Durable Infection Control and Function With the PROSTALAC Spacer in Two-stage Revision for Infected Knee Arthroplasty

Background A two-stage revision total knee arthroplasty is recognized as the gold standard in the treatment of infection. However, traditional spacers limit function in the interval between the two stages and may cause instability, scarring, and bone erosion. The PROSTALAC knee spacer is an antibiotic-loaded cement articulating spacer that allows some movement of the knee between stages. Whether motion enhances long-term function is unknown. Questions/purposes We therefore identify the rate of control of infection using the PROSTALAC exchange spacer and to assess the clinical outcome after implantation with a definitive implant. Methods We retrospectively reviewed 115 knees that underwent two-stage exchange with the PROSTALAC spacer. Forty-eight of these had a minimum followup of 5 years (mean, 9 years; range, 5–12 years). Results At last review, 101 of the 115 knees (88%) had no evidence of infection. Of the 14 knees that became reinfected, four were from the same organism and 10 were with a different organism. After further intervention, using the two-stage approach again, the infection was controlled in 12 of the 14 initially reinfected cases, resulting in a failure to cure in only two cases. We observed improvements in mean WOMAC, Oxford, UCLA, and Patient Satisfaction scores at last review. Conclusions The PROSTALAC functional spacer was associated with a 98% rate of control of infection and improvements in the quality-of-life outcomes in the treatment of chronically infected total knee arthroplasties. Level of Evidence Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.