The contamination of allografts in multi-organ donors: a bone bank experience

As a consequence of the preference for homologous tissues, bone banks are the primary source of bone and tendon grafts. However, the bacterial, viral, and fungal contamination of these grafts remains a considerable challenge in bone banks and often results in high rates of graft discarding and infections in patients. This study intended to investigate bacterial contamination in 509 bone grafts harvested from 110 multiorgan donors. Specimen collection included bone and soft tissue retrieved from culture-swabbing as well as bone and capsule for histopathology. Microbiological, histopathological, and radiographic analyses were carried out. Secondary sterilization was also conducted using cobalt 60 at the dose of 2.5 × 10⁴ Gy. There were 106 multi-organ donors. Of the 506 grafts, there were 54 Hemi pelvis, 191 femur, 142 tibia, and 119 fibulae. The surface swab contamination rate for all the grafts retrieved was 16.6%, and bone culture from all the grafts was 6.1%. When we looked at the incidence of contamination according to the location than the surface swab contamination rate for hemipelvis was 18 (33.3%), femur 30 (15.7%), tibia 21(14.7%) and fibula 15 (12.6%). The bone cultures were hemipelvis 12 (22.2%) femur 8 (4.1%), tibia 5 (3.5%) and fibula 6 (5.04%). These findings suggest that separate harvesting of the grafts in reverse order may help prevent contamination. The study also recommends discarding all grafts contaminated even with low pathogenicity organisms. However, bioburden needs to be further investigated to be detected and reduced.