Effect of bone bank processing on bone mineral density, histomorphometry & biomechanical strength of retrieved femoral head

A comprehensive systematic review of marketed bone grafts for load-bearing critical-sized bone defects

Treatment of critical-sized bone defects typically involves implantation of a bone graft. Various types of bone grafts are nowadays marketed, categorized by their origin as allografts, xenografts, or synthetic grafts. Despite their widespread use, a comprehensive understanding of their morphology and mechanical response remains elusive. Controlling these characteristics for promoting bone growth and ensuring mechanical resistance remains challenging, especially in load-bearing districts. This study aims to systematically review existing literature to delineate the principal morpho-mechanical characteristics of marketed bone grafts designed for load-bearing applications. Furthermore, the obtained data are organized and deeply discussed to find out the relationship between different graft characteristics. Among 196 documents identified through PRISMA guidelines, encompassing scientific papers and 510(k) documents, it was observed that a majority of marketed bone grafts exhibited porosity akin to bone (>60%) and mechanical properties resembling those of low-bone volume fraction trabecular bone. The present review underscores the dearth of information regarding the morpho-mechanical characteristics of bone grafts and the incomparability of data derived from different studies, due to the absence of suitable standards and guidelines. The need for new standards and complete and transparent morpho-mechanical characterization of marketed bone grafts is finally emphasized. Such an approach would enhance the comparability of data, aiding surgeons in selecting the optimal device to meet patient's needs.

Freezing does not influence the microarchitectural parameters of the microstructure of the freshly harvested femoral head bone

The femoral head is one of the most commonly used bones for allografts and biomechanical studies. However, there are few reports on the trabecular bone microarchitectural parameters of freshly harvested trabecular bones. To our knowledge, this is the first study to characterize the microstructure of femoral heads tested immediately after surgery and compare it with the microstructure obtained with conventional freezing. This study aims to investigate whether freezing at -80 °C for 6 weeks affects the trabecular microstructure of freshly harvested bone tissue. This study was divided into two groups: one with freshly harvested human femoral heads and the other with the same human femoral heads frozen at -80 °C for 6 weeks. Each femoral head was scanned using an X-ray microcomputed tomography scanner (µCT) to obtain the microarchitectural parameters, including the bone volume fraction (BV/TV), the mean trabecular thickness (Tb.th), the trabecular separation (Tb.sp), the degree of anisotropy (DA), and the connectivity density (Conn.D). There was no statistically significant difference between the fresh and the frozen groups for any of the parameters measured. This study shows that freezing at -80 °C for 6 weeks does not alter bone microstructure compared with freshly harvested femoral heads tested immediately after surgery.

Equal rates of bone healing and reduced surgical time with iliac crest allograft compared to autograft in medial opening wedge high tibial osteotomy: a randomized controlled clinical trial

INTRODUCTION

Iliac crest autograft is frequently used to fill in bone defects after osteotomies. Nonetheless, surgery for bone autograft procurement is associated with morbidity and pain at the donor site. Alternatives to it have been explored, but there is no consensus to guide their application as a routine practice in several orthopedic procedures. Thus, this study was designed to compare the efficacy and safety between iliac crest autograft and allograft in medial opening wedge high tibial osteotomy.

MATERIALS AND METHODS

Forty-seven patients with a symptomatic unilateral genu varum and an indication for high tibial osteotomy were randomly assigned to receive either autograft or allograft to fill the osteotomy site. Operative time, bone healing, and complication rates (delayed union, nonunion, superficial and deep infection, loss of correction, and hardware failure) were recorded after a one-year follow-up. Data were expressed as Mean ± Standard Deviation and considered statistically significant when p < 0.05.

RESULTS

The time to radiologic union was similar between both groups (Allograft: 2.38 ± 0.97 months vs. Autograft: 2.45 ± 0.91 months; p = 0.79). Complication rates were also similar in both groups, with one infection in the allograft group and two in the autograft group, two delayed unions in the allograft group, and three in the autograft group. The operative time differed by 11 min between the groups, being lower in the allograft group (Allograft: 65.4 ± 15.1 min vs. Autograft: 76.3 ± 15.2 min; p = 0.02).

CONCLUSION

Iliac crest allografts can be safely and effectively used in medial opening wedge high tibial osteotomy as it promotes the same rates of bone union as those achieved by autologous grafts, with the benefits of a shorter operative time.

TRIAL REGISTRATION NUMBER

U1111-1280-0637 1 December 2022, retrospectively registered.

Impaction Bone Grafting with Low Dose Irradiated Freeze-Dried Allograft Bone for Acetabular Reconstruction

OBJECTIVE

Reconstruction of acetabular defects has been extremely challenging in both primary and revision total hip arthroplasty (THA). Impaction bone grafting (IBG) can restore the acetabulum bone mass and anatomically reconstruct the acetabulum. Our study aimed to report the short and medium-term clinical and radiographic outcomes of IBG for acetabular reconstruction in the cemented THA in the Chinese population.

METHODS

This was a single-center retrospective review enrolling 57 patients between May 2013 and July 2019. The patients with acetabular defects were treated with IBG, using low dose irradiated freeze-dried allograft bone with or without autograft bone, in the cemented THA performed by one senior surgeon. Harris hip score (HHS), standard pelvis anterior-posterior radiograph and lateral hip radiograph were obtained before operation and at 1 week, 3 months, 12 months, and yearly. Graft osteointegration was evaluated by Oswestry's criteria, and complication was documented at the last follow-up. Independent sample ANOVA test and Pearson chi-square tests are used for statistical analysis.

