gms | German Medical Science

Introduction and objective: Sonication has emerged as a gold standard diagnostic tool to investigate implant-associated infection in arthroplasty, spinal and trauma surgery, but its role in non-spinal paediatric orthopaedics has not yet been described.

This study aimed at exploring the frequency of bacterial colonization of paediatric orthopaedic implants by sonication.

Materials and methods: Sonication culture results and relevant data of all patients who underwent implant removal between 01/2019 and 11/21 at a single institution and had been <18 years at index implantation were retrospectively reviewed. Sonication culture results were classified according to microbial growth as negative (no/non-significant growth) or positive (colonized significant growth). Descriptive statistics were performed, correlations were analyzed via crosstabs and univariate ANOVA (p < 0.05).

Results: 129 sonicated orthopaedic devices from 28 females and 35 males were included. Mean patient age at implantation was 9.8 (STD 3.4; range 3.0–15.6) years, mean implant in-situ time was 2.2 (STD 1.5; range 0.6–8.8) years. 63 tension band plates, 35 locking screw plates, 26 cannulated screws, three intramedullary nails, and two K-wires were evaluated. 128/129 (99.2%) of implant sites were asymptomatic. Sonication of 129 explants revealed bacterial growth on 25 devices (19.4%) from 22 patients. In one case, significant microbial growth was detected (Cutibacterium avidum). In 21 patients non-significant growth of pathogens mainly related to the human skin microbiome suggests contamination (Staphylococci (n=17 implants), Cutibacterium spp. (n=5 implants), Corynebacterium spp. (n=3 implants), and other (n=3 implants)).

Conclusions: Sonication demonstrated a positive microbiologic yield in <1% of all explants. 99% of implants were removed from asymptomatic sites.

Therefore, a historically anticipated risk of implant-associated infection should not be relevant for scheduling implant removal in children.

Further research is required to determine the diagnostic role of sonication in paediatric orthopaedics.