To control deep infections of prostheses of the knee joint several procedures are suggested. Antibiotic treatment, debridement and lavage, resection arthroplasty, one-stage, two-stage reim- plantation, arthrodesis and finally amputation. The method of choice is two-stage reimplantation using spacer embedded in cement. The spacer serves prevention of excessive contraction of soft tissues, supports the extremity, permits partial loading, improves bone quality and promotes antibiotic release. At the First Orthopaedic Clinic of the First Faculty Hospital of Charles University 12 patients with rheumatoid arthritis were treated where infection of a knee joint prosthesis occurred between 1990 – 1997. A total of 13 knee joints were involved, as in one female patient the infection was bilateral. The successfulness of two-stage reimplantation was 69.2 %. The mean flexion of the knee joint after reimplantation is 94 degrees. This confirms that restriction of mobility by a spacer and orthesis does not significantly affect the function of the knee joint. The mean follow up period is 4.3 years. In two cases the spacer had to be used twice. In one instance without success. Arthrodesis was used twice during revision of the spacers as the final solution. In one instance arthrodesis was used to resolve repeated infection after reimplantation of the knee joint. In one female patient the arthrodesis did not heal. In patients with rheumatoid arthritis the Coventry III type of infection prevails, i.e. late haematogenic infection, in 54 %. This fact prompts the necessity of intensive treatment of all intercurrent infections diseases as well as preventive antibiotic treatment to avoid all serious infections.

        Key words: RA, total knee prosthesis, complications, infection, spacer