Objective To compare the influence of the dynamic device(DD) of pedicle screw fixation and its equivalent rigid device (RD) on bone mineral density and bone structure of the vertebrae. Methods 24 goats were randomly divided into 4 groups: control group, single posterolateral fusion group, dynamic device with posterolateral fusion group and rigid device with posterolateral fusion group. After 24 weeks postoperative observation, the animals were sacrificed and the fixed lumbar spines were harvested. The bone mineral density (BMD) of these harvested specimens was measured by quantitative computed tomography (QCT). Then the L3 segment was embedded in methyl methacrylate and sectioned after alcoholic dehydration. Undecalcified slides (50 ?m in thickness) were stained with toluidine blue. Quantitative histologic analysis was performed in a semiautomatic way. The static parameters consisted of trabecular bone volume (TBV), the mean trabecular plate thickness (MTPT) and mean trabecular spacing (Tb.Sp). The main dynamic histomorphometric parameter, bone mineralization rate (MAR), was calculated by measuring the mean distance between two flurochrome labelings. Results The BMD in the rigid device group decreased significantly compared with control group (P

Objective To evaluate the effect of TGF-β3 on rabbit nucleus pulposus( NP) cells cultured in three-dimensional polylactic-co-glycolic acid (PLGA)scaffold in vitro.Methods PLGA scaffolds were fabricated by particulate leaching method and soaked in rabbit NP cells suspension(1 × 106/scaffold).PLGA-seeded NP cells were devided into 4 groups: 100 ng/mL TGF-β3/PLGA,500 ng/mL TGF-β3/PLGA,1 μg/mL TGF-β3/PLGA, PLGA control group.Cell proliferation activity was measured using MTT assay.The glycosaminoglycan ( GAG ) analysis were performed by 1, 9-dimethylmethylene blue(DMMB) assay.mRNA expression was measured by quantitive PCR at each time point.Histological observation was performed to elucidate the morphological changes of NP cells in PLGA effected by TGF-β3.Results Higher cellular proliferation activity, GAG production,Collagen type II, Aggrean expression were observed in TGF-β3 /PLGA-seeded NP cells compared with PLGA control group on day-7,day-14,day-21(P<0.05). Higher dose of TGF-β3 exhibited intense cellular proliferation activity and peri-cellular matrix by increasing trend(P<0.05).Histological observation showed TGF-β3/PLGA developed more significant disc cells cluster than PLGA groups on day-21.Conclusion The 3D porous PLGA scaffold-seeded cells using TGF-β3 can promotes cell proliferation, and prompt extracellular matrix(ECM) production.It is a potential biotherapy for the treatment of disc degeneration.

Objective To evaluate the clinical outcomes of minimally invasive internal fixation for femoral intertrochanteric fracture in osteoporotic elderly patients. Methods A retrospective study was conducted in 112 patients using interan nail (IN) or trochanteric antegrade nail (TAN) for the management of intertrochanteric femoral fracture from January 2009 to September 2015 in our hospital. According to AO classification, there were 34 cases of type 31-A.1, and 61 cases of type 31-A.2, 17 cases of type 31-A.3. Clinical and radiological follow-up were available. Surgical and fluoroscopic time, length of hospital stay, blood loss, complications and hip functions were compared between two groups. Results A total of 78 patients meeting the criteria were evaluated at a mean follow-up of 15 months (range, 3-27 months). The IN was used in 41 patients and the TAN in 37 patients. Operative time, fluoroscopy time and blood loss showed significant difference between the IN group and TAN group (respectively, 58.9±6.9 vs. 75.6±5.9min; 2.70±0.47 vs. 4.40±0.47min; 107.6±6.7 vs. 127.8±6.8ml, P<0.05), suggesting that patients treated with the IN experienced shorter operative and fluoroscopy times, less blood loss and better hip function (73%) than those with TAN (65%, P<0.05). Rate of postoperative complications was lower in the IN group (4.9%) than in the TAN group (10.8%, P<0.05). There was no difference in hospital stay and fracture healing time between the two groups (P>0.05). Conclusions For minimally invasive treatment of unstable femoral intertrochanteric fractures, use of either the IN or TAN is clinically effective. However, IN presents more advantages (e.g., easy operation, reliable fixation, less bleeding, better clinical outcomes, and less complications). The use of IN is a suitable option for the treatment of unstable intertrochanteric fractures in osteoporotic elderly patients.