The PROSTALAC functional spacer in two-stage revision for infected knee replacements

The PROSTALAC functional spacer is made of antibiotic-loaded acrylic cement but has a small metal-on-polythene articular surface. We have used it as a n interim spacer in two-stage exchange arthroplasty for infected total knee replacement. PROSTALAC allows continuous rehabilitation between stages as it maintains good alignment and stability of the knee and a reasonable rang e of movement. It also helps to maintain the soft-tissue planes, which faci litates the second-stage procedure. We reviewed 45 consecutive patients, treated over a period of nine years. T he mean follow-up was for 48 months (20 to 112), At final review, there was no evidence of infection in 41 patients (91%); only one had a recurrent in fection with the same organism. There was improvement in the Hospital for S pecial Surgery knee score between stages and at final review The range of m ovement was maintained between stages. Complications were primarily related to the extensor mechanism and stability of the knee between stages. Both o f these problems decreased with refinement of the design of the implant. The rate of cure of the infection in our patients was similar to that using other methods. Movement of the knee does not appear to hinder control of i nfection.