-
[show abstract]
[hide abstract]
ABSTRACT: To study the transverse thoracic pedicle diameter of a Chinese population and to determine the feasibility and safety of transpedicular screw fixation.
The authors studied the transverse pedicle diameter of the T1-T12 of the thoracic spine in a Chinese population using reformatted computed tomography. The data were compared with Caucasians and other Asians.
The mean outer pedicle widths of the thoracic spine from T1 to T12 were 8.43, 6.65, 5.20, 4.44, 4.50, 4.87, 5.04, 5.32, 5.66, 6.65, 8.08 and 8.27 mm in males and 7.91, 6.03, 4.55, 3.91, 4.05, 4.31, 4.39, 4.60, 5.13, 5.67, 7.21 and 7.50 mm in females, respectively. Female patients have smaller dimensions compared with male patients. A significant percentage of patients have an outer pedicle width of less than 4.5 mm from T3 to T8, which is not suitable for transpedicular screw fixation with a 3.5 mm screw.
The results of this study suggest that transpedicular screw fixation may not be suitable for the mid-thoracic regions in most Chinese females and that modified pedicle screw techniques or modified type of fixation is required in these patients. CT evaluation is a must before this procedure is performed.
Anatomia Clinica 11/2009; 32(5):463-8. · 0.93 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The scaffold is a key element to osteogenic tissue engineering as it provides a microenvironment for bone formation. Natural bone collagen scaffold (NBCS) is a novel biomaterial scaffold acid-extracted from organic human bone. The objective of this study was to characterize NBCS and evaluate the osteoconductivity of the scaffold, in combination with osteogenic protein-1 (OP-1), using a rabbit posteolateral lumbar fusion model. Thirty two rabbits were divided into 4 experimental groups, autograft, NBCS alone, OP-1 alone or NBCS combined with OP-1. Bone formation was evaluated by micro-CT, quantitative histological analysis, immunohistochemistry and semi-quantitative RT-PCR at 6 weeks postoperatively. By scanning electronic microscope, we showed that NBCS maintains a porous, interconnecting microarchitecture. Micro-CT analysis demonstrated that NBCS combined with OP-1 significantly induced (p < 0.01) bone formation at the fusion site as compared to control groups. This was confirmed by quantitative histological analysis which demonstrated that the NBCS combined with OP-1 significantly enhanced bone matrix area (17.7 mm(2)) (p < 0.05) and bone marrow cavity size (71.3 mm(2)) (p < 0.05) as compared to the controls. Immunohistochemical assessment and RT-PCR also demonstrated that NBCS combined with OP-1 enhanced type I collagen and osteonectin expression. Together, these results suggest that NBCS is an effective scaffold for osteogenesis, and combined with growth factors such as OP-1, possesses both osteoconductive and osteoinductive properties that are sufficient for bone regeneration.
Journal of Biomedical Materials Research Part B Applied Biomaterials 03/2009; 90(2):778-88. · 2.15 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Postero-lateral lumbar fusion in a rabbit model was performed to compare the bone induction potential of autograft, insoluble bone gelatin (ISBG), osteogenic protein-1 (OP-1), and the combination of ISBG and OP-1.
To evaluate the efficiency of ISBG as a carrier/enhancer for OP-1 in a rabbit spinal fusion model.
OP-1 or recombinant human BMP-7 has been shown to be effective in inducing new bone formation in surgical applications such as spinal arthrodesis. However, the lack of an ideal carrier contributes to its associated comorbidities (e.g., uncontrolled bone growth, local inflammatory over-response, nonfusion) and limits its use clinically.
Adult New Zealand white rabbits (n = 32) underwent bilateral lumbar intertransverse process fusion procedures at L5 to L6 and were randomized to receive: (1) autograft; (2) ISBG; (3) OP-1; or (4) ISBG in combination with OP-1 (ISBG + OP-1). Spinal fusion masses were evaluated by manual palpation, biomechanical testing, radiographic assessment, microcomputer tomography scanning and histologic examination at 6 weeks after surgery.
Treatment of ISBG + OP-1 resulted in higher spinal fusion rates (7 of 7, 100%) than that of autograft (3 of 7, 43%), ISBG (2 of 8, 25%), and OP-1 (2 of 7, 29%) based on manual palpation (P < 0.01). Greater fusion rates in the ISBG + OP-1 group were also evidenced by radiographic examination (P < 0.01), microcomputer tomography bone volume analysis (P < 0.01), and biomechanical testing (P < 0.05). Histologic assessment demonstrated that treatment of ISBG + OP-1 induces new contiguous bone formation in the interval between the transverse processes which was absent in the other groups.
In this study, ISBG + OP-1 resulted in more effective lumbar intertransverse process fusion than autograft, OP-1 putty or ISBG alone. ISBG is capable of enhancing OP-1-induced bone formation.
Spine 08/2008; 33(18):1935-42. · 2.08 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: V-ATPase plays important roles in controlling the extra- and intra-cellular pH in eukaryotic cell, which is most crucial for cellular processes. V-ATPases are composed of a peripheral V(1) domain responsible for ATP hydrolysis and integral V(0) domain responsible for proton translocation. Osteoclasts are multinucleated cells responsible for bone resorption and relate to many common lytic bone disorders such as osteoporosis, bone aseptic loosening, and tumor-induced bone loss. This review summarizes the structure and function of V-ATPase and its subunit, the role of V-ATPase subunits in osteoclast function, V-ATPase inhibitors for osteoclast function, and highlights the importance of V-ATPase as a potential prime target for anti-resorptive agents.
Biochemical and Biophysical Research Communications 07/2007; 357(4):821-7. · 2.48 Impact Factor
