Femoral head allograft bone banking

The quality assessment of the University hospital bone bank in Central Serbia: the second audit after fourteen years

We analyzed the prevalence and predisposing factors for the overall rejection rate after retrieval of 267 fresh femoral head allografts over the past 7 years. The present study aimed to assess the quality system of institutional bone banking that can provide high-standard allografts with a low infection rate. Retrospective analysis of bone banking from June 2013 to December 2019 was conducted on 267 donors and 153 recipients. Of the 267 donated femoral heads, 74 were rejected, giving an overall rejection rate of 27.71%. The leading cause of allograft rejection was the inability to perform serology tests due to donor death; the absence of serological tests itself, and the donor refusal to perform the serology 6-month retest in 42 donors (15.72%). At retrieval, 12 allografts were positive, giving an overall contamination rate of 4.49%. Seven (2.62%) of the 267 allografts failed the blood screening tests. Thirteen allografts (4.86%) were discarded because of suspected damage to the packaging or disuse during surgery. An infection rate of 1.30% was found following transplantation. Over the past 7 years of bone banking, our results show that the overall rejection rate and the allograft-related infection rate correlate with international standards. The leading cause of allograft rejection was the inability to perform serology tests due to donor death and their refusal to perform the serology retests. Besides stringent aseptic allograft handling, donor motivation to participate in bone banking is extremely important for its efficient functioning.

Study of Cell Viability and Etiology of Contamination in Decalcified Bone Allograft: A Pilot Study

BACKGROUND

Bone allografts can elicit immune responses which is correlated with the presence of Human Leukocyte Antigen (HLA) and cellular DNA. It also has risk of causing occult infection arising out of contamination during its processing and storage. The presence of immunogenic materials like cells, cellular remnants and DNA in a decalcified bone allograft during different phases of processing has never been studied. Present study was conducted to explore- the cell viability using routine Hematoxylin and Eosin, presence of DNA using Feulgen staining and etiology of contamination in decalcified bone allograft during procurement, demineralization and ethanol preservation.

METHODS

The harvested bones from patients undergoing hemireplacement/THR/TKR were processed to prepare decalcified bone allografts. The samples during procurement (A), HCL treatment (B) and ethanol preservation (C) were sent for histopathological analysis (number of osteocytes in the maximum density field under 40x and the cells demonstrating presence of DNA on feulgen stain) and microbiological assessment (aerobic/anaerobic/fungal cultures).

RESULTS

Histopathological study demonstrated the presence of osteocytes and other cells like bone marrow, adipocytes, endothelial cells in the decal bone allograft. The average number of osteocytes gradually decreased from 55.47, 9.6, 0.86 in sample A, B, C, respectively. Feulgen staining confirmed the presence of DNA in osteocytes and other cells which decreased both qualitatively and quantitatively in subsequent stages of processing. Rate of contamination demonstrated at the procurement was 6.67% (Staphylococcus aureus). After treatment with HCl (demineralisation), 7.14% of non-contaminated allografts were found contaminated (Staphylococcus epidermidis). None of the remaining 13 non-contaminated allografts showed contamination after storage in ethanol. Overall 13% of the patients had positive cultures on microbiological assessment.

CONCLUSION

The population of osteocytes in the harvested bone reduced significantly after processing with HCl and ethanol preservation. Presence of DNA, demonstrated by using Feulgen staining, was observed in bone marrow cells, adipocytes along with osteocytes which showed quantitative reduction on processing. Hence, antigenicity, conferred by cells and their DNA, reduced significantly after processing of decal bone. Contamination rate of banked decalcified allograft was 13%. Thus, culture and sensitivity tests should be carried out at each step of processing of decal bone allograft.

