Article

Thermal stability and structure of cancellous bone mineral from the femoral head of patients with osteoarthritis or osteoporosis

Department of Orthopaedic Surgery, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland, UK.
Annals of the Rheumatic Diseases (Impact Factor: 10.38). 03/2005; 64(2):222-5. DOI: 10.1136/ard.2004.021329
Source: PubMed

ABSTRACT Cancellous bone from patients with osteoarthritis (OA) has been reported to be undermineralised and that from patients with osteoporosis (OP) is more liable to fracture. Changes in the mineral component might be implicated in these processes.
To investigate the thermal stability and the mineral structure of cancellous bone from femoral heads of patients with either OA or OP.
Powdered bone was prepared from femoral heads of patients with either OA or OP and a control group. Composition and thermal stability were determined using a thermogravimetric analyser coupled to a mass spectrometer. Unit cell dimensions and the crystallite size of the mineral were measured using x ray diffraction.
Thermal stability of the bone matrix, or of the mineral phase alone, was little altered by disease, though OA bone contained less mineral than OP or control bone. In all three groups, x ray diffraction showed that the mineral unit cell dimensions and crystallite sizes were the same. The mean carbonate content in the mineral from all three groups was between 7.2 and 7.6% and is suggested to be located in both the A site (that is, substituting for hydroxyl groups), and the B site (that is, substituting for phosphate groups).
These results confirm that there is a lower mass fraction of mineral in OA bone, and indicate that the nature of the mineral is not a factor in either disease process.

Download full-text

Full-text

Available from: Richard Aspden, Aug 20, 2015
2 Followers
 · 
113 Views
  • Source
    • "Raman spectra were recorded longitudinally during treatment together with the gravimetric measurement of water loss. Thermogravimetric (TGA) analysis of bone by others has indicated that the adsorbed (i.e., bound) water was mostly removed at around 100 °C whereas so-called more tightly structural water is lost only after the decomposition of the organic matrix in temperature range of 200–600 °C (around 220 °C peaking at 340 °C) [23] [24]. Therefore, the oven drying at 40 °C employed in this study is expected to remove the unbound water and has minimal effect on the bound water compartment. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Matrix bound water is a correlate of bone's fracture resistance and assessment of bound water is emerging as a novel measure of bone's mechanical integrity. Raman spectroscopy is one of the few nondestructive modalities to assess the hydration status in bone; however, it has not been used to study the OH-band in bone. A sequential dehydration protocol was developed to replace unbound (heat drying) and bound (ethanol or deuterium) water in bone. Raman spectra were collected serially to track the OH-band during dehydration. Spectra of synthetic hydroxyapatite, demineralized bone and bulk water were collected to identify mineral and collagen contributions to the OH-band. Band assignments were supported by computational simulations of the molecular vibrations of Gly-Pro-Hyp amino acid sequence. Experimentally and theoretically obtained spectra were interpreted for band-assignments. Water loss was measured gravimetrically and correlated to Raman intensities. Four peaks were identified to be sensitive to dehydration: 3220 cm−1 (water), 3325 cm (N\H and water),3453 cm−1 (hydroxyproline and water), and 3584 cm−1 (mineral and water). These peaks were differentially sensitive to deuterium treatment such that some water peaks were replaced with deuterium oxide faster than the rest. Specifically, the peaks at 3325 and 3584 cm−1 were more tightly bound to the matrix than the remaining bands. Comparison of dehydration in mineralized and demineralized bone revealed a volume of water that may be locked in the matrix by mineral crystals. The OH-range of bone was dominated by collagen and the water since the spectral profile of dehydrated demineralized bone was similar to that of the mineralized bone. Furthermore, water associates to bone mainly by collagen as findings of experimentally and theoretically spectra. The current work is among the first thorough analysis of the Raman OH stretch band in bone and such spectral information may be used to understand the involvement of water in the fragility of aging and in diseased bone.
    Bone 07/2014; 67. DOI:10.1016/j.bone.2014.07.021 · 4.46 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A quadrupole mass spectrometer based evolved gas analyser has been built in our laboratory with necessary UHV hardware, computer interface and software for conducting real-time multiple ion detection mass spectrometry over a wide dynamic pressure regime. Thermal decomposition behaviour of model salts CaCO3, CuSO4.5H2O, Pb(NO3)2 and AlNH4(SO4)2.12H2O has been studied to standardise this system. Reaction parameters for the dehydration and decomposition of CuSO4 5H2O are computed and found to be in agreement with the reported literature values.
    Instrumentation Science & Technology 03/1995; 23(2):123-135. DOI:10.1080/10739149508013937 · 0.80 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To investigate the relationships between bone mineral density (BMD) in the hip, spine, distal femur and proximal tibia and minimum joint space width (mJSW) in the knees of healthy women. Women 22-68 years old without a history of knee pain, bone or joint disease or injury underwent a single, fixed-flexion knee X-ray. Radiographs were graded according to the Kellgren-Lawrence scale and analyzed for mJSW using a computer algorithm. Dual X-ray absorptiometry scans of the spine, hip, distal femur and proximal tibia were also acquired for each participant. Femur and tibia scans were acquired and analyzed using a modified version of the lumbar spine software. Forty-five females, mean [standard deviation (SD)] age and body mass index (BMI) of 40.1 (13.9) years and 24.6 (4.5)kg/m(2), respectively, participated. The mean (SD) mJSW was 4.64 (0.68)mm. Linear regression analyses controlling for age and BMI revealed that BMD in the femoral trochanter and the central two regions of the tibia (T2 and T3) was significantly related to mJSW in the knee. A backwards regression analysis performed to determine which region of interest is most significantly related to mJSW revealed that femoral trochanter BMD (beta-value=0.416) is the most significant. In contrast to the suggestion that BMD is negatively correlated with mJSW in the knees of osteoarthritic individuals, these results suggest that increasing BMD in the femoral trochanter and tibia is significantly associated with increasing mJSW in healthy females. Further investigation of this relationship is warranted.
    Osteoarthritis and Cartilage 11/2005; 13(10):872-8. DOI:10.1016/j.joca.2005.06.010 · 4.66 Impact Factor
Show more