TWO-STAGE REVISION OF INFECTED TOTAL HIP ARTHROPLASTIES USING AN ANTIBIOTIC-LOADED CEMENT SPACER

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.