Improving efficiency of a regional stand alone bone bank

The introduction of a stand-alone Bone Bank in our Regional Orthopaedic Hospital has improved the availability of femoral head allograft. Benninger et al. (Bone Joint J 96-B:1307-1311, 2014), demonstrated their institutions bank to be cost effective despite a 30 % discard rate for harvested allograft. We sought to audit our own discard rates and subsequent cost-effectiveness of our bone bank. Donor recruitment. Before approaching a potential donor, our establishment's nurse specialists review their clinical notes and biochemical laboratory results, available on a regional Electronic Care Records. They view femoral head architecture on radiographs against set criteria, Patient Archive and Communication system (SECTRA, Sweden). In total 1383 femoral heads were harvested, 247 were discarded giving an overall rate of 17.9 %. The most common reasons for discard of harvested graft was a positive microbiology/bacteriology result, n = 96 (38.9 %). After a rise in discard rates in 2007, we have steadily reduced our discard rates since 2006/2007 (28.2 %), 2008/2009 (17 %), 2010/2011 (14.8 %), and finally to 10.3 % in 2012/2013. In the current financial year, our cost to harvest, test, store and release a femoral head is £ 610. With a structured donor recruitment process and unique pre-operative radiographic analysis we have successfully reduced our discard rates bi-annually making our bone bank increasingly cost-effective.

Osteobiologics in foot and ankle surgery

Osteobiological agents are a welcome addition to the surgeon’s armamentarium. These products should always be thought of as a complement to good surgical principles and construct. As history has shown, nothing outperforms the osteogenic properties of autograft bone. Even if allograft is procured for use, an attempt should be made to combine it with autograft if possible, given the primary indexprocedure in which it will be used. Structural support from corticocancellous autografts is also greater than allografts, which lose mechanical strength during the sterilization and preservation process. Bone fillers without structural support should be used only when there are other means of cortical contact. The ability of the human skeletal system to repair itself is amazing. Osseous healing relieson a complicated series of intrinsic and extrinsic factors. Some of these factors include a stable fixation construct, nutritional status, good surgical technique, and good decision making. Autogenous bone graft remains the gold standard, and the presence of native growth factors and osteogenic cells is mandatory to repair these deformities. When this microenvironment is disruptive, nonunion may result.Understanding the mechanisms of bony healing contributes to the available osteobiologics, which give the foot and ankle surgeon additional tools to enhance the reparative process of bony defects and the ability of the foot to restore itself.

Fungal culture of musculoskeletal tissue: what's the point?

There have not been any studies that review the prevalence of fungal isolates using selective media from samples of banked musculoskeletal tissue retrieved from living and cadaveric donors. A total of 2,036 swab and 2,621 biopsy samples of musculoskeletal tissue from tissue banks were received from the 1st August 2008 till 31st December 2010. Routine culture for fungi using selective media with a prolonged incubation period failed to demonstrate a greater prevalence of fungal isolates than by using non-selective culture media alone. Using selective culture fungi were recovered from only two Sabouraud agar plates (0.1%) but not from non-selective media. During the same period fungi were isolated from three graft samples cultured in non-selective broth media only (0.1%). There was no correlation of fungal isolates from selective or non-selective media inoculated at the same time nor from multiple graft samples collected from the same donor supporting the possibility of an exogenous source for fungal isolates rather than an endogenous source.

Long-term outcome of total hip replacement in patients with or without femoral head contamination

PURPOSE

To compare long-term outcomes of total hip replacement (THR) in patients with or without contamination of the femoral head.

METHODS

After a mean period of 12 (range, 8-17) years, 104 female and 71 male THR patients aged 47 to 96 (mean, 77) years were reassessed via a self-administered questionnaire, and 25 other THR patients were reassessed by review of case notes. The questionnaires comprised the 12-item Oxford hip score and the European Quality Of Life (EuroQOL). 87 and 88 patients had positive and negative cultures in the donated femoral heads, respectively. The 2 groups were compared with respect to the Oxford hip score, the EuroQOL, and rates of complication and revision surgery.

