Assessment of a closed wash system developed for processing living donor femoral heads

NHS Blood and Transplant Tissue and Eye Services (TES) and Scottish National Blood Transfusion Services Tissues and Cells Directorate (TCD) currently bank whole, frozen femoral head bone from living donors who are undergoing primary hip replacement surgery. When required, the bone is issued to a surgeon still frozen on dry ice (- 79 °C). Consequently, the femoral head bone is not processed, is not sterilised and at the time of issue, it contains donor blood, bone marrow and associated cells. We have previously shown that, cut, shaped and washed bone from deceased donors can be processed to remove up to 99.9% of blood, bone marrow and associated cells (Eagle et al. 2015). However, cut and shaped bone is not suitable for some orthopaedic procedures and some orthopaedic surgeons do not wish to use irradiated bone; therefore in this report, a method has been developed in which whole femoral heads can be washed to remove donor blood and bone marrow components. Processing results in excess of 99% bone marrow component removal-soluble protein, haemoglobin and DNA; the procedure is performed inside a closed system, thereby eliminating the need for terminal sterilisation by irradiation. In addition, uniaxial testing demonstrated no difference in compressive strength between washed and unwashed bone. We suggest that this washed bone may be capable of improving incorporation after grafting without disturbing biomechanical properties of the graft.