Use of modular megaprosthesis in managing chronic end-stage periprosthetic hip and knee infections: Is there an increase in relapse rate?

Abstract

Background: Bone loss is a common problem in periprosthetic joint infection (PJI) scenarios. Modular megaprosthesis (MP) could offer a limb salvage solution in such situations. Concerns about risk of infection relapse, reinfection and implant longevity exist regarding MP use in cases of chronic PJI, rather than standard implants. We therefore sought to analyze our results with MP use in chronic PJI cases.

Methods: We performed a retrospective analysis of 29 MP patients. Inclusion criteria were the use of this type of modular megaimplant for reconstruction of segmental bone defects in chronically infected lower-extremity arthroplasties (hip or knee) and a minimum follow-up of 18 months. We evaluated the primary outcome of infection control or recurrence. The MPs were classified into 3 groups, according the bone segment replaced (proximal femur, distal femur or total femur). We further analyzed complications, pain, patient satisfaction and functional results.

Results: Mean age was 75 years; mean follow-up was 48 months (range 18-82). The most frequently involved pathogens were coagulase-negative staphylococci (62%). Polymicrobial infection was detected in 7 patients. Twenty-eight patients were managed with a two-stage approach. The infection-free rate at the end of follow-up was 82.8% (24 of 29 patients). Aside from infection relapse, the most frequent complication was dislocation. Final-point survival rate was 91.2% (CI 68.1-97.8). Clinical outcome data and satisfaction results were acceptable.

Conclusion: According our data, MP is a useful tool in treating end-stage PJI cases, achieving acceptable eradication, satisfaction and implant survivorship rates.

Keywords: Cement spacer; Infection relapse; Limb salvage; Modular megaprosthesis; Periprosthetic joint infection; Vancogenx.