RESULTS

Long-term outcomes of THR patients with or without femoral head contamination were not significantly different. Respectively, the mean Oxford hip scores were 36 and 39 (p=0.4); 16 and 14 patients had the maximum score of 48; 2 and 3 patients scored <10 (mostly owing to aseptic loosening). The respective mean visual analogue scale score of the EuroQOL were 65 and 73 (p=0.07); only the dimension of self care was significantly different between groups (p=0.04). Respectively, 14 and 12 patients had complications (16% vs. 15%, χ²=0.05, p=0.8), whereas 11 and 5 patients had revision surgery (13% vs. 6%, χ²=2.2, p>0.1).

CONCLUSION

Microbiological screening of donated femoral heads plays no role in predicting long-term failure of THR in the donors.

Cost comparison of femoral head banking versus bone substitutes

PURPOSE

To compare the costs of femoral head banking versus bone substitutes.

METHODS

Records of femoral head banking from 1998 to 2008 were reviewed. The cost of allogenic cancellous bone graft was calculated by estimating the direct expenditure of femoral head procurement, screening tests, and storage, and then divided by the amount of bone harvested.

RESULTS

326 females and 141 males (mean age, 80.3 years) donated 470 femoral heads. Each transplantable femoral head costs US$978. Each gram of transplantable allogenic bone graft costs US$86, compared with US$9 to 26 per gram for commercially available bone substitutes.

CONCLUSION

Compared with bone substitutes, femoral head banking in Hong Kong was less economical. Unless allografts yield superior outcomes, harvesting femoral heads for general usage (such as filling bone voids for fresh fractures) is not justified from a financial perspective, especially in banks dedicated to procuring bone from femoral heads only.

The clinical significance of femoral head culture results in donors after hip arthroplasty: a preliminary report

The aim of this study is to determine whether a link exists between clinical wound problems and positive bacterial culture of the femoral head after primary hip arthroplasty. Clinical data were retrieved for 24 culture-positive and 26 culture-negative patients. Coagulase-negative Staphylococcus was the commonest pathogen, cultured in 19 of the 24 culture-positive femoral heads donated to a regional bone bank. Wound problems occurred in 2 of the patients from the culture-positive group and 4 of the patients from the culture-negative group. The relative risk of wound problems was 0.54 in the culture-positive group. Based on the available evidence in this preliminary short-term retrospective review, positive microbiology from donated femoral heads has no clinical implication in the donors. The practice of reporting culture-positive femoral heads should be continued.

Contamination of banked femoral head allograft: incidence, bacteriology and donor follow up

BACKGROUND

Allograft donations are not uncommonly found to be contaminated. The issue of contaminated donations from live donors at the time of surgery, and the significance of this to the patient in terms of subsequent sepsis of the arthroplasty, were examined.

METHODS

The donations of femoral heads to the Queensland Bone Bank over a 9-year period were reviewed, and the incidence and bacteriology of contamination were detailed. Clinical outcomes were determined for donors who had positive cultures at the time of retrieval and they were compared with those of culture-negative donors.

RESULTS

Between March 1987 and February 1996, 232 femoral heads were donated to the Queensland Bone Bank. Four specimens were sent for culture with each femoral head (surface swab of femoral head, acetabular swab, bone biopsy and capsule). In 51 cases, one or more positive cultures were obtained (22% contamination rate). The majority of organisms cultured were Staphylococcus epidermidis. One hundred and seventy donations came from surgery performed at the Princess Alexandra Hospital, and 40 femoral heads were considered contaminated. Deep infection was recorded in one of the 40 cases with contaminated donations and three out of 130 non-contaminated donations had subsequent septic episodes.

CONCLUSION

The contamination rate detailed in the present report is higher than in most series. This may be due to the fact that four bacteriological specimens are taken to assess contamination. Two of these specimens are tissue samples which yielded more positive results than did the two swabs. All other series take no more than two bacteriological specimens, which are usually bone swabs. These are shown to have a poor yield of positive cultures. Therefore there is a significant underestimation of contamination rates by other bone banks. This has implications for the recipients of bone from those banks, particularly when the allograft material is not secondarily sterilized. This is important given increasing allograft usage, and the increasing numbers of revision joint arthroplasty and impaction grafting procedures being performed. Sterilization of all bone by irradiation to 25 kGy is recommended.

