Periprosthetic knee infection reconstruction with a hinged prosthesis: Implant survival and risk factors for treatment failure

Severe bone and soft tissue defects are common after failed two-stage exchange arthroplasty for periprosthetic joint infection (PJI). There is a paucity of evidence on the outcomes of using a hinged prosthesis for knee PJI reconstruction during second-stage re-implantation, especially regarding implant survivorship, reinfection risk factors, and functionality after successful reconstruction.

A total of 58 knee PJI patients with Anderson Orthopaedic Research Institute (AORI) type II/III defect and soft tissue insufficiency underwent reconstruction with hinged prosthesis. Enrolled patients adhered to a two-stage exchange arthroplasty protocol and were evaluated for a mean follow up of 65.1 months. Kaplan–Meier analysis was conducted for implant survivorship and infection-free survival. Multivariate analysis was used to determine independent risk factors for recurrent infections. Knee Society Score (KSS) was used to evaluate functional outcomes.

The survivorship of hinged prosthesis was 86.2% at 2 years and 70.2% at 5 years. Infection-free analysis revealed an estimation of 68.9% at 2 years and 60.6% at 5 years. Of the 58 patients, 13 (22.4%) developed recurrent PJI, three (5.2%) aseptic loosening, and one (1.7%) periprosthetic fracture. Multivariate analysis revealed that obesity (hazard ratio (HR), 3.11), high-virulent pathogen (HR, 3.44), and polymicrobial infection (HR, 3.59) were independent risk factors for reinfection. Patients showed a mean improvement of 32.8 ± 7.7 in Knee Society Clinical Score (KSCS) and 30.8 ± 11.0 in Knee Society Function Score (KSFS) after successful reconstruction ( P < 0.001).

Using hinged knee prosthesis for PJI reconstruction provided an overall implant survival of 70.2% and an infection-free survival of 60.6% at mid-term follow up. Obesity, virulent pathogens, and polymicrobial infections were independent risk factors for infection recurrence.