Clinical trial NCT06944184: Antibiotic Elution After Two-stage Knee Revision
Official title: In Vivo Antibiotic Elution During Two-Stage Knee Revision: A Microdialysis Study
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Periprosthetic Knee Infection
Keywords: two-stage exchange
infection
arthroplasty
PJI
microdialysis
minimal inhibitory concentration
bone cement
treatment monitoring
Lead sponsor: University Hospital, Bonn
Sponsor class: OTHER
First posted: 2025-04-25
Enrollment: 10
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Ten patients over 18 years with a periprosthetic knee infection after total knee arthorplasty and indication for prosthesis explanation and temporary spacer implantation.

Brief summary: The goal of this observational study is to monitor the eluted antibiotic concentrations of gentamicin and vancomycin by a static knee cement spacer in patients being treated for periprosthetic infections of the knee. The main question aims to answer if eluted antibiotics are in a therapeutic range for treatment at sight of infection. Secondarily, local antibiotic concentrations are compared with systemic blood levels, as are systemically applied antibiotics compared to intra-articular concentrations. Intra-articular samples are collected over a 72 hour postoperative period.

Detailed description: The present study moinitors antibiotic concentrations eluted by a static cement knee spacer as two-stage revision treatment of a knee PJI. The static cement spacer consists of COPAL G+V cement containing 2g of vancomycin and 0.5g of gentamicin. Microdialysis is used as a technique for continuous extra cellular sample collection directly from the knee joint cavity. It is implemented guided by a drainage tube during the surgery to remove the infected prosthesis and implement the spacer. Over a 72 hour period samples directly from the knee joint are generated continiously. These are analyzed for the eluded antibiotic concentrations of gentamicin and vancomycin from the knee spacer. Once every 24 hours venous blood samples were collected as well and analyzed for gentamicin and vancomycin and also systemically applied antibiotics (a.e. cefuroxim, clindamycin).

Eligibility criteria: Inclusion Criteria:

* clinical indication for a two-staged revision of a knee PJI
* approval for surgery by the orthopedic and anesthesiologic departments
* being over 18 years of age
* written, informed consent after detailed patient information about the study protocol and possible study-dependent risks

Exclusion Criteria:

* known allergies to the antibiotics gentamicin and vancomycin contained in the spacer

Primary outcomes:
measure: antibiotic concentrations in intra-articular samples
timeFrame: Concentrations are measured for 72 hours after spacer implantation.
Secondary outcomes:
measure: Antibiotic concentrations in blood samples
timeFrame: Antibiotic concentrations are measured once every 24 hours after spacer implantation. In total at three time points during the 72 hour observation period.
Other outcomes:
Locations:
city: Bonn
country: Germany
facility: University Hospital Bonn
state: North Rhine-Westphalia
Study officials:
References:
citation: Lazic I, Scheele C, Pohlig F, von Eisenhart-Rothe R, Suren C. Treatment options in PJI - is two-stage still gold standard? J Orthop. 2021 Jan 20;23:180-184. doi: 10.1016/j.jor.2020.12.021. eCollection 2021 Jan-Feb.
citation: Dhanani JA, Parker SL, Lipman J, Wallis SC, Cohen J, Fraser J, Barnett A, Chew M, Roberts JA. Recovery rates of combination antibiotic therapy using in vitro microdialysis simulating in vivo conditions. J Pharm Anal. 2018 Dec;8(6):407-412. doi: 10.1016/j.jpha.2018.07.003. Epub 2018 Jul 6.
citation: Moojen DJ, Hentenaar B, Charles Vogely H, Verbout AJ, Castelein RM, Dhert WJ. In vitro release of antibiotics from commercial PMMA beads and articulating hip spacers. J Arthroplasty. 2008 Dec;23(8):1152-6. doi: 10.1016/j.arth.2007.08.020. Epub 2008 Mar 4.