Background and objectives: In the treatment of bone-related diseases, the biomechanical testing data of cadaveric bone plays a fundamental role in the design and application of orthopedic prosthesis and artificial bone materials, as well as the building of FEMs. Of these, the sample preparation is directly related to the accuracy of test results, including the removal of bone marrow, and the treatment of chemical solutions. In addition, it is also essential to evaluate the bone quality of bone specimens being tested prior to mechanical testing. Based on these issues, in this thesis, our studies aimed to systematically summarize the methods currently available for assessing bone quality in human bone tissue, as well as to investigate the efficiency of different chemical solvents on the removal of marrow from cancellous bone and their effects on the mechanical properties.
Methods: In the first study (i), a systematic review of the literature was conducted using PubMed and Web of Science databases with the goal of finding all articles describing the methods of assessing bone quality in human bone specimens. The search terms were “bone quality [Title/Abstract]” AND “human bone specimens”. In the second study (ii), cylindrical cancellous bone samples (Ø8 × 2 mm) were obtained from fresh-frozen human cadaver femoral condyles and assigned to two groups, treated with chemical solvent soaking (solvent group) and ultrasonic cleaning (ultrasound group), respectively. Each group was divided into several
subgroups based on different treatments. The differences in material density (Δρb), apparent density (Δρapp), and porosity (ΔP) before and after treatment were used as evaluation indications. In the third study (iii), cylindrical cancellous bone samples (Ø6 × 12 mm) were harvested from fresh-frozen human bones, including spinal vertebrae and femoral heads. All samples were divided into two groups, i.e., immersed in physiological saline (saline-immersed group) and treated with a combination of acetone and physiological saline (acetone and saline-treated group). Before and after treatment, all samples were subjected to non-destructive compression tests (0.45% strain), and finally destructive tests with a strain of 50%. Actual density (ρact), initial modulus (E0), maximum stress (σmax), energy absorption (W), and plateau stress (σp) were calculated as evaluation indicators.
Results: Firstly, based on previous studies, our systematic review (i) found that advanced techniques are playing an increasingly important role based on their multiple advantages. Non- invasive imaging modalities and mechanical testing techniques, as well as the assessment of bone composition, need to complement each other to provide comprehensive and ideal information on the bone quality of human bone specimens. Secondly, our second study (ii) showed that a combination of 99% ethanol and detergent solution (v/ v = 1:20), as well as a mixture of 99% ethanol and acetone (v/v = 1:1), seem to be the optimal defatting methods for
2 mm thick cancellous bone slices because of their advantages of effectiveness, easy- availability, low-cost and relative-safety. Moreover, chemical soaking for 24h indicated better marrow removal than ultrasonic cleaning with 99% ethanol or acetone for 20 or 40min. Finally, for the larger samples, which were investigated in the third study (iii), according to the results, a combination of acetone and ultrasonic bath for 4h failed to completely remove bone marrow from cancellous bone samples (Ø6×12mm). In this study, it was also observed that short-term storage in physiological saline is an appropriate choice and has no effect on the E0 of cancellous bone. However, treatment of cancellous bone with acetone resulted in changes in mechanical properties that could not be reversed by subsequent immersion in physiological saline. Conclusions: The results of this work provide a reference for bone quality assessment, sample preservation, and mechanical testing of cancellous bone, which is important for obtaining accurate biomechanical data. It may serve as a basis for future clinical applications and in vitro model building.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:85847 |
| Date | 07 June 2023 |
| Creators | Wang, Fangxing |
| Contributors | Universität Leipzig |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
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