Bacterial contamination rates during bone allograft retrieval

A retrospective study of allograft bone retrieved from 401 donors between January 1987 and March 1996 was performed to determine the incidence of bacterial contamination. Contamination according to type of donor (live, multiorgan, cadaveric) was also determined. Live donors donating a femoral head demonstrated a contamination rate of 13%; multiorgan donors, 24%; and cadaveric donors, 35%. Donor contamination by type of bone (hemipelvis, femur, tibia) showed no significant difference in the multiorgan donors. In cadaveric donors, there was a significant increase in contamination of the hemipelves as compared to the femur and tibias. Recommendations for contamination control in allograft retrieval are given. Our findings are of great significance for musculoskeletal banks that do not secondarily irradiate and rely on screening of allograft bone for contamination alone.

Role of the blood transfusion service in tissue banking

Tissue transplantation and banking are rapidly growing services throughout the world reflecting the widening availability of transplantable cadaver tissue and the mounting clinical indications particularly in orthopaedic, plastic and cardiovascular surgery. In the US tissue banking is more established, yet continues to show a rapid growth profile. In the UK it is currently organised in a variety of different ways and by a number of different organisations. The risks of disease transmission by tissue transplantation are similar to those for blood transfusion and the majority of tissues are grafted during procedures that are not life saving. The danger of disease transmission has resulted in the introduction of legislation in the US which allows the FDA to inspect tissue banks and to recall and destroy tissues. In the UK, there is currently no regulation or inspection of tissue banks to demonstrate that donor selection, tissue processing and tracking are conducted to acceptable standards. Blood transfusion services in the UK, US, New Zealand, Australia and possibly other countries have extended their roles to include organ and tissue donation to varying degrees, with the collection, processing and distribution of bone and tendon allografts most commonly undertaken. They have readily available special capabilities and experience with an established infrastructure, compliant with Good Manufacturing Practice, placing them in an ideal position to provide this service safely and cost-effectively.

Bone allograft banking in South Australia

The South Australian Bone Bank had expanded to meet an increased demand for allograft bone. During a 5 year period from 1988 to 1992, 2361 allografts were harvested from 2146 living donors and 30 cadaveric donors. The allografts were screened by contemporary banking techniques which include a social history, donor serum tests for HIV-1, HIV-2, hepatitis B and C, syphilis serology, graft microbiology and histology. Grafts were irradiated with 25 kGy. The majority of grafts were used for arthroplasty or spinal surgery and 99 were used for tumour reconstruction. Of the donated grafts 336 were rejected by the bank. One donor was HIV-positive and two had false positive screens. There were seven donors with positive serology for hepatitis B, eight for hepatitis C and nine for syphilis. Twenty-seven grafts had positive cultures. Bone transplantation is the most frequent non-haematogenous allograft in South Australia and probably nationally. The low incidence of infectious viral disease in the donor population combined with an aggressive discard policy has ensured relative safety of the grafts. The frequency of graft rejection was similar to other bone banks but the incidence of HIV was lower.

Bone banking: from Tamworth Base Hospital to Royal Newcastle Hospital

During the first 6 months of 1992, orthopaedic surgeons at Tamworth Base Hospital were involved in a feasibility study using allograft bone and donating femoral heads to Royal Newcastle Hospital Bone Bank. The two hospitals being separated by 300 km meant that storage, packaging and transportation had to be refined in order to ensure sterility and safe delivery of the bone. This study was undertaken because of the growing need for allograft bone in revision hip arthroplasty at Tamworth Base Hospital. This need for allograft bone has been expressed by other country based orthopaedic surgeons and will only increase during the next few years as primary hip prostheses age and revision hip surgery continues to advance.