ABSTRACT: Osteoporosis mainly involves cancellous bone, and the spine and hip, with their relatively high cancellous bone to cortical bone ratio, are severely affected. Studies of bone mesenchymal stem cells (BMSCs) from osteoporotic patients and animal models have revealed that osteoporosis is often associated with reduction of BMSCs' proliferation and osteogenic differentiation. Our aim was to test whether polylactic acid-polyglycolic acid copolymer(PLGA)/collagen type I(CoI) microspheres combined with BMSCs could be used as injectable scaffolds to improve bone quality in osteoporotic female rats.
PLGA microspheres were coated with CoI. BMSCs of the third passage and were cultured with PLGA/CoI microspheres for seven days. Forty three-month-old female non-pregnant SD rats were ovariectomized to establish osteoporotic animal models. Three months after being ovariectomized, the osteoporotic rats were randomly divided into five groups: SHAM group, PBS group, cell group, microsphere (MS) group, and cell+MS group. Varying materials were injected into the intertrochanters of each group's rats. Twenty rats were sacrificed at one month and three months post-op, respectively. The femora were harvested in order to measure the intertrochanteric bone mineral density (BMD) with DEXA and trabecular thickness (Tb.Th), percentage of trabecular area (%Tb.Ar), bone volume fraction (BV/TV) and trabecular spacing (Tb.Sp) with Micro CT. One-way ANOVA and Kruskal-Wallis tests were used.
BMSCs seeded on PLGA/CoI microspheres had a nice adhesion and proliferation. At one month post-op, the BMD (0.33 ± 0.01 g/cm(2)), Tb.Th (459.65 ± 28.31 μm), %Tb.Ar (9.61 ± 0.29 %) and Tb.Sp (2645.81 ± 94.91 μm) of the cell+ MS group were better than those of the SHAM group and the cell group. At three months post-op, the BMD (0.32 ± 0.01 g/cm(2)), Tb.Th (372.81 ± 38.45 μm), %Tb.Ar (6.65 ± 0.25 %), BV/TV (6.62 ± 0.25 %) and Tb.Sp (1559.03 ± 57.06 μm) of the cell + MS group were also better than those of the SHAM group and the cell group.
The PLGA/CoI microspheres combined with BMSCs can repair bone defects more quickly. This means that PLGA/CoI microspheres combined with BMSCs can promote trabecular reconstruction and improve bone quality in osteoporotic rats. This scaffold can provide a promising minimally invasive surgical tool for enhancement of bone fracture healing or prevention of fracture occurrence which will in turn minimize complications endemic to patients with osteoporosis.
International Orthopaedics 04/2012; 36(10):2163-71. · 2.03 Impact Factor
ABSTRACT: A total of 25 consecutive patients suffering from degenerative cervical disc disease who underwent three-level anterior cervical discectomy and fusion (ACDF) including polyetheretherketone (PEEK) cages packed with allograft were followed up for at least two years. The fusion rate reached 72% (18/25), and asymptomatic pseudarthrosis was seen in 6 patients but without mobility on flexion-extension radiographs, and revision surgery was not needed. Cage subsidence occurred at one level (C67), but it was not progressive, and reoperation was not necessary. A significant increase (P < 0.001) in fused segment angle (FSA) and fused segment height (FSH) was observed postoperatively. Similarly, a significant clinical improvement (P < 0.001) was demonstrated postoperatively in terms of Japanese Orthopedic Association (JOA) score and visual analog scales (VASs) score. PEEK cages alone with allograft proved to be a safe and effective surgical option in the treatment of three-level degenerative cervical disc disease. Although the fusion rate was not high, this technique may offer improvement of symptomatology and maintenance of cervical spine's sagittal profile.
ISRN neurology. 01/2012; 2012:452703.
ABSTRACT: An in vivo landrace model of cement augmentation of pedicle screw was established, and axial pull-out tests and histological analysis were performed.
To investigate the long-term in vivo biomechanical performance of pedicle screws augmented with calcium sulfate cement.
Little information is available on the long-term biomechanical performance of pedicle screws augmented with calcium sulfate cement in vivo.
Ten pedicle screws were implanted into the lumbar vertebrae of 15 adult females landraces weighing 105 to 115 kg. The pedicle screws were augmented with Polymethyl methacrylate (PMMA), augmented with the calcium sulfate cement, or not augmented. The landraces were randomized into 3 study periods of day 1, 6 weeks, and 12 weeks. At the end of the assigned study periods, the animals were killed and axial pull-out tests and histological analyses were conducted on the isolated specimen vertebrae.
No significant difference was found among the 1-day, 6-week,and 12-week control group (P > 0.18), no significant difference was found among the 1-day, 6-week and 12-week PMMA group (P > 0.59), and no significant difference was found among the 1-day, 6-week and 12-week calcium sulfate group (P > 0.27). The maximum POS of the PMMA groups was significantly greater than that of the calcium sulfate groups (P < 0.002), the maximum POS of the calcium sulfate groups was significantly greater than that of the control groups (P < 0.004). Histologically progressive absorption of the calcium sulfate was evident. The bone walls around the screws in the 12-week calcium sulfate group were statistically significantly thicker than that of the 12-week control group and that of the 12-week PMMA group.
Results of this study demonstrate that the injectable calcium sulfate cement can significantly improve the immediate POS of pedicle screw fixation, and this effect can be maintained even if the calcium sulfate cement has been absorbed completely, which may result from that the calcium sulfate cement resorption paralleled bone ingrowth.
Spine 11/2008; 33(23):2503-9. · 2.08 Impact Factor
ABSTRACT: To investigate the effect of cervical spine instability on sympathetic cervical spondylosis.
Twelve patients with cervical spondylosis showing sympathetic symptoms from 1992 to 2 000 were evaluated for cervical spine instability, immobilization of collar brace, MRI and surgical results.
Radiologic evaluation cervical instability was observed radiologically in 7 of the 12 cases. Collar brace was obviously effective in 5 of the 12 cases and slightly effective in 7 cases. MRI showed abnormal signal for instability of the cervical spine in 7 cases. Surgery was markedly effective in 7 cases and moderately effective in 4 cases.
Cervical spine instability was an important factor for sympathetic cervical spondylosis, which can be improved effectively by surgery.
Zhonghua wai ke za zhi [Chinese journal of surgery] 11/2002; 40(10):730-2.