Background
Periprosthetic joint infection (PJI) is one of the most severe complications in hip arthroplasty, and treatment of PJI is associated with high re-infection rates and significant loss of quality of life for patients, as well as socio-economic impact to health systems. Antimicrobial coating of implants with silver is a promising option to improve the outcome of PJI. However, there is no data from randomized control trials on silver-coated versus standard non-silver-coated implants in patients with PJI. Therefore, the aim of the current study is to assess clinical outcome for the use of silver-coated hip implants (further referred to as IP-coated) versus non-IP-coated implants in patients requiring surgical revision for hip PJI.
Methods
This is a multicenter confirmatory interventional randomized controlled superiority single-blinded study with two stages: pilot stage (part A) and pivotal stage (part B). Patients indicated for unilateral cementless acetabular and hip stem revision due to chronic periprosthetic infection planned for single-stage or two-stage surgical procedures are included. Patients will randomly be assigned either to the IP-coated or the non-IP-coated implant group. The primary outcome parameter is infection-free survival within 12 months after hip PJI. The underlying hypothesis is that the IP coating significantly reduces the risk of periprosthetic reinfection compared to the non-IP-coated implants. Secondary outcome parameters include data on the safety and performance of the prostheses through a 2-year clinical follow-up, including patient-related outcome parameters, such as Harris Hip Score, EQ-5D, radiographical assessment, and blood silver concentrations. An adaptive study design is planned with the inclusion of 268 subjects according to initial sample size calculations. Upon follow-up of 134 patients for 12 months or inclusion of 90% of the study patients, preliminary study results will be used to re-estimate the sample size, which may be extended up to 400 subjects.
Discussion
The current study aims to fill the evidence gap for the idea of IP-coated implants to reduce re-infection rates in the treatment of hip PJI. To the authors’ best knowledge, this is the first randomized controlled superiority trial evaluating the outcome of a silver-coated versus a non-silver-coated prosthesis for the treatment of hip PJI. The adaptive study design allows an adjustment of the initial sample size to reduce the risk of an underpowered superiority.