AbstractsBiology & Animal Science

[Truncated abstract] Musculoskeletal allografts are one of the most transplanted human tissues in Australia. The majority of musculoskeletal allografts are used for reconstructive surgery following trauma, limb salvage following tumour resection, prosthetic joint revision surgery, spinal surgery and non‐union fracture healing. Musculoskeletal tissues, including bone and tendons, are sourced from both living and deceased donors in Australia. As with the use of any human tissue there is a risk of disease transmission. Although vigilant screening of donors' serology and medical history, microbiological monitoring of grafts during processing and treatment with gamma irradiation now occurs, there is still a risk of viral and bacterial transmission from donated grafts. The aim of this thesis is to assess current screening protocols for musculoskeletal tissue allografts, determine the risks associated with tissue allograft, and propose strategies to increase safety associated with their use based on evidence‐based risk estimates. Areas with a current need for focus include hepatitis B virus screening protocols, histopathological examination of donated bone, and bone allograft recipient monitoring. In order to carry out these objectives, data was retrieved and analysed retrospectively from the Perth Bone and Tissue Bank (PBTB) in Western Australia. These databases are maintained as part of standard tissue bank practice and in accordance with the Therapeutic Goods Act. Additional supporting data was retrieved from the state-wide Western Australian Cancer Registry, Hospital Morbidity Data Collection, Emergency Department Data Collection and Death Registry. Histopathological examination and follow-up investigations of 6161 femoral heads donated for allografts between 1993 and 2006 revealed a total of 105 femoral heads demonstrating abnormal or reactive histopathological features, and thus these donations were rejected for use as allograft. Of these, two patients we Confirmed malignancies accounted for 1 in 770 patients undergoing total hip arthroplasty in this cohort. Our findings indicate that, even with detailed historical and medical review, clinically significant diseases, including neoplasms and Paget's disease, are observed in patients diagnosed with osteoarthritis prior to total hip arthroplasty. Histological examination therefore plays an integral role in quality assurance in femoral head banking, and represents a possible early diagnostic test for bone and bone-marrow related diseases in total hip arthroplasty patients. Between 2000 and 2009, rejection of musculoskeletal donors due to positive Hepatitis B serology screening accounted for 3.49% (206/5901) of the donors in Western Australia. Of these donors 94.2% were anti-HBc positive and HBsAg negative. From donors with an available anti-HBs titre, 45.2% (28/62; 95% CI: 32.5-58.3%) were determined to have a level >100IU/L. In light of evidence that up to 20% of HBsAg positive blood samples test negative for HBV DNA, HBV NAT should not replace current serological…