Introduction

There is no literature regarding the risk of a patient developing PJI after primary TKA if the patient has previously experienced PJI of a TKA or THA in another joint. The goal of this study was to compare the risk of PJI of primary TKA in this patient population compared to matched controls.

Abstract. Aims. The primary aim of this study was to evaluate the outcomes of fungal knee periprosthetic joint infection following knee arthroplasty. The secondary aim was to evaluate risk factors for acquiring a fungal PJI. Patients and Methods. This was a retrospective analysis of patients presenting with a confirmed fungal PJI of the knee in two tertiary centres. There were a total of 45 cases. Isolated fungal infections along with mixed bacterial and fungal infections were included. Mean follow up was 40 months (range 3–118). Results. The mean age at presentation was 69 years (range 46 to 87) and mean BMI was 31 kg/m2 (range 20 to 44). The median number of procedures that patients had on the affected limb from the index primary arthroplasty procedure was 6 (range 2–17). The median procedure number at which a fungal infection was identified was 5 (range 2–10). A history of prolonged antibiotic therapy (above 6 months total) was present in 37 patients (88%). During the study period 22 patients were infection free, 14 treated with lifelong suppression, 7 had above knee amputations and 6 had died. Overall infection cure rate was 49%. Conclusions. Patients with fungal PJI are generally poor hosts with multiple co-morbidities, long term exposure to antibiotics and high rates of open wounds and sinuses. The poor outcome associated with fungal PJI relative to bacterial PJI should be shared with patients in order to manage the expectations of this complex cohort

Introduction. Our objective is to describe early and midterm results with the use of a new knee prosthesis as an articulating spacer in planned two-stage management for infected total knee arthroplasty. As a second objective, we compared outcomes between the group with a retained first stage and those with a completed 2-stage revision. Methods. Forty-seven patients (48 knees) from January 2012 and November 2017 underwent a 2-stage exchange with an articulating spacer with new implants was used for a chronic knee periprosthetic joint infection with a mean follow-up of 3.7 years (2–6.5 years). The most frequently identified infecting organism was MSSA (31%), MRSA (21%) or MRSE (20%). At the first stage, a new PS femoral component and a new all-polyethylene posterior stabilized (PS) tibial component or a standard PS tibial liner were cemented with antibiotic-cement, typically 3.6 gm tobramycin and vancomycin 1.5 gm. IV antibiotics for six weeks were administered. The planned reimplantation was at 3 months, but ninetteen spacers (14 all poly tibias and 5 tibial liner) were retained for over 12 months. Postoperative assessment included knee range of motion (ROM), quality of life (QOL) scores (SF-12, WOMAC, KOOS, Oxford, and UCLA scores), and a satisfaction scale from 0–100%. Results. Of the 48 knees, 8 failed due to lack of infection control, and 2 died within the first year for medical reasons (4%), giving a failure rate of 17% (8/46). One of these knees was not revised due to poor medical status. Of the remaining 7, 2 had a repeat 2-stage exchange, one a single stage revision and 4 irrigation and debridement with retained implants. All 7 had a successful outcome with infection control after this, leaving a permanent failure rate of 2% (1/46). Five of the 19 knees with initially retained implants were revised to a second stage after 12 months for continued pain or instability (1/14 all poly tibia and 4/5 PS liner). There were no significant differences in final range of motion or QOL scores between patients with a retained first stage procedure and those who underwent a second stage operation. Also, there was no statistically significant difference in the initial failure rate due to infection between patients with a complete 2-stage revision and those with a retained first stage (19% (6/31) vs. 14% (2/14), respectively; p=0.613). Conclusions. When an all poly tibial implant is used a spacer in two-stage exchange arthroplasty, it may be retained for over 12 months, with no difference in infection control, range of motion, and quality of life assessment to patients with complete 2-stage revision surgery. With this technique, the second stage may be delayed in patients who are doing well, and may never need to be revised, hence we propose the new term “one-and-a-half stage exchange”