Background: Short-term cure rates of two stage revision for infection after TKR are approximately 90%. Little is known about the long-term reinfection-free survival or the mechanical durability of the reimplanted prostheses. The purpose of the study is to evaluate the mid to long term results of this technique with regards to persistence of infection, clinical and radiographic results. The hypothesis is that the success rate of the technique is maintained through long term follow-up, with a low rate of recurrent infection and mechanical implant failure.

Methods: from January 1990 to august 2002, 124 two stage revision TKR for infection were performed at Our Institution with mean follow-up of 9,8 years (5 to 17,5).

The clinical results were evaluated with SF12, WOMAC, and KSCRS performed preoperatively and postoperatively at 5 and 10 years. A radiographic analysis was performed using x-rays of the last available follow-up.

Results: the WOMAC and KSCRS significantly improved at the 5 years follow-up decreasing slightly at 10 years. The SF12 postoperative variation was not significant. The radiographic results showed possible loosening of the tibial or femoral components on 17% and 12% of patients respectively. There were 17 reoperations, 10 of which for persistent infection (85% of survival at 10 years).

Discusssion and conclusion: we are encouraged by the rate of eradication of infection at 10 or more years in these difficult cases. The long term clinical and radiographic results are satisfactory. The study supports the sustained use of this technique for infected total knee arthroplasties.

Introduction: In the two-stage revision procedure for infected total hip arthroplasty (THA), healing of the infection can be enhanced by using an antibiotic-loaded acrylic cement (ALAC) spacer. The spacer also acts as a temporary implant, preserving the gap between bone segments and a certain degree of joint motion.

Materials and methods: Between 1995 and 2003, 19 infected THAs were surgically treated by two-stage revision procedures, using gentamicin-loaded spacers. The infections were sustained by Staph. aureus in 7 cases, Staph. aureus + Enterococcus faecalis in 1 case, Staph. epidermidis in 4 cases, Strept, agalactiae in 1 case and Strept, β-haemoliticus in 1 case. In 5 hips presenting with secreting fistulae, no causative microrganisms were isolated.

Average interval between the two surgical stages was 5.5 months (range, 2 weeks to 13 months). Systemic antibiotics were administered to all patients for a minimum period of 6 weeks after removal of the infected implant. The revision stem was cemented in 5 patients and not cemented in 13 patients. All the acetabular components were uncemented. In one patient, the second stage procedure consisted exclusively in removal of the spacer and debridement, owing to persisting infection sustained by Staph. aureus + Staph. epidermidis.

Results: Seventeen patients were evaluated at an average follow up of 42.3 months (range, 6 to 92 months).

Recurrence of infection (Staph. aureus) occurred in 1 patient and was treated by resection-arthroplasty. Aseptic loosening of the stem was observed in 1 patient, who was subsequently treated by stem revision. Average Harris Hip Score was 78 points (range, 65 to 90 points).

Conclusions: The low incidence and the pathophysiologic heterogeneity of THA infections do not allow to identify standardised protocols for their treatment. Two-stage revision is one available option and several authors demonstrated higher rates of success when compared to one-stage revision. The use of ALAC spacers increases the efficacy of the procedure and in our experience positively influenced the clinical-functional outcome.