stage revision protocol including the use of custom hand-made antibiotic loaded articulating spacers.

Spacers were built intraoperatively, without specific tools, regarless the defect being considered cavitary or segmentary.

Patients were allowed to walk with an orthosis. Range of motion (ROM) with the articulating spacer averaged 80° and after reimplantation 106.5°. All but two patients in our series were treated with a combination of antibiotics including rifampicin and the antibiotics used in the spacers constituted from 7.5% of its final weight.

Reimplantation was successfully performed in 33 out of 35 cases at an average time of 10.2 weeks, excluding a patient were we had to wait 2.5 years. An extended exposure at reimplantation was necessary in 21% of the patients (five “Q-snip” and two anterior tibial tuberosity osteotomies).

According to the Knee Society Score (KSS) the results were considered excellent or good in 27 patients (84.8%), and fair or poor in 6 patients (14.2%) out of the 33 reimplantated. No significant differences related to the micro-organism or the time elapsed until reimplantation, as compared for ROM and functional and clinical KSS were found but early infections had significant worst ROM than late or sub-acute infections. Intercondylar constrained designs had better functional, clinic KSS and ROM that posterostabilised designs or hinge designs without significant differences.

Our modified technique for custom made spacers can be applied in any surgical theatre with a minimum cost. Our results are comparable to those reported in the literature, demonstrating the consistency of the two-stage reimplantation protocol despite multiple modifications and different dosages of antibiotic used in the cement spacers.