RESULTS

There were 61 hips in 57 patients. The average follow-up time was 35.59 months (5-77 months). According to AAOS classification, a total of 18 hips were identified as segmental bone deficiency (type I), with 21 and 22 hips for cavitary bone deficiency (type II) and the combined bone deficiency (type III), respectively. The average HHS was improved from 44.49 (range: 32-58) preoperatively to 86.98 (range: 78-93) postoperatively. Graft osteointegration was satisfactory (Oswestry score ≥2) in all patients. No dislocation occurred in the 57 patients (61 hips) during follow-up. Although one cup migrated, no revision, re-revision, radiographic loosening, graft bone lysis, or postoperative complications were detected at the final follow-up.

CONCLUSIONS

IBG with low-dose irradiated freeze-dried allograft bone in acetabular bone defect reconstruction is a reliable technique for restoring acetabular bone defects in THA.

Allograft bone banking experience in Pakistan

To share our experience of establishing a bone bank in Pakistan, and the clinical use of these indigenously produced bone grafts. We retrospectively reviewed our experience of the procurement, processing, and storage of bone grafts at a bone bank in Karachi, Pakistan, the first bone bank to be established in a public sector hospital in Pakistan. The bone bank was established at Sindh Institute of Urology and Transplantation (SIUT), Karachi, in collaboration with Department of Orthopaedic Surgery, Dow University of Health Sciences/Civil Hospital, Karachi (CHK) in May, 2015. Since then, a large number of bone grafts from the tissue bank have been used for various orthopedic procedures. This paper describes the problems and challenges faced in establishing and running a tissue bank in a Muslim and a developing country and the progress of the bone bank over the first 4 years. A total of 93 bone grafts were retrieved and preserved in the bone bank over the 4-year period. Among these, 56 (60.2%) bones were retrieved from male donors and 37 (39.8%) from females. The mean age of all donors was 55.9 ± 15.34 years (range: 16-90 years). All bone donors were living patients. No c bones were obtained from deceased donors. Types of bone grafts included: femoral heads, 68; head with neck of femur, 19; radius and ulna, 1; lower femur, knee joint, lower leg and foot bones, 4; and skull bone, 1. All grafts were subjected to aerobic and anaerobic bacterial cultures, as well as fungal cultures. Microbiological contamination was observed in 18/93 (19.35%). All culture positive bones were discarded. Bone grafts issued from the bank and transplanted were 51/93 (54.8%) in all. Bone grafts were used in a variety of tumor and non-tumor orthopaedic procedures in CHK. Nine bone grafts were donated to the other hospitals to be used for revision total hip replacement and tumor surgeries. There were no service charges. Two patients (3.92%) developed infections postoperatively, one superficial and one deep. No other complications were noted. This is the preliminary report on the establishment and functioning of a bone bank in a public sector hospital in Pakistan. The favorable outcome has inculcated confidence in orthopedic surgeons for greater use of bone allografts for a variety of indications in this country.

Diabetes is associated with a lower minimum moment of inertia among older women: An analysis of 3D reconstructions of clinical CT scans

Hip fractures are a significant burden on the aging population, often resulting in reduced mobility, loss of independence, and elevated risk of mortality. While fracture risk is generally inversely related to bone mineral density (BMD), people with diabetes suffer a higher fracture rate despite having a higher BMD. To better understand the connection between diabetes and fracture risk, we developed a method to measure the minimum moment of inertia (mMOI; a geometric factor associated with fracture risk) from clinical CT scans of the pelvis. Since hip fractures are more prevalent in women, we focused on females in this study. We hypothesized that females with diabetes would have a lower mMOI along the femoral neck than those without diabetes, indicative of a higher fracture risk. Three-dimensional models of each hip were created from clinical CT scans of 40 older women (27 with diabetes: 10 fracture/17 non-fractured; 13 without diabetes: non-fractured controls). The mMOI of each hip (n = 80) was reported as the average from three trials. People with diabetes had an 18% lower mMOI as compared to those without diabetes after adjusting for age and BMI (p = 0.02). No differences in the mMOIs between the fractured and contralateral hips in the diabetic group were observed (p = 0.78). Similarly, no differences were observed between the fractured and non-fractured hips of people with diabetes (p = 0.29) when accounting for age and BMI. This suggests structural differences in the hips of individuals with diabetes (measured by the mMOI) may be associated with their elevated fracture risk.

ESTABLISHMENT OF THE BONE TISSUE BANK AT MOSTAR UNIVERSITY CLINICAL HOSPITAL

Bone tissue banks are necessary for collection, production, testing, packaging, storage and delivery of bone transplants. Bone tissue bank is a link between the donor and the recipient by which the donation becomes a medium of health improvement for both the donor and the recipient. At the Department of Orthopedics, Mostar University Clinical Hospital, about 200 total hip replacements are performed per year. Most patients undergoing total hip replacement surgery (90%) have been diagnosed with osteoarthritis, and they are suitable donors, having in mind their age and comorbidities. In the same Department, around 50 procedures that require bone transplants are performed per year. A team of highly competent surgeons are working on an intensive process of adaptation oriented to quality improvement and intensification of the activity, both with the goal of meeting the standards of excellence in orthopedic surgery. The presence of a bone tissue bank has a favorable impact on the quality of health care owing to bone transplant availability, as well as on the scientific role of a highly specialized institution that examines the properties of bone tissue.