Abstract
Introduction: The National Bone Bank of Ireland was established in June 1996 at Cappagh National Orthopaedic Hospital, Dublin in response to the increased demand of allogenic bone grafts in Ireland. We reviewed the Bone Bank performance since it started with special emphasis on Microbiological monitoring of bone allograft as infection is the main complication of bone allograft (Chapman and Villar 1992).
Material and Methods: The femoral head allograft is harvested from living volunteer donors who are undergoing primary total hip replacement at Cappagh Hospital and have been assessed by the Bone Bank Co-Ordinator.
Harvesting: The bone is retrieved and harvested at the time of total hip replacement according to a strict protocol.
Storage: The bone is stored in the “Quarantine” freezer at −80 degrees C for a minimum period of 180 days. Each specimen is subjected to a full technical review by the Bone Bank Co-Ordinator and Medical Director and only when results of screening confirmed negative, the bone designated suitable for “Issue Stock” freezer.
Issue of Allografts: Bone is supplied for use, only after receiving full details of recipient to allow tracking. The results of the culture swab taken at the time of implantation and details of any post operative infection in recipients are forwarded to the bone bank.
Results: From June 1996 to December 2003, 5089 Primary Total Hip Replacements done at Cappagh Hospital and 1921 (38%) femoral heads were harvested. 109 (5.7%) of grafts had initial positive swabs/chips and 22 of these were discarded because of second positive chips. 1457 femoral head grafts supplied to 876 recipients and were used in Revision Total Hip Replacement (60%), Spine Surgeries (15%), Revision Total Knee (12%), Fractures, Tumours, Foot and Ankle (12%). 6 swabs at the time of grafting in recipients grew Staphylococcus Epidermidis but no clinical infection reported in our follow-up system. To double check, we posted a questioner to all consultants with list and details of their recipient patients and only 2 cases of suspected grafts related infection reported.
Discussion and Conclusion: Microbiological surveillance of bone grafts protect recipients from infection and is useful as a quality control of the process of bone banking (Farrington et al 1998). Our study showed contamination rate of 5.7%. Minimum infection rate post Revision Hip Replacement has been reported by Tomford in 1990, but after massive femoral allograft, infection has been reported 4% – 5% (Tomford 1990) and over 11% by Lord et al in 1988. Our experience showed only 2 cases in spite of strict follow-up protocol. We follow the policy of discarding the heavily contaminated grafts (Chapman 1992).
The quality performance of a Bone Bank depend on a full time bone bank co-ordinator, identification of donors, retrieval and harvesting of grafts, blood and microbiological assessment, medical supervision for decisions about contaminated grafts, a strict follow-up protocol and a regular audit of bone bank (Ivory and Thomas 1993). We also suggest that regular correspondence to the consultant using the bone grafts will improve the accuracy of follow-up.
The abstracts were prepared by Emer Agnew. Correspondence should be addressed to Irish Orthopaedic Association, Secretariat, c/o Cappagh National Orthopaedic Hospital, Finglas, Dublin 11, Ireland.
