A novel technique to preserve range of motion in two-stage revision of infected total knee arthroplasty

Two-stage revision represents the gold standard in the treatment of infected total knee arthroplasty. Different techniques have been proposed, mostly not preserving range of motion. An articulated antibiotic-loaded cement spacer made in association with two unicompartmental implants has been used as an alternative to a static spacer in an effort to retain as much movement as possible between the stages in young, high-demand patients with preserved ROM. We evaluated nine consecutive patients with a mean age of 66.5 years. The second stage was performed after lab tests returned to normal and culture proved negative. Mean follow-up was 4.6 years. Mean ROM from a preoperative value of 105.6A degrees was 103.5A degrees after the first stage, and improved to 110.0A degrees after the definitive implant. Mean Knee Society score was 27.6 preoperatively improving to 86.4 points postoperatively. WOMAC score showed that six patients were very satisfied with the overall result of their reimplanted knee, three subjects were somewhat satisfied. No recurrence of infection, no significant radiolucent lines or osteolysis were recorded at clinical and radiological follow-up and the patients were satisfied with the outcome. Results indicated that this technique may ensure the advantages of a static spacer, but allow a greater ROM and better functional recovery. It may be considered as a viable option in selected cases even though the higher costs of two unicompartmental implants should be considered in the light of other aspects, such as prolonged hospital stay and rehabilitation in revision of infected total knee arthroplasty.